From 488c09b6a0319db7049b0b52d43af7af5b9452bb Mon Sep 17 00:00:00 2001
From: peverwhee <courtneyp@ucar.edu>
Date: Tue, 28 Oct 2025 17:07:31 -0600
Subject: [PATCH 01/19] initial commit; generate very basic physics restart
 file

---
 cime_config/cam_autogen.py         |  57 +++++++-
 cime_config/cam_build_cache.py     |  24 ++-
 cime_config/cam_config.py          |  16 +-
 src/data/generate_registry_data.py |  32 +++-
 src/data/write_physics_restart.py  | 227 +++++++++++++++++++++++++++++
 5 files changed, 350 insertions(+), 6 deletions(-)
 create mode 100644 src/data/write_physics_restart.py

diff --git a/cime_config/cam_autogen.py b/cime_config/cam_autogen.py
index 695364b24..548cb19ea 100644
--- a/cime_config/cam_autogen.py
+++ b/cime_config/cam_autogen.py
@@ -33,6 +33,7 @@
 # Import needed registry and other src/data scripts:
 from generate_registry_data import gen_registry
 from write_init_files import write_init_files
+from write_physics_restart import write_physics_restart
 
 ###############################################################################
 
@@ -392,7 +393,7 @@ def generate_registry(data_search, build_cache, atm_root, bldroot,
                                    gen_fort_indent, source_mods_dir, atm_root,
                                    logger=_LOGGER, schema_paths=data_search,
                                    error_on_no_validate=True)
-            retcode, reg_file_list, ic_names, registry_constituents, vars_init_value = retvals
+            retcode, reg_file_list, ic_names, registry_constituents, restart_vars, vars_init_value = retvals
             # Raise error if gen_registry failed:
             if retcode != 0:
                 emsg = "ERROR:Unable to generate CAM data structures from {}, err = {}"
@@ -406,16 +407,17 @@ def generate_registry(data_search, build_cache, atm_root, bldroot,
         # Save build details in the build cache
         reg_file_paths = [x.file_path for x in reg_file_list if x.file_path]
         build_cache.update_registry(gen_reg_file, registry_files, dycore,
-                                    reg_file_paths, ic_names, registry_constituents, vars_init_value)
+                                    reg_file_paths, ic_names, registry_constituents, restart_vars, vars_init_value)
     else:
         # If we did not run the registry generator, retrieve info from cache
         reg_file_paths = build_cache.reg_file_list()
         ic_names = build_cache.ic_names()
         registry_constituents = build_cache.constituents()
+        restart_vars = build_cache.restart_vars()
         vars_init_value = build_cache.vars_init_value()
     # End if
 
-    return genreg_dir, do_gen_registry, reg_file_paths, ic_names, registry_constituents, vars_init_value
+    return genreg_dir, do_gen_registry, reg_file_paths, ic_names, registry_constituents, restart_vars, vars_init_value
 
 ###############################################################################
 def generate_physics_suites(build_cache, preproc_defs, host_name,
@@ -740,6 +742,55 @@ def generate_init_routines(build_cache, bldroot, force_ccpp, force_init,
 
     return init_dir
 
+###############################################################################
+def generate_restart_routines(build_cache, bldroot, force_ccpp, force_restart,
+                              source_mods_dir, gen_fort_indent, cap_database,
+                              ic_names, registry_constituents, restart_vars):
+###############################################################################
+    """
+    Generate the physics restart routines (restart_physics.F90) using
+    both the registry and the CCPP physics suites if required
+    (new case or changes to registry or CCPP source(s), meta-data,
+    and/or script).
+    """
+
+    #Add new directory to build path:
+    restart_dir = os.path.join(bldroot, "phys_restart")
+    # Use this for cache check
+    gen_restart_file = os.path.join(_REG_GEN_DIR, "write_physics_restart.py")
+
+    # Figure out if we need to generate new restart routines:
+    if os.path.exists(restart_dir):
+        # Check if registry and / or CCPP suites were modified:
+        if force_ccpp or force_init:
+            do_gen_restart = True
+        else:
+            #If not, then check cache to see if actual
+            #"restart_physics.py" was modified:
+            do_gen_restart = build_cache.init_write_mismatch(gen_restart_file)
+    else:
+        #If no directory exists, then one will need
+        # to create new routines:
+        os.mkdir(restart_dir)
+        do_gen_restart = True
+    # End if
+    if do_gen_restart:
+        source_paths = [source_mods_dir, _REG_GEN_DIR]
+        retmsg = write_physics_restart(cap_database, ic_names, registry_constituents,
+                                       restart_vars, restart_dir, _find_file, 
+                                       source_paths, gen_fort_indent, _LOGGER)
+        
+        #Check that script ran properly
+        if retmsg:
+            emsg = f"ERROR: Unable to generate CAM restart source code, error message is:\n{retmsg}"
+            raise CamAutoGenError(emsg)
+        #-----
+
+        # save build details in the build cache
+        build_cache.update_restart_gen(gen_restart_file)
+
+    return restart_dir
+
 #############
 # End of file
 #############
diff --git a/cime_config/cam_build_cache.py b/cime_config/cam_build_cache.py
index 3e23b74a8..a2ed8e331 100644
--- a/cime_config/cam_build_cache.py
+++ b/cime_config/cam_build_cache.py
@@ -227,6 +227,7 @@ def __init__(self, build_cache):
         self.__reg_gen_files = []
         self.__ic_names = {}
         self.__constituents = []
+        self.__restart_list = []
         self.__vars_init_value = []
         if os.path.exists(build_cache):
             # Initialize build cache state
@@ -258,6 +259,10 @@ def __init__(self, build_cache):
                             stdname = item.get('standard_name')
                             itext = clean_xml_text(item)
                             self.__constituents.append(itext)
+                        elif item.tag == 'restart_entry':
+                            stdname = item.get('standard_name')
+                            itext = clean_xml_text(item)
+                            self.__restart_list.append(itext)
                         elif item.tag == 'vars_init_value_entry':
                             itext = clean_xml_text(item)
                             self.__vars_init_value.append(itext)
@@ -322,7 +327,8 @@ def __init__(self, build_cache):
         # end if
 
     def update_registry(self, gen_reg_file, registry_source_files,
-                        dycore, reg_file_list, ic_names, constituents, vars_init_value):
+                        dycore, reg_file_list, ic_names, constituents,
+                        restart_list, vars_init_value):
         """Replace the registry cache data with input data
         """
         self.__dycore = dycore
@@ -338,6 +344,7 @@ def update_registry(self, gen_reg_file, registry_source_files,
         # and should already be of type dict:
         self.__ic_names = ic_names
         self.__constituents = constituents
+        self.__restart_list = restart_list
         self.__vars_init_value = vars_init_value
 
     def update_ccpp(self, suite_definition_files, scheme_files, host_files,
@@ -383,6 +390,14 @@ def update_init_gen(self, gen_init_file):
         """
         self.__gen_init_file = FileStatus(gen_init_file, 'generate_init_file')
 
+    def update_restart_gen(self, gen_restart_file):
+        """
+        Replace the restart writer
+        (write_physics_restart.py) cache
+        data with input data
+        """
+        self.__gen_restart_file = FileStatus(gen_restart_file, 'generate_restart_file')
+
     def write(self):
         """Write out the current cache state"""
         new_cache = ET.Element("CAMBuildCache")
@@ -415,6 +430,9 @@ def write(self):
             const_entry = ET.SubElement(registry, 'constituent_entry')
             const_entry.text = stdname
         # end for
+        for stdname in self.__restart_list:
+            restart_entry = ET.SubElement(registry, 'restart_entry')
+            restart_entry.text = stdname
         for stdname in self.__vars_init_value:
             var_entry = ET.SubElement(registry, 'vars_init_value_entry')
             var_entry.text = stdname
@@ -625,6 +643,10 @@ def constituents(self):
         """Return a copy of the registry constituents list"""
         return list(self.__constituents)
 
+    def restart_vars(self):
+        """Return a copy of the registry's list of variables for the restart file"""
+        return list(self.__restart_list)
+
     def vars_init_value(self):
         """Return a copy of the list of variables with initial_value"""
         return list(self.__vars_init_value)
diff --git a/cime_config/cam_config.py b/cime_config/cam_config.py
index 20e3b3f5e..1dc799be8 100644
--- a/cime_config/cam_config.py
+++ b/cime_config/cam_config.py
@@ -32,6 +32,7 @@
 # Import fortran auto-generation routines:
 from cam_autogen import generate_registry, generate_physics_suites
 from cam_autogen import generate_init_routines
+from cam_autogen import generate_restart_routines
 
 ###############################################################################
 #HELPER FUNCTIONS
@@ -854,7 +855,7 @@ def generate_cam_src(self, gen_fort_indent):
         retvals = generate_registry(data_search, build_cache, self.__atm_root,
                                     self.__bldroot, source_mods_dir,
                                     dyn, gen_fort_indent)
-        reg_dir, force_ccpp, reg_files, ic_names, registry_constituents, vars_init_value = retvals
+        reg_dir, force_ccpp, reg_files, ic_names, registry_constituents, restart_vars, vars_init_value = retvals
 
         #Add registry path to config object:
         reg_dir_desc = "Location of auto-generated registry code."
@@ -894,6 +895,19 @@ def generate_cam_src(self, gen_fort_indent):
         init_dir_desc = "Location of auto-generated physics initialization code."
         self.create_config("init_dir", init_dir_desc, init_dir)
 
+        #---------------------------------------------------------
+        # Create restart init/write/read routines
+        #---------------------------------------------------------
+        restart_dir = generate_restart_routines(build_cache, self.__bldroot,
+                                                force_ccpp, force_init,
+                                                source_mods_dir, gen_fort_indent,
+                                                capgen_db, ic_names,
+                                                registry_constituents, restart_vars)
+
+        #Add registry path to config object:
+        restart_dir_desc = "Location of auto-generated physics restart code."
+        self.create_config("restart_dir", restart_dir_desc, restart_dir)
+
         #--------------------------------------------------------------
         # write out the cache here as we have completed pre-processing
         #--------------------------------------------------------------
diff --git a/src/data/generate_registry_data.py b/src/data/generate_registry_data.py
index 0d0e93b3d..1c214b895 100755
--- a/src/data/generate_registry_data.py
+++ b/src/data/generate_registry_data.py
@@ -165,6 +165,7 @@ def __init__(self, elem_node, local_name, dimensions, known_types,
         self.__allocatable = elem_node.get('allocatable', default=alloc_default)
         self.__constituent = elem_node.get("constituent", default=False)
         self.__advected    = elem_node.get("advected", default=False)
+        self.__restart     = elem_node.get("restart", default=False)
         self.__tstep_init  = elem_node.get("phys_timestep_init_zero",
                                            default=tstep_init_default)
         if self.__allocatable == "none":
@@ -426,6 +427,11 @@ def is_advected(self):
         """Return True if this variable is advected"""
         return self.__advected
 
+    @property
+    def is_restart(self):
+        """Return True if this variable should be included on the physics restart file"""
+        return self.__restart
+
     @property
     def tstep_init(self):
         """Return True if variable will be set to zero every physics timestep."""
@@ -1792,6 +1798,29 @@ def _create_constituent_list(registry):
     # end for
     return constituent_list
 
+###############################################################################
+def _create_restart_list(registry):
+###############################################################################
+    """
+    Create a list of all registry variables that need to be included in
+    the physics restart file.
+    To be used by write_physics_restart.py
+    """
+    restart_list = []
+    for section in registry:
+        if section.tag == 'file':
+            for obj in section:
+                if obj.tag == 'variable':
+                    if obj.get('restart'):
+                        stdname = obj.get('standard_name')
+                        restart_list.append(stdname)
+                    # end if (ignore non-restart variables)
+                # end if (ignore other node types)
+            # end for
+        # end if (ignore other node types)
+    # end for
+    return restart_list
+
 ###############################################################################
 def _create_variables_with_initial_value_list(registry):
 ###############################################################################
@@ -1889,10 +1918,11 @@ def gen_registry(registry_file, dycore, outdir, indent,
         # See comment in _create_ic_name_dict
         ic_names = _create_ic_name_dict(registry)
         registry_constituents = _create_constituent_list(registry)
+        restart_vars = _create_restart_list(registry)
         vars_init_value = _create_variables_with_initial_value_list(registry)
         retcode = 0 # Throw exception on error
     # end if
-    return retcode, files, ic_names, registry_constituents, vars_init_value
+    return retcode, files, ic_names, registry_constituents, restart_vars, vars_init_value
 
 def main():
     """Function to execute when module called as a script"""
diff --git a/src/data/write_physics_restart.py b/src/data/write_physics_restart.py
new file mode 100644
index 000000000..d9dfbcdbd
--- /dev/null
+++ b/src/data/write_physics_restart.py
@@ -0,0 +1,227 @@
+"""
+Use variable meta-data from "generate_registry_data.py"
+to generate a CAM fortran file to manage physics restart 
+information and writing (restart_physics.F90).
+"""
+
+# Python library import statements:
+from collections import OrderedDict
+import os.path
+
+# CCPP Framework import statements
+from ccpp_state_machine import CCPP_STATE_MACH
+from fortran_tools import FortranWriter
+# Exclude these standard names from init processing
+# Some are internal names (e.g., suite_name)
+# Some are from the CCPP framework (e.g., ccpp_num_constituents)
+# Some are for efficiency and to avoid dependency loops (e.g., log_output_unit)
+_EXCLUDED_STDNAMES = {'suite_name', 'suite_part',
+                          'number_of_ccpp_constituents',
+                          'number_of_ccpp_advected_constituents',
+                          'ccpp_constituents',
+                          'ccpp_constituent_tendencies',
+                          'ccpp_constituent_properties',
+                          'ccpp_constituent_minimum_values',
+                          'ccpp_error_message',
+                          'ccpp_error_code',
+                          'log_output_unit', 'do_log_output',
+                          'mpi_communicator', 'mpi_root', 'mpi_rank',
+                          'number_of_mpi_tasks'}
+# Variable input types
+_INPUT_TYPES = set(['in', 'inout'])
+_OUTPUT_TYPES = set(['out', 'inout'])
+
+# Increase allowed line lengths needed to fit extra-long CCPP standard names:
+_LINE_FILL_LEN = 150
+_MAX_LINE_LEN = 200
+
+##############
+#Main function
+##############
+
+def write_physics_restart(cap_database, ic_names, registry_constituents,
+                     restart_vars, outdir, file_find_func, source_paths, indent, logger,
+                     phys_restart_filename=None):
+
+    """
+    Create restart_physics.F90 using a database created
+       by the CCPP Framework generator (capgen).
+    """
+
+    #Initialize return message:
+    retmsg = ""
+
+    # Gather all the host model variables that are required by
+    #    any of the compiled CCPP physics suites.
+    in_vars, out_vars, constituent_set, retmsg = gather_ccpp_req_vars(cap_database, registry_constituents)
+
+    # Quit now if there are missing variables
+    if retmsg:
+        return retmsg
+    # end if
+
+    # -----------------------------------------
+    # Generate "restart_physics.F90" file:
+    # -----------------------------------------
+
+    # Open new file:
+    if phys_restart_filename:
+        ofilename = os.path.join(outdir, phys_restart_filename)
+        # Get file name, ignoring file type:
+        phys_restart_fname_str = os.path.splitext(phys_restart_filename)[0]
+    else:
+        ofilename = os.path.join(outdir, "restart_physics.F90")
+        phys_restart_fname_str = "restart_physics"
+    # end if
+
+    # Log file creation:
+    logger.info(f"Writing restart physics source file, {ofilename}")
+
+    # Open file using CCPP's FortranWriter:
+    file_desc = "Physics restart source file"
+    with FortranWriter(ofilename, "w", file_desc,
+                       phys_restart_fname_str,
+                       line_fill=_LINE_FILL_LEN,
+                       line_max=_MAX_LINE_LEN,
+                       indent=indent) as outfile:
+
+        # Add boilerplate code:
+        outfile.write_preamble()
+
+        # Add public function declarations:
+        outfile.write("!! public interfaces", 0)
+        outfile.write("public :: restart_physics_init", 1)
+        outfile.write("public :: restart_physics_write", 1)
+        outfile.write("public :: restart_physics_read", 1)
+
+        all_req_vars = in_vars + out_vars
+        # Grab the required variables that are also restart variables
+        print(restart_vars)
+        required_restart_vars, required_restart_constituents = gather_required_restart_variables(all_req_vars, constituent_set, restart_vars)
+
+        # Add "contains" statement:
+        outfile.end_module_header()
+        outfile.blank_line()
+
+#################
+#HELPER FUNCTIONS
+#################
+
+##############################################################################
+def _find_and_add_host_variable(stdname, host_dict, var_dict):
+    """Find <stdname> in <host_dict> and add it to <var_dict> if found and
+          not of type, 'host'.
+       If not found, add <stdname> to <missing_vars>.
+       If found and added to <var_dict>, also process the standard names of
+          any intrinsic sub-elements of <stdname>.
+       Return the list of <missing_vars> (if any).
+       Note: This function has a side effect (adding to <var_dict>).
+    """
+    missing_vars = []
+    hvar = host_dict.find_variable(stdname)
+    if hvar and (hvar.source.ptype != 'host'):
+        var_dict[stdname] = hvar
+        # Process elements (if any)
+        ielem = hvar.intrinsic_elements()
+        # List elements are the only ones we care about
+        if isinstance(ielem, list):
+            for sname in ielem:
+                smissing = _find_and_add_host_variable(sname, host_dict,
+                                                       var_dict)
+                missing_vars.extend(smissing)
+            # end for
+        # end if
+    # end if
+    if not hvar:
+        missing_vars.append(stdname)
+    # end if
+    return missing_vars
+
+##############################################################################
+def gather_ccpp_req_vars(cap_database, registry_constituents):
+    """
+    Generate a list of host-model and constituent variables
+    required by the CCPP physics suites potentially being used
+    in this model run.
+    <cap_database> is the database object returned by capgen.
+    It is an error if any physics suite variable is not accessible in
+       the host model.
+    Return several values:
+    - A list of host model variables
+    - An error message (blank for no error)
+    """
+
+    # Dictionary of all 'in' and 'inout' suite variables.
+    # Key is standard name, value is host-model or constituent variable
+    in_vars = {}
+    out_vars = {}
+    missing_vars = set()
+    constituent_vars = set()
+    retmsg = ""
+    # Host model dictionary
+    host_dict = cap_database.host_model_dict()
+
+    # Create CCPP datatable required variables-listing object:
+    # XXgoldyXX: Choose only some phases here?
+    for phase in CCPP_STATE_MACH.transitions():
+        for cvar in cap_database.call_list(phase).variable_list():
+            stdname = cvar.get_prop_value('standard_name')
+            intent = cvar.get_prop_value('intent')
+            is_const = cvar.get_prop_value('advected') or cvar.get_prop_value('constituent')
+            if ((intent in _INPUT_TYPES) and
+                (stdname not in in_vars) and
+                (stdname not in _EXCLUDED_STDNAMES)):
+                if is_const:
+                    #Add variable to constituent set:
+                    constituent_vars.add(stdname)
+                    #Add variable to required variable list if it's not a registry constituent
+                    if stdname not in registry_constituents:
+                        in_vars[stdname] = cvar
+                    # end if
+                else:
+                    # We need to work with the host model version of this variable
+                    missing = _find_and_add_host_variable(stdname, host_dict,
+                                                          in_vars)
+                    missing_vars.update(missing)
+                # end if
+            # end if (only input variables)
+            if ((intent in _OUTPUT_TYPES) and
+                  (stdname not in out_vars) and
+                  (stdname not in _EXCLUDED_STDNAMES)):
+                if not is_const:
+                    missing = _find_and_add_host_variable(stdname, host_dict,
+                                                          out_vars)
+                    # do nothing with missing variables
+                # end if
+            # end if (only output variables)
+        # end for (loop over call list)
+    # end for (loop over phases)
+
+    if missing_vars:
+        mvlist = ', '.join(sorted(missing_vars))
+        retmsg = f"Error: Missing required host variables: {mvlist}"
+    # end if
+    # Return the required variables as a list
+    return list(in_vars.values()), list(out_vars.values()), constituent_vars, retmsg
+
+##############################################################################
+def gather_required_restart_variables(all_req_vars, registry_constituents, restart_vars):
+    """
+    Return lists of the required restart non-constituent variables, and the required
+    restart constituent variables
+    """
+
+    required_restart_vars = []
+    required_constituent_restart_vars = []
+
+    for restart_var in restart_vars:
+        if restart_var in all_req_vars:
+            if restart_var in registry_constituents:
+                required_constituent_restart_vars.append(restart_var)
+            else:
+                required_restart_vars.append(restart_var)
+            # end if
+        # end if (ignore all non-required variables)
+    # end for
+
+    return required_restart_vars, required_constituent_restart_vars

From 13ea150b924a70780c2b7d4afad16d03057543d0 Mon Sep 17 00:00:00 2001
From: peverwhee <courtneyp@ucar.edu>
Date: Mon, 3 Nov 2025 11:43:10 -0700
Subject: [PATCH 02/19] grab diagnostic name instead of local name to deal with
 case inconsistency

---
 cime_config/cam_autogen.py         |   2 +-
 cime_config/cam_build_cache.py     |  16 ++--
 src/data/generate_registry_data.py |  18 ++--
 src/data/registry.xml              | 132 +++++++++++++++++++----------
 src/data/registry_v1_0.xsd         |   8 ++
 src/data/write_physics_restart.py  |  63 ++++++++++++--
 6 files changed, 175 insertions(+), 64 deletions(-)

diff --git a/cime_config/cam_autogen.py b/cime_config/cam_autogen.py
index 548cb19ea..ca26c8928 100644
--- a/cime_config/cam_autogen.py
+++ b/cime_config/cam_autogen.py
@@ -762,7 +762,7 @@ def generate_restart_routines(build_cache, bldroot, force_ccpp, force_restart,
     # Figure out if we need to generate new restart routines:
     if os.path.exists(restart_dir):
         # Check if registry and / or CCPP suites were modified:
-        if force_ccpp or force_init:
+        if force_ccpp or force_restart:
             do_gen_restart = True
         else:
             #If not, then check cache to see if actual
diff --git a/cime_config/cam_build_cache.py b/cime_config/cam_build_cache.py
index a2ed8e331..20c1ba622 100644
--- a/cime_config/cam_build_cache.py
+++ b/cime_config/cam_build_cache.py
@@ -227,7 +227,7 @@ def __init__(self, build_cache):
         self.__reg_gen_files = []
         self.__ic_names = {}
         self.__constituents = []
-        self.__restart_list = []
+        self.__restart_dict = {}
         self.__vars_init_value = []
         if os.path.exists(build_cache):
             # Initialize build cache state
@@ -262,7 +262,7 @@ def __init__(self, build_cache):
                         elif item.tag == 'restart_entry':
                             stdname = item.get('standard_name')
                             itext = clean_xml_text(item)
-                            self.__restart_list.append(itext)
+                            self.__restart_dict[stdname] = itext
                         elif item.tag == 'vars_init_value_entry':
                             itext = clean_xml_text(item)
                             self.__vars_init_value.append(itext)
@@ -328,7 +328,7 @@ def __init__(self, build_cache):
 
     def update_registry(self, gen_reg_file, registry_source_files,
                         dycore, reg_file_list, ic_names, constituents,
-                        restart_list, vars_init_value):
+                        restart_dict, vars_init_value):
         """Replace the registry cache data with input data
         """
         self.__dycore = dycore
@@ -344,7 +344,7 @@ def update_registry(self, gen_reg_file, registry_source_files,
         # and should already be of type dict:
         self.__ic_names = ic_names
         self.__constituents = constituents
-        self.__restart_list = restart_list
+        self.__restart_dict = restart_dict
         self.__vars_init_value = vars_init_value
 
     def update_ccpp(self, suite_definition_files, scheme_files, host_files,
@@ -430,9 +430,11 @@ def write(self):
             const_entry = ET.SubElement(registry, 'constituent_entry')
             const_entry.text = stdname
         # end for
-        for stdname in self.__restart_list:
+        for stdname, restart_name in self.__restart_dict.items():
             restart_entry = ET.SubElement(registry, 'restart_entry')
-            restart_entry.text = stdname
+            restart_entry.set('standard_name', stdname)
+            restart_entry.text = restart_name
+        # end for
         for stdname in self.__vars_init_value:
             var_entry = ET.SubElement(registry, 'vars_init_value_entry')
             var_entry.text = stdname
@@ -645,7 +647,7 @@ def constituents(self):
 
     def restart_vars(self):
         """Return a copy of the registry's list of variables for the restart file"""
-        return list(self.__restart_list)
+        return dict(self.__restart_dict)
 
     def vars_init_value(self):
         """Return a copy of the list of variables with initial_value"""
diff --git a/src/data/generate_registry_data.py b/src/data/generate_registry_data.py
index 1c214b895..7d8644880 100755
--- a/src/data/generate_registry_data.py
+++ b/src/data/generate_registry_data.py
@@ -166,6 +166,7 @@ def __init__(self, elem_node, local_name, dimensions, known_types,
         self.__constituent = elem_node.get("constituent", default=False)
         self.__advected    = elem_node.get("advected", default=False)
         self.__restart     = elem_node.get("restart", default=False)
+        self.__diag_name   = elem_node.get("diagnostic_name", default=local_name)
         self.__tstep_init  = elem_node.get("phys_timestep_init_zero",
                                            default=tstep_init_default)
         if self.__allocatable == "none":
@@ -539,7 +540,8 @@ class Variable(VarBase):
                         "constituent", "dycore", "extends",
                         "kind", "local_name", "name",
                         "phys_timestep_init_zero", "standard_name",
-                        "type", "units", "version"]
+                        "type", "units", "version", "restart",
+                        "diagnostic_name"]
 
     def __init__(self, var_node, known_types, vdict, dycore, logger):
         # pylint: disable=too-many-locals
@@ -1799,21 +1801,27 @@ def _create_constituent_list(registry):
     return constituent_list
 
 ###############################################################################
-def _create_restart_list(registry):
+def _create_restart_dict(registry):
 ###############################################################################
     """
     Create a list of all registry variables that need to be included in
     the physics restart file.
     To be used by write_physics_restart.py
     """
-    restart_list = []
+    restart_list = {}
     for section in registry:
         if section.tag == 'file':
             for obj in section:
                 if obj.tag == 'variable':
                     if obj.get('restart'):
                         stdname = obj.get('standard_name')
-                        restart_list.append(stdname)
+                        diagnostic_name = obj.get('diagnostic_name')
+                        if diagnostic_name:
+                            restart_list[stdname] = diagnostic_name
+                        else:
+                            local_name = obj.get('local_name')
+                            restart_list[stdname] = local_name
+                        # end if
                     # end if (ignore non-restart variables)
                 # end if (ignore other node types)
             # end for
@@ -1918,7 +1926,7 @@ def gen_registry(registry_file, dycore, outdir, indent,
         # See comment in _create_ic_name_dict
         ic_names = _create_ic_name_dict(registry)
         registry_constituents = _create_constituent_list(registry)
-        restart_vars = _create_restart_list(registry)
+        restart_vars = _create_restart_dict(registry)
         vars_init_value = _create_variables_with_initial_value_list(registry)
         retcode = 0 # Throw exception on error
     # end if
diff --git a/src/data/registry.xml b/src/data/registry.xml
index 9985d559a..5ce09a8ac 100644
--- a/src/data/registry.xml
+++ b/src/data/registry.xml
@@ -127,14 +127,16 @@
     <variable local_name="frontgf"
               standard_name="frontogenesis_function"
               units="K m-1 s-1" type="real" kind="kind_phys"
-              allocatable="pointer">
+              allocatable="pointer" restart="true"
+	      diagnostic_name="FRONTGF">
       <dimensions>horizontal_dimension vertical_layer_dimension</dimensions>
       <ic_file_input_names>frontgf pbuf_frontgf</ic_file_input_names>
     </variable>
     <variable local_name="frontga"
               standard_name="frontogenesis_angle"
               units="radians" type="real" kind="kind_phys"
-              allocatable="pointer">
+              allocatable="pointer" restart="true"
+	      diagnostic_name="FRONTGA">
       <dimensions>horizontal_dimension vertical_layer_dimension</dimensions>
       <ic_file_input_names>frontga pbuf_frontga</ic_file_input_names>
     </variable>
@@ -142,7 +144,8 @@
     <variable local_name="qpert"
               standard_name="convective_water_vapor_mixing_ratio_wrt_moist_air_and_condensed_water_perturbation_due_to_pbl_eddies"
               units="kg kg-1" type="real" kind="kind_phys"
-              allocatable="allocatable">
+              allocatable="allocatable" restart="true"
+	      diagnostic_name="QPERT">
       <dimensions>horizontal_dimension</dimensions>
       <initial_value>0.0_kind_phys</initial_value>
       <ic_file_input_names>qpert pbuf_qpert</ic_file_input_names>
@@ -158,7 +161,8 @@
     <variable local_name="cmfmc_dp"
               standard_name="atmosphere_convective_mass_flux_due_to_deep_convection"
               units="kg m-2 s-1" type="real" kind="kind_phys"
-              allocatable="allocatable">
+	      allocatable="allocatable" restart="true"
+              diagnostic_name="CMFMC_DP">
       <dimensions>horizontal_dimension vertical_interface_dimension</dimensions>
       <initial_value>0.0_kind_phys</initial_value>
       <ic_file_input_names>cmfmc_dp pbuf_CMFMC_DP</ic_file_input_names>
@@ -166,7 +170,8 @@
     <variable local_name="cmfmc_sh"
               standard_name="atmosphere_convective_mass_flux_due_to_shallow_convection"
               units="kg m-2 s-1" type="real" kind="kind_phys"
-              allocatable="allocatable">
+	      allocatable="allocatable" restart="true"
+              diagnostic_name="CMFMC_SH">
       <dimensions>horizontal_dimension vertical_interface_dimension</dimensions>
       <initial_value>0.0_kind_phys</initial_value>
       <ic_file_input_names>cmfmc_sh pbuf_CMFMC_SH</ic_file_input_names>
@@ -174,7 +179,8 @@
     <variable local_name="dlfzm"
               standard_name="detrainment_of_cloud_liquid_water_wrt_moist_air_and_condensed_water_due_to_deep_convection"
               units="kg kg-1 s-1" type="real" kind="kind_phys"
-              allocatable="allocatable">
+	      allocatable="allocatable" restart="true"
+	      diagnostic_name="DLFZM">
       <dimensions>horizontal_dimension vertical_layer_dimension</dimensions>
       <initial_value>0.0_kind_phys</initial_value>
       <ic_file_input_names>dlfzm pbuf_DLFZM</ic_file_input_names>
@@ -198,7 +204,8 @@
     <variable local_name="rprddp"
               standard_name="tendency_of_precipitation_wrt_moist_air_and_condensed_water_due_to_deep_convection_excluding_subcloud_evaporation"
               units="kg kg-1 s-1" type="real" kind="kind_phys"
-              allocatable="allocatable">
+	      allocatable="allocatable" restart="true"
+	      diagnostic_name="RPRDDP">
       <dimensions>horizontal_dimension vertical_layer_dimension</dimensions>
       <initial_value>0.0_kind_phys</initial_value>
       <ic_file_input_names>pbuf_RPRDDP</ic_file_input_names>
@@ -581,7 +588,8 @@
     <variable local_name="landm"
               standard_name="smoothed_land_area_fraction"
               units="fraction" type="real" kind="kind_phys"
-              allocatable="allocatable">
+	      allocatable="allocatable" restart="true"
+	      diagnostic_name="LANDM">
       <dimensions>horizontal_dimension</dimensions>
       <!-- Note: In CAM, landm is read from the topo dataset (or if disabled, set to zero) -->
       <initial_value>0.0_kind_phys</initial_value>
@@ -590,7 +598,8 @@
     <variable local_name="ast"
               standard_name="stratiform_cloud_area_fraction"
               units="fraction" type="real" kind="kind_phys"
-              allocatable="allocatable">
+	      allocatable="allocatable" restart="true"
+	      diagnostic_name="AST">
       <dimensions>horizontal_dimension vertical_layer_dimension</dimensions>
       <initial_value>0.0_kind_phys</initial_value>
       <ic_file_input_names>pbuf_AST</ic_file_input_names>
@@ -632,7 +641,8 @@
     <variable local_name="cflx"
               standard_name="surface_upward_ccpp_constituent_fluxes_from_coupler"
               units="kg m-2 s-1" type="real" kind="kind_phys"
-              allocatable="allocatable">
+	      allocatable="allocatable" restart="true"
+	      diagnostic_name="CFLX">
       <dimensions>horizontal_dimension number_of_ccpp_constituents</dimensions>
       <initial_value>0.0_kind_phys</initial_value>
       <ic_file_input_names>cflx cam_in_cflx</ic_file_input_names>
@@ -790,7 +800,8 @@
     <variable local_name="shf"
               standard_name="surface_upward_sensible_heat_flux_from_coupler"
               units="W m-2" type="real" kind="kind_phys"
-              allocatable="allocatable">
+	      allocatable="allocatable" restart="true"
+	      diagnostic_name="SHF">
       <dimensions>horizontal_dimension</dimensions>
       <initial_value>0.0_kind_phys</initial_value>
       <ic_file_input_names>shf cam_in_shf</ic_file_input_names>
@@ -895,7 +906,8 @@
     <variable local_name="wsx"
               standard_name="surface_eastward_wind_stress_from_coupler"
               units="N m-2" type="real" kind="kind_phys"
-              allocatable="allocatable">
+	      allocatable="allocatable" restart="true"
+	      diagnostic_name="wsx">
       <dimensions>horizontal_dimension</dimensions>
       <initial_value>0.0_kind_phys</initial_value>
       <ic_file_input_names>wsx cam_in_wsx</ic_file_input_names>
@@ -903,7 +915,8 @@
     <variable local_name="wsy"
               standard_name="surface_northward_wind_stress_from_coupler"
               units="N m-2" type="real" kind="kind_phys"
-              allocatable="allocatable">
+	      allocatable="allocatable" restart="true"
+	      diagnostic_name="wsy">
       <dimensions>horizontal_dimension</dimensions>
       <initial_value>0.0_kind_phys</initial_value>
       <ic_file_input_names>wsy cam_in_wsy</ic_file_input_names>
@@ -913,7 +926,8 @@
     <variable local_name="bcphidry"
               standard_name="dry_deposition_flux_of_hydrophilic_black_carbon_at_surface_to_coupler"
               units="kg m-2 s-1" type="real" kind="kind_phys"
-              allocatable="allocatable">
+	      allocatable="allocatable" restart="true"
+	      diagnostic_name="BCPHIDRY">
       <dimensions>horizontal_dimension</dimensions>
       <initial_value>0.0_kind_phys</initial_value>
       <ic_file_input_names>bcphidry cam_out_bcphidry</ic_file_input_names>
@@ -929,7 +943,8 @@
     <variable local_name="bcphodry"
               standard_name="dry_deposition_flux_of_hydrophobic_black_carbon_at_surface_to_coupler"
               units="kg m-2 s-1" type="real" kind="kind_phys"
-              allocatable="allocatable">
+	      allocatable="allocatable" restart="true"
+	      diagnostic_name="BCPHODRY">
       <dimensions>horizontal_dimension</dimensions>
       <initial_value>0.0_kind_phys</initial_value>
       <ic_file_input_names>bcphodry cam_out_bcphodry</ic_file_input_names>
@@ -937,7 +952,8 @@
     <variable local_name="co2diag"
               standard_name="co2diag_tbd"
               units="tbd" type="real" kind="kind_phys"
-              allocatable="allocatable">
+	      allocatable="allocatable" restart="true"
+	      diagnostic_name="CO2DIAG">
       <dimensions>horizontal_dimension</dimensions>
       <initial_value>0.0_kind_phys</initial_value>
       <ic_file_input_names>co2diag cam_out_co2diag</ic_file_input_names>
@@ -945,7 +961,8 @@
     <variable local_name="co2prog"
               standard_name="co2prog_tbd"
               units="tbd" type="real" kind="kind_phys"
-              allocatable="allocatable">
+	      allocatable="allocatable" restart="true"
+	      diagnostic_name="CO2PROG">
       <dimensions>horizontal_dimension</dimensions>
       <initial_value>0.0_kind_phys</initial_value>
       <ic_file_input_names>co2prog cam_out_co2prog</ic_file_input_names>
@@ -953,7 +970,8 @@
     <variable local_name="dstdry1"
               standard_name="dry_deposition_of_dust_bin1_at_surface_to_coupler"
               units="kg m-2 s-1" type="real" kind="kind_phys"
-              allocatable="allocatable">
+	      allocatable="allocatable" restart="true"
+	      diagnostic_name="DSTDRY1">
       <dimensions>horizontal_dimension</dimensions>
       <initial_value>0.0_kind_phys</initial_value>
       <ic_file_input_names>dstdry1 cam_out_dstdry1</ic_file_input_names>
@@ -961,7 +979,8 @@
     <variable local_name="dstdry2"
               standard_name="dry_deposition_of_dust_bin2_at_surface_to_coupler"
               units="kg m-2 s-1" type="real" kind="kind_phys"
-              allocatable="allocatable">
+	      allocatable="allocatable" restart="true"
+	      diagnostic_name="DSTDRY2">
       <dimensions>horizontal_dimension</dimensions>
       <initial_value>0.0_kind_phys</initial_value>
       <ic_file_input_names>dstdry2 cam_out_dstdry2</ic_file_input_names>
@@ -969,7 +988,8 @@
     <variable local_name="dstdry3"
               standard_name="dry_deposition_of_dust_bin3_at_surface_to_coupler"
               units="kg m-2 s-1" type="real" kind="kind_phys"
-              allocatable="allocatable">
+	      allocatable="allocatable" restart="true"
+	      diagnostic_name="DSTDRY3">
       <dimensions>horizontal_dimension</dimensions>
       <initial_value>0.0_kind_phys</initial_value>
       <ic_file_input_names>dstdry3 cam_out_dstdry3</ic_file_input_names>
@@ -977,7 +997,8 @@
     <variable local_name="dstdry4"
               standard_name="dry_deposition_of_dust_bin4_at_surface_to_coupler"
               units="kg m-2 s-1" type="real" kind="kind_phys"
-              allocatable="allocatable">
+	      allocatable="allocatable" restart="true"
+              diagnostic_name="DSTDRY4">
       <dimensions>horizontal_dimension</dimensions>
       <initial_value>0.0_kind_phys</initial_value>
       <ic_file_input_names>dstdry4 cam_out_dstdry4</ic_file_input_names>
@@ -1017,7 +1038,8 @@
     <variable local_name="flwds"
               standard_name="longwave_downward_radiative_flux_at_surface_to_coupler"
               units="W m-2" type="real" kind="kind_phys"
-              allocatable="allocatable">
+	      allocatable="allocatable" restart="true"
+	      diagnostic_name="FLWDS">
       <dimensions>horizontal_dimension</dimensions>
       <initial_value>0.0_kind_phys</initial_value>
       <ic_file_input_names>flwds cam_out_flwds</ic_file_input_names>
@@ -1057,7 +1079,8 @@
     <variable local_name="ocphidry"
               standard_name="dry_deposition_flux_of_hydrophilic_organic_carbon_at_surface_to_coupler"
               units="kg m-2 s-1" type="real" kind="kind_phys"
-              allocatable="allocatable">
+	      allocatable="allocatable" restart="true"
+	      diagnostic_name="OCPHIDRY">
       <dimensions>horizontal_dimension</dimensions>
       <initial_value>0.0_kind_phys</initial_value>
       <ic_file_input_names>ocphidry cam_out_ocphidry</ic_file_input_names>
@@ -1073,7 +1096,8 @@
     <variable local_name="ocphodry"
               standard_name="dry_deposition_flux_of_hydrophobic_organic_carbon_at_surface_to_coupler"
               units="kg m-2 s-1" type="real" kind="kind_phys"
-              allocatable="allocatable">
+	      allocatable="allocatable" restart="true"
+	      diagnostic_name="OCPHODRY">
       <dimensions>horizontal_dimension</dimensions>
       <initial_value>0.0_kind_phys</initial_value>
       <ic_file_input_names>ocphodry cam_out_ocphodry</ic_file_input_names>
@@ -1154,7 +1178,8 @@
     <variable local_name="soll"
               standard_name="direct_solar_radiative_flux_at_surface_ge_700nm_to_coupler"
               units="W m-2" type="real" kind="kind_phys"
-              allocatable="allocatable">
+	      allocatable="allocatable" restart="true"
+	      diagnostic_name="SOLL">
       <dimensions>horizontal_dimension</dimensions>
       <initial_value>0.0_kind_phys</initial_value>
       <ic_file_input_names>soll cam_out_soll</ic_file_input_names>
@@ -1162,7 +1187,8 @@
     <variable local_name="solld"
               standard_name="diffuse_solar_radiative_flux_at_surface_ge_700nm_to_coupler"
               units="W m-2" type="real" kind="kind_phys"
-              allocatable="allocatable">
+	      allocatable="allocatable" restart="true"
+	      diagnostic_name="SOLLD">
       <dimensions>horizontal_dimension</dimensions>
       <initial_value>0.0_kind_phys</initial_value>
       <ic_file_input_names>solld cam_out_solld</ic_file_input_names>
@@ -1170,7 +1196,8 @@
     <variable local_name="sols"
               standard_name="direct_solar_radiative_flux_at_surface_lt_700nm_to_coupler"
               units="W m-2" type="real" kind="kind_phys"
-              allocatable="allocatable">
+	      allocatable="allocatable" restart="true"
+	      diagnostic_name="SOLS">
       <dimensions>horizontal_dimension</dimensions>
       <initial_value>0.0_kind_phys</initial_value>
       <ic_file_input_names>sols cam_out_sols</ic_file_input_names>
@@ -1178,7 +1205,8 @@
     <variable local_name="solsd"
               standard_name="diffuse_solar_radiative_flux_at_surface_lt_700nm_to_coupler"
               units="W m-2" type="real" kind="kind_phys"
-              allocatable="allocatable">
+	      allocatable="allocatable" restart="true"
+	      diagnostic_name="SOLSD">
       <dimensions>horizontal_dimension</dimensions>
       <initial_value>0.0_kind_phys</initial_value>
       <ic_file_input_names>solsd cam_out_solsd</ic_file_input_names>
@@ -1329,7 +1357,8 @@
     <variable local_name="pblh"
               standard_name="atmosphere_boundary_layer_thickness"
               units="m" type="real" kind="kind_phys"
-              allocatable="allocatable">
+	      allocatable="allocatable" restart="true"
+	      diagnostic_name="PBLH">
       <dimensions>horizontal_dimension</dimensions>
       <!-- FIXME: this is a temporary initialization to allow CAM4/CAM7 suites to run standalone,
            while a PBL scheme is unavailable. -->
@@ -1339,7 +1368,8 @@
     <variable local_name="tpert"
               standard_name="convective_temperature_perturbation_due_to_pbl_eddies"
               units="K" type="real" kind="kind_phys"
-              allocatable="allocatable">
+	      allocatable="allocatable" restart="true"
+	      diagnostic_name="TPERT">
       <dimensions>horizontal_dimension</dimensions>
       <initial_value>273.15_kind_phys</initial_value>
       <ic_file_input_names>tpert pbuf_tpert</ic_file_input_names>
@@ -1374,7 +1404,8 @@
     <variable local_name="qcwat"
               standard_name="water_vapor_mixing_ratio_wrt_moist_air_and_condensed_water_on_previous_timestep"
               units="kg kg-1" type="real" kind="kind_phys"
-              allocatable="allocatable">
+	      allocatable="allocatable" restart="true"
+	      diagnostic_name="QCWAT">
       <dimensions>horizontal_dimension vertical_layer_dimension</dimensions>
       <!-- set to negative if not read from the snapshot. -->
       <initial_value>-1.0_kind_phys</initial_value>
@@ -1383,7 +1414,8 @@
     <variable local_name="tcwat"
               standard_name="air_temperature_on_previous_timestep"
               units="K" type="real" kind="kind_phys"
-              allocatable="allocatable">
+	      allocatable="allocatable" restart="true"
+	      diagnostic_name="TCWAT">
       <dimensions>horizontal_dimension vertical_layer_dimension</dimensions>
       <!-- set to negative if not read from the snapshot. -->
       <initial_value>-1.0_kind_phys</initial_value>
@@ -1392,7 +1424,8 @@
     <variable local_name="lcwat"
               standard_name="cloud_water_mixing_ratio_wrt_moist_air_and_condensed_water_on_previous_timestep"
               units="kg kg-1" type="real" kind="kind_phys"
-              allocatable="allocatable">
+	      allocatable="allocatable" restart="true"
+	      diagnostic_name="LCWAT">
       <dimensions>horizontal_dimension vertical_layer_dimension</dimensions>
       <!-- set to negative if not read from the snapshot. -->
       <initial_value>-1.0_kind_phys</initial_value>
@@ -1403,7 +1436,8 @@
     <variable local_name="tauresx"
               standard_name="eastward_reserved_stress_at_surface_on_previous_timestep"
               units="N m-2" type="real" kind="kind_phys"
-              allocatable="allocatable">
+	      allocatable="allocatable" restart="true"
+	      diagnostic_name="TAURESX">
       <dimensions>horizontal_dimension</dimensions>
       <initial_value>0.0_kind_phys</initial_value>
       <ic_file_input_names>pbuf_tauresx</ic_file_input_names>
@@ -1411,7 +1445,8 @@
     <variable local_name="tauresy"
               standard_name="northward_reserved_stress_at_surface_on_previous_timestep"
               units="N m-2" type="real" kind="kind_phys"
-              allocatable="allocatable">
+	      allocatable="allocatable" restart="true"
+	      diagnostic_name="TAURESY">
       <dimensions>horizontal_dimension</dimensions>
       <initial_value>0.0_kind_phys</initial_value>
       <ic_file_input_names>pbuf_tauresy</ic_file_input_names>
@@ -1419,7 +1454,8 @@
     <variable local_name="dragblj"
               standard_name="turbulent_orographic_form_drag_coefficent"
               units="s-1" type="real" kind="kind_phys"
-              allocatable="allocatable">
+	      allocatable="allocatable" restart="true"
+	      diagnostic_name="DRAGBLJ">
       <dimensions>horizontal_dimension vertical_layer_dimension</dimensions>
       <initial_value>0.0_kind_phys</initial_value>
       <ic_file_input_names>pbuf_dragblj</ic_file_input_names>
@@ -1432,7 +1468,8 @@
     <variable local_name="taubljx"
               standard_name="eastward_beljaars_surface_stress_tbd"
               units="N m-2" type="real" kind="kind_phys"
-              allocatable="allocatable">
+	      allocatable="allocatable" restart="true"
+	      diagnostic_name="TAUBLJX">
       <dimensions>horizontal_dimension</dimensions>
       <initial_value>0.0_kind_phys</initial_value>
       <ic_file_input_names>pbuf_taubljx</ic_file_input_names>
@@ -1440,7 +1477,8 @@
     <variable local_name="taubljy"
               standard_name="northward_beljaars_surface_stress_tbd"
               units="N m-2" type="real" kind="kind_phys"
-              allocatable="allocatable">
+	      allocatable="allocatable" restart="true"
+	      diagnostic_name="TAUBLJY">
       <dimensions>horizontal_dimension</dimensions>
       <initial_value>0.0_kind_phys</initial_value>
       <ic_file_input_names>pbuf_taubljy</ic_file_input_names>
@@ -1455,7 +1493,8 @@
     <variable local_name="clubbtop"
               standard_name="vertical_layer_index_of_clubb_top_tbd"
               units="index" type="real" kind="kind_phys"
-              allocatable="allocatable">
+	      allocatable="allocatable" restart="true"
+	      diagnostic_name="CLUBBTOP">
       <!-- REMOVECAM: once CAM snapshots are no longer used, change to integer. -->
       <long_name>vertical layer index for top of CLUBB for running HB above</long_name>
       <dimensions>horizontal_dimension</dimensions>
@@ -1467,14 +1506,16 @@
     <variable local_name="ql"
               standard_name="in_cloud_water_vapor_mixing_ratio_wrt_moist_air_and_condensed_water_due_to_deep_convection"
               units="kg kg-1" type="real" kind="kind_phys"
-              allocatable="allocatable">
+	      allocatable="allocatable" restart="true"
+	      diagnostic_name="QL">
       <dimensions>horizontal_dimension vertical_layer_dimension</dimensions>
       <ic_file_input_names>ICWMRDP pbuf_ICWMRDP</ic_file_input_names>
     </variable>
     <variable local_name="cldfrc"
               standard_name="cloud_area_fraction"
               units="fraction" type="real" kind="kind_phys"
-              allocatable="allocatable">
+	      allocatable="allocatable" restart="true"
+	      diagnostic_name="CLDFRC">
       <dimensions>horizontal_dimension vertical_layer_dimension</dimensions>
       <initial_value>0.7_kind_phys</initial_value>
       <ic_file_input_names>CLD pbuf_CLD</ic_file_input_names>
@@ -1510,21 +1551,24 @@
     <variable local_name="qini"
               standard_name="water_vapor_mixing_ratio_wrt_moist_air_and_condensed_water_before_physics"
               units="kg kg-1" type="real" kind="kind_phys"
-              allocatable="allocatable">
+	      allocatable="allocatable" restart="true"
+	      diagnostic_name="QINI">
       <dimensions>horizontal_dimension vertical_layer_dimension</dimensions>
       <ic_file_input_names>QINI pbuf_QINI</ic_file_input_names>
     </variable>
     <variable local_name="liqini"
               standard_name="total_liquid_water_mixing_ratio_wrt_moist_air_and_condensed_water_before_physics"
               units="kg kg-1" type="real" kind="kind_phys"
-              allocatable="allocatable">
+ 	      allocatable="allocatable" restart="true"
+	      diagnostic_name="LIQINI">
       <dimensions>horizontal_dimension vertical_layer_dimension</dimensions>
       <ic_file_input_names>TOTLIQINI pbuf_TOTLIQINI</ic_file_input_names>
     </variable>
     <variable local_name="iceini"
               standard_name="total_ice_water_mixing_ratio_wrt_moist_air_and_condensed_water_before_physics"
               units="kg kg-1" type="real" kind="kind_phys"
-              allocatable="allocatable">
+	      allocatable="allocatable" restart="true"
+	      diagnostic_name="ICEINI">
       <dimensions>horizontal_dimension vertical_layer_dimension</dimensions>
       <ic_file_input_names>TOTICEINI pbuf_TOTICEINI</ic_file_input_names>
     </variable>
diff --git a/src/data/registry_v1_0.xsd b/src/data/registry_v1_0.xsd
index d6a28461c..0f7a45191 100644
--- a/src/data/registry_v1_0.xsd
+++ b/src/data/registry_v1_0.xsd
@@ -110,10 +110,14 @@
 
   <xs:attribute name="constituent"             type="xs:boolean"
                 default="false"/>
+  <xs:attribute name="restart"             type="xs:boolean"
+                default="false"/>
   <xs:attribute name="advected"                type="xs:boolean"
                 default="false"/>
   <xs:attribute name="phys_timestep_init_zero" type="xs:boolean"
                 default="false"/>
+  <xs:attribute name="diagnostic_name" type="fortran_id_type"
+                default="none"/>
 
   <!-- definition of simple types -->
 
@@ -147,8 +151,10 @@
     <xs:attribute ref="standard_name" use="required"/>
     <xs:attribute ref="units"         use="optional"/>
     <xs:attribute ref="constituent"   use="optional"/>
+    <xs:attribute ref="restart"       use="optional"/>
     <xs:attribute ref="advected"      use="optional"/>
     <xs:attribute ref="phys_timestep_init_zero" use="optional"/>
+    <xs:attribute ref="diagnostic_name" use="optional"/>
     <!-- array element-specific attributes -->
     <xs:attribute name="index_name"    type="standard_name_type"
                   use="required"/>
@@ -171,8 +177,10 @@
     <xs:attribute ref="allocatable"   use="optional" default="none"/>
     <xs:attribute ref="access"        use="optional" default="public"/>
     <xs:attribute ref="constituent"   use="optional"/>
+    <xs:attribute ref="restart"   use="optional"/>
     <xs:attribute ref="advected"      use="optional"/>
     <xs:attribute ref="phys_timestep_init_zero" use="optional"/>
+    <xs:attribute ref="diagnostic_name" use="optional"/>
   </xs:complexType>
 
   <xs:complexType name="array_type">
diff --git a/src/data/write_physics_restart.py b/src/data/write_physics_restart.py
index d9dfbcdbd..53a9508c9 100644
--- a/src/data/write_physics_restart.py
+++ b/src/data/write_physics_restart.py
@@ -96,13 +96,60 @@ def write_physics_restart(cap_database, ic_names, registry_constituents,
 
         all_req_vars = in_vars + out_vars
         # Grab the required variables that are also restart variables
-        print(restart_vars)
         required_restart_vars, required_restart_constituents = gather_required_restart_variables(all_req_vars, constituent_set, restart_vars)
 
+        outfile.blank_line()
+        outfile.comment("Private module data", 0)
+        for required_var in required_restart_vars:
+            outfile.write(f"type(var_desc_t) :: {required_var.lower()}_desc", 1)
+        # end for
+
         # Add "contains" statement:
         outfile.end_module_header()
         outfile.blank_line()
 
+        # Write the restart init subroutine
+        write_restart_physics_init(outfile, required_restart_vars, required_restart_constituents)
+
+def write_restart_physics_init(outfile, required_vars, constituent_vars):
+    """
+    Write the init routine for the physics restart variables. This
+    routine initializes the physics fields on the restart (cam.r) file
+    """
+
+    outfile.write("subroutine restart_physics_init(file, hdimids, errmsg, errflg)", 1)
+
+    # peverwhee - figure out use statements
+    # pio: pio_bcast_error, file_desc_t, pio_seterrorhandling, pio_double
+    
+    outfile.write("type(file_desc_t), intent(inout) :: file", 2)
+    outfile.write("integer,           intent(in)    :: hdimids(:)", 2)
+    outfile.write("character(len=512),intent(out)   :: errmsg", 2)
+    outfile.write("integer,           intent(out)   :: errflg", 2)
+    outfile.blank_line()
+
+    # Local variables
+    outfile.write("integer :: ierr", 2)
+
+    outfile.blank_line()
+
+    outfile.write("call pio_seterrorhandling(file, PIO_BCAST_ERROR)", 2)
+    outfile.blank_line()
+
+    outfile.comment("Define required restart variables on the restart file", 2)
+    for required_var in required_vars:
+        desc_name = f"{required_var.lower()}_desc"
+        outfile.write(f"ierr = pio_def_var(file, '{required_var}', pio_double, hdimids, {desc_name})", 2)
+        outfile.write("if (ierr /= 0) then", 2)
+        outfile.write(f"write(errmsg,*) 'restart_physics_init: error defining variable {required_var}'", 3)
+        outfile.write("errflg = ierr", 3)
+        outfile.write("return", 3)
+        outfile.write("end if", 2)
+        outfile.blank_line()
+    # end for
+
+    outfile.write("end subroutine restart_physics_init", 1)
+
 #################
 #HELPER FUNCTIONS
 #################
@@ -214,14 +261,16 @@ def gather_required_restart_variables(all_req_vars, registry_constituents, resta
     required_restart_vars = []
     required_constituent_restart_vars = []
 
-    for restart_var in restart_vars:
-        if restart_var in all_req_vars:
-            if restart_var in registry_constituents:
-                required_constituent_restart_vars.append(restart_var)
+    for required_var in all_req_vars:
+        stdname = required_var.get_prop_value('standard_name')
+        if stdname in restart_vars.keys():
+            diagnostic_name = restart_vars[stdname]
+            if stdname in registry_constituents:
+                required_constituent_restart_vars.append(diagnostic_name)
             else:
-                required_restart_vars.append(restart_var)
+                required_restart_vars.append(diagnostic_name)
             # end if
-        # end if (ignore all non-required variables)
+        # end if (ignore all non-restart variables)
     # end for
 
     return required_restart_vars, required_constituent_restart_vars

From 05f6de6acf7fdffb517727d2e4b0879cb1a0c81b Mon Sep 17 00:00:00 2001
From: peverwhee <courtneyp@ucar.edu>
Date: Mon, 3 Nov 2025 16:29:07 -0700
Subject: [PATCH 03/19] rename file; add handling for constituent-dimensioned
 fields

---
 cime_config/cam_autogen.py                    |   6 +-
 cime_config/cam_build_cache.py                |   2 +-
 ...cs_restart.py => write_restart_physics.py} | 103 ++++++++++++++++--
 3 files changed, 96 insertions(+), 15 deletions(-)
 rename src/data/{write_physics_restart.py => write_restart_physics.py} (69%)

diff --git a/cime_config/cam_autogen.py b/cime_config/cam_autogen.py
index ca26c8928..b6565672e 100644
--- a/cime_config/cam_autogen.py
+++ b/cime_config/cam_autogen.py
@@ -33,7 +33,7 @@
 # Import needed registry and other src/data scripts:
 from generate_registry_data import gen_registry
 from write_init_files import write_init_files
-from write_physics_restart import write_physics_restart
+from write_restart_physics import write_restart_physics
 
 ###############################################################################
 
@@ -757,7 +757,7 @@ def generate_restart_routines(build_cache, bldroot, force_ccpp, force_restart,
     #Add new directory to build path:
     restart_dir = os.path.join(bldroot, "phys_restart")
     # Use this for cache check
-    gen_restart_file = os.path.join(_REG_GEN_DIR, "write_physics_restart.py")
+    gen_restart_file = os.path.join(_REG_GEN_DIR, "write_restart_physics.py")
 
     # Figure out if we need to generate new restart routines:
     if os.path.exists(restart_dir):
@@ -776,7 +776,7 @@ def generate_restart_routines(build_cache, bldroot, force_ccpp, force_restart,
     # End if
     if do_gen_restart:
         source_paths = [source_mods_dir, _REG_GEN_DIR]
-        retmsg = write_physics_restart(cap_database, ic_names, registry_constituents,
+        retmsg = write_restart_physics(cap_database, ic_names, registry_constituents,
                                        restart_vars, restart_dir, _find_file, 
                                        source_paths, gen_fort_indent, _LOGGER)
         
diff --git a/cime_config/cam_build_cache.py b/cime_config/cam_build_cache.py
index 20c1ba622..f9d66b65c 100644
--- a/cime_config/cam_build_cache.py
+++ b/cime_config/cam_build_cache.py
@@ -393,7 +393,7 @@ def update_init_gen(self, gen_init_file):
     def update_restart_gen(self, gen_restart_file):
         """
         Replace the restart writer
-        (write_physics_restart.py) cache
+        (write_restart_physics.py) cache
         data with input data
         """
         self.__gen_restart_file = FileStatus(gen_restart_file, 'generate_restart_file')
diff --git a/src/data/write_physics_restart.py b/src/data/write_restart_physics.py
similarity index 69%
rename from src/data/write_physics_restart.py
rename to src/data/write_restart_physics.py
index 53a9508c9..9404bbd35 100644
--- a/src/data/write_physics_restart.py
+++ b/src/data/write_restart_physics.py
@@ -39,7 +39,7 @@
 #Main function
 ##############
 
-def write_physics_restart(cap_database, ic_names, registry_constituents,
+def write_restart_physics(cap_database, ic_names, registry_constituents,
                      restart_vars, outdir, file_find_func, source_paths, indent, logger,
                      phys_restart_filename=None):
 
@@ -96,7 +96,7 @@ def write_physics_restart(cap_database, ic_names, registry_constituents,
 
         all_req_vars = in_vars + out_vars
         # Grab the required variables that are also restart variables
-        required_restart_vars, required_restart_constituents = gather_required_restart_variables(all_req_vars, constituent_set, restart_vars)
+        required_restart_vars, required_restart_constituents, constituent_dimmed_vars = gather_required_restart_variables(all_req_vars, constituent_set, restart_vars)
 
         outfile.blank_line()
         outfile.comment("Private module data", 0)
@@ -104,14 +104,18 @@ def write_physics_restart(cap_database, ic_names, registry_constituents,
             outfile.write(f"type(var_desc_t) :: {required_var.lower()}_desc", 1)
         # end for
 
+        for required_var in constituent_dimmed_vars:
+            outfile.write(f"type(var_desc_t), allocatable :: {required_var.lower()}_desc(:)", 1)
+        # end for
+
         # Add "contains" statement:
         outfile.end_module_header()
         outfile.blank_line()
 
         # Write the restart init subroutine
-        write_restart_physics_init(outfile, required_restart_vars, required_restart_constituents)
+        write_restart_physics_init(outfile, required_restart_vars, required_restart_constituents, constituent_dimmed_vars)
 
-def write_restart_physics_init(outfile, required_vars, constituent_vars):
+def write_restart_physics_init(outfile, required_vars, constituent_vars, constituent_dimmed_vars):
     """
     Write the init routine for the physics restart variables. This
     routine initializes the physics fields on the restart (cam.r) file
@@ -119,7 +123,23 @@ def write_restart_physics_init(outfile, required_vars, constituent_vars):
 
     outfile.write("subroutine restart_physics_init(file, hdimids, errmsg, errflg)", 1)
 
-    # peverwhee - figure out use statements
+    use_stmts = [["pio", ["file_desc_t", "pio_bcast_error",
+                          "pio_set_errorhandling", "pio_double",
+                          "pio_def_var"]],
+                 ["cam_abortutils", ["endrun"]],
+                 ["shr_kind_mod", ["SHR_KIND_CS, SHR_KIND_CL, SHR_KIND_CX"]],
+                 ["cam_ccpp_cap", ["cam_model_const_properties"]],
+                 ["ccpp_kinds", ["kind_phys"]],
+                 ["cam_logfile", ["iulog"]],
+                 ["spmd_utils", ["masterproc"]],
+                 ["ccpp_constituent_prop_mod", ["ccpp_constituent_prop_ptr_t"]]]
+
+    # Add in host model data use statements
+#    use_stmts.extend(host_imports)
+
+    # Output required, registered Fortran module use statements:
+    write_use_statements(outfile, use_stmts, 2)
+
     # pio: pio_bcast_error, file_desc_t, pio_seterrorhandling, pio_double
     
     outfile.write("type(file_desc_t), intent(inout) :: file", 2)
@@ -129,7 +149,9 @@ def write_restart_physics_init(outfile, required_vars, constituent_vars):
     outfile.blank_line()
 
     # Local variables
-    outfile.write("integer :: ierr", 2)
+    outfile.write("integer :: constituent_idx", 2)
+    outfile.write("type(ccpp_constituent_prop_ptr_t), pointer :: const_props(:)", 2)
+    outfile.write("character(len=512) :: const_locname", 2)
 
     outfile.blank_line()
 
@@ -139,15 +161,38 @@ def write_restart_physics_init(outfile, required_vars, constituent_vars):
     outfile.comment("Define required restart variables on the restart file", 2)
     for required_var in required_vars:
         desc_name = f"{required_var.lower()}_desc"
-        outfile.write(f"ierr = pio_def_var(file, '{required_var}', pio_double, hdimids, {desc_name})", 2)
-        outfile.write("if (ierr /= 0) then", 2)
+        outfile.write(f"errflg = pio_def_var(file, '{required_var}', pio_double, hdimids, {desc_name})", 2)
+        outfile.write("if (errflg /= 0) then", 2)
         outfile.write(f"write(errmsg,*) 'restart_physics_init: error defining variable {required_var}'", 3)
-        outfile.write("errflg = ierr", 3)
         outfile.write("return", 3)
         outfile.write("end if", 2)
         outfile.blank_line()
     # end for
 
+    # Handle constituent-dimensioned variables
+    if constituent_dimmed_vars:
+        outfile.write("const_props => cam_model_const_properties()", 2)
+        outfile.blank_line()
+        for required_var in constituent_dimmed_vars:
+            outfile.comment(f"Handling for constituent-dimensioned variable '{required_var}'", 2)
+            outfile.write(f"allocate({required_var.lower()}_desc(size(const_props)), stat=errflg, errmsg=errmsg)", 2)
+            outfile.write("if (errflg /= 0) then", 2)
+            outfile.write("return", 3)
+            outfile.write("end if", 2)
+            outfile.write("do constituent_idx = 1, size(const_props)", 2)
+            outfile.comment("Grab constituent local name:", 3)
+            outfile.write("call const_props(constituent_idx)%local_name(const_locname)", 3)
+            desc_name = f"{required_var.lower()}_desc"
+            outfile.write(f"errflg = pio_def_var(file, '{required_var}_'//trim(const_locname), pio_double, hdimids, {desc_name}(constituent_idx))", 3)
+            outfile.write("if (errflg /= 0) then", 3)
+            outfile.write(f"write(errmsg,*) 'restart_physics_init: error defining variable {required_var}_'//trim(const_locname)", 4)
+            outfile.write("end if", 3)
+            outfile.write("end do", 2)
+            outfile.blank_line()
+        # end for
+    # end if
+
+
     outfile.write("end subroutine restart_physics_init", 1)
 
 #################
@@ -260,6 +305,7 @@ def gather_required_restart_variables(all_req_vars, registry_constituents, resta
 
     required_restart_vars = []
     required_constituent_restart_vars = []
+    required_constituent_dimensioned_vars = []
 
     for required_var in all_req_vars:
         stdname = required_var.get_prop_value('standard_name')
@@ -268,9 +314,44 @@ def gather_required_restart_variables(all_req_vars, registry_constituents, resta
             if stdname in registry_constituents:
                 required_constituent_restart_vars.append(diagnostic_name)
             else:
-                required_restart_vars.append(diagnostic_name)
+                if 'ccpp_constant_one:number_of_ccpp_constituents' in required_var.get_dimensions():
+                    print('HI THERE!')
+                    required_constituent_dimensioned_vars.append(diagnostic_name)
+                else:
+                    required_restart_vars.append(diagnostic_name)
             # end if
         # end if (ignore all non-restart variables)
     # end for
 
-    return required_restart_vars, required_constituent_restart_vars
+    return required_restart_vars, required_constituent_restart_vars, required_constituent_dimensioned_vars
+
+#####
+
+def write_use_statements(outfile, use_stmts, indent):
+    """Output Fortran module use (import) statements listed in <use_stmts>.
+    """
+
+    # The plus one is for a comma
+    max_modname = max(len(x[0]) for x in use_stmts) + 1
+    # max_modspace is the max chars of the module plus other 'use' statement
+    #    syntax (e.g., 'only:')
+    max_modspace = (outfile.indent_size * indent) + max_modname + 10
+    mod_space = outfile.line_fill - max_modspace
+    for use_item in use_stmts:
+        # Break up imported interfaces to clean up use statements
+        larg = 0
+        num_imports = len(use_item[1])
+        while larg < num_imports:
+            int_str = use_item[1][larg]
+            larg = larg + 1
+            while ((larg < num_imports) and
+                   ((len(int_str) + len(use_item[1][larg]) + 2) < mod_space)):
+                int_str += f", {use_item[1][larg]}"
+                larg = larg + 1
+            # end while
+            modname = use_item[0] + ','
+            outfile.write(f"use {modname: <{max_modname}} only: {int_str}",
+                          indent)
+        # end while
+    # end for
+

From 206936cbb1562951bb4a4c5ff31bb26cb4c5f5fe Mon Sep 17 00:00:00 2001
From: Courtney Peverley <courtneyp@izumi.cgd.ucar.edu>
Date: Tue, 18 Nov 2025 13:50:15 -0700
Subject: [PATCH 04/19] auto-generate physics restart from registry; init file
 working with necessary imports

---
 cime_config/buildlib              |   3 +-
 src/control/cam_comp.F90          |  12 +-
 src/control/cam_restart.F90       | 122 ++++++++++
 src/data/registry.xml             |   2 +-
 src/data/write_restart_physics.py | 357 +++++++++++++++++++++++++-----
 5 files changed, 434 insertions(+), 62 deletions(-)
 create mode 100644 src/control/cam_restart.F90

diff --git a/cime_config/buildlib b/cime_config/buildlib
index 4d9222c8b..64834b1ee 100755
--- a/cime_config/buildlib
+++ b/cime_config/buildlib
@@ -84,6 +84,7 @@ def _build_cam():
         dycore = config.get_value('dyn')
         reg_dir = config.get_value('reg_dir')
         init_dir = config.get_value('init_dir')
+        restart_dir = config.get_value('restart_dir')
         phys_dirs_str = config.get_value('phys_dirs')
 
         #Convert the phys_dirs_str into a proper list:
@@ -96,7 +97,7 @@ def _build_cam():
         filepath_src = os.path.join(caseroot, "Buildconf",
                                     "camconf", "Filepath")
         filepath_dst = os.path.join(bldroot, "Filepath")
-        paths = [source_mods_dir, reg_dir, init_dir,
+        paths = [source_mods_dir, reg_dir, init_dir, restart_dir,
                  os.path.join(atm_root, "src", "data"),
                  os.path.join(atm_root, "src", "control"),
                  os.path.join(atm_root, "src", "cpl",
diff --git a/src/control/cam_comp.F90 b/src/control/cam_comp.F90
index 84c845a17..595de0dc3 100644
--- a/src/control/cam_comp.F90
+++ b/src/control/cam_comp.F90
@@ -456,7 +456,7 @@ subroutine cam_run4(rstwr, nlend,                         &
       !           file output.
       !
       !-----------------------------------------------------------------------
-!      use cam_restart,  only: cam_write_restart
+      use cam_restart,  only: cam_write_restart
 !      use qneg_module,  only: qneg_print_summary
 
       logical,         intent(in)           :: rstwr    ! write restart file
@@ -473,14 +473,10 @@ subroutine cam_run4(rstwr, nlend,                         &
          call t_startf('cam_write_restart')
          if (present(yr_spec) .and. present(mon_spec) .and.                   &
               present(day_spec).and.present(sec_spec)) then
-!!XXgoldyXX: v need to import this
-!            call cam_write_restart(cam_in, cam_out, dyn_out, yr_spec=yr_spec, &
-!                 mon_spec=mon_spec, day_spec=day_spec, sec_spec= sec_spec)
-!!XXgoldyXX: ^ need to import this
+            call cam_write_restart(dyn_out, yr_spec=yr_spec, &
+                 mon_spec=mon_spec, day_spec=day_spec, sec_spec= sec_spec)
          else
-!!XXgoldyXX: v need to import this
-!            call cam_write_restart(cam_in, cam_out, dyn_out)
-!!XXgoldyXX: ^ need to import this
+            call cam_write_restart(dyn_out)
          end if
          call t_stopf('cam_write_restart')
       end if
diff --git a/src/control/cam_restart.F90 b/src/control/cam_restart.F90
new file mode 100644
index 000000000..909418707
--- /dev/null
+++ b/src/control/cam_restart.F90
@@ -0,0 +1,122 @@
+module cam_restart
+
+  implicit none
+  private
+
+  public :: cam_write_restart
+
+CONTAINS
+  subroutine cam_write_restart(dyn_out, yr_spec, mon_spec, day_spec, sec_spec)
+    use cam_filenames,    only: interpret_filename_spec
+    use cam_pio_utils,    only: cam_pio_createfile, cam_pio_set_fill
+    !use restart_dynamics, only: write_restart_dynamics, init_restart_dynamics
+    use restart_physics,  only: restart_physics_write, restart_physics_init
+    use cam_instance,     only: inst_suffix
+    use pio,              only: file_desc_t, io_desc_t, pio_double, pio_global
+    use pio,              only: pio_put_att, pio_enddef, pio_closefile
+    use cam_grid_support, only: cam_grid_write_attr, cam_grid_id
+    use cam_grid_support, only: cam_grid_header_info_t, cam_grid_write_var
+    use cam_grid_support, only: cam_grid_dimensions, cam_grid_get_decomp
+    use physics_grid,     only: phys_decomp, num_global_phys_cols
+    use dyn_comp,         only: dyn_export_t
+    use cam_control_mod,  only: caseid
+    use cam_abortutils,   only: endrun, check_allocate
+    use shr_kind_mod,     only: cl=>shr_kind_cl
+    use vert_coord, only: pver
+    use cam_logfile, only: iulog
+
+    ! Arguments
+    type(dyn_export_t),      intent(in) :: dyn_out
+    integer,       optional, intent(in) :: yr_spec         ! Simulation year
+    integer,       optional, intent(in) :: mon_spec        ! Simulation month
+    integer,       optional, intent(in) :: day_spec        ! Simulation day
+    integer,       optional, intent(in) :: sec_spec        ! Seconds into current simulation day
+
+    ! Local variables
+    character(len=cl) :: rfilename_spec ! filename specifier for primary restart file
+    character(len=cl) :: fname          ! Restart filename
+    type(file_desc_t) :: fh
+    integer           :: ierr, i, errflg
+    character(len=512) :: errmsg
+    integer           :: grid_id
+    integer           :: hdimcnt
+    integer           :: dimids(4)
+    integer           :: dims(3), gdims(3)
+    integer           :: nhdims, ndims
+    type(io_desc_t), pointer     :: iodesc
+    integer, allocatable         :: hdimids(:)
+    type(cam_grid_header_info_t) :: info
+
+    ! Set template for primary restart filename based on instance suffix
+    ! (%c = caseid, $y = year, $m = month, $d = day, $s = seconds in day, %t = number)
+    rfilename_spec = '%c.cam' // trim(inst_suffix) //'.r.%y-%m-%d-%s.nc'
+    fname = interpret_filename_spec(rfilename_spec, yr_spec=yr_spec, &
+            mon_spec=mon_spec, day_spec=day_spec, sec_spec= sec_spec)
+
+    call cam_pio_createfile(fh, trim(fname), 0)
+    ierr = cam_pio_set_fill(fh)
+
+!    call init_restart_dynamics(fh, dyn_out)
+
+    ! TODO: initialize ionosphere restart
+
+    ! Grab physics grid info
+    grid_id = cam_grid_id('physgrid')
+    call cam_grid_write_attr(fh, grid_id, info)
+    hdimcnt = info%num_hdims()
+
+    allocate(hdimids(hdimcnt), stat=ierr, errmsg=errmsg)
+    call check_allocate(ierr, 'cam_write_restart', 'hdimids', errmsg)
+
+    do i = 1, hdimcnt
+       hdimids(i) = info%get_hdimid(i)
+    end do
+
+    call restart_physics_init(fh, errmsg, errflg)
+    if (errflg /= 0) then
+       call endrun(errmsg)
+    end if
+    !call init_restart_history(fh)
+
+    ierr = pio_put_att(fh, pio_global, 'caseid', caseid)
+    ierr = pio_enddef(fh)
+
+!    call write_restart_dynamics(fh, dyn_out)
+
+    ! TODO: write ionosphere restart
+
+
+    ! Write physics grid info
+    ndims = nhdims + 1
+    call cam_grid_write_var(fh, phys_decomp)
+    call cam_grid_dimensions(grid_id, gdims(1:3), nhdims)
+!    dims(1) = columns_on_task
+!    call cam_grid_get_decomp(grid_id, (/dims(1)/), gdims(1:nhdims), &
+!               pio_double, iodesc)
+    !dims(1) = num_global_phys_cols
+    !dims(2) = pver
+    !write(iulog,*) 'peverwhee - physics grid dims'
+    !write(iulog,*) nhdims
+    !write(iulog,*) dims
+    !write(iulog,*) gdims
+    !gdims(2) = pver
+    !call cam_grid_get_decomp(grid_id, dims(1:2), gdims(1:2), pio_double, iodesc)
+    call restart_physics_write(fh, gdims, nhdims, grid_id, errmsg, errflg)
+    if (errflg /= 0) then
+       call endrun(errmsg)
+    end if
+
+!    call write_restart_history(fh, yr_spec=yr_spec, mon_spec=mon_spec, &
+!            day_spec=day_spec, sec_spec= sec_spec )
+
+    ! Close the primary restart file
+    call pio_closefile(fh)
+
+    ! Update the restart pointer file
+!    call write_rest_pfile(fname, yr_spec=yr_spec, mon_spec=mon_spec, &
+!                          day_spec=day_spec, sec_spec= sec_spec )
+
+
+  end subroutine cam_write_restart
+
+end module cam_restart
diff --git a/src/data/registry.xml b/src/data/registry.xml
index 5ce09a8ac..7e090935b 100644
--- a/src/data/registry.xml
+++ b/src/data/registry.xml
@@ -552,7 +552,7 @@
     </variable>
     <variable local_name="cldliq"
               standard_name="cloud_liquid_water_mixing_ratio_wrt_moist_air_and_condensed_water"
-              units="kg kg-1" type="real" constituent="true">
+              units="kg kg-1" type="real" constituent="true" restart="true" diagnostic_name="cldliq">
       <long_name>Cloud water mass mixing ratio with respect to moist air plus all airborne condensates</long_name>
       <dimensions>horizontal_dimension vertical_layer_dimension</dimensions>
       <ic_file_input_names>CLDLIQ cnst_CLDLIQ</ic_file_input_names>
diff --git a/src/data/write_restart_physics.py b/src/data/write_restart_physics.py
index 9404bbd35..53420bde8 100644
--- a/src/data/write_restart_physics.py
+++ b/src/data/write_restart_physics.py
@@ -78,13 +78,16 @@ def write_restart_physics(cap_database, ic_names, registry_constituents,
     logger.info(f"Writing restart physics source file, {ofilename}")
 
     # Open file using CCPP's FortranWriter:
-    file_desc = "Physics restart source file"
+    file_desc = "physics restart source file"
     with FortranWriter(ofilename, "w", file_desc,
                        phys_restart_fname_str,
                        line_fill=_LINE_FILL_LEN,
                        line_max=_MAX_LINE_LEN,
                        indent=indent) as outfile:
 
+        # Add use statements
+        outfile.write("use pio, only: var_desc_t", 1)
+        outfile.blank_line()
         # Add boilerplate code:
         outfile.write_preamble()
 
@@ -96,26 +99,37 @@ def write_restart_physics(cap_database, ic_names, registry_constituents,
 
         all_req_vars = in_vars + out_vars
         # Grab the required variables that are also restart variables
-        required_restart_vars, required_restart_constituents, constituent_dimmed_vars = gather_required_restart_variables(all_req_vars, constituent_set, restart_vars)
+        host_dict = cap_database.host_model_dict()
+        required_restart_vars, constituent_dimmed_vars, used_vars = gather_required_restart_variables(all_req_vars, constituent_set, restart_vars, host_dict)
 
         outfile.blank_line()
         outfile.comment("Private module data", 0)
-        for required_var in required_restart_vars:
-            outfile.write(f"type(var_desc_t) :: {required_var.lower()}_desc", 1)
+        for key, value in required_restart_vars.items():
+            outfile.write(f"type(var_desc_t) :: {value['diag_name'].lower()}_desc", 1)
         # end for
 
-        for required_var in constituent_dimmed_vars:
-            outfile.write(f"type(var_desc_t), allocatable :: {required_var.lower()}_desc(:)", 1)
+        for key, value in constituent_dimmed_vars.items():
+            outfile.write(f"type(var_desc_t), allocatable :: {value['diag_name'].lower()}_desc(:)", 1)
         # end for
 
         # Add "contains" statement:
         outfile.end_module_header()
-        outfile.blank_line()
 
         # Write the restart init subroutine
-        write_restart_physics_init(outfile, required_restart_vars, required_restart_constituents, constituent_dimmed_vars)
+        outfile.blank_line()
+        write_restart_physics_init(outfile, required_restart_vars, constituent_dimmed_vars, host_dict)
+
+        # Write the restart write subroutine
+        outfile.blank_line()
+        write_restart_physics_write(outfile, required_restart_vars, constituent_dimmed_vars, used_vars)
 
-def write_restart_physics_init(outfile, required_vars, constituent_vars, constituent_dimmed_vars):
+        # Write the restart read subroutine
+        outfile.blank_line()
+        write_restart_physics_read(outfile, required_restart_vars, constituent_dimmed_vars, used_vars)
+
+    # end with
+
+def write_restart_physics_init(outfile, required_vars, constituent_dimmed_vars, host_dict):
     """
     Write the init routine for the physics restart variables. This
     routine initializes the physics fields on the restart (cam.r) file
@@ -123,47 +137,115 @@ def write_restart_physics_init(outfile, required_vars, constituent_vars, constit
 
     outfile.write("subroutine restart_physics_init(file, hdimids, errmsg, errflg)", 1)
 
-    use_stmts = [["pio", ["file_desc_t", "pio_bcast_error",
-                          "pio_set_errorhandling", "pio_double",
-                          "pio_def_var"]],
-                 ["cam_abortutils", ["endrun"]],
-                 ["shr_kind_mod", ["SHR_KIND_CS, SHR_KIND_CL, SHR_KIND_CX"]],
+    dimensions_dict = {}
+    num_dimensions = 0
+    dim_use_stmt_dict = {}
+
+    # Find all unique dimensions
+    for _, value in required_vars.items():
+        for dimension in value['dims']:
+            dim_name = dimension.split(':')[1]
+            if dim_name not in dimensions_dict.keys():
+                var = host_dict.find_variable(dim_name)
+                dimensions_dict[dim_name] = {'local_name': var.get_prop_value('local_name'), 'index': -1}
+                num_dimensions = num_dimensions + 1
+                # Add dimension to use statement dictionary
+                if var.source.name not in dim_use_stmt_dict.keys():
+                    dim_use_stmt_dict[var.source.name] = set()
+                # end if
+                dim_use_stmt_dict[var.source.name].add(var.get_prop_value('local_name'))
+            # end if
+        # end for
+    # end for
+    for _, value in constituent_dimmed_vars.items():
+        for dimension in value['dims']:
+            dim_name = dimension.split(':')[1]
+            if dim_name not in dimensions_dict.keys() and dim_name != 'number_of_ccpp_constituents':
+                var = host_dict.find_variable(dim_name)
+                dimensions_dict[dim_name] = {'local_name': var.get_prop_value('local_name'), 'index': -1}
+                num_dimensions = num_dimensions + 1
+                # Add dimension to use statement dictionary
+                if var.source.name not in dim_use_stmt_dict.keys():
+                    dim_use_stmt_dict[var.source.name] = set()
+                # end if
+                dim_use_stmt_dict[var.source.name].add(var.get_prop_value('local_name'))
+            # end if
+        # end for
+    # end for
+
+    static_use_stmts = [["pio", ["file_desc_t", "pio_double"]],
+                 ["cam_pio_utils", ["cam_pio_def_dim", "cam_pio_def_var"]],
                  ["cam_ccpp_cap", ["cam_model_const_properties"]],
-                 ["ccpp_kinds", ["kind_phys"]],
-                 ["cam_logfile", ["iulog"]],
-                 ["spmd_utils", ["masterproc"]],
                  ["ccpp_constituent_prop_mod", ["ccpp_constituent_prop_ptr_t"]]]
 
-    # Add in host model data use statements
-#    use_stmts.extend(host_imports)
+    # Gather up dimension imports
+    dim_use_stmts = []
+    for key, value in dim_use_stmt_dict.items():
+        imports = []
+        dim_use_stmt = []
+        for var_import in value:
+            imports.append(f"{var_import}")
+        # end for
+        dim_use_stmt.append(key)
+        dim_use_stmt.append(imports)
+        dim_use_stmts.append(dim_use_stmt)
+    # end for
 
     # Output required, registered Fortran module use statements:
-    write_use_statements(outfile, use_stmts, 2)
+    write_use_statements(outfile, static_use_stmts, 2)
+    write_use_statements(outfile, dim_use_stmts, 2)
 
-    # pio: pio_bcast_error, file_desc_t, pio_seterrorhandling, pio_double
-    
     outfile.write("type(file_desc_t), intent(inout) :: file", 2)
-    outfile.write("integer,           intent(in)    :: hdimids(:)", 2)
     outfile.write("character(len=512),intent(out)   :: errmsg", 2)
     outfile.write("integer,           intent(out)   :: errflg", 2)
     outfile.blank_line()
 
-    # Local variables
+    outfile.comment("Local variables", 2)
+    outfile.write("integer, allocatable :: dimids(:)", 2)
     outfile.write("integer :: constituent_idx", 2)
     outfile.write("type(ccpp_constituent_prop_ptr_t), pointer :: const_props(:)", 2)
-    outfile.write("character(len=512) :: const_locname", 2)
+    outfile.write("character(len=256) :: const_stdname", 2)
 
     outfile.blank_line()
 
-    outfile.write("call pio_seterrorhandling(file, PIO_BCAST_ERROR)", 2)
     outfile.blank_line()
+    outfile.comment("Allocate dimids to the number of unique dimensions", 2)
+    outfile.write(f"allocate(dimids({num_dimensions}), stat=errflg, errmsg=errmsg", 2)
+    outfile.write("if (errflg /= 0) then", 2)
+    outfile.write("return", 3)
+    outfile.write("end if", 2)
+
+    dim_index = 1
 
     outfile.comment("Define required restart variables on the restart file", 2)
-    for required_var in required_vars:
-        desc_name = f"{required_var.lower()}_desc"
-        outfile.write(f"errflg = pio_def_var(file, '{required_var}', pio_double, hdimids, {desc_name})", 2)
+    for key, value in required_vars.items():
+        hdimids = []
+        for dimension in value['dims']:
+            dimname = dimension.split(':')[1]
+            if dimensions_dict[dimname]['index'] < 0:
+                outfile.comment(f"Define potentially new dimension '{dimname}'", 2)
+                if dimname == 'horizontal_dimension':
+                   dim_loc_name = 'ncol'
+                   dimsize = 'num_global_phys_cols'
+                elif dimname == 'vertical_layer_dimension':
+                   dim_loc_name = 'lev'
+                   dimsize = 'pver'
+                elif dimname == 'vertical_interface_dimension':
+                   dim_loc_name = 'ilev'
+                   dimsize = 'pverp'
+                else:
+                   dim_loc_name = dimensions_dict[dimname]['local_name']
+                outfile.write(f"call cam_pio_def_dim(file, '{dim_loc_name}', {dimsize}, dimids({dim_index}), existOK=.true.)", 2) # grab use statements for phys variables for nonstandard dimensions!
+                dimensions_dict[dimname]['index'] = dim_index
+                dim_index = dim_index + 1
+            # end if
+            hdimids.append(dimensions_dict[dimname]['index'])
+        # end for
+        desc_name = f"{value['diag_name'].lower()}_desc"
+        dimids_array = ", ".join([f"dimids({i})" for i in hdimids])
+        outfile.write(f"call cam_pio_def_var(file, '{value['diag_name']}', pio_double, (/{dimids_array}/), {desc_name}, existOK=.false.)", 2)
         outfile.write("if (errflg /= 0) then", 2)
-        outfile.write(f"write(errmsg,*) 'restart_physics_init: error defining variable {required_var}'", 3)
+        outfile.write(f"write(errmsg,*) 'restart_physics_init: error defining variable {value['diag_name']}'", 3)
         outfile.write("return", 3)
         outfile.write("end if", 2)
         outfile.blank_line()
@@ -173,28 +255,200 @@ def write_restart_physics_init(outfile, required_vars, constituent_vars, constit
     if constituent_dimmed_vars:
         outfile.write("const_props => cam_model_const_properties()", 2)
         outfile.blank_line()
-        for required_var in constituent_dimmed_vars:
-            outfile.comment(f"Handling for constituent-dimensioned variable '{required_var}'", 2)
-            outfile.write(f"allocate({required_var.lower()}_desc(size(const_props)), stat=errflg, errmsg=errmsg)", 2)
+        for key, value in constituent_dimmed_vars.items():
+            hdimids = []
+            for dimension in value['dims']:
+                dimname = dimension.split(':')[1]
+                if dimname != 'number_of_ccpp_constituents':
+                    if dimensions_dict[dimname]['index'] < 0:
+                        outfile.comment(f"Define potentially new dimension '{dimname}'", 2)
+                        if dimname == 'horizontal_dimension':
+                           dim_loc_name = 'ncol'
+                           dimsize = 'num_global_phys_cols'
+                        elif dimname == 'vertical_layer_dimension':
+                           dim_loc_name = 'lev'
+                           dimsize = 'pver'
+                        elif dimname == 'vertical_interface_dimension':
+                           dim_loc_name = 'ilev'
+                           dimsize = 'pverp'
+                        else:
+                           dim_loc_name = dimensions_dict[dimname]['local_name']
+                        # end if
+                        outfile.write(f"call cam_pio_def_dim(file, '{dim_loc_name}', {dimsize}, dimids({dim_index}), existOK=.true.)", 2) # grab use statements for phys variables for nonstandard dimensions!
+                        dimensions_dict[dimname]['index'] = dim_index
+                        dim_index = dim_index + 1
+                    # end if
+                    hdimids.append(dimensions_dict[dimname]['index'])
+                # end if (ignore number of constituents dimensions)
+            # end for
+            outfile.comment(f"Handling for constituent-dimensioned variable '{value['diag_name']}'", 2)
+            outfile.write(f"allocate({value['diag_name'].lower()}_desc(size(const_props)), stat=errflg, errmsg=errmsg)", 2)
             outfile.write("if (errflg /= 0) then", 2)
             outfile.write("return", 3)
             outfile.write("end if", 2)
             outfile.write("do constituent_idx = 1, size(const_props)", 2)
-            outfile.comment("Grab constituent local name:", 3)
-            outfile.write("call const_props(constituent_idx)%local_name(const_locname)", 3)
-            desc_name = f"{required_var.lower()}_desc"
-            outfile.write(f"errflg = pio_def_var(file, '{required_var}_'//trim(const_locname), pio_double, hdimids, {desc_name}(constituent_idx))", 3)
+            outfile.comment("Grab constituent standard name:", 3)
+            outfile.write("call const_props(constituent_idx)%standard_name(const_stdname)", 3)
+            desc_name = f"{value['diag_name'].lower()}_desc"
+            dimids_array = ", ".join([f"dimids({i})" for i in hdimids])
+            outfile.comment("PEVERWHEE todo: add diagnostic name and/or local name to constituents object. For now, use standard name", 3)
+            outfile.write(f"call cam_pio_def_var(file, '{value['diag_name']}_'//trim(const_stdname), pio_double, (/{dimids_array}/), {desc_name}(constituent_idx), existOK=.false.)", 3)
             outfile.write("if (errflg /= 0) then", 3)
-            outfile.write(f"write(errmsg,*) 'restart_physics_init: error defining variable {required_var}_'//trim(const_locname)", 4)
+            outfile.write(f"write(errmsg,*) 'restart_physics_init: error defining variable {value['diag_name']}_'//trim(const_stdname)", 4)
             outfile.write("end if", 3)
             outfile.write("end do", 2)
             outfile.blank_line()
         # end for
     # end if
 
-
     outfile.write("end subroutine restart_physics_init", 1)
 
+def write_restart_physics_write(outfile, required_vars, constituent_dimmed_vars, used_vars):
+    """
+    Write the 'write' routine for the physics restart variables. This
+    routine writes the physics fields to the restart (cam.r) file
+    """
+    outfile.write("subroutine restart_physics_write(file, gdims, nhdims, grid_id, errmsg, errflg)", 1)
+
+    use_stmts = [["pio", ["file_desc_t", "io_desc_t", "pio_write_darray", "pio_double"]],
+                 ["cam_ccpp_cap", ["cam_model_const_properties","cam_constituents_array"]],
+                 ["ccpp_kinds", ["kind_phys"]],
+                 ["ccpp_constituent_prop_mod", ["ccpp_constituent_prop_ptr_t"]],
+                 ["physics_grid", ["num_global_phys_cols"]],
+                 ["vert_coord", ["pver", "pverp"]],
+                 ["cam_grid_support", ["cam_grid_id","cam_grid_dimensions","cam_grid_write_dist_array"]]]
+
+    write_use_statements(outfile, use_stmts, 2)
+    for var in used_vars:
+        outfile.write(f"use physics_types, only: {var}", 2)
+    # end for
+
+    outfile.blank_line()
+    outfile.write("type(file_desc_t), intent(inout) :: file",   2)
+    outfile.write("integer,            intent(in)   :: gdims(:)",  2)
+    outfile.write("integer,            intent(in)   :: nhdims", 2)
+    outfile.write("integer,            intent(in)   :: grid_id", 2)
+    outfile.write("character(len=512),intent(out)   :: errmsg", 2)
+    outfile.write("integer,           intent(out)   :: errflg", 2)
+
+    outfile.blank_line()
+
+    outfile.comment("Local variables", 2)
+#    outfile.write("type(io_desc_t),         pointer :: iodesc_2d", 2)
+#    outfile.write("type(io_desc_t),         pointer :: iodesc_3d_layers", 2)
+#    outfile.write("type(io_desc_t),         pointer :: iodesc_3d_interfaces", 2)
+    outfile.write("integer                          :: dims(2)",   2)
+    outfile.write("integer                          :: grid_decomp", 2)
+    outfile.write("integer                          :: grid_dims(2)", 2)
+    outfile.write("integer                          :: field_shape(2)", 2)
+    outfile.write("integer                          :: rank", 2)
+    outfile.write("integer                          :: constituent_idx", 2)
+    outfile.write("type(ccpp_constituent_prop_ptr_t), pointer :: const_props(:)", 2)
+    outfile.write("character(len=256)               :: const_stdname", 2)
+
+#    assigned_2d = False
+#    assigned_3d_layers = False
+#    assigned_3d_interfaces = False
+    outfile.comment("Grab physics grid", 2)
+    outfile.write("grid_decomp = cam_grid_id('physgrid')", 2)
+    outfile.write("call cam_grid_dimensions(grid_decomp, grid_dims, rank)", 2)
+    outfile.write("dims(1) = grid_dims(1)", 2)
+    outfile.write("dims(2) = pver", 2)
+    outfile.comment("Write required restart variables to the restart file", 2)
+    for key, value in required_vars.items():
+        desc_name = f"{value['diag_name'].lower()}_desc"
+        if len(value['dims']) == 1 and 'horizontal_dimension' in value['dims'][0]:
+            outfile.comment("Handle horizontal-only field", 2)
+            outfile.write("field_shape(1) = num_global_phys_cols", 2)
+            outfile.write(f"call cam_grid_write_dist_array(file, grid_decomp, (/dims(1)/), (/field_shape(1)/), {key}, {desc_name})", 2)
+        elif len(value["dims"]) == 2:
+            if 'vertical_layer_dimension' in value['dims'][1] and 'horizontal_dimension' in value['dims'][0]:
+                outfile.comment("Handle field with vertical layer dimension (pver)", 2)
+                outfile.write("field_shape(1) = num_global_phys_cols", 2)
+                outfile.write("field_shape(2) = pver", 2)
+                outfile.write(f"call cam_grid_write_dist_array(file, grid_decomp, dims, field_shape, {key}, {desc_name})", 2)
+            elif 'vertical_interface_dimsnsion' in value['dims'][1] and 'horizontal_dimension' in value['dims'][0]:
+                outfile.comment("Handle field with vertical layer dimension (pver)", 2)
+                outfile.write("field_shape(1) = num_global_phys_cols", 2)
+                outfile.write("field_shape(2) = pverp", 2)
+                outfile.write(f"call cam_grid_write_dist_array(file, grid_decomp, dims, field_shape, {key}, {desc_name})", 2)
+            # end if
+        # end if
+    # end for
+    """
+    for key, value in required_vars.items():
+        if len(value['dims']) == 1:
+            iodesc = 'iodesc_2d'
+            if not assigned_2d:
+                # Associate the 2d iodesc pointer
+                outfile.write("dims(1) = columns_on_task", 2)
+                outfile.write(f"call cam_grid_get_decomp(grid_id, (/dims(1)/), gdims(1:nhdims), pio_double, {iodesc})", 2)
+                assigned_2d = True
+            # end if
+        else:
+            for dim in value['dims']:
+                if 'vertical_layer_dimension' in dim:
+                    iodesc = 'iodesc_3d_layers'
+                    if not assigned_3d_layers:
+                        # Associate the 3d iodesc pointer for layers
+                        outfile.write("dims(1) = columns_on_task", 2)
+                        outfile.write("dims(2) = pver", 2)
+                        outfile.write(f"call cam_grid_get_decomp(grid_id, dims(1:2), gdims(1:nhdims), pio_double, {iodesc})", 2)
+                        assigned_3d_layers = True
+                    # end if
+                elif 'vertical_interface_dimension' in dim:
+                    iodesc = 'iodesc_3d_interfaces'
+                    if not assigned_3d_interfaces:
+                        # Associate the 3d iodesc pointer for interfaces
+                        outfile.write("dims(1) = columns_on_task", 2)
+                        outfile.write("dims(2) = pverp", 2)
+                        outfile.write(f"call cam_grid_get_decomp(grid_id, dims(1:2), gdims(1:nhdims), pio_double, {iodesc})", 2)
+                        assigned_3d_layers = True
+                    # end if
+                # end if
+            # end if
+        # end if
+        desc_name = f"{value['diag_name'].lower()}_desc"
+        outfile.write(f"call pio_write_darray(file, {desc_name}, {iodesc}, {key}, errflg)", 2)
+        outfile.write("if (errflg /= 0) then", 2)
+        outfile.write(f"write(errmsg,*) 'restart_physics_write: error writing variable {value['diag_name']}'", 3)
+        outfile.write("return", 3)
+        outfile.write("end if", 2)
+        outfile.blank_line()
+    # end for
+"""
+    # Handle constituent-dimensioned variables
+    if constituent_dimmed_vars:
+        outfile.write("const_props => cam_model_const_properties()", 2)
+        outfile.blank_line()
+        for key, value in constituent_dimmed_vars.items():
+            outfile.comment(f"Handling for constituent-dimensioned variable '{value['diag_name']}'", 2)
+            outfile.write("do constituent_idx = 1, size(const_props)", 2)
+            outfile.comment("Grab constituent standard name:", 3)
+            outfile.write("call const_props(constituent_idx)%standard_name(const_stdname)", 3)
+            desc_name = f"{value['diag_name'].lower()}_desc"
+            outfile.write("field_shape(1) = num_global_phys_cols", 3)
+            outfile.write(f"call cam_grid_write_dist_array(file, grid_decomp, (/dims(1)/), (/field_shape(1)/), {key}(:,constituent_idx), {desc_name}(constituent_idx))", 3)
+#            outfile.write(f"call pio_write_darray(file, {desc_name}(constituent_idx), iodesc_2d, {key}(:,constituent_idx), errflg)", 3)
+#            outfile.write("if (errflg /= 0) then", 3)
+#            outfile.write(f"write(errmsg,*) 'restart_physics_write: error defining variable {value['diag_name']}_'//trim(const_stdname)", 4)
+#            outfile.write("end if", 3)
+            outfile.write("end do", 2)
+            outfile.blank_line()
+        # end for
+    # end if
+#    for key,value in required_vars.items():
+#        desc_name = f"{value['diag_name'].lower()}_desc"
+#        if len(value['dims']) == 1:
+#            outfile.write(f"call pio_write_darray(file, {desc_name}, iodesc, {key}, errflg)", 2)
+#        # end if
+#    # end for
+    outfile.write("end subroutine restart_physics_write", 1)
+
+def write_restart_physics_read(outfile, required_vars, constituent_dimmed_vars, used_vars):
+    outfile.write("subroutine restart_physics_read()", 1)
+    outfile.write("end subroutine restart_physics_read", 1)
+
 #################
 #HELPER FUNCTIONS
 #################
@@ -297,33 +551,33 @@ def gather_ccpp_req_vars(cap_database, registry_constituents):
     return list(in_vars.values()), list(out_vars.values()), constituent_vars, retmsg
 
 ##############################################################################
-def gather_required_restart_variables(all_req_vars, registry_constituents, restart_vars):
+def gather_required_restart_variables(all_req_vars, registry_constituents, restart_vars, host_dict):
     """
     Return lists of the required restart non-constituent variables, and the required
     restart constituent variables
     """
 
-    required_restart_vars = []
-    required_constituent_restart_vars = []
-    required_constituent_dimensioned_vars = []
+    required_restart_vars = {}
+    required_constituent_dimensioned_vars = {}
+    used_vars = set()
 
     for required_var in all_req_vars:
         stdname = required_var.get_prop_value('standard_name')
+        local_name = required_var.call_string(host_dict)
+        used_var = required_var.var.get_prop_value('local_name')
         if stdname in restart_vars.keys():
             diagnostic_name = restart_vars[stdname]
-            if stdname in registry_constituents:
-                required_constituent_restart_vars.append(diagnostic_name)
+            used_vars.add(used_var)
+            dimensions = required_var.get_dimensions()
+            if 'ccpp_constant_one:number_of_ccpp_constituents' in dimensions:
+                required_constituent_dimensioned_vars[local_name] = {'diag_name': diagnostic_name, 'dims': dimensions}
             else:
-                if 'ccpp_constant_one:number_of_ccpp_constituents' in required_var.get_dimensions():
-                    print('HI THERE!')
-                    required_constituent_dimensioned_vars.append(diagnostic_name)
-                else:
-                    required_restart_vars.append(diagnostic_name)
+                required_restart_vars[local_name] = {'diag_name': diagnostic_name, 'dims': dimensions}
             # end if
         # end if (ignore all non-restart variables)
     # end for
 
-    return required_restart_vars, required_constituent_restart_vars, required_constituent_dimensioned_vars
+    return required_restart_vars, required_constituent_dimensioned_vars, used_vars
 
 #####
 
@@ -354,4 +608,3 @@ def write_use_statements(outfile, use_stmts, indent):
                           indent)
         # end while
     # end for
-

From 6c72d525b956b052e6df028b515fad0c21768fc1 Mon Sep 17 00:00:00 2001
From: peverwhee <courtneyp@ucar.edu>
Date: Wed, 19 Nov 2025 12:32:31 -0700
Subject: [PATCH 05/19] update externals; add diagnostic name to instantiated
 constituent in host

---
 .gitmodules              | 8 ++++----
 ccpp_framework           | 2 +-
 src/control/cam_comp.F90 | 1 +
 src/physics/ncar_ccpp    | 2 +-
 4 files changed, 7 insertions(+), 6 deletions(-)

diff --git a/.gitmodules b/.gitmodules
index 5d1800afb..000e1cac9 100644
--- a/.gitmodules
+++ b/.gitmodules
@@ -1,7 +1,7 @@
 [submodule "ccpp-framework"]
         path          = ccpp_framework
-        url           = https://github.com/NCAR/ccpp-framework
-        fxtag         = 2025-10-01-dev
+	url           = https://github.com/peverwhee/ccpp-framework
+        fxtag         = 9d8fe6a6eb5debfc01af39abe2589aeafc5f4363
         fxrequired    = AlwaysRequired
 	fxDONOTUSEurl = https://github.com/NCAR/ccpp-framework
 [submodule "history"]
@@ -19,8 +19,8 @@
         fxDONOTUSEurl = https://github.com/MPAS-Dev/MPAS-Model.git
 [submodule "ncar-physics"]
         path          = src/physics/ncar_ccpp
-	url           = https://github.com/ESCOMP/atmospheric_physics
-	fxtag         = 73fce2706c1f70e1ba63ff4bb3dcb80323bb9cc6
+	url           = https://github.com/peverwhee/atmospheric_physics
+	fxtag         = 2c3b06bf427eb0a4aa18b2213c01af3e12c03b7d
         fxrequired    = AlwaysRequired
         fxDONOTUSEurl = https://github.com/ESCOMP/atmospheric_physics
 [submodule "rrtmgp-data"]
diff --git a/ccpp_framework b/ccpp_framework
index d20a1858f..9d8fe6a6e 160000
--- a/ccpp_framework
+++ b/ccpp_framework
@@ -1 +1 @@
-Subproject commit d20a1858f9ce0d12c1cbe2757fcbdb979c421333
+Subproject commit 9d8fe6a6eb5debfc01af39abe2589aeafc5f4363
diff --git a/src/control/cam_comp.F90 b/src/control/cam_comp.F90
index 84c845a17..3bd9b2049 100644
--- a/src/control/cam_comp.F90
+++ b/src/control/cam_comp.F90
@@ -632,6 +632,7 @@ subroutine cam_register_constituents(cam_runtime_opts)
          call host_constituents(1)%instantiate( &
               std_name=wv_stdname,              &
               long_name="water vapor mixing ratio w.r.t moist air and condensed_water", &
+              diag_name="Q",                                                            &
               units="kg kg-1",                                                          &
               default_value=0._kind_phys,                                               &
               vertical_dim="vertical_layer_dimension",                                  &
diff --git a/src/physics/ncar_ccpp b/src/physics/ncar_ccpp
index 73fce2706..2c3b06bf4 160000
--- a/src/physics/ncar_ccpp
+++ b/src/physics/ncar_ccpp
@@ -1 +1 @@
-Subproject commit 73fce2706c1f70e1ba63ff4bb3dcb80323bb9cc6
+Subproject commit 2c3b06bf427eb0a4aa18b2213c01af3e12c03b7d

From ff249de616829ce6a1997149eda8ea42af36c697 Mon Sep 17 00:00:00 2001
From: Courtney Peverley <courtneyp@izumi.cgd.ucar.edu>
Date: Wed, 19 Nov 2025 12:46:29 -0700
Subject: [PATCH 06/19] use diagnostic name instead of standard name for
 constituent-dimmed variables

---
 src/data/write_restart_physics.py | 25 ++++++-------------------
 1 file changed, 6 insertions(+), 19 deletions(-)

diff --git a/src/data/write_restart_physics.py b/src/data/write_restart_physics.py
index 53420bde8..e1893cb97 100644
--- a/src/data/write_restart_physics.py
+++ b/src/data/write_restart_physics.py
@@ -204,7 +204,7 @@ def write_restart_physics_init(outfile, required_vars, constituent_dimmed_vars,
     outfile.write("integer, allocatable :: dimids(:)", 2)
     outfile.write("integer :: constituent_idx", 2)
     outfile.write("type(ccpp_constituent_prop_ptr_t), pointer :: const_props(:)", 2)
-    outfile.write("character(len=256) :: const_stdname", 2)
+    outfile.write("character(len=256) :: const_diag_name", 2)
 
     outfile.blank_line()
 
@@ -287,14 +287,13 @@ def write_restart_physics_init(outfile, required_vars, constituent_dimmed_vars,
             outfile.write("return", 3)
             outfile.write("end if", 2)
             outfile.write("do constituent_idx = 1, size(const_props)", 2)
-            outfile.comment("Grab constituent standard name:", 3)
-            outfile.write("call const_props(constituent_idx)%standard_name(const_stdname)", 3)
+            outfile.comment("Grab constituent diagnostic name:", 3)
+            outfile.write("call const_props(constituent_idx)%diagnostic_name(const_diag_name)", 3)
             desc_name = f"{value['diag_name'].lower()}_desc"
             dimids_array = ", ".join([f"dimids({i})" for i in hdimids])
-            outfile.comment("PEVERWHEE todo: add diagnostic name and/or local name to constituents object. For now, use standard name", 3)
-            outfile.write(f"call cam_pio_def_var(file, '{value['diag_name']}_'//trim(const_stdname), pio_double, (/{dimids_array}/), {desc_name}(constituent_idx), existOK=.false.)", 3)
+            outfile.write(f"call cam_pio_def_var(file, '{value['diag_name']}_'//trim(const_diag_name), pio_double, (/{dimids_array}/), {desc_name}(constituent_idx), existOK=.false.)", 3)
             outfile.write("if (errflg /= 0) then", 3)
-            outfile.write(f"write(errmsg,*) 'restart_physics_init: error defining variable {value['diag_name']}_'//trim(const_stdname)", 4)
+            outfile.write(f"write(errmsg,*) 'restart_physics_init: error defining variable {value['diag_name']}_'//trim(const_diag_name)", 4)
             outfile.write("end if", 3)
             outfile.write("end do", 2)
             outfile.blank_line()
@@ -344,7 +343,7 @@ def write_restart_physics_write(outfile, required_vars, constituent_dimmed_vars,
     outfile.write("integer                          :: rank", 2)
     outfile.write("integer                          :: constituent_idx", 2)
     outfile.write("type(ccpp_constituent_prop_ptr_t), pointer :: const_props(:)", 2)
-    outfile.write("character(len=256)               :: const_stdname", 2)
+    outfile.write("character(len=256)               :: const_diag_name", 2)
 
 #    assigned_2d = False
 #    assigned_3d_layers = False
@@ -424,25 +423,13 @@ def write_restart_physics_write(outfile, required_vars, constituent_dimmed_vars,
         for key, value in constituent_dimmed_vars.items():
             outfile.comment(f"Handling for constituent-dimensioned variable '{value['diag_name']}'", 2)
             outfile.write("do constituent_idx = 1, size(const_props)", 2)
-            outfile.comment("Grab constituent standard name:", 3)
-            outfile.write("call const_props(constituent_idx)%standard_name(const_stdname)", 3)
             desc_name = f"{value['diag_name'].lower()}_desc"
             outfile.write("field_shape(1) = num_global_phys_cols", 3)
             outfile.write(f"call cam_grid_write_dist_array(file, grid_decomp, (/dims(1)/), (/field_shape(1)/), {key}(:,constituent_idx), {desc_name}(constituent_idx))", 3)
-#            outfile.write(f"call pio_write_darray(file, {desc_name}(constituent_idx), iodesc_2d, {key}(:,constituent_idx), errflg)", 3)
-#            outfile.write("if (errflg /= 0) then", 3)
-#            outfile.write(f"write(errmsg,*) 'restart_physics_write: error defining variable {value['diag_name']}_'//trim(const_stdname)", 4)
-#            outfile.write("end if", 3)
             outfile.write("end do", 2)
             outfile.blank_line()
         # end for
     # end if
-#    for key,value in required_vars.items():
-#        desc_name = f"{value['diag_name'].lower()}_desc"
-#        if len(value['dims']) == 1:
-#            outfile.write(f"call pio_write_darray(file, {desc_name}, iodesc, {key}, errflg)", 2)
-#        # end if
-#    # end for
     outfile.write("end subroutine restart_physics_write", 1)
 
 def write_restart_physics_read(outfile, required_vars, constituent_dimmed_vars, used_vars):

From 4906271ed4b13005537161ef9b3416dd7b2c6158 Mon Sep 17 00:00:00 2001
From: Courtney Peverley <courtneyp@izumi.cgd.ucar.edu>
Date: Wed, 19 Nov 2025 23:33:23 -0700
Subject: [PATCH 07/19] physics restart write working

---
 .gitmodules                       |  2 +-
 src/data/write_restart_physics.py | 42 +++++++++++++------------------
 src/physics/ncar_ccpp             |  2 +-
 3 files changed, 20 insertions(+), 26 deletions(-)

diff --git a/.gitmodules b/.gitmodules
index 000e1cac9..14c3f998d 100644
--- a/.gitmodules
+++ b/.gitmodules
@@ -20,7 +20,7 @@
 [submodule "ncar-physics"]
         path          = src/physics/ncar_ccpp
 	url           = https://github.com/peverwhee/atmospheric_physics
-	fxtag         = 2c3b06bf427eb0a4aa18b2213c01af3e12c03b7d
+	fxtag         = 4698ee46bb7b8e8aa4715912ef3816f8888d3047
         fxrequired    = AlwaysRequired
         fxDONOTUSEurl = https://github.com/ESCOMP/atmospheric_physics
 [submodule "rrtmgp-data"]
diff --git a/src/data/write_restart_physics.py b/src/data/write_restart_physics.py
index e1893cb97..2a0b88092 100644
--- a/src/data/write_restart_physics.py
+++ b/src/data/write_restart_physics.py
@@ -117,11 +117,11 @@ def write_restart_physics(cap_database, ic_names, registry_constituents,
 
         # Write the restart init subroutine
         outfile.blank_line()
-        write_restart_physics_init(outfile, required_restart_vars, constituent_dimmed_vars, host_dict)
+        dim_use_stmts = write_restart_physics_init(outfile, required_restart_vars, constituent_dimmed_vars, host_dict)
 
         # Write the restart write subroutine
         outfile.blank_line()
-        write_restart_physics_write(outfile, required_restart_vars, constituent_dimmed_vars, used_vars)
+        write_restart_physics_write(outfile, required_restart_vars, constituent_dimmed_vars, used_vars, dim_use_stmts)
 
         # Write the restart read subroutine
         outfile.blank_line()
@@ -135,7 +135,7 @@ def write_restart_physics_init(outfile, required_vars, constituent_dimmed_vars,
     routine initializes the physics fields on the restart (cam.r) file
     """
 
-    outfile.write("subroutine restart_physics_init(file, hdimids, errmsg, errflg)", 1)
+    outfile.write("subroutine restart_physics_init(file, errmsg, errflg)", 1)
 
     dimensions_dict = {}
     num_dimensions = 0
@@ -176,6 +176,7 @@ def write_restart_physics_init(outfile, required_vars, constituent_dimmed_vars,
     static_use_stmts = [["pio", ["file_desc_t", "pio_double"]],
                  ["cam_pio_utils", ["cam_pio_def_dim", "cam_pio_def_var"]],
                  ["cam_ccpp_cap", ["cam_model_const_properties"]],
+                 ["physics_grid", ["num_global_phys_cols"]],
                  ["ccpp_constituent_prop_mod", ["ccpp_constituent_prop_ptr_t"]]]
 
     # Gather up dimension imports
@@ -210,7 +211,7 @@ def write_restart_physics_init(outfile, required_vars, constituent_dimmed_vars,
 
     outfile.blank_line()
     outfile.comment("Allocate dimids to the number of unique dimensions", 2)
-    outfile.write(f"allocate(dimids({num_dimensions}), stat=errflg, errmsg=errmsg", 2)
+    outfile.write(f"allocate(dimids({num_dimensions}), stat=errflg, errmsg=errmsg)", 2)
     outfile.write("if (errflg /= 0) then", 2)
     outfile.write("return", 3)
     outfile.write("end if", 2)
@@ -301,8 +302,9 @@ def write_restart_physics_init(outfile, required_vars, constituent_dimmed_vars,
     # end if
 
     outfile.write("end subroutine restart_physics_init", 1)
+    return dim_use_stmts
 
-def write_restart_physics_write(outfile, required_vars, constituent_dimmed_vars, used_vars):
+def write_restart_physics_write(outfile, required_vars, constituent_dimmed_vars, used_vars, dim_use_stmts):
     """
     Write the 'write' routine for the physics restart variables. This
     routine writes the physics fields to the restart (cam.r) file
@@ -314,10 +316,10 @@ def write_restart_physics_write(outfile, required_vars, constituent_dimmed_vars,
                  ["ccpp_kinds", ["kind_phys"]],
                  ["ccpp_constituent_prop_mod", ["ccpp_constituent_prop_ptr_t"]],
                  ["physics_grid", ["num_global_phys_cols"]],
-                 ["vert_coord", ["pver", "pverp"]],
-                 ["cam_grid_support", ["cam_grid_id","cam_grid_dimensions","cam_grid_write_dist_array"]]]
+                 ["cam_grid_support", ["cam_grid_id", "cam_grid_write_dist_array"]]]
 
     write_use_statements(outfile, use_stmts, 2)
+    write_use_statements(outfile, dim_use_stmts, 2)
     for var in used_vars:
         outfile.write(f"use physics_types, only: {var}", 2)
     # end for
@@ -333,25 +335,16 @@ def write_restart_physics_write(outfile, required_vars, constituent_dimmed_vars,
     outfile.blank_line()
 
     outfile.comment("Local variables", 2)
-#    outfile.write("type(io_desc_t),         pointer :: iodesc_2d", 2)
-#    outfile.write("type(io_desc_t),         pointer :: iodesc_3d_layers", 2)
-#    outfile.write("type(io_desc_t),         pointer :: iodesc_3d_interfaces", 2)
     outfile.write("integer                          :: dims(2)",   2)
     outfile.write("integer                          :: grid_decomp", 2)
     outfile.write("integer                          :: grid_dims(2)", 2)
     outfile.write("integer                          :: field_shape(2)", 2)
-    outfile.write("integer                          :: rank", 2)
     outfile.write("integer                          :: constituent_idx", 2)
     outfile.write("type(ccpp_constituent_prop_ptr_t), pointer :: const_props(:)", 2)
-    outfile.write("character(len=256)               :: const_diag_name", 2)
 
-#    assigned_2d = False
-#    assigned_3d_layers = False
-#    assigned_3d_interfaces = False
     outfile.comment("Grab physics grid", 2)
     outfile.write("grid_decomp = cam_grid_id('physgrid')", 2)
-    outfile.write("call cam_grid_dimensions(grid_decomp, grid_dims, rank)", 2)
-    outfile.write("dims(1) = grid_dims(1)", 2)
+    outfile.write("dims(1) = columns_on_task", 2)
     outfile.write("dims(2) = pver", 2)
     outfile.comment("Write required restart variables to the restart file", 2)
     for key, value in required_vars.items():
@@ -361,17 +354,18 @@ def write_restart_physics_write(outfile, required_vars, constituent_dimmed_vars,
             outfile.write("field_shape(1) = num_global_phys_cols", 2)
             outfile.write(f"call cam_grid_write_dist_array(file, grid_decomp, (/dims(1)/), (/field_shape(1)/), {key}, {desc_name})", 2)
         elif len(value["dims"]) == 2:
-            if 'vertical_layer_dimension' in value['dims'][1] and 'horizontal_dimension' in value['dims'][0]:
-                outfile.comment("Handle field with vertical layer dimension (pver)", 2)
+            if 'horizontal_dimension' in value['dims'][0]:
+                outfile.comment("Handle field with horizontal dimension and additional, vertical dimension", 2)
                 outfile.write("field_shape(1) = num_global_phys_cols", 2)
-                outfile.write("field_shape(2) = pver", 2)
+                outfile.write(f"field_shape(2) = size({key}, 2)", 2)
                 outfile.write(f"call cam_grid_write_dist_array(file, grid_decomp, dims, field_shape, {key}, {desc_name})", 2)
-            elif 'vertical_interface_dimsnsion' in value['dims'][1] and 'horizontal_dimension' in value['dims'][0]:
-                outfile.comment("Handle field with vertical layer dimension (pver)", 2)
-                outfile.write("field_shape(1) = num_global_phys_cols", 2)
-                outfile.write("field_shape(2) = pverp", 2)
+            else:
+                outfile.comment("Handle field with two non-horizontal dimensions", 2)
+                outfile.write(f"field_shape(1) = size({key}, 1)", 2)
+                outfile.write(f"field_shape(2) = size({key}, 2)", 2)
                 outfile.write(f"call cam_grid_write_dist_array(file, grid_decomp, dims, field_shape, {key}, {desc_name})", 2)
             # end if
+        # PEVERWHEE - TODO: handle >2 dims!
         # end if
     # end for
     """
diff --git a/src/physics/ncar_ccpp b/src/physics/ncar_ccpp
index 2c3b06bf4..4698ee46b 160000
--- a/src/physics/ncar_ccpp
+++ b/src/physics/ncar_ccpp
@@ -1 +1 @@
-Subproject commit 2c3b06bf427eb0a4aa18b2213c01af3e12c03b7d
+Subproject commit 4698ee46bb7b8e8aa4715912ef3816f8888d3047

From e2b39d1105baa19133cf10ac184a36b128653bc7 Mon Sep 17 00:00:00 2001
From: Courtney Peverley <courtneyp@izumi.cgd.ucar.edu>
Date: Fri, 21 Nov 2025 17:56:20 -0700
Subject: [PATCH 08/19] init restart dynamics working

---
 src/control/cam_restart.F90          |  38 +----
 src/data/write_restart_physics.py    |  68 +-------
 src/dynamics/se/restart_dynamics.F90 | 236 +++++++++++++++++++++++++++
 src/physics/utils/physics_data.F90   |   2 +
 4 files changed, 254 insertions(+), 90 deletions(-)
 create mode 100644 src/dynamics/se/restart_dynamics.F90

diff --git a/src/control/cam_restart.F90 b/src/control/cam_restart.F90
index 909418707..505e3874d 100644
--- a/src/control/cam_restart.F90
+++ b/src/control/cam_restart.F90
@@ -9,7 +9,8 @@ module cam_restart
   subroutine cam_write_restart(dyn_out, yr_spec, mon_spec, day_spec, sec_spec)
     use cam_filenames,    only: interpret_filename_spec
     use cam_pio_utils,    only: cam_pio_createfile, cam_pio_set_fill
-    !use restart_dynamics, only: write_restart_dynamics, init_restart_dynamics
+    use restart_dynamics, only: init_restart_dynamics
+!    use restart_dynamics, only: write_restart_dynamics, init_restart_dynamics
     use restart_physics,  only: restart_physics_write, restart_physics_init
     use cam_instance,     only: inst_suffix
     use pio,              only: file_desc_t, io_desc_t, pio_double, pio_global
@@ -22,8 +23,6 @@ subroutine cam_write_restart(dyn_out, yr_spec, mon_spec, day_spec, sec_spec)
     use cam_control_mod,  only: caseid
     use cam_abortutils,   only: endrun, check_allocate
     use shr_kind_mod,     only: cl=>shr_kind_cl
-    use vert_coord, only: pver
-    use cam_logfile, only: iulog
 
     ! Arguments
     type(dyn_export_t),      intent(in) :: dyn_out
@@ -39,12 +38,9 @@ subroutine cam_write_restart(dyn_out, yr_spec, mon_spec, day_spec, sec_spec)
     integer           :: ierr, i, errflg
     character(len=512) :: errmsg
     integer           :: grid_id
-    integer           :: hdimcnt
-    integer           :: dimids(4)
     integer           :: dims(3), gdims(3)
     integer           :: nhdims, ndims
     type(io_desc_t), pointer     :: iodesc
-    integer, allocatable         :: hdimids(:)
     type(cam_grid_header_info_t) :: info
 
     ! Set template for primary restart filename based on instance suffix
@@ -56,21 +52,13 @@ subroutine cam_write_restart(dyn_out, yr_spec, mon_spec, day_spec, sec_spec)
     call cam_pio_createfile(fh, trim(fname), 0)
     ierr = cam_pio_set_fill(fh)
 
-!    call init_restart_dynamics(fh, dyn_out)
+    call init_restart_dynamics(fh, dyn_out)
 
     ! TODO: initialize ionosphere restart
 
-    ! Grab physics grid info
+    ! Initialize physics grid variable
     grid_id = cam_grid_id('physgrid')
     call cam_grid_write_attr(fh, grid_id, info)
-    hdimcnt = info%num_hdims()
-
-    allocate(hdimids(hdimcnt), stat=ierr, errmsg=errmsg)
-    call check_allocate(ierr, 'cam_write_restart', 'hdimids', errmsg)
-
-    do i = 1, hdimcnt
-       hdimids(i) = info%get_hdimid(i)
-    end do
 
     call restart_physics_init(fh, errmsg, errflg)
     if (errflg /= 0) then
@@ -85,23 +73,11 @@ subroutine cam_write_restart(dyn_out, yr_spec, mon_spec, day_spec, sec_spec)
 
     ! TODO: write ionosphere restart
 
-
     ! Write physics grid info
-    ndims = nhdims + 1
     call cam_grid_write_var(fh, phys_decomp)
-    call cam_grid_dimensions(grid_id, gdims(1:3), nhdims)
-!    dims(1) = columns_on_task
-!    call cam_grid_get_decomp(grid_id, (/dims(1)/), gdims(1:nhdims), &
-!               pio_double, iodesc)
-    !dims(1) = num_global_phys_cols
-    !dims(2) = pver
-    !write(iulog,*) 'peverwhee - physics grid dims'
-    !write(iulog,*) nhdims
-    !write(iulog,*) dims
-    !write(iulog,*) gdims
-    !gdims(2) = pver
-    !call cam_grid_get_decomp(grid_id, dims(1:2), gdims(1:2), pio_double, iodesc)
-    call restart_physics_write(fh, gdims, nhdims, grid_id, errmsg, errflg)
+
+    ! Write physics restart variables
+    call restart_physics_write(fh, grid_id, errmsg, errflg)
     if (errflg /= 0) then
        call endrun(errmsg)
     end if
diff --git a/src/data/write_restart_physics.py b/src/data/write_restart_physics.py
index 2a0b88092..305449f4f 100644
--- a/src/data/write_restart_physics.py
+++ b/src/data/write_restart_physics.py
@@ -293,9 +293,6 @@ def write_restart_physics_init(outfile, required_vars, constituent_dimmed_vars,
             desc_name = f"{value['diag_name'].lower()}_desc"
             dimids_array = ", ".join([f"dimids({i})" for i in hdimids])
             outfile.write(f"call cam_pio_def_var(file, '{value['diag_name']}_'//trim(const_diag_name), pio_double, (/{dimids_array}/), {desc_name}(constituent_idx), existOK=.false.)", 3)
-            outfile.write("if (errflg /= 0) then", 3)
-            outfile.write(f"write(errmsg,*) 'restart_physics_init: error defining variable {value['diag_name']}_'//trim(const_diag_name)", 4)
-            outfile.write("end if", 3)
             outfile.write("end do", 2)
             outfile.blank_line()
         # end for
@@ -309,7 +306,7 @@ def write_restart_physics_write(outfile, required_vars, constituent_dimmed_vars,
     Write the 'write' routine for the physics restart variables. This
     routine writes the physics fields to the restart (cam.r) file
     """
-    outfile.write("subroutine restart_physics_write(file, gdims, nhdims, grid_id, errmsg, errflg)", 1)
+    outfile.write("subroutine restart_physics_write(file, grid_id, errmsg, errflg)", 1)
 
     use_stmts = [["pio", ["file_desc_t", "io_desc_t", "pio_write_darray", "pio_double"]],
                  ["cam_ccpp_cap", ["cam_model_const_properties","cam_constituents_array"]],
@@ -326,8 +323,6 @@ def write_restart_physics_write(outfile, required_vars, constituent_dimmed_vars,
 
     outfile.blank_line()
     outfile.write("type(file_desc_t), intent(inout) :: file",   2)
-    outfile.write("integer,            intent(in)   :: gdims(:)",  2)
-    outfile.write("integer,            intent(in)   :: nhdims", 2)
     outfile.write("integer,            intent(in)   :: grid_id", 2)
     outfile.write("character(len=512),intent(out)   :: errmsg", 2)
     outfile.write("integer,           intent(out)   :: errflg", 2)
@@ -353,63 +348,18 @@ def write_restart_physics_write(outfile, required_vars, constituent_dimmed_vars,
             outfile.comment("Handle horizontal-only field", 2)
             outfile.write("field_shape(1) = num_global_phys_cols", 2)
             outfile.write(f"call cam_grid_write_dist_array(file, grid_decomp, (/dims(1)/), (/field_shape(1)/), {key}, {desc_name})", 2)
-        elif len(value["dims"]) == 2:
-            if 'horizontal_dimension' in value['dims'][0]:
-                outfile.comment("Handle field with horizontal dimension and additional, vertical dimension", 2)
-                outfile.write("field_shape(1) = num_global_phys_cols", 2)
-                outfile.write(f"field_shape(2) = size({key}, 2)", 2)
-                outfile.write(f"call cam_grid_write_dist_array(file, grid_decomp, dims, field_shape, {key}, {desc_name})", 2)
-            else:
-                outfile.comment("Handle field with two non-horizontal dimensions", 2)
-                outfile.write(f"field_shape(1) = size({key}, 1)", 2)
-                outfile.write(f"field_shape(2) = size({key}, 2)", 2)
-                outfile.write(f"call cam_grid_write_dist_array(file, grid_decomp, dims, field_shape, {key}, {desc_name})", 2)
-            # end if
-        # PEVERWHEE - TODO: handle >2 dims!
-        # end if
-    # end for
-    """
-    for key, value in required_vars.items():
-        if len(value['dims']) == 1:
-            iodesc = 'iodesc_2d'
-            if not assigned_2d:
-                # Associate the 2d iodesc pointer
-                outfile.write("dims(1) = columns_on_task", 2)
-                outfile.write(f"call cam_grid_get_decomp(grid_id, (/dims(1)/), gdims(1:nhdims), pio_double, {iodesc})", 2)
-                assigned_2d = True
-            # end if
-        else:
-            for dim in value['dims']:
-                if 'vertical_layer_dimension' in dim:
-                    iodesc = 'iodesc_3d_layers'
-                    if not assigned_3d_layers:
-                        # Associate the 3d iodesc pointer for layers
-                        outfile.write("dims(1) = columns_on_task", 2)
-                        outfile.write("dims(2) = pver", 2)
-                        outfile.write(f"call cam_grid_get_decomp(grid_id, dims(1:2), gdims(1:nhdims), pio_double, {iodesc})", 2)
-                        assigned_3d_layers = True
-                    # end if
-                elif 'vertical_interface_dimension' in dim:
-                    iodesc = 'iodesc_3d_interfaces'
-                    if not assigned_3d_interfaces:
-                        # Associate the 3d iodesc pointer for interfaces
-                        outfile.write("dims(1) = columns_on_task", 2)
-                        outfile.write("dims(2) = pverp", 2)
-                        outfile.write(f"call cam_grid_get_decomp(grid_id, dims(1:2), gdims(1:nhdims), pio_double, {iodesc})", 2)
-                        assigned_3d_layers = True
-                    # end if
+        elif len(value["dims"]) > 1:
+            for index, dim in enumerate(value["dims"]):
+                if 'horizontal_dimension' in dim:
+                    outfile.write("field_shape(1) = num_global_phys_cols", 2)
+                else:
+                    outfile.write(f"field_shape({index + 1}) = size({key}, {index + 1})", 2)
                 # end if
             # end if
+            outfile.write(f"call cam_grid_write_dist_array(file, grid_decomp, dims, field_shape, {key}, {desc_name})", 2)
         # end if
-        desc_name = f"{value['diag_name'].lower()}_desc"
-        outfile.write(f"call pio_write_darray(file, {desc_name}, {iodesc}, {key}, errflg)", 2)
-        outfile.write("if (errflg /= 0) then", 2)
-        outfile.write(f"write(errmsg,*) 'restart_physics_write: error writing variable {value['diag_name']}'", 3)
-        outfile.write("return", 3)
-        outfile.write("end if", 2)
-        outfile.blank_line()
     # end for
-"""
+
     # Handle constituent-dimensioned variables
     if constituent_dimmed_vars:
         outfile.write("const_props => cam_model_const_properties()", 2)
diff --git a/src/dynamics/se/restart_dynamics.F90 b/src/dynamics/se/restart_dynamics.F90
new file mode 100644
index 000000000..ba0861d45
--- /dev/null
+++ b/src/dynamics/se/restart_dynamics.F90
@@ -0,0 +1,236 @@
+module restart_dynamics
+
+! Write and read dynamics fields from the restart file.  For exact restart
+! it is necessary to write all element data, including duplicate columns,
+! to the file.  The namelist option, se_write_restart_unstruct, is
+! available to write just the unique columns to the restart file using the
+! same unstructured grid used by the history and initial files.  This
+! results in the introduction of a roundoff size difference on restart, but
+! writes the fields in the unstructured grid format which is easier to
+! modify if the user desires to introduce perturbations or other
+! adjustments into the run.  The restart file containing the unstructured
+! grid format may also be used for an initial run.
+
+use shr_kind_mod,     only: r8 => shr_kind_r8
+use spmd_utils,       only: iam, masterproc
+
+use dyn_grid,         only: timelevel, fvm, elem, edgebuf
+use dyn_comp,         only: dyn_import_t, dyn_export_t, dyn_init, write_restart_unstruct
+use hycoef,           only: init_restart_hycoef, write_restart_hycoef, &
+                            hyai, hybi, ps0
+use ref_pres,         only: ptop_ref
+
+use pio,              only: pio_global, pio_unlimited, pio_offset_kind, pio_int, pio_double, &
+                            pio_seterrorhandling, pio_bcast_error, pio_noerr, &
+                            file_desc_t, var_desc_t, io_desc_t, &
+                            pio_inq_dimid, pio_inq_dimlen, pio_inq_varid, &
+                            pio_def_dim, pio_def_var,  &
+                            pio_enddef, &
+                            pio_initdecomp, pio_freedecomp, pio_setframe, &
+                            pio_put_att, pio_put_var, pio_write_darray, &
+                            pio_get_att, pio_get_var, pio_read_darray
+
+use cam_pio_utils,    only: pio_subsystem, cam_pio_handle_error
+use cam_grid_support, only: cam_grid_header_info_t, &
+                            cam_grid_write_var, cam_grid_get_decomp, cam_grid_dimensions
+
+use parallel_mod,     only: par
+use thread_mod,       only: horz_num_threads
+use dof_mod,          only: UniquePoints
+use element_mod,      only: element_t
+
+use edge_mod,         only: initEdgeBuffer, edgeVpack, edgeVunpack, FreeEdgeBuffer
+use edgetype_mod,     only: EdgeBuffer_t
+use bndry_mod,        only: bndry_exchange
+
+use fvm_control_volume_mod, only: fvm_struct
+
+implicit none
+private
+save
+
+public :: init_restart_dynamics
+!public :: write_restart_dynamics
+!public :: read_restart_dynamics
+
+! these variables are module data so they can be shared between the
+! file definition and write phases
+type(var_desc_t)              :: psdry_desc, udesc, vdesc, tdesc
+type(var_desc_t), allocatable :: qdesc_dp(:)
+type(var_desc_t)              :: dp_fvm_desc
+type(var_desc_t), pointer     :: c_fvm_desc(:)
+
+integer, private :: nelem_tot = -1 ! Correct total number of elements
+
+!=========================================================================================
+CONTAINS
+!=========================================================================================
+
+subroutine init_nelem_tot()
+  use spmd_utils,     only: mpicom
+  use mpi,            only: mpi_integer, mpi_sum
+  use dimensions_mod, only: nelemd
+
+  integer :: ierr
+
+  if (nelem_tot < 0) then
+    call MPI_Allreduce(nelemd, nelem_tot, 1, MPI_INTEGER, MPI_SUM, mpicom, ierr)
+  end if
+end subroutine init_nelem_tot
+
+subroutine init_restart_dynamics(file, dyn_out)
+   use cam_ccpp_cap,              only: cam_model_const_properties
+   use ccpp_constituent_prop_mod, only: ccpp_constituent_prop_ptr_t
+   use pio, only: file_desc_t
+   use dyn_comp, only: dyn_export_t
+   use cam_grid_support, only: cam_grid_header_info_t, cam_grid_id
+   use cam_grid_support, only: cam_grid_write_attr
+   use dimensions_mod,   only: np, npsq, ne, nelemd, ntrac, fv_nphys
+   ! Define dimensions, variables, attributes for restart file.
+
+   ! This is not really an "init" routine.  It is called before
+   ! write_restart_dynamics every time an restart is written.
+
+   ! arguments
+   type(file_desc_t),  intent(inout) :: file
+   type(dyn_export_t), intent(in)    :: dyn_out
+
+   ! local variables
+   integer :: i
+   integer :: vdimids(2)
+   integer :: nlev_dimid
+   integer :: ncol_dimid
+   integer :: ncol_fvm_dimid
+   integer :: time_dimid
+
+   integer :: ierr, err_handling
+
+   integer :: grid_id
+   type(cam_grid_header_info_t) :: info
+   integer :: constituent_idx
+   type(ccpp_constituent_prop_ptr_t), pointer :: const_props(:)
+   character(len=256) :: const_diag_name
+
+   !----------------------------------------------------------------------------
+
+   call init_nelem_tot()
+   call init_restart_hycoef(file, vdimids)
+   nlev_dimid = vdimids(1)
+
+   call pio_seterrorhandling(File, pio_bcast_error, err_handling)
+
+   ierr = PIO_Def_Dim(File, 'time', PIO_UNLIMITED, time_dimid)
+
+   ! GLL restart fields
+
+   ! number of columns written to restart depends on whether all columns in the
+   ! element structures are written, or just the unique columns (unstructured grid)
+   if (write_restart_unstruct) then
+      grid_id = cam_grid_id('GLL')
+      call cam_grid_write_attr(File, grid_id, info)
+      ncol_dimid = info%get_hdimid(1)
+   else
+      ierr = PIO_Def_Dim(File,'nenpnp', nelem_tot*np*np, ncol_dimid)
+      ierr = PIO_Put_Att(File, PIO_GLOBAL, 'ne', ne)
+      ierr = PIO_Put_Att(File, PIO_GLOBAL, 'np', np)
+   end if
+
+   ierr = PIO_Def_Var(File, 'PSDRY', pio_double, (/ncol_dimid, time_dimid/), psdry_desc)
+   ierr = PIO_Def_Var(File, 'U', pio_double, (/ncol_dimid, nlev_dimid, time_dimid/), Udesc)
+   ierr = PIO_Def_Var(File, 'V', pio_double, (/ncol_dimid, nlev_dimid, time_dimid/), Vdesc)
+   ierr = PIO_Def_Var(File, 'T', pio_double, (/ncol_dimid, nlev_dimid, time_dimid/), Tdesc)
+
+   const_props => cam_model_const_properties()
+   allocate(qdesc_dp(size(const_props)))
+   do constituent_idx = 1, size(const_props)
+      ! Grab constituent diagnostic name:
+      call const_props(constituent_idx)%diagnostic_name(const_diag_name)
+      ierr = PIO_Def_Var(File,"dp"//trim(const_diag_name), pio_double, &
+                         (/ncol_dimid, nlev_dimid, time_dimid/), Qdesc_dp(constituent_idx))
+   end do
+
+   ! CSLAM restart fields
+
+   if (fv_nphys > 0) then
+
+      grid_id = cam_grid_id('FVM')
+      call cam_grid_write_attr(File, grid_id, info)
+      ncol_fvm_dimid = info%get_hdimid(1)
+
+      ierr = PIO_Def_Var(File, 'dp_fvm', pio_double, &
+         (/ncol_fvm_dimid, nlev_dimid, time_dimid/), dp_fvm_desc)
+
+      allocate(c_fvm_desc(size(const_props)))
+      do constituent_idx = 1, size(const_props)
+         call const_props(constituent_idx)%diagnostic_name(const_diag_name)
+         ierr = PIO_Def_Var(File, trim(const_diag_name)//"_fvm", pio_double, &
+            (/ncol_fvm_dimid, nlev_dimid, time_dimid/), c_fvm_desc(constituent_idx))
+      end do
+
+   end if
+
+   call pio_seterrorhandling(File, err_handling)
+
+end subroutine init_restart_dynamics
+
+!=========================================================================================
+! Private
+!=========================================================================================
+
+function get_restart_decomp(elem, lev) result(ldof)
+   use dimensions_mod, only: nelemd, np
+
+   ! Get the integer mapping of a variable in the dynamics decomp in memory.
+   ! The canonical ordering is as on the file. A 0 value indicates that the
+   ! variable is not on the file (eg halo or boundary values)
+
+   type(element_t), intent(in) :: elem(:)
+   integer,         intent(in) :: lev
+   integer,         pointer    :: ldof(:)
+
+   integer :: i, j, k, ie
+   !----------------------------------------------------------------------------
+
+   allocate(ldof(nelemd*np*np*lev))
+
+   j = 1
+   do k = 1, lev
+      do ie = 1, nelemd
+         do i = 1, np*np
+            ldof(j) = (elem(ie)%GlobalID-1)*np*np + (k-1)*nelem_tot*np*np + i
+            j = j + 1
+         end do
+      end do
+   end do
+
+end function get_restart_decomp
+
+!=========================================================================================
+
+function get_restart_decomp_fvm(elem, lev) result(ldof)
+   use dimensions_mod, only: nc, nelemd
+
+   type(element_t), intent(in) :: elem(:)
+   integer,         intent(in) :: lev
+   integer,         pointer    :: ldof(:)
+
+   integer :: i, j, k, ie
+   !----------------------------------------------------------------------------
+
+   allocate(ldof(nelemd*nc*nc*lev))
+
+   j = 1
+   do k = 1, lev
+      do ie = 1, nelemd
+         do i = 1, nc*nc
+            ldof(j) = (elem(ie)%GlobalID-1)*nc*nc + (k-1)*nelem_tot*nc*nc + i
+            j = j + 1
+         end do
+      end do
+   end do
+
+end function get_restart_decomp_fvm
+
+!=========================================================================================
+
+end module restart_dynamics
diff --git a/src/physics/utils/physics_data.F90 b/src/physics/utils/physics_data.F90
index 7cf1f8ef5..017ebf455 100644
--- a/src/physics/utils/physics_data.F90
+++ b/src/physics/utils/physics_data.F90
@@ -446,6 +446,8 @@ subroutine read_constituent_dimensioned_field_2d(const_props, file, std_name, ba
 
       if(.not. var_found .and. error_on_not_found_local) then
          call endrun(subname//'Required constituent-dimensioned variables not found: No match for ' // trim(std_name))
+      else if (.not. var_found) then
+         return
       end if
 
       ! Once base_idx is identified, use it in the actual constituent loop:

From be1437d3f3c0a499197386951f88a14c288d4bab Mon Sep 17 00:00:00 2001
From: Courtney Peverley <courtneyp@izumi.cgd.ucar.edu>
Date: Fri, 21 Nov 2025 18:38:13 -0700
Subject: [PATCH 09/19] dynamics restart write working; cleaned up code

---
 src/control/cam_restart.F90          |   5 +-
 src/dynamics/se/restart_dynamics.F90 | 401 ++++++++++++++++++++++++---
 2 files changed, 366 insertions(+), 40 deletions(-)

diff --git a/src/control/cam_restart.F90 b/src/control/cam_restart.F90
index 505e3874d..098a1da43 100644
--- a/src/control/cam_restart.F90
+++ b/src/control/cam_restart.F90
@@ -9,8 +9,7 @@ module cam_restart
   subroutine cam_write_restart(dyn_out, yr_spec, mon_spec, day_spec, sec_spec)
     use cam_filenames,    only: interpret_filename_spec
     use cam_pio_utils,    only: cam_pio_createfile, cam_pio_set_fill
-    use restart_dynamics, only: init_restart_dynamics
-!    use restart_dynamics, only: write_restart_dynamics, init_restart_dynamics
+    use restart_dynamics, only: write_restart_dynamics, init_restart_dynamics
     use restart_physics,  only: restart_physics_write, restart_physics_init
     use cam_instance,     only: inst_suffix
     use pio,              only: file_desc_t, io_desc_t, pio_double, pio_global
@@ -69,7 +68,7 @@ subroutine cam_write_restart(dyn_out, yr_spec, mon_spec, day_spec, sec_spec)
     ierr = pio_put_att(fh, pio_global, 'caseid', caseid)
     ierr = pio_enddef(fh)
 
-!    call write_restart_dynamics(fh, dyn_out)
+    call write_restart_dynamics(fh, dyn_out)
 
     ! TODO: write ionosphere restart
 
diff --git a/src/dynamics/se/restart_dynamics.F90 b/src/dynamics/se/restart_dynamics.F90
index ba0861d45..3704c1a54 100644
--- a/src/dynamics/se/restart_dynamics.F90
+++ b/src/dynamics/se/restart_dynamics.F90
@@ -11,46 +11,14 @@ module restart_dynamics
 ! adjustments into the run.  The restart file containing the unstructured
 ! grid format may also be used for an initial run.
 
-use shr_kind_mod,     only: r8 => shr_kind_r8
-use spmd_utils,       only: iam, masterproc
-
-use dyn_grid,         only: timelevel, fvm, elem, edgebuf
-use dyn_comp,         only: dyn_import_t, dyn_export_t, dyn_init, write_restart_unstruct
-use hycoef,           only: init_restart_hycoef, write_restart_hycoef, &
-                            hyai, hybi, ps0
-use ref_pres,         only: ptop_ref
-
-use pio,              only: pio_global, pio_unlimited, pio_offset_kind, pio_int, pio_double, &
-                            pio_seterrorhandling, pio_bcast_error, pio_noerr, &
-                            file_desc_t, var_desc_t, io_desc_t, &
-                            pio_inq_dimid, pio_inq_dimlen, pio_inq_varid, &
-                            pio_def_dim, pio_def_var,  &
-                            pio_enddef, &
-                            pio_initdecomp, pio_freedecomp, pio_setframe, &
-                            pio_put_att, pio_put_var, pio_write_darray, &
-                            pio_get_att, pio_get_var, pio_read_darray
-
-use cam_pio_utils,    only: pio_subsystem, cam_pio_handle_error
-use cam_grid_support, only: cam_grid_header_info_t, &
-                            cam_grid_write_var, cam_grid_get_decomp, cam_grid_dimensions
-
-use parallel_mod,     only: par
-use thread_mod,       only: horz_num_threads
-use dof_mod,          only: UniquePoints
-use element_mod,      only: element_t
-
-use edge_mod,         only: initEdgeBuffer, edgeVpack, edgeVunpack, FreeEdgeBuffer
-use edgetype_mod,     only: EdgeBuffer_t
-use bndry_mod,        only: bndry_exchange
-
-use fvm_control_volume_mod, only: fvm_struct
+use pio,              only: var_desc_t
 
 implicit none
 private
 save
 
 public :: init_restart_dynamics
-!public :: write_restart_dynamics
+public :: write_restart_dynamics
 !public :: read_restart_dynamics
 
 ! these variables are module data so they can be shared between the
@@ -79,13 +47,15 @@ subroutine init_nelem_tot()
 end subroutine init_nelem_tot
 
 subroutine init_restart_dynamics(file, dyn_out)
+   use hycoef,           only: init_restart_hycoef
    use cam_ccpp_cap,              only: cam_model_const_properties
    use ccpp_constituent_prop_mod, only: ccpp_constituent_prop_ptr_t
-   use pio, only: file_desc_t
-   use dyn_comp, only: dyn_export_t
+   use pio, only: file_desc_t, pio_global, pio_unlimited, pio_double, pio_seterrorhandling
+   use pio, only: pio_bcast_error, pio_def_dim, pio_def_var, pio_put_att
+   use dyn_comp, only: dyn_export_t, write_restart_unstruct
    use cam_grid_support, only: cam_grid_header_info_t, cam_grid_id
    use cam_grid_support, only: cam_grid_write_attr
-   use dimensions_mod,   only: np, npsq, ne, nelemd, ntrac, fv_nphys
+   use dimensions_mod,   only: np, npsq, ne, nelemd, fv_nphys
    ! Define dimensions, variables, attributes for restart file.
 
    ! This is not really an "init" routine.  It is called before
@@ -173,12 +143,368 @@ subroutine init_restart_dynamics(file, dyn_out)
 
 end subroutine init_restart_dynamics
 
+!=========================================================================================
+
+subroutine write_restart_dynamics(File, dyn_out)
+  use control_mod,               only: qsplit
+  use pio,                       only: file_desc_t, pio_offset_kind, io_desc_t, pio_double
+  use pio,                       only: pio_initdecomp, pio_freedecomp, pio_setframe, pio_write_darray
+  use dyn_comp,                  only: dyn_export_t, write_restart_unstruct
+  use dyn_grid,                  only: timelevel
+  use cam_grid_support,          only: cam_grid_id, cam_grid_write_var, cam_grid_get_decomp, cam_grid_dimensions
+  use element_mod,               only: element_t
+  use fvm_control_volume_mod,    only: fvm_struct
+  use hycoef,                    only: write_restart_hycoef
+  use time_mod,                  only: TimeLevel_Qdp
+  use parallel_mod,              only: par
+  use dimensions_mod,            only: nc, np, npsq, ne, nelemd, fv_nphys, nlev
+  use cam_ccpp_cap,              only: cam_model_const_properties
+  use ccpp_constituent_prop_mod, only: ccpp_constituent_prop_ptr_t
+  use cam_pio_utils,             only: pio_subsystem
+  use thread_mod,                only: horz_num_threads
+  use spmd_utils,                only: iam
+  use shr_kind_mod,              only: r8 => shr_kind_r8
+
+   type(file_desc_t), intent(inout) :: File
+   type(dyn_export_t), intent(in)   :: dyn_out
+
+   ! local variables
+   integer(pio_offset_kind), parameter :: t_idx = 1
+
+   type(element_t),  pointer :: elem(:)
+   type(fvm_struct), pointer :: fvm(:)
+
+   integer :: tl, tlqdp
+   integer :: i, ie, ii, j, k, m
+   integer :: ierr
+
+   integer :: grid_id
+   integer :: grid_dimlens(2)
+
+
+
+   integer :: array_lens(3)
+   integer :: file_lens(2)
+   type(io_desc_t), pointer :: iodesc3d_fvm
+   real(r8),    allocatable :: buf3d(:,:,:)
+   type(ccpp_constituent_prop_ptr_t), pointer :: const_props(:)
+
+
+
+   character(len=*), parameter :: sub = 'write_restart_dynamics'
+   !----------------------------------------------------------------------------
+
+   call write_restart_hycoef(File)
+
+   tl = timelevel%n0
+   call TimeLevel_Qdp(timelevel, qsplit, tlQdp)
+   const_props => cam_model_const_properties()
+
+   if (iam .lt. par%nprocs) then
+      elem => dyn_out%elem
+      fvm => dyn_out%fvm
+   else
+      allocate (elem(0), fvm(0))
+   endif
+
+   ! write fields on GLL grid
+
+   if (write_restart_unstruct) then
+      call write_unstruct()
+   else
+      call write_elem()
+   end if
+
+   ! write CSLAM fields
+
+   if (fv_nphys > 0) then
+
+      grid_id = cam_grid_id('FVM')
+
+      ! write coords for FVM grid
+      call cam_grid_write_var(File, grid_id)
+
+      call cam_grid_dimensions(grid_id, grid_dimlens)
+      allocate(buf3d(nc*nc,nlev,nelemd))
+      array_lens = (/nc*nc, nlev, nelemd/)
+      file_lens  = (/grid_dimlens(1), nlev/)
+      call cam_grid_get_decomp(grid_id, array_lens, file_lens, pio_double, iodesc3d_fvm)
+
+      do ie = 1, nelemd
+         do k = 1, nlev
+            ii = 1
+            do j = 1, nc
+               do i = 1, nc
+                  buf3d(ii,k,ie) = fvm(ie)%dp_fvm(i,j,k)
+                  ii = ii + 1
+               end do
+            end do
+         end do
+      end do
+      call PIO_Setframe(file, dp_fvm_desc, t_idx)
+      call PIO_Write_Darray(file, dp_fvm_desc, iodesc3d_fvm, buf3d, ierr)
+
+      do m = 1, size(const_props)
+         do ie = 1, nelemd
+            do k = 1, nlev
+               ii = 1
+               do j = 1, nc
+                  do i = 1, nc
+                     buf3d(ii,k,ie) = fvm(ie)%c(i,j,k,m)
+                     ii = ii + 1
+                  end do
+               end do
+            end do
+         end do
+         call PIO_Setframe(file, c_fvm_desc(m), t_idx)
+         call PIO_Write_Darray(file, c_fvm_desc(m), iodesc3d_fvm, buf3d, ierr)
+      end do
+
+      deallocate(c_fvm_desc)
+      deallocate(buf3d)
+      ! should this call be made on a pointer?
+      !call pio_freedecomp(File, iodesc3d_fvm)
+
+   end if
+
+   if (iam >= par%nprocs) then
+      deallocate(elem, fvm)
+   endif
+
+!-------------------------------------------------------------------------------
+contains
+!-------------------------------------------------------------------------------
+
+subroutine write_elem()
+
+   ! local variables
+   integer          :: i, ie, j, k
+   integer          :: ierr
+   integer, pointer :: ldof(:)
+
+   type(io_desc_t)  :: iodesc2d, iodesc3d
+
+   real(kind=r8), pointer :: var3d(:,:,:,:), var2d(:,:,:)
+   !----------------------------------------------------------------------------
+
+   ldof => get_restart_decomp(elem, 1)
+   call PIO_InitDecomp(pio_subsystem, pio_double, (/nelem_tot*np*np/), ldof, iodesc2d)
+   deallocate(ldof)
+
+   ldof => get_restart_decomp(elem, nlev)
+   call PIO_InitDecomp(pio_subsystem, pio_double, (/nelem_tot*np*np,nlev/), ldof, iodesc3d)
+   deallocate(ldof)
+
+   allocate(var2d(np,np,nelemd))
+   allocate(var3d(np,np,nelemd,nlev))
+
+   !$omp parallel do num_threads(horz_num_threads) private(ie, j, i)
+   do ie = 1, nelemd
+      do j = 1, np
+         do i = 1, np
+            var2d(i,j,ie) = elem(ie)%state%psdry(i,j)
+         end do
+      end do
+   end do
+   call PIO_Setframe(File, psdry_desc, t_idx)
+   call PIO_Write_Darray(File, psdry_desc, iodesc2d, var2d, ierr)
+
+   !$omp parallel do num_threads(horz_num_threads) private(ie, k, j, i)
+   do ie = 1, nelemd
+      do k = 1, nlev
+         do j = 1, np
+            do i = 1, np
+               var3d(i,j,ie,k) = elem(ie)%state%V(i,j,1,k,tl)
+            end do
+         end do
+      end do
+   end do
+   call PIO_Setframe(File, Udesc, t_idx)
+   call PIO_Write_Darray(File, Udesc, iodesc3d, var3d, ierr)
+
+   !$omp parallel do num_threads(horz_num_threads) private(ie, k, j, i)
+   do ie = 1, nelemd
+      do k = 1, nlev
+         do j = 1, np
+            do i = 1, np
+               var3d(i,j,ie,k) = elem(ie)%state%V(i,j,2,k,tl)
+            end do
+         end do
+      end do
+   end do
+   call PIO_Setframe(File, Vdesc, t_idx)
+   call PIO_Write_Darray(File, Vdesc, iodesc3d, var3d, ierr)
+
+   !$omp parallel do num_threads(horz_num_threads) private(ie, k, j, i)
+   do ie = 1, nelemd
+      do k = 1, nlev
+         do j = 1, np
+            do i = 1, np
+               var3d(i,j,ie,k) = elem(ie)%state%T(i,j,k,tl)
+            end do
+         end do
+      end do
+   end do
+   call PIO_Setframe(File, Tdesc, t_idx)
+   call PIO_Write_Darray(File, Tdesc, iodesc3d, var3d, ierr)
+
+   do m = 1, size(const_props)
+
+      !$omp parallel do num_threads(horz_num_threads) private(ie, k, j, i)
+      do ie = 1, nelemd
+         do k = 1, nlev
+            do j = 1, np
+               do i = 1, np
+                  var3d(i,j,ie,k) = elem(ie)%state%Qdp(i,j,k,m,tlQdp)
+               end do
+            end do
+         end do
+      end do
+      call PIO_Setframe(File, Qdesc_dp(m), t_idx)
+      call PIO_Write_Darray(File, Qdesc_dp(m), iodesc3d, var3d, ierr)
+
+   end do
+
+   deallocate(var2d)
+   deallocate(var3d)
+   deallocate(qdesc_dp)
+
+   call pio_freedecomp(File, iodesc2d)
+   call pio_freedecomp(File, iodesc3d)
+
+end subroutine write_elem
+
+!-------------------------------------------------------------------------------
+
+subroutine write_unstruct()
+
+   ! local variables
+   integer          :: i, ie, ii, j, k
+   integer          :: ierr
+
+   integer :: array_lens_3d(3), array_lens_2d(2)
+   integer :: file_lens_2d(2), file_lens_1d(1)
+
+   type(io_desc_t), pointer :: iodesc
+   real(r8),    allocatable :: var2d(:,:), var3d(:,:,:)
+   !----------------------------------------------------------------------------
+
+   grid_id = cam_grid_id('GLL')
+
+   ! write coordinate variables for unstructured GLL grid
+   call cam_grid_write_var(File, grid_id)
+
+   ! create map for distributed write
+   call cam_grid_dimensions(grid_id, grid_dimlens)
+
+   ! create map for distributed write of 2D fields
+   array_lens_2d = (/npsq, nelemd/)
+   file_lens_1d  = (/grid_dimlens(1)/)
+   call cam_grid_get_decomp(grid_id, array_lens_2d, file_lens_1d, pio_double, iodesc)
+
+   allocate(var2d(npsq,nelemd))
+
+   do ie = 1, nelemd
+      ii = 1
+      do j = 1, np
+         do i = 1, np
+            var2d(ii,ie) = elem(ie)%state%psdry(i,j)
+            ii = ii + 1
+         end do
+      end do
+   end do
+   call PIO_Setframe(File, psdry_desc, t_idx)
+   call PIO_Write_Darray(File, psdry_desc, iodesc, var2d, ierr)
+
+   nullify(iodesc)
+   deallocate(var2d)
+
+   ! create map for distributed write of 3D fields
+   array_lens_3d = (/npsq, nlev, nelemd/)
+   file_lens_2d  = (/grid_dimlens(1), nlev/)
+   call cam_grid_get_decomp(grid_id, array_lens_3d, file_lens_2d, pio_double, iodesc)
+
+   allocate(var3d(npsq,nlev,nelemd))
+
+   do ie = 1, nelemd
+      do k = 1, nlev
+         ii = 1
+         do j = 1, np
+            do i = 1, np
+               var3d(ii,k,ie) = elem(ie)%state%V(i,j,1,k,tl)
+               ii = ii + 1
+            end do
+         end do
+      end do
+   end do
+   call PIO_Setframe(File, Udesc, t_idx)
+   call PIO_Write_Darray(File, Udesc, iodesc, var3d, ierr)
+
+   do ie = 1, nelemd
+      do k = 1, nlev
+         ii = 1
+         do j = 1, np
+            do i = 1, np
+               var3d(ii,k,ie) = elem(ie)%state%V(i,j,2,k,tl)
+               ii = ii + 1
+            end do
+         end do
+      end do
+   end do
+   call PIO_Setframe(File, Vdesc, t_idx)
+   call PIO_Write_Darray(File, Vdesc, iodesc, var3d, ierr)
+
+   do ie = 1, nelemd
+      do k = 1, nlev
+         ii = 1
+         do j = 1, np
+            do i = 1, np
+               var3d(ii,k,ie) = elem(ie)%state%T(i,j,k,tl)
+               ii = ii + 1
+            end do
+         end do
+      end do
+   end do
+   call PIO_Setframe(File, Tdesc, t_idx)
+   call PIO_Write_Darray(File, Tdesc, iodesc, var3d, ierr)
+
+   do m = 1, size(const_props)
+
+      !$omp parallel do num_threads(horz_num_threads) private(ie, k, j, i)
+      do ie = 1, nelemd
+         do k = 1, nlev
+            ii = 1
+            do j = 1, np
+               do i = 1, np
+                  var3d(ii,k,ie) = elem(ie)%state%Qdp(i,j,k,m,tlQdp)
+                  ii = ii + 1
+               end do
+            end do
+         end do
+      end do
+      call PIO_Setframe(File, Qdesc_dp(m), t_idx)
+      call PIO_Write_Darray(File, Qdesc_dp(m), iodesc, var3d, ierr)
+
+   end do
+
+   deallocate(var3d)
+   deallocate(qdesc_dp)
+
+end subroutine write_unstruct
+
+!-------------------------------------------------------------------------------
+
+end subroutine write_restart_dynamics
+
+!=========================================================================================
+
 !=========================================================================================
 ! Private
 !=========================================================================================
 
 function get_restart_decomp(elem, lev) result(ldof)
    use dimensions_mod, only: nelemd, np
+   use element_mod,    only: element_t
 
    ! Get the integer mapping of a variable in the dynamics decomp in memory.
    ! The canonical ordering is as on the file. A 0 value indicates that the
@@ -209,6 +535,7 @@ end function get_restart_decomp
 
 function get_restart_decomp_fvm(elem, lev) result(ldof)
    use dimensions_mod, only: nc, nelemd
+   use element_mod,    only: element_t
 
    type(element_t), intent(in) :: elem(:)
    integer,         intent(in) :: lev

From 3f166b680f9434cb30f14b4740d4b72552fd7b35 Mon Sep 17 00:00:00 2001
From: peverwhee <courtneyp@ucar.edu>
Date: Thu, 16 Apr 2026 14:00:17 -0600
Subject: [PATCH 10/19] fix merge

---
 src/control/cam_comp.F90 | 1 -
 1 file changed, 1 deletion(-)

diff --git a/src/control/cam_comp.F90 b/src/control/cam_comp.F90
index e52703b88..f7ebcd4d6 100644
--- a/src/control/cam_comp.F90
+++ b/src/control/cam_comp.F90
@@ -649,7 +649,6 @@ subroutine cam_register_constituents(cam_runtime_opts)
          call host_constituents(1)%instantiate( &
               std_name=wv_stdname,              &
               long_name="water vapor mixing ratio w.r.t moist air and condensed_water", &
-              diag_name="Q",                                                            &
               units="kg kg-1",                                                          &
               default_value=0._kind_phys,                                               &
               vertical_dim="vertical_layer_dimension",                                  &

From 73af38772838bae60ed6eeb0b239de33d2082779 Mon Sep 17 00:00:00 2001
From: peverwhee <courtneyp@ucar.edu>
Date: Tue, 28 Apr 2026 16:38:05 -0600
Subject: [PATCH 11/19] new file for hist restart files; set up restart objects

---
 src/control/cam_comp.F90              |  57 +++---
 src/control/cam_restart.F90           |   3 +-
 src/cpl/nuopc/atm_comp_nuopc.F90      |   6 +-
 src/history/cam_hist_file.F90         |  16 +-
 src/history/cam_hist_restart_file.F90 | 253 ++++++++++++++++++++++++++
 src/history/cam_history.F90           |  33 +++-
 src/history/cam_history_support.F90   |   6 +-
 7 files changed, 331 insertions(+), 43 deletions(-)
 create mode 100644 src/history/cam_hist_restart_file.F90

diff --git a/src/control/cam_comp.F90 b/src/control/cam_comp.F90
index f7ebcd4d6..3d05bf7c0 100644
--- a/src/control/cam_comp.F90
+++ b/src/control/cam_comp.F90
@@ -467,47 +467,24 @@ end subroutine cam_run3
    !-----------------------------------------------------------------------
    !
 
-   subroutine cam_run4(rstwr, nlend,                         &
-        yr_spec, mon_spec, day_spec, sec_spec)
+   subroutine cam_run4(rstwr, nlend)
+      logical, intent(in)  :: rstwr    ! write restart file
+      logical, intent(in)  :: nlend    ! this is final timestep
 
       !-----------------------------------------------------------------------
       !
-      ! Purpose:  Final phase of atmosphere model run method. This consists
-      !           of all the restart output, history writes, and other
-      !           file output.
+      ! Purpose:
       !
       !-----------------------------------------------------------------------
-      use cam_restart,  only: cam_write_restart
 !      use qneg_module,  only: qneg_print_summary
 
-      logical,         intent(in)           :: rstwr    ! write restart file
-      logical,         intent(in)           :: nlend    ! this is final timestep
-      integer,         intent(in), optional :: yr_spec  ! Simulation year
-      integer,         intent(in), optional :: mon_spec ! Simulation month
-      integer,         intent(in), optional :: day_spec ! Simulation day
-      integer,         intent(in), optional :: sec_spec ! Secs in current simulation day
-
-      !
-      ! Write restart files
-      !
-      if (rstwr) then
-         call t_startf('cam_write_restart')
-         if (present(yr_spec) .and. present(mon_spec) .and.                   &
-              present(day_spec).and.present(sec_spec)) then
-            call cam_write_restart(dyn_out, yr_spec=yr_spec, &
-                 mon_spec=mon_spec, day_spec=day_spec, sec_spec= sec_spec)
-         else
-            call cam_write_restart(dyn_out)
-         end if
-         call t_stopf('cam_write_restart')
-      end if
-
    end subroutine cam_run4
 
    !
    !-----------------------------------------------------------------------
    !
-   subroutine cam_timestep_final(rstwr, nlend, do_ncdata_check, do_history_write)
+   subroutine cam_timestep_final(rstwr, nlend, do_ncdata_check, &
+                   yr_spec, mon_spec, day_spec, sec_spec, do_history_write)
       !-----------------------------------------------------------------------
       !
       ! Purpose:   Timestep final runs at the end of each timestep
@@ -517,15 +494,20 @@ subroutine cam_timestep_final(rstwr, nlend, do_ncdata_check, do_history_write)
       use phys_comp,    only: phys_timestep_final
       use cam_history,  only: history_write_files
       use cam_history,  only: history_wrap_up
+      use cam_restart,  only: cam_write_restart
       logical, intent(in)  :: rstwr    ! write restart file
       logical, intent(in)  :: nlend    ! this is final timestep
       !Flag for whether a snapshot (ncdata) check should be run or not
       ! - flag is true if this is not the first or last step
       logical, intent(in)  :: do_ncdata_check
+      integer,         intent(in), optional :: yr_spec  ! Simulation year
+      integer,         intent(in), optional :: mon_spec ! Simulation month
+      integer,         intent(in), optional :: day_spec ! Simulation day
+      integer,         intent(in), optional :: sec_spec ! Secs in current simulation day
       !Flag for whether to perform the history write
       logical, optional, intent(in) :: do_history_write
 
-      logical :: history_write_loc
+      logical                               :: history_write_loc
 
       if (present(do_history_write)) then
          history_write_loc = do_history_write
@@ -536,7 +518,20 @@ subroutine cam_timestep_final(rstwr, nlend, do_ncdata_check, do_history_write)
       if (history_write_loc) then
          call history_write_files()
       end if
-      ! peverwhee - todo: handle restarts
+      !
+      ! Write restart files
+      !
+      if (rstwr) then
+         call t_startf('cam_write_restart')
+         if (present(yr_spec) .and. present(mon_spec) .and.                   &
+              present(day_spec).and.present(sec_spec)) then
+            call cam_write_restart(dyn_out, yr_spec=yr_spec, &
+                 mon_spec=mon_spec, day_spec=day_spec, sec_spec= sec_spec)
+         else
+            call cam_write_restart(dyn_out)
+         end if
+         call t_stopf('cam_write_restart')
+      end if
       call history_wrap_up(rstwr, nlend)
 
       !
diff --git a/src/control/cam_restart.F90 b/src/control/cam_restart.F90
index 098a1da43..137fb1b9d 100644
--- a/src/control/cam_restart.F90
+++ b/src/control/cam_restart.F90
@@ -11,6 +11,7 @@ subroutine cam_write_restart(dyn_out, yr_spec, mon_spec, day_spec, sec_spec)
     use cam_pio_utils,    only: cam_pio_createfile, cam_pio_set_fill
     use restart_dynamics, only: write_restart_dynamics, init_restart_dynamics
     use restart_physics,  only: restart_physics_write, restart_physics_init
+    use cam_history,      only: history_restart_init
     use cam_instance,     only: inst_suffix
     use pio,              only: file_desc_t, io_desc_t, pio_double, pio_global
     use pio,              only: pio_put_att, pio_enddef, pio_closefile
@@ -63,7 +64,7 @@ subroutine cam_write_restart(dyn_out, yr_spec, mon_spec, day_spec, sec_spec)
     if (errflg /= 0) then
        call endrun(errmsg)
     end if
-    !call init_restart_history(fh)
+    call history_restart_init()
 
     ierr = pio_put_att(fh, pio_global, 'caseid', caseid)
     ierr = pio_enddef(fh)
diff --git a/src/cpl/nuopc/atm_comp_nuopc.F90 b/src/cpl/nuopc/atm_comp_nuopc.F90
index d67b08c4a..6535aaddc 100644
--- a/src/cpl/nuopc/atm_comp_nuopc.F90
+++ b/src/cpl/nuopc/atm_comp_nuopc.F90
@@ -1183,10 +1183,10 @@ subroutine ModelAdvance(gcomp, rc)
        call t_stopf  ('CAM_run3')
 
        call t_startf ('CAM_run4')
-       call cam_run4( rstwr, nlend, &
-            yr_spec=yr_sync, mon_spec=mon_sync, day_spec=day_sync, sec_spec=tod_sync)
+       call cam_run4(rstwr, nlend)
        call t_stopf  ('CAM_run4')
-       call cam_timestep_final(rstwr, nlend, do_ncdata_check=do_ncdata_check)
+       call cam_timestep_final(rstwr, nlend, do_ncdata_check=do_ncdata_check, &
+               yr_spec=yr_sync, mon_spec=mon_sync, day_spec=day_sync, sec_spec=tod_sync)
 
        ! Advance cam time step
 
diff --git a/src/history/cam_hist_file.F90 b/src/history/cam_hist_file.F90
index 15dc06439..902997fa1 100644
--- a/src/history/cam_hist_file.F90
+++ b/src/history/cam_hist_file.F90
@@ -1691,7 +1691,8 @@ end function count_array
    ! ========================================================================
 
    subroutine read_namelist_entry(unitn, hfile_config, hist_inst_fields,      &
-        hist_avg_fields, hist_min_fields, hist_max_fields, hist_var_fields)
+        hist_avg_fields, hist_min_fields, hist_max_fields, hist_var_fields,   &
+        num_fields)
       use mpi,            only: MPI_CHARACTER, MPI_INTEGER, MPI_LOGICAL
       use string_utils,   only: stringify
       use spmd_utils,     only: masterproc, masterprocid, mpicom
@@ -1713,6 +1714,7 @@ subroutine read_namelist_entry(unitn, hfile_config, hist_inst_fields,      &
       character(len=max_fldlen), allocatable, intent(inout) :: hist_min_fields(:)
       character(len=max_fldlen), allocatable, intent(inout) :: hist_max_fields(:)
       character(len=max_fldlen), allocatable, intent(inout) :: hist_var_fields(:)
+      integer,           intent(out)   :: num_fields
       ! Local variables (namelist)
       character(len=vlen) :: hist_volume
       character(len=vlen) :: hist_precision
@@ -1869,6 +1871,8 @@ subroutine read_namelist_entry(unitn, hfile_config, hist_inst_fields,      &
            interp_nlat=hist_interp_nlat, interp_nlon=hist_interp_nlon,        &
            interp_grid=hist_interp_grid, interp_type=hist_interp_type)
       call hfile_config%print_config()
+      num_fields = num_fields_inst + num_fields_avg + num_fields_min + &
+              num_fields_max + num_fields_var
 
    end subroutine read_namelist_entry
 
@@ -1975,7 +1979,7 @@ end subroutine allocate_field_arrays
 
    ! ========================================================================
 
-   subroutine hist_read_namelist_config(filename, config_arr)
+   subroutine hist_read_namelist_config(filename, config_arr, max_fields)
       use mpi,            only: MPI_CHARACTER, MPI_INTEGER
       use shr_kind_mod,   only: max_str =>SHR_KIND_CXX, CM => shr_kind_cm
       use shr_nl_mod,     only: shr_nl_find_group_name
@@ -1989,6 +1993,7 @@ subroutine hist_read_namelist_config(filename, config_arr)
       ! Dummy arguments
       character(len=*), intent(in) :: filename
       type(hist_file_t), allocatable, intent(inout) :: config_arr(:)
+      integer, intent(out) :: max_fields
       ! Local variables
       integer                                :: unitn
       integer                                :: read_status
@@ -1996,6 +2001,7 @@ subroutine hist_read_namelist_config(filename, config_arr)
       integer                                :: line_num
       integer                                :: lindex
       integer                                :: num_configs
+      integer                                :: num_fields
       logical                                :: filefound
       character(len=max_fldlen), allocatable :: hist_inst_fields(:)
       character(len=max_fldlen), allocatable :: hist_avg_fields(:)
@@ -2010,6 +2016,7 @@ subroutine hist_read_namelist_config(filename, config_arr)
       ! Variables for reading a namelist entry
       unitn = -1 ! Prevent reads on error or wrong tasks
       ierr = 0
+      max_fields = 0
 
       errmsg = ''
       if (masterproc) then
@@ -2084,7 +2091,10 @@ subroutine hist_read_namelist_config(filename, config_arr)
          end if
          call read_namelist_entry(unitn, config_arr(lindex),                  &
               hist_inst_fields, hist_avg_fields, hist_min_fields,             &
-              hist_max_fields, hist_var_fields)
+              hist_max_fields, hist_var_fields, num_fields)
+         if (num_fields > max_fields) then
+            max_fields = num_fields
+         end if
       end do
       !
       ! Cleanup
diff --git a/src/history/cam_hist_restart_file.F90 b/src/history/cam_hist_restart_file.F90
new file mode 100644
index 000000000..d0f7effd2
--- /dev/null
+++ b/src/history/cam_hist_restart_file.F90
@@ -0,0 +1,253 @@
+module cam_hist_restart_file
+   use pio,                 only: var_desc_t
+   use cam_history_support, only: max_fieldname_len
+   use shr_kind_mod,        only: r4 => shr_kind_r4
+   use shr_kind_mod,        only: r8 => shr_kind_r8
+
+   implicit none
+   private
+
+   integer, parameter :: max_dimensions = 4
+
+   type restart_variable_t
+      type(var_desc_t), pointer        :: vdesc => null()
+      integer                          :: var_type
+      integer                          :: number_of_dimensions
+      integer                          :: dimension_ids(max_dimensions)
+      character(len=max_fieldname_len) :: var_name
+      logical                          :: fill_set = .false.
+      integer                          :: integer_fill
+      real(r4)                         :: real_fill
+      real(r8)                         :: double_fill
+    end type restart_variable_t
+
+    type restart_dimension_t
+      integer                          :: dimension_length
+      integer                          :: dimension_id
+      character(len=max_fieldname_len) :: dimension_name
+    end type restart_dimension_t
+
+    !
+    !   The size of these parameters should match the assignments in restart_vars_setnames and restart_dims_setnames below
+    !
+    integer, parameter :: num_restart_vars = 24
+    integer, parameter :: num_restart_dims =  9
+    type(restart_variable_t)  :: restart_vars(num_restart_vars)
+    type(restart_dimension_t) :: restart_dims(num_restart_dims)
+
+    integer, parameter :: max_num_fields = 1000
+    integer, parameter :: max_var_mdims  = 1
+
+    integer, parameter :: num_configs_dim_ind        =  1
+    integer, parameter :: max_string_len_dim_ind     =  2
+    integer, parameter :: max_fieldname_len_dim_ind  =  3
+    integer, parameter :: max_num_fields_dim_ind     =  4
+    integer, parameter :: max_chars_dim_ind          =  5
+    integer, parameter :: maxvarmdims_dim_ind        =  6
+    integer, parameter :: registeredmdims_dim_ind    =  7
+    integer, parameter :: max_hcoordname_len_dim_ind =  8
+    integer, parameter :: max_num_split_files_dim_ind    =  9
+
+    public :: set_restart_variable_names
+    public :: set_restart_dimension_names
+
+CONTAINS
+
+   subroutine set_restart_variable_names()
+      use pio, only: pio_int, pio_double, pio_char
+      integer :: rvar_index
+
+      rvar_index = 1
+      restart_vars(rvar_index)%var_name = 'has_rh_file'
+      restart_vars(rvar_index)%var_type = pio_int
+      restart_vars(rvar_index)%number_of_dimensions = 1
+      restart_vars(rvar_index)%dimension_ids(1) = num_configs_dim_ind
+
+      rvar_index = rvar_index + 1
+      restart_vars(rvar_index)%var_name = 'output_frequency'
+      restart_vars(rvar_index)%var_type = pio_char
+      restart_vars(rvar_index)%number_of_dimensions = 2
+      restart_vars(rvar_index)%dimension_ids(1) = max_chars_dim_ind
+      restart_vars(rvar_index)%dimension_ids(2) = num_configs_dim_ind
+
+      rvar_index = rvar_index + 1
+      restart_vars(rvar_index)%var_name = 'number_of_fields'
+      restart_vars(rvar_index)%var_type = pio_int
+      restart_vars(rvar_index)%number_of_dimensions = 1
+      restart_vars(rvar_index)%dimension_ids(1) = num_configs_dim_ind
+
+      rvar_index = rvar_index + 1
+      restart_vars(rvar_index)%var_name = 'num_satellite_columns'
+      restart_vars(rvar_index)%var_type = pio_int
+      restart_vars(rvar_index)%number_of_dimensions = 1
+      restart_vars(rvar_index)%dimension_ids(1) = num_configs_dim_ind
+
+      rvar_index = rvar_index + 1
+      restart_vars(rvar_index)%var_name = 'max_samples'
+      restart_vars(rvar_index)%var_type = pio_int
+      restart_vars(rvar_index)%number_of_dimensions = 1
+      restart_vars(rvar_index)%dimension_ids(1) = num_configs_dim_ind
+
+      rvar_index = rvar_index + 1
+      restart_vars(rvar_index)%var_name = 'current_file_path'
+      restart_vars(rvar_index)%var_type = pio_char
+      restart_vars(rvar_index)%number_of_dimensions = 3
+      restart_vars(rvar_index)%dimension_ids(1) = max_string_len_dim_ind
+      restart_vars(rvar_index)%dimension_ids(2) = num_configs_dim_ind
+      restart_vars(rvar_index)%dimension_ids(3) = max_num_split_files_dim_ind
+
+      rvar_index = rvar_index + 1
+      restart_vars(rvar_index)%var_name = 'current_file_name'
+      restart_vars(rvar_index)%var_type = pio_char
+      restart_vars(rvar_index)%number_of_dimensions = 3
+      restart_vars(rvar_index)%dimension_ids(1) = max_string_len_dim_ind
+      restart_vars(rvar_index)%dimension_ids(2) = num_configs_dim_ind
+      restart_vars(rvar_index)%dimension_ids(3) = max_num_split_files_dim_ind
+
+      rvar_index = rvar_index + 1
+      restart_vars(rvar_index)%var_name = 'precision'
+      restart_vars(rvar_index)%var_type = pio_char
+      restart_vars(rvar_index)%number_of_dimensions = 2
+      restart_vars(rvar_index)%dimension_ids(1) = max_chars_dim_ind
+      restart_vars(rvar_index)%dimension_ids(2) = num_configs_dim_ind
+
+      rvar_index = rvar_index + 1
+      restart_vars(rvar_index)%var_name = 'interval_start_time'
+      restart_vars(rvar_index)%var_type = pio_double
+      restart_vars(rvar_index)%number_of_dimensions = 1
+      restart_vars(rvar_index)%dimension_ids(1) = num_configs_dim_ind
+
+      rvar_index = rvar_index + 1
+      restart_vars(rvar_index)%var_name = 'field_name'
+      restart_vars(rvar_index)%var_type = pio_char
+      restart_vars(rvar_index)%number_of_dimensions = 3
+      restart_vars(rvar_index)%dimension_ids(1) = max_fieldname_len_dim_ind
+      restart_vars(rvar_index)%dimension_ids(2) = max_num_fields_dim_ind
+      restart_vars(rvar_index)%dimension_ids(3) = num_configs_dim_ind
+
+      rvar_index = rvar_index + 1
+      restart_vars(rvar_index)%var_name = 'field_avg_flag'
+      restart_vars(rvar_index)%var_type = pio_char
+      restart_vars(rvar_index)%number_of_dimensions = 3
+      restart_vars(rvar_index)%dimension_ids(1) = max_chars_dim_ind
+      restart_vars(rvar_index)%dimension_ids(2) = max_num_fields_dim_ind
+      restart_vars(rvar_index)%dimension_ids(3) = num_configs_dim_ind
+
+      rvar_index = rvar_index + 1
+      restart_vars(rvar_index)%var_name = 'field_decomposition_type'
+      restart_vars(rvar_index)%var_type = pio_int
+      restart_vars(rvar_index)%number_of_dimensions = 2
+      restart_vars(rvar_index)%dimension_ids(1) = max_num_fields_dim_ind
+      restart_vars(rvar_index)%dimension_ids(2) = num_configs_dim_ind
+      restart_vars(rvar_index)%fill_set = .true.
+      restart_vars(rvar_index)%integer_fill = 0
+
+      rvar_index = rvar_index + 1
+      restart_vars(rvar_index)%var_name = 'field_num_vertical_levels'
+      restart_vars(rvar_index)%var_type = pio_int
+      restart_vars(rvar_index)%number_of_dimensions = 2
+      restart_vars(rvar_index)%dimension_ids(1) = max_num_fields_dim_ind
+      restart_vars(rvar_index)%dimension_ids(2) = num_configs_dim_ind
+      restart_vars(rvar_index)%fill_set = .true.
+      restart_vars(rvar_index)%integer_fill = 0
+
+      rvar_index = rvar_index + 1
+      restart_vars(rvar_index)%var_name = 'history_restart_path'
+      restart_vars(rvar_index)%var_type = pio_char
+      restart_vars(rvar_index)%number_of_dimensions = 2
+      restart_vars(rvar_index)%dimension_ids(1) = max_string_len_dim_ind
+      restart_vars(rvar_index)%dimension_ids(2) = num_configs_dim_ind
+
+      rvar_index = rvar_index + 1
+      restart_vars(rvar_index)%var_name = 'field_cell_methods'
+      restart_vars(rvar_index)%var_type = pio_char
+      restart_vars(rvar_index)%number_of_dimensions = 3
+      restart_vars(rvar_index)%dimension_ids(1) = max_chars_dim_ind
+      restart_vars(rvar_index)%dimension_ids(2) = max_num_fields_dim_ind
+      restart_vars(rvar_index)%dimension_ids(3) = num_configs_dim_ind
+
+      rvar_index = rvar_index + 1
+      restart_vars(rvar_index)%var_name = 'field_long_name'
+      restart_vars(rvar_index)%var_type = pio_char
+      restart_vars(rvar_index)%number_of_dimensions = 3
+      restart_vars(rvar_index)%dimension_ids(1) = max_chars_dim_ind
+      restart_vars(rvar_index)%dimension_ids(2) = max_num_fields_dim_ind
+      restart_vars(rvar_index)%dimension_ids(3) = num_configs_dim_ind
+
+      rvar_index = rvar_index + 1
+      restart_vars(rvar_index)%var_name = 'field_units'
+      restart_vars(rvar_index)%var_type = pio_char
+      restart_vars(rvar_index)%number_of_dimensions = 3
+      restart_vars(rvar_index)%dimension_ids(1) = max_chars_dim_ind
+      restart_vars(rvar_index)%dimension_ids(2) = max_num_fields_dim_ind
+      restart_vars(rvar_index)%dimension_ids(3) = num_configs_dim_ind
+
+      rvar_index = rvar_index + 1
+      restart_vars(rvar_index)%var_name = 'field_fill_flag'
+      restart_vars(rvar_index)%var_type = pio_int
+      restart_vars(rvar_index)%number_of_dimensions = 2
+      restart_vars(rvar_index)%dimension_ids(1) = max_num_fields_dim_ind
+      restart_vars(rvar_index)%dimension_ids(2) = num_configs_dim_ind
+
+      rvar_index = rvar_index + 1
+      restart_vars(rvar_index)%var_name = 'field_fill_value'
+      restart_vars(rvar_index)%var_type = pio_double
+      restart_vars(rvar_index)%number_of_dimensions = 2
+      restart_vars(rvar_index)%dimension_ids(1) = max_num_fields_dim_ind
+      restart_vars(rvar_index)%dimension_ids(2) = num_configs_dim_ind
+      restart_vars(rvar_index)%fill_set = .true.
+      restart_vars(rvar_index)%double_fill = 0.0_r8
+
+      rvar_index = rvar_index + 1
+      restart_vars(rvar_index)%var_name = 'field_mdims'
+      restart_vars(rvar_index)%var_type = pio_int
+      restart_vars(rvar_index)%number_of_dimensions = 3
+      restart_vars(rvar_index)%dimension_ids(1) = maxvarmdims_dim_ind
+      restart_vars(rvar_index)%dimension_ids(2) = max_num_fields_dim_ind
+      restart_vars(rvar_index)%dimension_ids(3) = num_configs_dim_ind
+
+      rvar_index = rvar_index + 1
+      restart_vars(rvar_index)%var_name = 'mdim_names'
+      restart_vars(rvar_index)%var_type = pio_char
+      restart_vars(rvar_index)%number_of_dimensions = 2
+      restart_vars(rvar_index)%dimension_ids(1) = max_hcoordname_len_dim_ind
+      restart_vars(rvar_index)%dimension_ids(2) = registeredmdims_dim_ind
+
+   end subroutine set_restart_variable_names
+
+   subroutine set_restart_dimension_names(num_hist_configs, max_fields)
+      use cam_history_support, only: max_string_len, max_chars, max_fieldname_len, registeredmdims
+      use cam_grid_support,    only: max_hcoordname_len, max_split_files
+      integer, intent(in) :: num_hist_configs
+      integer, intent(in) :: max_fields
+
+      restart_dims(num_configs_dim_ind)%dimension_name = 'number_of_hist_configs'
+      restart_dims(num_configs_dim_ind)%dimension_length = num_hist_configs
+
+      restart_dims(max_string_len_dim_ind)%dimension_name = 'max_string_length'
+      restart_dims(max_string_len_dim_ind)%dimension_length = max_string_len
+
+      restart_dims(max_fieldname_len_dim_ind)%dimension_name = 'max_fieldname_length'
+      restart_dims(max_fieldname_len_dim_ind)%dimension_length = max_fieldname_len
+
+      restart_dims(max_num_fields_dim_ind)%dimension_name = 'max_fields_per_configuration'
+      restart_dims(max_num_fields_dim_ind)%dimension_length = max_fields
+
+      restart_dims(max_chars_dim_ind)%dimension_name = 'max_chars'
+      restart_dims(max_chars_dim_ind)%dimension_length = max_chars
+
+      restart_dims(maxvarmdims_dim_ind)%dimension_name = 'max_variable_mdims'
+      restart_dims(maxvarmdims_dim_ind)%dimension_length = max_var_mdims
+
+      restart_dims(registeredmdims_dim_ind)%dimension_name = 'registered_mdims'
+      restart_dims(registeredmdims_dim_ind)%dimension_length = registeredmdims
+
+      restart_dims(max_hcoordname_len_dim_ind)%dimension_name = 'max_hcoordname_len'
+      restart_dims(max_hcoordname_len_dim_ind)%dimension_length = max_hcoordname_len
+
+      restart_dims(max_num_split_files_dim_ind)%dimension_name = 'max_num_split_files'
+      restart_dims(max_num_split_files_dim_ind)%dimension_length = max_split_files
+
+   end subroutine set_restart_dimension_names
+
+end module cam_hist_restart_file
diff --git a/src/history/cam_history.F90 b/src/history/cam_history.F90
index d96d9c466..be6a09e70 100644
--- a/src/history/cam_history.F90
+++ b/src/history/cam_history.F90
@@ -13,6 +13,7 @@ module cam_history
    use cam_hist_file,        only: hist_file_t
    use hist_field,           only: hist_field_info_t
    use hist_hash_table,      only: hist_hash_table_t
+   use cam_logfile, only: iulog
 
    implicit none
    private
@@ -31,6 +32,7 @@ module cam_history
    public :: history_add_field      ! Write to list of possible history fields for this run
    public :: history_out_field      ! Accumulate field if its in use by one or more tapes
    public :: history_wrap_up        ! Process history files at end of timestep or run
+   public :: history_restart_init   ! Initialize restart files, if necessary
 
    interface history_out_field
       module procedure history_out_field_1d
@@ -48,6 +50,8 @@ module cam_history
    type(hist_field_info_t), pointer :: possible_field_list_head
    type(hist_hash_table_t)          :: possible_field_list
    integer                          :: num_possible_fields
+   logical,           allocatable   :: just_wrote(:)
+   integer                          :: max_num_fields
 
 CONTAINS
 
@@ -57,13 +61,23 @@ subroutine history_readnl(nlfile)
       ! Purpose: Read in history namelist and set hist_configs
       !
       !-----------------------------------------------------------------------
-      use cam_hist_file, only: hist_read_namelist_config
+      use cam_hist_file,  only: hist_read_namelist_config
+      use cam_abortutils, only: endrun
 
       ! Dummy argument
       character(len=*), intent(in) :: nlfile ! path of namelist input file
+      integer :: ierr
+      character(len=256) :: alloc_errmsg
+      character(len=512) :: errmsg
 
       ! Read in CAM history configuration
-      call hist_read_namelist_config(nlfile, hist_configs)
+      call hist_read_namelist_config(nlfile, hist_configs, max_num_fields)
+      allocate(just_wrote(size(hist_configs)), stat=ierr, errmsg=alloc_errmsg)
+      if (ierr /= 0) then
+         write(errmsg,*) 'history_readnl: failed to allocate hist_configs; errmsg = ', alloc_errmsg
+         call endrun(errmsg)
+      end if
+      just_wrote = .false.
 
    end subroutine history_readnl
 
@@ -111,6 +125,8 @@ subroutine history_write_files()
       ! peverwhee - TODO: remove when restarts are implemented
       restart = .false.
 
+      just_wrote = .false.
+
       ! Loop over history volumes
       do file_idx = 1, size(hist_configs)
          ! Determine if it's time to write!
@@ -211,6 +227,7 @@ subroutine history_write_files()
             call hist_configs(file_idx)%define_file(restart, logname, host, model_doi_url)
          end if
          call hist_configs(file_idx)%write_time_dependent_variables(restart)
+         just_wrote(file_idx) = .true.
       end do
 
    end subroutine history_write_files
@@ -850,6 +867,18 @@ subroutine history_wrap_up(restart_write, last_timestep)
 
    end subroutine history_wrap_up
 
+!#######################################################################
+
+   subroutine history_restart_init()
+      use cam_hist_restart_file, only: set_restart_variable_names, set_restart_dimension_names
+      ! Local variables
+      write(iulog,*) 'peverwhee - which have we just written'
+      write(iulog,*) just_wrote
+      write(iulog,*) max_num_fields
+      call set_restart_variable_names()
+      call set_restart_dimension_names(size(hist_configs), max_num_fields)
+   end subroutine history_restart_init
+
 !#######################################################################
 
    recursive function get_entry_by_name(listentry, name) result(entry)
diff --git a/src/history/cam_history_support.F90 b/src/history/cam_history_support.F90
index c5a26d148..178e43269 100644
--- a/src/history/cam_history_support.F90
+++ b/src/history/cam_history_support.F90
@@ -17,13 +17,13 @@ module cam_history_support
    integer, parameter, public :: fieldname_len = 32              ! max chars for field name
    integer, parameter, public :: fieldname_suffix_len =  3       ! length of field name suffix ("&IC")
    ! max_fieldname_len = max chars for field name (including suffix)
-   integer, parameter, public :: max_fieldname_len    = fieldname_len + fieldname_suffix_len
+   integer, parameter, public :: max_fieldname_len = fieldname_len + fieldname_suffix_len
    ! default fill value for history NetCDF fields
    real(r8), parameter, public :: hist_default_fillvalue = 1.e36_r8
-   integer,  parameter, public :: pfiles = 12        ! max number of tapes
+   integer,  parameter, public :: pfiles = 12             ! max number of history configurations
    integer, parameter, public :: max_chars = shr_kind_cl  ! max chars for char variables
    integer, parameter, public :: max_string_len = shr_kind_cxx
-   real(r8), parameter, public :: fillvalue = 1.e36_r8     ! fill value for netcdf fields
+   real(r8), parameter, public :: fillvalue = 1.e36_r8    ! default fill value for netcdf fields
    ! A special symbol for declaring a field which has no vertical or
    ! non-grid dimensions. It is here (rather than cam_history) so that it
    ! can be checked by add_hist_coord

From 255b9cc88644d5d40196c2a1dda2178b423a62d4 Mon Sep 17 00:00:00 2001
From: peverwhee <courtneyp@ucar.edu>
Date: Mon, 11 May 2026 20:01:27 -0600
Subject: [PATCH 12/19] most of .r. history fields

---
 src/control/cam_restart.F90           |   5 +-
 src/history/cam_hist_file.F90         | 257 ++++++++++++++-
 src/history/cam_hist_restart.F90      | 429 ++++++++++++++++++++++++++
 src/history/cam_hist_restart_file.F90 | 253 ---------------
 src/history/cam_history.F90           |  38 ++-
 src/history/cam_history_support.F90   |  20 ++
 6 files changed, 737 insertions(+), 265 deletions(-)
 create mode 100644 src/history/cam_hist_restart.F90
 delete mode 100644 src/history/cam_hist_restart_file.F90

diff --git a/src/control/cam_restart.F90 b/src/control/cam_restart.F90
index 137fb1b9d..81858720b 100644
--- a/src/control/cam_restart.F90
+++ b/src/control/cam_restart.F90
@@ -11,7 +11,7 @@ subroutine cam_write_restart(dyn_out, yr_spec, mon_spec, day_spec, sec_spec)
     use cam_pio_utils,    only: cam_pio_createfile, cam_pio_set_fill
     use restart_dynamics, only: write_restart_dynamics, init_restart_dynamics
     use restart_physics,  only: restart_physics_write, restart_physics_init
-    use cam_history,      only: history_restart_init
+    use cam_history,      only: history_restart_init, history_restart_write
     use cam_instance,     only: inst_suffix
     use pio,              only: file_desc_t, io_desc_t, pio_double, pio_global
     use pio,              only: pio_put_att, pio_enddef, pio_closefile
@@ -64,7 +64,7 @@ subroutine cam_write_restart(dyn_out, yr_spec, mon_spec, day_spec, sec_spec)
     if (errflg /= 0) then
        call endrun(errmsg)
     end if
-    call history_restart_init()
+    call history_restart_init(fh)
 
     ierr = pio_put_att(fh, pio_global, 'caseid', caseid)
     ierr = pio_enddef(fh)
@@ -84,6 +84,7 @@ subroutine cam_write_restart(dyn_out, yr_spec, mon_spec, day_spec, sec_spec)
 
 !    call write_restart_history(fh, yr_spec=yr_spec, mon_spec=mon_spec, &
 !            day_spec=day_spec, sec_spec= sec_spec )
+    call history_restart_write(fh)
 
     ! Close the primary restart file
     call pio_closefile(fh)
diff --git a/src/history/cam_hist_file.F90 b/src/history/cam_hist_file.F90
index 902997fa1..a60f57ac4 100644
--- a/src/history/cam_hist_file.F90
+++ b/src/history/cam_hist_file.F90
@@ -14,6 +14,7 @@ module cam_hist_file
    use runtime_obj,         only: UNSET_I => unset_int
    use runtime_obj,         only: UNSET_C => unset_str
    use runtime_obj,         only: UNSET_R8 => unset_real
+   use cam_logfile, only: iulog
 
    implicit none
    private
@@ -101,6 +102,18 @@ module cam_hist_file
       procedure :: max_frame => config_max_frame
       procedure :: get_num_samples => config_get_num_samples
       procedure :: get_beg_time => config_get_beg_time
+      procedure :: get_field_list => config_get_field_list
+      procedure :: get_averaging_flags => config_get_averaging_flags
+      procedure :: get_decompositions => config_get_decompositions
+      procedure :: get_num_levels => config_get_num_levels
+      procedure :: get_cell_methods => config_get_cell_methods
+      procedure :: get_long_names => config_get_long_names
+      procedure :: get_units => config_get_units
+      procedure :: get_fill_flags => config_get_fill_flags
+      procedure :: get_fill_values => config_get_fill_values
+      procedure :: get_dimension_indices => config_get_dimension_indices
+      procedure :: get_num_dimensions => config_get_num_dimensions
+      procedure :: get_num_fields => config_get_num_fields
       procedure :: output_freq => config_output_freq
       procedure :: output_freq_separate => config_output_freq_separate
       procedure :: is_history_file => config_history_file
@@ -110,6 +123,7 @@ module cam_hist_file
       procedure :: do_write_nstep0 => config_do_write_nstep0
       procedure :: file_is_setup => config_file_is_setup
       procedure :: are_files_open => config_files_open
+      procedure :: has_accumulated_fields => config_has_accumulated_fields
       ! Actions
       procedure :: reset        => config_reset
       procedure :: configure    => config_configure
@@ -314,6 +328,238 @@ end function config_get_beg_time
 
    ! ========================================================================
 
+   function config_get_field_list(this) result(field_list)
+      use cam_abortutils, only: endrun
+      ! Dummy arguments
+      class(hist_file_t), intent(in) :: this
+      character(len=max_fldlen), allocatable :: field_list(:)
+      ! Local variables
+      character(len=512) :: errmsg
+      integer :: ierr, idx
+
+      allocate(field_list(size(this%field_list)), stat=ierr, errmsg=errmsg)
+      if (ierr /= 0) then
+         call endrun('config_get_field_list: failed to allocate field_list; errmsg = '//errmsg)
+      end if
+      do idx = 1, size(this%field_list)
+         field_list(idx) = this%field_list(idx)%diag_name()
+      end do
+
+   end function config_get_field_list
+
+   ! ========================================================================
+
+   function config_get_averaging_flags(this) result(avgflags)
+      use cam_abortutils, only: endrun
+      use cam_history_support, only: max_chars
+      ! Dummy arguments
+      class(hist_file_t), intent(in) :: this
+      character(len=max_chars), allocatable :: avgflags(:)
+      ! Local variables
+      character(len=512) :: errmsg
+      integer :: ierr, idx
+
+      allocate(avgflags(size(this%field_list)), stat=ierr, errmsg=errmsg)
+      if (ierr /= 0) then
+         call endrun('config_get_averaging_flags: failed to allocate avgflags; errmsg = '//errmsg)
+      end if
+      do idx = 1, size(this%field_list)
+         avgflags(idx) = this%field_list(idx)%accumulate_type()
+      end do
+   end function config_get_averaging_flags
+
+   ! ========================================================================
+
+   function config_get_decompositions(this) result(decomps)
+      use cam_abortutils, only: endrun
+      ! Dummy arguments
+      class(hist_file_t), intent(in) :: this
+      integer,           allocatable :: decomps(:)
+      ! Local variables
+      character(len=512) :: errmsg
+      integer :: ierr, idx
+      allocate(decomps(size(this%field_list)), stat=ierr, errmsg=errmsg)
+      if (ierr /= 0) then
+         call endrun('config_get_decompositions: failed to allocate decomps; errmsg = '//errmsg)
+      end if
+      do idx = 1, size(this%field_list)
+         decomps(idx) = this%field_list(idx)%decomp()
+      end do
+   end function config_get_decompositions
+
+   ! ========================================================================
+
+   function config_get_num_levels(this) result(numlevs)
+      use cam_abortutils, only: endrun
+      ! Dummy arguments
+      class(hist_file_t), intent(in) :: this
+      integer,           allocatable :: numlevs(:)
+      ! Local variables
+      character(len=512) :: errmsg
+      integer :: ierr, idx
+      allocate(numlevs(size(this%field_list)), stat=ierr, errmsg=errmsg)
+      if (ierr /= 0) then
+         call endrun('config_get_num_levels: failed to allocate numlevs; errmsg = '//errmsg)
+      end if
+      do idx = 1, size(this%field_list)
+         numlevs(idx) = this%field_list(idx)%num_levels()
+      end do
+   end function config_get_num_levels
+
+   ! ========================================================================
+
+   function config_get_cell_methods(this) result(cell_methods)
+      use cam_abortutils, only: endrun
+      use cam_history_support, only: max_chars
+      ! Dummy arguments
+      class(hist_file_t), intent(in) :: this
+      character(len=max_chars), allocatable :: cell_methods(:)
+      ! Local variables
+      character(len=512) :: errmsg
+      integer :: ierr, idx
+      allocate(cell_methods(size(this%field_list)), stat=ierr, errmsg=errmsg)
+      if (ierr /= 0) then
+         call endrun('config_get_cell_methods: failed to allocate cell_methods; errmsg = '//errmsg)
+      end if
+      do idx = 1, size(this%field_list)
+         cell_methods(idx) = this%field_list(idx)%cell_methods()
+      end do
+   end function config_get_cell_methods
+
+   ! ========================================================================
+
+   function config_get_long_names(this) result(long_names)
+      use cam_abortutils, only: endrun
+      use cam_history_support, only: max_chars
+      ! Dummy arguments
+      class(hist_file_t), intent(in) :: this
+      character(len=max_chars), allocatable :: long_names(:)
+      ! Local variables
+      character(len=512) :: errmsg
+      integer :: idx, ierr
+      allocate(long_names(size(this%field_list)), stat=ierr, errmsg=errmsg)
+      if (ierr /= 0) then
+         call endrun('config_get_long_names: failed to allocate long_names; errmsg = '//errmsg)
+      end if
+      do idx = 1, size(this%field_list)
+         long_names(idx) = this%field_list(idx)%long_name()
+      end do
+   end function config_get_long_names
+
+   ! ========================================================================
+
+   function config_get_units(this) result(units)
+      use cam_abortutils, only: endrun
+      use cam_history_support, only: max_chars
+      ! Dummy arguments
+      class(hist_file_t), intent(in) :: this
+      character(len=max_chars), allocatable :: units(:)
+      ! Local variables
+      character(len=512) :: errmsg
+      integer :: idx, ierr
+      allocate(units(size(this%field_list)), stat=ierr, errmsg=errmsg)
+      if (ierr /= 0) then
+         call endrun('config_get_units: failed to allocate units; errmsg = '//errmsg)
+      end if
+      do idx = 1, size(this%field_list)
+         units(idx) = this%field_list(idx)%units()
+      end do
+   end function config_get_units
+
+   ! ========================================================================
+
+   function config_get_fill_flags(this) result(flags)
+      use cam_abortutils, only: endrun
+      ! Dummy arguments
+      class(hist_file_t), intent(in) :: this
+      integer,           allocatable :: flags(:)
+      ! Local variables
+      character(len=512) :: errmsg
+      integer :: idx, ierr
+      allocate(flags(size(this%field_list)), stat=ierr, errmsg=errmsg)
+      if (ierr /= 0) then
+         call endrun('config_get_fill_flags: failed to allocate flags; errmsg = '//errmsg)
+      end if
+      flags = 0
+      do idx = 1, size(this%field_list)
+         if (this%field_list(idx)%flag_xyfill()) then
+            flags(idx) = 1
+         end if
+      end do
+   end function config_get_fill_flags
+
+   ! ========================================================================
+
+   function config_get_fill_values(this) result(fill_values)
+      use cam_abortutils, only: endrun
+      ! Dummy arguments
+      class(hist_file_t), intent(in) :: this
+      real(r8),          allocatable :: fill_values(:)
+      ! Local variables
+      character(len=512) :: errmsg
+      integer :: idx, ierr
+      allocate(fill_values(size(this%field_list)), stat=ierr, errmsg=errmsg)
+      if (ierr /= 0) then
+         call endrun('config_get_fill_values: failed to allocate fill_values; errmsg = '//errmsg)
+      end if
+!      do idx = 1, size(this%field_list)
+!         fill_values(idx) = this%field_list(idx)%fill_value()
+!      end do
+      fill_values = 0._r8
+   end function config_get_fill_values
+
+   ! ========================================================================
+
+   function config_get_dimension_indices(this) result(dimids)
+      use cam_abortutils, only: endrun
+      ! Dummy arguments
+      class(hist_file_t), intent(in) :: this
+      integer,           allocatable :: dimids(:,:)
+      ! Local variables
+      character(len=512) :: errmsg
+      integer :: idx, ierr
+      allocate(dimids(4, size(this%field_list)), stat=ierr, errmsg=errmsg)
+      if (ierr /= 0) then
+         call endrun('config_get_dimension_indices: failed to allocate dimids; errmsg = '//errmsg)
+      end if
+      dimids = 0
+      do idx = 1, size(this%field_list)
+         if (size(this%field_list(idx)%dimensions()) > 0) then
+            dimids(1:size(this%field_list(idx)%dimensions()), idx) = this%field_list(idx)%dimensions()
+         end if
+      end do
+   end function config_get_dimension_indices
+
+   ! ========================================================================
+
+   function config_get_num_dimensions(this) result (ndims)
+      use cam_abortutils, only: endrun
+      class(hist_file_t), intent(in) :: this
+      integer,           allocatable :: ndims(:)
+      ! Local variables
+      character(len=512) :: errmsg
+      integer :: ierr, idx
+
+      allocate(ndims(size(this%field_list)), stat=ierr, errmsg=errmsg)
+      if (ierr /= 0) then
+         call endrun('config_get_num_dimensions: failed to allocate ndims; errmsg = '//errmsg)
+      end if
+      do idx = 1, size(this%field_list)
+         ndims(idx) = size(this%field_list(idx)%dimensions())
+      end do
+   end function config_get_num_dimensions
+
+   ! ========================================================================
+
+   pure function config_get_num_fields(this) result(nflds)
+      class(hist_file_t), intent(in)  :: this
+      integer                         :: nflds
+
+      nflds = size(this%field_list)
+      
+   end function config_get_num_fields
+   ! ========================================================================
+
    function config_output_freq(this) result(out_freq)
       use shr_kind_mod,   only: CS => SHR_KIND_CS
       use shr_string_mod, only: to_lower => shr_string_toLower
@@ -432,6 +678,16 @@ end function config_files_open
 
    ! ========================================================================
 
+   pure function config_has_accumulated_fields(this) result(has_accum)
+      ! Dummy arguments
+      class(hist_file_t), intent(in) :: this
+      logical                        :: has_accum
+
+      has_accum = this%has_accumulated
+   end function config_has_accumulated_fields
+
+   ! ========================================================================
+
    subroutine config_reset(this)
       ! Dummy argument
       class(hist_file_t), intent(inout) :: this
@@ -762,7 +1018,6 @@ subroutine config_set_up_fields(this, possible_field_list)
             write(errmsg,'(3a)') 'ERROR Field : ',trim(this%field_names(idx)),' not available'
             call endrun(subname//errmsg, file=__FILE__, line=__LINE__)
          end select
-         !call field_ptr%dimensions(dimensions)
          dimensions = field_ptr%dimensions()
          field_shape = field_ptr%shape()
          beg_dim = field_ptr%beg_dims()
diff --git a/src/history/cam_hist_restart.F90 b/src/history/cam_hist_restart.F90
new file mode 100644
index 000000000..e21c5a306
--- /dev/null
+++ b/src/history/cam_hist_restart.F90
@@ -0,0 +1,429 @@
+module cam_hist_restart
+   use pio,                 only: var_desc_t
+   use cam_history_support, only: max_fieldname_len
+   use shr_kind_mod,        only: r4 => shr_kind_r4
+   use shr_kind_mod,        only: r8 => shr_kind_r8
+   use cam_logfile,         only: iulog
+
+   implicit none
+   private
+
+   integer, parameter :: max_dimensions = 4
+
+   type restart_variable_t
+      type(var_desc_t), pointer        :: vdesc => null()
+      integer                          :: var_type
+      integer                          :: number_of_dimensions
+      integer                          :: dimension_ids(max_dimensions)
+      character(len=max_fieldname_len) :: var_name
+      logical                          :: fill_set = .false.
+      integer                          :: integer_fill
+      real(r4)                         :: real_fill
+      real(r8)                         :: double_fill
+    end type restart_variable_t
+
+    type restart_dimension_t
+      integer                          :: dimension_length
+      integer                          :: dimension_id
+      character(len=max_fieldname_len) :: dimension_name
+    end type restart_dimension_t
+
+    !
+    !   The size of these parameters should match the assignments in restart_vars_setnames and restart_dims_setnames below
+    !
+    integer, parameter :: num_restart_vars = 20
+    integer, parameter :: num_restart_dims =  9
+    type(restart_variable_t)  :: restart_vars(num_restart_vars)
+    type(restart_dimension_t) :: restart_dims(num_restart_dims)
+
+    integer, parameter :: max_num_fields = 1000
+
+    integer, parameter :: num_configs_dim_ind         =  1
+    integer, parameter :: max_string_len_dim_ind      =  2
+    integer, parameter :: max_fieldname_len_dim_ind   =  3
+    integer, parameter :: max_num_fields_dim_ind      =  4
+    integer, parameter :: max_chars_dim_ind           =  5
+    integer, parameter :: max_dims_dim_ind            =  6
+    integer, parameter :: registeredmdims_dim_ind     =  7
+    integer, parameter :: max_hcoordname_len_dim_ind  =  8
+    integer, parameter :: max_num_split_files_dim_ind =  9
+
+    private :: set_restart_variable_names
+    private :: set_restart_dimension_names
+
+    public :: hist_restart_init
+    public :: hist_restart_write
+
+CONTAINS
+
+   subroutine hist_restart_init(restart_file, num_hist_configs, max_fields)
+      use pio,           only: file_desc_t, pio_def_var
+      use cam_pio_utils, only: cam_pio_handle_error, cam_pio_def_dim
+      type(file_desc_t), intent(inout) :: restart_file
+      integer,           intent(in)    :: num_hist_configs
+      integer,           intent(in)    :: max_fields
+
+      ! Local variables
+      integer :: idx, ndims, kdx, ierr
+      integer :: dimids(4)
+
+      ! Set the restart dimensions and variables for writing to the file
+      call set_restart_variable_names()
+      call set_restart_dimension_names(num_hist_configs, max_fields)
+
+      do idx = 1, num_restart_dims
+        ! it's possible that one or more of these have been defined elsewhere
+        call cam_pio_def_dim(restart_file, restart_dims(idx)%dimension_name, restart_dims(idx)%dimension_length, &
+             restart_dims(idx)%dimension_id, existOK=.true.)
+      end do
+
+      do idx = 1, num_restart_vars
+        ndims= restart_vars(idx)%number_of_dimensions
+        do kdx = 1, ndims
+          dimids(kdx)=restart_dims(restart_vars(idx)%dimension_ids(kdx))%dimension_id
+        end do
+        allocate(restart_vars(idx)%vdesc)
+        ierr = pio_def_var(restart_file, restart_vars(idx)%var_name, restart_vars(idx)%var_type, dimids(1:ndims), restart_vars(idx)%vdesc)
+        call cam_pio_handle_error(ierr, 'INIT_RESTART_HISTORY: Error defining '//trim(restart_vars(idx)%var_name))
+      end do
+
+   end subroutine hist_restart_init
+
+   subroutine hist_restart_write(restart_file, hist_configs, max_num_fields, just_written)
+      use pio,                 only: file_desc_t, pio_put_var
+      use cam_hist_file,       only: hist_file_t
+      use cam_history_support, only: max_chars, max_string_len, get_hist_coord_names
+      use cam_grid_support,    only: max_split_files, max_hcoordname_len
+      use cam_abortutils,      only: endrun
+      type(file_desc_t), intent(inout) :: restart_file
+      type(hist_file_t), intent(in)    :: hist_configs(:)
+      integer,           intent(in)    :: max_num_fields
+      logical,           intent(in)    :: just_written(:)
+
+      ! Local variables
+      integer :: idx, jdx, ierr
+      integer :: has_rh_int(size(hist_configs))
+      integer :: num_fields(size(hist_configs))
+      integer :: num_frames(size(hist_configs))
+      integer :: max_frames(size(hist_configs))
+      integer :: ndims(max_num_fields)
+      integer :: decomp(max_num_fields, size(hist_configs))
+      integer :: num_levels(max_num_fields, size(hist_configs))
+      integer :: fill_flag(max_num_fields, size(hist_configs))
+      integer :: dimensions(max_dimensions, max_num_fields, size(hist_configs))
+      character(len=max_fieldname_len) :: field_list(max_num_fields, size(hist_configs))
+      character(len=max_fieldname_len), allocatable :: field_list_config(:)
+      character(len=max_chars) :: output_freq(size(hist_configs))
+      character(len=max_string_len) :: current_files(size(hist_configs), max_split_files)
+      character(len=max_chars) :: hist_precision(size(hist_configs))
+      character(len=max_chars) :: avg_flag(max_num_fields, size(hist_configs))
+      character(len=max_chars) :: long_name(max_num_fields, size(hist_configs))
+      character(len=max_chars) :: cell_methods(max_num_fields, size(hist_configs))
+      character(len=max_chars) :: units(max_num_fields, size(hist_configs))
+      character(len=max_hcoordname_len) :: dim_names(max_dimensions)
+      real(r8) :: beg_time(size(hist_configs))
+      real(r8) :: fill_value(max_num_fields, size(hist_configs))
+      logical :: has_accum
+
+      field_list = ''
+      has_rh_int = 0
+      avg_flag = ''
+      decomp = 0
+      num_levels = 0
+      cell_methods = ''
+      long_name = ''
+      units = ''
+      fill_flag = 0
+      fill_value = 0
+      dimensions = 0
+      ! Compile all the necessary info for the restart file from the hist_configs array
+      do idx = 1, size(hist_configs)
+          ! Grab the field list
+          field_list_config = hist_configs(idx)%get_field_list()
+          num_fields(idx) = hist_configs(idx)%get_num_fields()
+          field_list(1:num_fields(idx), idx) = field_list_config(1:num_fields(idx))
+          ! Determine whether or not there will be an rh file
+          if (hist_configs(idx)%has_accumulated_fields() .and. .not. just_written(idx)) then
+             has_rh_int(idx) = 1
+          end if
+          ! Get the output frequency
+          output_freq(idx) = hist_configs(idx)%output_freq()
+          ! Get the number of samples written to the hist file
+          num_frames(idx) = hist_configs(idx)%get_num_samples()
+          ! Get the maximum number of samples written to the hist file
+          max_frames(idx) = hist_configs(idx)%max_frame()
+          ! Get the file names
+          current_files(idx,:) = hist_configs(idx)%get_filenames()
+          ! Get the precision
+          hist_precision(idx) = hist_configs(idx)%precision()
+          ! Get the interval start time
+          beg_time(idx) = hist_configs(idx)%get_beg_time()
+          ! Get field-specific info vv
+          ! Get accumulated flags for each field
+          avg_flag(1:num_fields(idx), idx) = hist_configs(idx)%get_averaging_flags()
+          ! Get field decompositions
+          decomp(1:num_fields(idx), idx) = hist_configs(idx)%get_decompositions()
+          ! Get num vertical levels
+          num_levels(1:num_fields(idx), idx) = hist_configs(idx)%get_num_levels()
+          ! Get cell methods
+          cell_methods(1:num_fields(idx), idx) = hist_configs(idx)%get_cell_methods()
+          ! Get long names
+          long_name(1:num_fields(idx), idx) = hist_configs(idx)%get_long_names()
+          ! Get units
+          units(1:num_fields(idx), idx) = hist_configs(idx)%get_units()
+          ! Get fill value flag and fill value
+          fill_flag(1:num_fields(idx), idx) = hist_configs(idx)%get_fill_flags()
+          fill_value(1:num_fields(idx), idx) = hist_configs(idx)%get_fill_values()
+          ! Get field dimension indices
+          ndims(1:num_fields(idx)) = hist_configs(idx)%get_num_dimensions()
+          do jdx = 1, num_fields(idx)
+             dimensions(1:ndims(jdx), 1:num_fields(idx), idx) = hist_configs(idx)%get_dimension_indices()
+          end do
+          ! End field specific info ^^
+      end do
+
+      ! Grab the dimension names
+      dim_names = get_hist_coord_names()
+      write(iulog,*) 'peverwhee - dim_names'
+      write(iulog,*) dim_names
+
+      ! Loop over the restart vars and write them to the file
+      do idx = 1, num_restart_vars
+         select case(trim(restart_vars(idx)%var_name))
+         case ('has_rh_file')
+            ierr = pio_put_var(restart_file, restart_vars(idx)%vdesc, has_rh_int)            
+         case ('output_frequency')
+            ierr = pio_put_var(restart_file, restart_vars(idx)%vdesc, output_freq)
+         case ('field_list')
+            ierr = pio_put_var(restart_file, restart_vars(idx)%vdesc, field_list)
+         case ('number_of_fields')
+            ierr = pio_put_var(restart_file, restart_vars(idx)%vdesc, num_fields)
+         case ('number_of_frames')
+            ierr = pio_put_var(restart_file, restart_vars(idx)%vdesc, num_frames)
+         case ('max_frames')
+            ierr = pio_put_var(restart_file, restart_vars(idx)%vdesc, max_frames)
+         case ('current_file_name')
+            ierr = pio_put_var(restart_file, restart_vars(idx)%vdesc, current_files)
+         case ('precision')
+            ierr = pio_put_var(restart_file, restart_vars(idx)%vdesc, hist_precision)
+         case ('interval_start_time')
+            ierr = pio_put_var(restart_file, restart_vars(idx)%vdesc, beg_time)
+         case ('field_average_flag')
+            ierr = pio_put_var(restart_file, restart_vars(idx)%vdesc, avg_flag)
+         case ('field_decomposition_type')
+            ierr = pio_put_var(restart_file, restart_vars(idx)%vdesc, decomp)
+         case ('field_num_vertical_levels')
+            ierr = pio_put_var(restart_file, restart_vars(idx)%vdesc, num_levels)
+         case ('field_cell_methods')
+            ierr = pio_put_var(restart_file, restart_vars(idx)%vdesc, cell_methods)
+         case ('field_long_name')
+            ierr = pio_put_var(restart_file, restart_vars(idx)%vdesc, long_name)
+         case ('field_units')
+            ierr = pio_put_var(restart_file, restart_vars(idx)%vdesc, units)
+         case ('field_fill_flag')
+            ierr = pio_put_var(restart_file, restart_vars(idx)%vdesc, fill_flag)
+         case ('field_fill_value')
+            ierr = pio_put_var(restart_file, restart_vars(idx)%vdesc, fill_value)
+         case ('field_dimensions')
+            ierr = pio_put_var(restart_file, restart_vars(idx)%vdesc, dimensions)
+         case ('dimension_names')
+            ierr = pio_put_var(restart_file, restart_vars(idx)%vdesc, dim_names)
+         case ('history_restart_path')
+         case default
+         end select
+         if (ierr /= 0) then
+            call endrun('hist_restart_write: failed to write variable '//restart_vars(idx)%var_name)
+         end if
+      end do
+   end subroutine hist_restart_write
+
+   subroutine set_restart_variable_names()
+      use pio, only: pio_int, pio_double, pio_char
+      integer :: rvar_index
+
+      rvar_index = 1
+      restart_vars(rvar_index)%var_name = 'has_rh_file'
+      restart_vars(rvar_index)%var_type = pio_int
+      restart_vars(rvar_index)%number_of_dimensions = 1
+      restart_vars(rvar_index)%dimension_ids(1) = num_configs_dim_ind
+
+      rvar_index = rvar_index + 1
+      restart_vars(rvar_index)%var_name = 'output_frequency'
+      restart_vars(rvar_index)%var_type = pio_char
+      restart_vars(rvar_index)%number_of_dimensions = 2
+      restart_vars(rvar_index)%dimension_ids(1) = max_chars_dim_ind
+      restart_vars(rvar_index)%dimension_ids(2) = num_configs_dim_ind
+
+      rvar_index = rvar_index + 1
+      restart_vars(rvar_index)%var_name = 'field_list'
+      restart_vars(rvar_index)%var_type = pio_char
+      restart_vars(rvar_index)%number_of_dimensions = 3
+      restart_vars(rvar_index)%dimension_ids(1) = max_fieldname_len_dim_ind
+      restart_vars(rvar_index)%dimension_ids(2) = max_num_fields_dim_ind
+      restart_vars(rvar_index)%dimension_ids(3) = num_configs_dim_ind
+
+      rvar_index = rvar_index + 1
+      restart_vars(rvar_index)%var_name = 'number_of_fields'
+      restart_vars(rvar_index)%var_type = pio_int
+      restart_vars(rvar_index)%number_of_dimensions = 1
+      restart_vars(rvar_index)%dimension_ids(1) = num_configs_dim_ind
+
+      rvar_index = rvar_index + 1
+      restart_vars(rvar_index)%var_name = 'number_of_frames'
+      restart_vars(rvar_index)%var_type = pio_int
+      restart_vars(rvar_index)%number_of_dimensions = 1
+      restart_vars(rvar_index)%dimension_ids(1) = num_configs_dim_ind
+
+      rvar_index = rvar_index + 1
+      restart_vars(rvar_index)%var_name = 'max_frames'
+      restart_vars(rvar_index)%var_type = pio_int
+      restart_vars(rvar_index)%number_of_dimensions = 1
+      restart_vars(rvar_index)%dimension_ids(1) = num_configs_dim_ind
+
+      rvar_index = rvar_index + 1
+      restart_vars(rvar_index)%var_name = 'current_file_name'
+      restart_vars(rvar_index)%var_type = pio_char
+      restart_vars(rvar_index)%number_of_dimensions = 3
+      restart_vars(rvar_index)%dimension_ids(1) = max_string_len_dim_ind
+      restart_vars(rvar_index)%dimension_ids(2) = num_configs_dim_ind
+      restart_vars(rvar_index)%dimension_ids(3) = max_num_split_files_dim_ind
+
+      rvar_index = rvar_index + 1
+      restart_vars(rvar_index)%var_name = 'precision'
+      restart_vars(rvar_index)%var_type = pio_char
+      restart_vars(rvar_index)%number_of_dimensions = 2
+      restart_vars(rvar_index)%dimension_ids(1) = max_chars_dim_ind
+      restart_vars(rvar_index)%dimension_ids(2) = num_configs_dim_ind
+
+      rvar_index = rvar_index + 1
+      restart_vars(rvar_index)%var_name = 'interval_start_time'
+      restart_vars(rvar_index)%var_type = pio_double
+      restart_vars(rvar_index)%number_of_dimensions = 1
+      restart_vars(rvar_index)%dimension_ids(1) = num_configs_dim_ind
+
+      rvar_index = rvar_index + 1
+      restart_vars(rvar_index)%var_name = 'field_average_flag'
+      restart_vars(rvar_index)%var_type = pio_char
+      restart_vars(rvar_index)%number_of_dimensions = 3
+      restart_vars(rvar_index)%dimension_ids(1) = max_chars_dim_ind
+      restart_vars(rvar_index)%dimension_ids(2) = max_num_fields_dim_ind
+      restart_vars(rvar_index)%dimension_ids(3) = num_configs_dim_ind
+
+      rvar_index = rvar_index + 1
+      restart_vars(rvar_index)%var_name = 'field_decomposition_type'
+      restart_vars(rvar_index)%var_type = pio_int
+      restart_vars(rvar_index)%number_of_dimensions = 2
+      restart_vars(rvar_index)%dimension_ids(1) = max_num_fields_dim_ind
+      restart_vars(rvar_index)%dimension_ids(2) = num_configs_dim_ind
+      restart_vars(rvar_index)%fill_set = .true.
+      restart_vars(rvar_index)%integer_fill = 0
+
+      rvar_index = rvar_index + 1
+      restart_vars(rvar_index)%var_name = 'field_num_vertical_levels'
+      restart_vars(rvar_index)%var_type = pio_int
+      restart_vars(rvar_index)%number_of_dimensions = 2
+      restart_vars(rvar_index)%dimension_ids(1) = max_num_fields_dim_ind
+      restart_vars(rvar_index)%dimension_ids(2) = num_configs_dim_ind
+      restart_vars(rvar_index)%fill_set = .true.
+      restart_vars(rvar_index)%integer_fill = 0
+
+      rvar_index = rvar_index + 1
+      restart_vars(rvar_index)%var_name = 'field_cell_methods'
+      restart_vars(rvar_index)%var_type = pio_char
+      restart_vars(rvar_index)%number_of_dimensions = 3
+      restart_vars(rvar_index)%dimension_ids(1) = max_chars_dim_ind
+      restart_vars(rvar_index)%dimension_ids(2) = max_num_fields_dim_ind
+      restart_vars(rvar_index)%dimension_ids(3) = num_configs_dim_ind
+
+      rvar_index = rvar_index + 1
+      restart_vars(rvar_index)%var_name = 'field_long_name'
+      restart_vars(rvar_index)%var_type = pio_char
+      restart_vars(rvar_index)%number_of_dimensions = 3
+      restart_vars(rvar_index)%dimension_ids(1) = max_chars_dim_ind
+      restart_vars(rvar_index)%dimension_ids(2) = max_num_fields_dim_ind
+      restart_vars(rvar_index)%dimension_ids(3) = num_configs_dim_ind
+
+      rvar_index = rvar_index + 1
+      restart_vars(rvar_index)%var_name = 'field_units'
+      restart_vars(rvar_index)%var_type = pio_char
+      restart_vars(rvar_index)%number_of_dimensions = 3
+      restart_vars(rvar_index)%dimension_ids(1) = max_chars_dim_ind
+      restart_vars(rvar_index)%dimension_ids(2) = max_num_fields_dim_ind
+      restart_vars(rvar_index)%dimension_ids(3) = num_configs_dim_ind
+
+      rvar_index = rvar_index + 1
+      restart_vars(rvar_index)%var_name = 'field_fill_flag'
+      restart_vars(rvar_index)%var_type = pio_int
+      restart_vars(rvar_index)%number_of_dimensions = 2
+      restart_vars(rvar_index)%dimension_ids(1) = max_num_fields_dim_ind
+      restart_vars(rvar_index)%dimension_ids(2) = num_configs_dim_ind
+
+      rvar_index = rvar_index + 1
+      restart_vars(rvar_index)%var_name = 'field_fill_value'
+      restart_vars(rvar_index)%var_type = pio_double
+      restart_vars(rvar_index)%number_of_dimensions = 2
+      restart_vars(rvar_index)%dimension_ids(1) = max_num_fields_dim_ind
+      restart_vars(rvar_index)%dimension_ids(2) = num_configs_dim_ind
+      restart_vars(rvar_index)%fill_set = .true.
+      restart_vars(rvar_index)%double_fill = 0.0_r8
+
+      rvar_index = rvar_index + 1
+      restart_vars(rvar_index)%var_name = 'field_dimensions'
+      restart_vars(rvar_index)%var_type = pio_int
+      restart_vars(rvar_index)%number_of_dimensions = 3
+      restart_vars(rvar_index)%dimension_ids(1) = max_dims_dim_ind
+      restart_vars(rvar_index)%dimension_ids(2) = max_num_fields_dim_ind
+      restart_vars(rvar_index)%dimension_ids(3) = num_configs_dim_ind
+
+      rvar_index = rvar_index + 1
+      restart_vars(rvar_index)%var_name = 'dimension_names'
+      restart_vars(rvar_index)%var_type = pio_char
+      restart_vars(rvar_index)%number_of_dimensions = 2
+      restart_vars(rvar_index)%dimension_ids(1) = max_hcoordname_len_dim_ind
+      restart_vars(rvar_index)%dimension_ids(2) = registeredmdims_dim_ind
+
+      rvar_index = rvar_index + 1
+      restart_vars(rvar_index)%var_name = 'history_restart_path'
+      restart_vars(rvar_index)%var_type = pio_char
+      restart_vars(rvar_index)%number_of_dimensions = 2
+      restart_vars(rvar_index)%dimension_ids(1) = max_string_len_dim_ind
+      restart_vars(rvar_index)%dimension_ids(2) = num_configs_dim_ind
+
+   end subroutine set_restart_variable_names
+
+   subroutine set_restart_dimension_names(num_hist_configs, max_fields)
+      use cam_history_support, only: max_string_len, max_chars, max_fieldname_len, registeredmdims
+      use cam_grid_support,    only: max_hcoordname_len, max_split_files
+      integer, intent(in) :: num_hist_configs
+      integer, intent(in) :: max_fields
+
+      restart_dims(num_configs_dim_ind)%dimension_name = 'number_of_hist_configs'
+      restart_dims(num_configs_dim_ind)%dimension_length = num_hist_configs
+
+      restart_dims(max_string_len_dim_ind)%dimension_name = 'max_string_length'
+      restart_dims(max_string_len_dim_ind)%dimension_length = max_string_len
+
+      restart_dims(max_fieldname_len_dim_ind)%dimension_name = 'max_fieldname_length'
+      restart_dims(max_fieldname_len_dim_ind)%dimension_length = max_fieldname_len
+
+      restart_dims(max_num_fields_dim_ind)%dimension_name = 'max_fields_per_configuration'
+      restart_dims(max_num_fields_dim_ind)%dimension_length = max_fields
+
+      restart_dims(max_chars_dim_ind)%dimension_name = 'max_chars'
+      restart_dims(max_chars_dim_ind)%dimension_length = max_chars
+
+      restart_dims(max_dims_dim_ind)%dimension_name = 'max_variable_mdims'
+      restart_dims(max_dims_dim_ind)%dimension_length = max_dimensions
+
+      restart_dims(registeredmdims_dim_ind)%dimension_name = 'registered_mdims'
+      restart_dims(registeredmdims_dim_ind)%dimension_length = registeredmdims
+
+      restart_dims(max_hcoordname_len_dim_ind)%dimension_name = 'max_hcoordname_len'
+      restart_dims(max_hcoordname_len_dim_ind)%dimension_length = max_hcoordname_len
+
+      restart_dims(max_num_split_files_dim_ind)%dimension_name = 'max_num_split_files'
+      restart_dims(max_num_split_files_dim_ind)%dimension_length = max_split_files
+
+   end subroutine set_restart_dimension_names
+
+end module cam_hist_restart
diff --git a/src/history/cam_hist_restart_file.F90 b/src/history/cam_hist_restart_file.F90
deleted file mode 100644
index d0f7effd2..000000000
--- a/src/history/cam_hist_restart_file.F90
+++ /dev/null
@@ -1,253 +0,0 @@
-module cam_hist_restart_file
-   use pio,                 only: var_desc_t
-   use cam_history_support, only: max_fieldname_len
-   use shr_kind_mod,        only: r4 => shr_kind_r4
-   use shr_kind_mod,        only: r8 => shr_kind_r8
-
-   implicit none
-   private
-
-   integer, parameter :: max_dimensions = 4
-
-   type restart_variable_t
-      type(var_desc_t), pointer        :: vdesc => null()
-      integer                          :: var_type
-      integer                          :: number_of_dimensions
-      integer                          :: dimension_ids(max_dimensions)
-      character(len=max_fieldname_len) :: var_name
-      logical                          :: fill_set = .false.
-      integer                          :: integer_fill
-      real(r4)                         :: real_fill
-      real(r8)                         :: double_fill
-    end type restart_variable_t
-
-    type restart_dimension_t
-      integer                          :: dimension_length
-      integer                          :: dimension_id
-      character(len=max_fieldname_len) :: dimension_name
-    end type restart_dimension_t
-
-    !
-    !   The size of these parameters should match the assignments in restart_vars_setnames and restart_dims_setnames below
-    !
-    integer, parameter :: num_restart_vars = 24
-    integer, parameter :: num_restart_dims =  9
-    type(restart_variable_t)  :: restart_vars(num_restart_vars)
-    type(restart_dimension_t) :: restart_dims(num_restart_dims)
-
-    integer, parameter :: max_num_fields = 1000
-    integer, parameter :: max_var_mdims  = 1
-
-    integer, parameter :: num_configs_dim_ind        =  1
-    integer, parameter :: max_string_len_dim_ind     =  2
-    integer, parameter :: max_fieldname_len_dim_ind  =  3
-    integer, parameter :: max_num_fields_dim_ind     =  4
-    integer, parameter :: max_chars_dim_ind          =  5
-    integer, parameter :: maxvarmdims_dim_ind        =  6
-    integer, parameter :: registeredmdims_dim_ind    =  7
-    integer, parameter :: max_hcoordname_len_dim_ind =  8
-    integer, parameter :: max_num_split_files_dim_ind    =  9
-
-    public :: set_restart_variable_names
-    public :: set_restart_dimension_names
-
-CONTAINS
-
-   subroutine set_restart_variable_names()
-      use pio, only: pio_int, pio_double, pio_char
-      integer :: rvar_index
-
-      rvar_index = 1
-      restart_vars(rvar_index)%var_name = 'has_rh_file'
-      restart_vars(rvar_index)%var_type = pio_int
-      restart_vars(rvar_index)%number_of_dimensions = 1
-      restart_vars(rvar_index)%dimension_ids(1) = num_configs_dim_ind
-
-      rvar_index = rvar_index + 1
-      restart_vars(rvar_index)%var_name = 'output_frequency'
-      restart_vars(rvar_index)%var_type = pio_char
-      restart_vars(rvar_index)%number_of_dimensions = 2
-      restart_vars(rvar_index)%dimension_ids(1) = max_chars_dim_ind
-      restart_vars(rvar_index)%dimension_ids(2) = num_configs_dim_ind
-
-      rvar_index = rvar_index + 1
-      restart_vars(rvar_index)%var_name = 'number_of_fields'
-      restart_vars(rvar_index)%var_type = pio_int
-      restart_vars(rvar_index)%number_of_dimensions = 1
-      restart_vars(rvar_index)%dimension_ids(1) = num_configs_dim_ind
-
-      rvar_index = rvar_index + 1
-      restart_vars(rvar_index)%var_name = 'num_satellite_columns'
-      restart_vars(rvar_index)%var_type = pio_int
-      restart_vars(rvar_index)%number_of_dimensions = 1
-      restart_vars(rvar_index)%dimension_ids(1) = num_configs_dim_ind
-
-      rvar_index = rvar_index + 1
-      restart_vars(rvar_index)%var_name = 'max_samples'
-      restart_vars(rvar_index)%var_type = pio_int
-      restart_vars(rvar_index)%number_of_dimensions = 1
-      restart_vars(rvar_index)%dimension_ids(1) = num_configs_dim_ind
-
-      rvar_index = rvar_index + 1
-      restart_vars(rvar_index)%var_name = 'current_file_path'
-      restart_vars(rvar_index)%var_type = pio_char
-      restart_vars(rvar_index)%number_of_dimensions = 3
-      restart_vars(rvar_index)%dimension_ids(1) = max_string_len_dim_ind
-      restart_vars(rvar_index)%dimension_ids(2) = num_configs_dim_ind
-      restart_vars(rvar_index)%dimension_ids(3) = max_num_split_files_dim_ind
-
-      rvar_index = rvar_index + 1
-      restart_vars(rvar_index)%var_name = 'current_file_name'
-      restart_vars(rvar_index)%var_type = pio_char
-      restart_vars(rvar_index)%number_of_dimensions = 3
-      restart_vars(rvar_index)%dimension_ids(1) = max_string_len_dim_ind
-      restart_vars(rvar_index)%dimension_ids(2) = num_configs_dim_ind
-      restart_vars(rvar_index)%dimension_ids(3) = max_num_split_files_dim_ind
-
-      rvar_index = rvar_index + 1
-      restart_vars(rvar_index)%var_name = 'precision'
-      restart_vars(rvar_index)%var_type = pio_char
-      restart_vars(rvar_index)%number_of_dimensions = 2
-      restart_vars(rvar_index)%dimension_ids(1) = max_chars_dim_ind
-      restart_vars(rvar_index)%dimension_ids(2) = num_configs_dim_ind
-
-      rvar_index = rvar_index + 1
-      restart_vars(rvar_index)%var_name = 'interval_start_time'
-      restart_vars(rvar_index)%var_type = pio_double
-      restart_vars(rvar_index)%number_of_dimensions = 1
-      restart_vars(rvar_index)%dimension_ids(1) = num_configs_dim_ind
-
-      rvar_index = rvar_index + 1
-      restart_vars(rvar_index)%var_name = 'field_name'
-      restart_vars(rvar_index)%var_type = pio_char
-      restart_vars(rvar_index)%number_of_dimensions = 3
-      restart_vars(rvar_index)%dimension_ids(1) = max_fieldname_len_dim_ind
-      restart_vars(rvar_index)%dimension_ids(2) = max_num_fields_dim_ind
-      restart_vars(rvar_index)%dimension_ids(3) = num_configs_dim_ind
-
-      rvar_index = rvar_index + 1
-      restart_vars(rvar_index)%var_name = 'field_avg_flag'
-      restart_vars(rvar_index)%var_type = pio_char
-      restart_vars(rvar_index)%number_of_dimensions = 3
-      restart_vars(rvar_index)%dimension_ids(1) = max_chars_dim_ind
-      restart_vars(rvar_index)%dimension_ids(2) = max_num_fields_dim_ind
-      restart_vars(rvar_index)%dimension_ids(3) = num_configs_dim_ind
-
-      rvar_index = rvar_index + 1
-      restart_vars(rvar_index)%var_name = 'field_decomposition_type'
-      restart_vars(rvar_index)%var_type = pio_int
-      restart_vars(rvar_index)%number_of_dimensions = 2
-      restart_vars(rvar_index)%dimension_ids(1) = max_num_fields_dim_ind
-      restart_vars(rvar_index)%dimension_ids(2) = num_configs_dim_ind
-      restart_vars(rvar_index)%fill_set = .true.
-      restart_vars(rvar_index)%integer_fill = 0
-
-      rvar_index = rvar_index + 1
-      restart_vars(rvar_index)%var_name = 'field_num_vertical_levels'
-      restart_vars(rvar_index)%var_type = pio_int
-      restart_vars(rvar_index)%number_of_dimensions = 2
-      restart_vars(rvar_index)%dimension_ids(1) = max_num_fields_dim_ind
-      restart_vars(rvar_index)%dimension_ids(2) = num_configs_dim_ind
-      restart_vars(rvar_index)%fill_set = .true.
-      restart_vars(rvar_index)%integer_fill = 0
-
-      rvar_index = rvar_index + 1
-      restart_vars(rvar_index)%var_name = 'history_restart_path'
-      restart_vars(rvar_index)%var_type = pio_char
-      restart_vars(rvar_index)%number_of_dimensions = 2
-      restart_vars(rvar_index)%dimension_ids(1) = max_string_len_dim_ind
-      restart_vars(rvar_index)%dimension_ids(2) = num_configs_dim_ind
-
-      rvar_index = rvar_index + 1
-      restart_vars(rvar_index)%var_name = 'field_cell_methods'
-      restart_vars(rvar_index)%var_type = pio_char
-      restart_vars(rvar_index)%number_of_dimensions = 3
-      restart_vars(rvar_index)%dimension_ids(1) = max_chars_dim_ind
-      restart_vars(rvar_index)%dimension_ids(2) = max_num_fields_dim_ind
-      restart_vars(rvar_index)%dimension_ids(3) = num_configs_dim_ind
-
-      rvar_index = rvar_index + 1
-      restart_vars(rvar_index)%var_name = 'field_long_name'
-      restart_vars(rvar_index)%var_type = pio_char
-      restart_vars(rvar_index)%number_of_dimensions = 3
-      restart_vars(rvar_index)%dimension_ids(1) = max_chars_dim_ind
-      restart_vars(rvar_index)%dimension_ids(2) = max_num_fields_dim_ind
-      restart_vars(rvar_index)%dimension_ids(3) = num_configs_dim_ind
-
-      rvar_index = rvar_index + 1
-      restart_vars(rvar_index)%var_name = 'field_units'
-      restart_vars(rvar_index)%var_type = pio_char
-      restart_vars(rvar_index)%number_of_dimensions = 3
-      restart_vars(rvar_index)%dimension_ids(1) = max_chars_dim_ind
-      restart_vars(rvar_index)%dimension_ids(2) = max_num_fields_dim_ind
-      restart_vars(rvar_index)%dimension_ids(3) = num_configs_dim_ind
-
-      rvar_index = rvar_index + 1
-      restart_vars(rvar_index)%var_name = 'field_fill_flag'
-      restart_vars(rvar_index)%var_type = pio_int
-      restart_vars(rvar_index)%number_of_dimensions = 2
-      restart_vars(rvar_index)%dimension_ids(1) = max_num_fields_dim_ind
-      restart_vars(rvar_index)%dimension_ids(2) = num_configs_dim_ind
-
-      rvar_index = rvar_index + 1
-      restart_vars(rvar_index)%var_name = 'field_fill_value'
-      restart_vars(rvar_index)%var_type = pio_double
-      restart_vars(rvar_index)%number_of_dimensions = 2
-      restart_vars(rvar_index)%dimension_ids(1) = max_num_fields_dim_ind
-      restart_vars(rvar_index)%dimension_ids(2) = num_configs_dim_ind
-      restart_vars(rvar_index)%fill_set = .true.
-      restart_vars(rvar_index)%double_fill = 0.0_r8
-
-      rvar_index = rvar_index + 1
-      restart_vars(rvar_index)%var_name = 'field_mdims'
-      restart_vars(rvar_index)%var_type = pio_int
-      restart_vars(rvar_index)%number_of_dimensions = 3
-      restart_vars(rvar_index)%dimension_ids(1) = maxvarmdims_dim_ind
-      restart_vars(rvar_index)%dimension_ids(2) = max_num_fields_dim_ind
-      restart_vars(rvar_index)%dimension_ids(3) = num_configs_dim_ind
-
-      rvar_index = rvar_index + 1
-      restart_vars(rvar_index)%var_name = 'mdim_names'
-      restart_vars(rvar_index)%var_type = pio_char
-      restart_vars(rvar_index)%number_of_dimensions = 2
-      restart_vars(rvar_index)%dimension_ids(1) = max_hcoordname_len_dim_ind
-      restart_vars(rvar_index)%dimension_ids(2) = registeredmdims_dim_ind
-
-   end subroutine set_restart_variable_names
-
-   subroutine set_restart_dimension_names(num_hist_configs, max_fields)
-      use cam_history_support, only: max_string_len, max_chars, max_fieldname_len, registeredmdims
-      use cam_grid_support,    only: max_hcoordname_len, max_split_files
-      integer, intent(in) :: num_hist_configs
-      integer, intent(in) :: max_fields
-
-      restart_dims(num_configs_dim_ind)%dimension_name = 'number_of_hist_configs'
-      restart_dims(num_configs_dim_ind)%dimension_length = num_hist_configs
-
-      restart_dims(max_string_len_dim_ind)%dimension_name = 'max_string_length'
-      restart_dims(max_string_len_dim_ind)%dimension_length = max_string_len
-
-      restart_dims(max_fieldname_len_dim_ind)%dimension_name = 'max_fieldname_length'
-      restart_dims(max_fieldname_len_dim_ind)%dimension_length = max_fieldname_len
-
-      restart_dims(max_num_fields_dim_ind)%dimension_name = 'max_fields_per_configuration'
-      restart_dims(max_num_fields_dim_ind)%dimension_length = max_fields
-
-      restart_dims(max_chars_dim_ind)%dimension_name = 'max_chars'
-      restart_dims(max_chars_dim_ind)%dimension_length = max_chars
-
-      restart_dims(maxvarmdims_dim_ind)%dimension_name = 'max_variable_mdims'
-      restart_dims(maxvarmdims_dim_ind)%dimension_length = max_var_mdims
-
-      restart_dims(registeredmdims_dim_ind)%dimension_name = 'registered_mdims'
-      restart_dims(registeredmdims_dim_ind)%dimension_length = registeredmdims
-
-      restart_dims(max_hcoordname_len_dim_ind)%dimension_name = 'max_hcoordname_len'
-      restart_dims(max_hcoordname_len_dim_ind)%dimension_length = max_hcoordname_len
-
-      restart_dims(max_num_split_files_dim_ind)%dimension_name = 'max_num_split_files'
-      restart_dims(max_num_split_files_dim_ind)%dimension_length = max_split_files
-
-   end subroutine set_restart_dimension_names
-
-end module cam_hist_restart_file
diff --git a/src/history/cam_history.F90 b/src/history/cam_history.F90
index be6a09e70..9fa12aa52 100644
--- a/src/history/cam_history.F90
+++ b/src/history/cam_history.F90
@@ -32,7 +32,8 @@ module cam_history
    public :: history_add_field      ! Write to list of possible history fields for this run
    public :: history_out_field      ! Accumulate field if its in use by one or more tapes
    public :: history_wrap_up        ! Process history files at end of timestep or run
-   public :: history_restart_init   ! Initialize restart files, if necessary
+   public :: history_restart_init   ! Initialize history fields on restart file, if necessary
+   public :: history_restart_write  ! Write restart files, if necessary
 
    interface history_out_field
       module procedure history_out_field_1d
@@ -869,16 +870,35 @@ end subroutine history_wrap_up
 
 !#######################################################################
 
-   subroutine history_restart_init()
-      use cam_hist_restart_file, only: set_restart_variable_names, set_restart_dimension_names
-      ! Local variables
-      write(iulog,*) 'peverwhee - which have we just written'
-      write(iulog,*) just_wrote
-      write(iulog,*) max_num_fields
-      call set_restart_variable_names()
-      call set_restart_dimension_names(size(hist_configs), max_num_fields)
+   subroutine history_restart_init(restart_file)
+      use cam_hist_restart, only: hist_restart_init
+      use pio,              only: file_desc_t
+      type(file_desc_t), intent(inout) :: restart_file
+
+      if (max_num_fields > 0) then
+         call hist_restart_init(restart_file, size(hist_configs), max_num_fields)
+      end if
+
+      ! Create restart files for history tapes if necessary (.rhX.)
+
+      ! Add history restart variables to overall restart file (.r.)
    end subroutine history_restart_init
 
+!#######################################################################
+
+   subroutine history_restart_write(restart_file)
+      use pio,              only: file_desc_t
+      use cam_hist_restart, only: hist_restart_write
+!      use cam_hist_file, only: hist_file_restart_write
+      type(file_desc_t), intent(inout) :: restart_file
+
+      if (max_num_fields == 0) then
+         ! Don't do anything if there aren't any history fields
+         return
+      end if
+      call hist_restart_write(restart_file, hist_configs, max_num_fields, just_wrote)
+
+   end subroutine history_restart_write
 !#######################################################################
 
    recursive function get_entry_by_name(listentry, name) result(entry)
diff --git a/src/history/cam_history_support.F90 b/src/history/cam_history_support.F90
index 178e43269..06a948ef2 100644
--- a/src/history/cam_history_support.F90
+++ b/src/history/cam_history_support.F90
@@ -9,6 +9,7 @@ module cam_history_support
 
    use shr_kind_mod,     only: r8=>shr_kind_r8, shr_kind_cl, shr_kind_cxx
    use cam_grid_support, only: max_hcoordname_len
+   use cam_logfile, only: iulog
 
    implicit none
    private
@@ -118,6 +119,7 @@ module cam_history_support
   public     :: lookup_hist_coord_indices
   public     :: hist_coord_find_levels
   public     :: get_hist_coord_index
+  public     :: get_hist_coord_names
   public     :: parse_multiplier     ! Parse a repeat count and a token from input
 
   interface add_hist_coord
@@ -162,6 +164,24 @@ pure integer function get_hist_coord_index(mdimname)
 
   end function get_hist_coord_index
 
+  function get_hist_coord_names() result(mdimnames)
+     use cam_abortutils, only: endrun
+     character(len=max_hcoordname_len), allocatable :: mdimnames(:)
+     character(len=512) :: errmsg
+     integer :: ierr, idx
+
+     allocate(mdimnames(registeredmdims), stat=ierr, errmsg=errmsg)
+     if (ierr /= 0) then
+        call endrun('get_hist_coord_names: failed to allocate mdimnames; errmsg = '//trim(errmsg))
+     end if
+     write(iulog,*) "peverwhee - num hist coords"
+     write(iulog,*) registeredmdims
+     do idx = 1, registeredmdims
+        mdimnames(idx) = hist_coords(idx)%name
+     end do
+
+  end function get_hist_coord_names
+
 
   ! Functions to check consistent term definition for hist coords
   pure logical function check_hist_coord_char(defined, input)

From b2ce9544ed3c922a9d42d6f564e6a351e89989f9 Mon Sep 17 00:00:00 2001
From: peverwhee <courtneyp@ucar.edu>
Date: Thu, 18 Jun 2026 16:56:11 -0600
Subject: [PATCH 13/19] restart history working

---
 src/history/cam_hist_file.F90       | 1377 +++++++++++++++++++--------
 src/history/cam_hist_restart.F90    |   24 +-
 src/history/cam_history.F90         |   36 +-
 src/history/cam_history_support.F90 |    2 -
 src/utils/cam_grid_support.F90      |   76 +-
 5 files changed, 1109 insertions(+), 406 deletions(-)

diff --git a/src/history/cam_hist_file.F90 b/src/history/cam_hist_file.F90
index d472375e7..8f03456df 100644
--- a/src/history/cam_hist_file.F90
+++ b/src/history/cam_hist_file.F90
@@ -28,6 +28,7 @@ module cam_hist_file
    integer,          parameter :: nl_gname_len = len(hist_nl_group_name)
    integer, public,  parameter :: instantaneous_file_index = 1
    integer, public,  parameter :: accumulated_file_index   = 2
+   integer, public,  parameter :: restart_file_index       = 3
    character(len=fieldname_suffix_len ) :: fieldname_suffix = '&IC' ! Suffix appended to field names for IC file
 
    logical, parameter                      :: PATCH_DEF = .true.
@@ -42,10 +43,13 @@ module cam_hist_file
    integer, parameter                      :: hfile_type_sat_track  =  3
    integer, parameter                      :: hfile_type_restart    =  4
 
+   character(len=*), parameter :: rh_filename_spec = '%c.cam.r%u.%y-%m-%d-%s.nc'
+
    type :: hist_file_t
       ! History file configuration information
       character(len=vlen),           private :: volume = UNSET_C
       type(file_desc_t),             private :: hist_files(max_split_files) ! PIO file ids
+      type(file_desc_t),             private :: restart_file                ! PIO file id for restart file
       integer,                       private :: rl_kind = OUTPUT_DEF
       integer,                       private :: max_frames = UNSET_I
       integer,                       private :: output_freq_mult = UNSET_I
@@ -57,6 +61,8 @@ module cam_hist_file
       character(len=max_fldlen), allocatable, private :: field_names(:)
       character(len=3), allocatable, private :: accumulate_types(:)
       type(var_desc_t), allocatable, private :: file_varids(:,:)
+      type(var_desc_t), allocatable, private :: nacs_varids(:,:)
+      type(var_desc_t), allocatable, private :: varbuff_varids(:,:)
       integer, allocatable,          private :: grids(:)
       integer,                       private :: hfile_type = hfile_type_default
       logical,                       private :: collect_patch_output = PATCH_DEF
@@ -68,6 +74,7 @@ module cam_hist_file
       logical,                       private :: files_open = .false.
       type(interp_info_t), pointer,  private :: interp_info => NULL()
       character(len=CL), allocatable, private :: file_names(:)
+      character(len=CL), allocatable, private :: restart_file_name
       ! PIO IDs
       type(var_desc_t),              private :: timeid
       type(var_desc_t),              private :: dateid
@@ -96,6 +103,7 @@ module cam_hist_file
       procedure :: get_volume => config_volume
       procedure :: get_filenames => config_get_filenames
       procedure :: get_filename_spec => config_get_filename_spec
+      procedure :: get_restart_filename => config_get_restart_filename
       procedure :: get_last_month_written => config_get_last_month_written
       procedure :: get_last_year_written => config_get_last_year_written
       procedure :: precision => config_precision
@@ -127,6 +135,14 @@ module cam_hist_file
       ! Actions
       procedure :: reset        => config_reset
       procedure :: configure    => config_configure
+      procedure :: set_up_dimensions => config_set_up_dimensions
+      procedure :: define_dimensions => config_define_dimensions
+      procedure :: define_header_info => config_define_header_info
+      procedure :: define_instantaneous_header_info => config_define_instantaneous_header_info
+      procedure :: define_additional_header_info => config_define_additional_header_info
+      procedure :: define_fields => config_define_fields
+      procedure :: define_restart_fields => config_define_restart_fields
+      procedure :: write_invariant_header => config_write_invariant_header
       procedure :: print_config => config_print_config
       procedure :: set_beg_time => config_set_beg_time
       procedure :: set_end_time => config_set_end_time
@@ -136,9 +152,13 @@ module cam_hist_file
       procedure :: set_up_fields => config_set_up_fields
       procedure :: find_in_field_list => config_find_in_field_list
       procedure :: define_file => config_define_file
+      procedure :: define_restart_file => config_define_restart_file
       procedure :: write_time_dependent_variables => config_write_time_dependent_variables
+      procedure :: write_restart_file => config_write_restart_file
       procedure :: write_field => config_write_field
+      procedure :: write_restart_fields => config_write_restart_fields
       procedure :: close_files => config_close_files
+      procedure :: close_restart_file => config_close_restart_file
       procedure :: clear_buffers => config_clear_buffers
       procedure :: reset_samples => config_reset_samples
    end type hist_file_t
@@ -201,6 +221,9 @@ subroutine config_set_filenames(this)
            incomplete_ok=.false.)
       end do
 
+      this%restart_file_name = interpret_filename_spec(rh_filename_spec, &
+              unit=this%volume, incomplete_ok=.false.)
+
    end subroutine config_set_filenames
 
    ! ========================================================================
@@ -238,6 +261,18 @@ end function config_get_filenames
 
    ! ========================================================================
 
+   function config_get_restart_filename(this) result(rhfile)
+      use cam_filenames,  only: interpret_filename_spec
+      ! Dummy arguments
+      class(hist_file_t), intent(in) :: this
+      character(len=CL)              :: rhfile
+
+      rhfile = this%restart_file_name
+
+   end function config_get_restart_filename
+
+   ! ========================================================================
+
    pure function config_get_filename_spec(this) result(filename_spec)
       ! Dummy arguments
       class(hist_file_t), intent(in) :: this
@@ -1157,24 +1192,16 @@ end subroutine AvgflagToString
 
    ! ========================================================================
 
-   subroutine config_define_file(this, restart, logname, host, model_doi_url)
-      use pio,                 only: PIO_CLOBBER, pio_file_is_open, pio_unlimited
-      use pio,                 only: pio_double, pio_def_var, pio_put_att, pio_int
-      use pio,                 only: PIO_GLOBAL, pio_char, pio_real, PIO_NOERR, pio_enddef
-      use pio,                 only: pio_put_var
-      use cam_pio_utils,       only: cam_pio_createfile, cam_pio_def_var
-      use cam_pio_utils,       only: cam_pio_def_dim, cam_pio_handle_error
+   subroutine config_define_file(this, logname, host, model_doi_url)
+      use pio,                 only: PIO_CLOBBER, pio_file_is_open
+      use pio,                 only: PIO_NOERR, pio_enddef
+      use cam_pio_utils,       only: cam_pio_createfile
       use cam_grid_support,    only: cam_grid_header_info_t, cam_grid_write_attr
-      use cam_grid_support,    only: cam_grid_write_var
-      use cam_history_support, only: write_hist_coord_attrs
       use cam_history_support, only: write_hist_coord_vars
       use cam_history_support, only: max_chars
       use shr_kind_mod,        only: r4 => shr_kind_r4
       use time_manager,        only: get_ref_date, timemgr_get_calendar_cf
       use time_manager,        only: get_step_size
-      use string_utils,        only: date2yyyymmdd, sec2hms, stringify
-      use cam_control_mod,     only: caseid
-      use cam_initfiles,       only: ncdata, bnd_topo
       use cam_abortutils,      only: check_allocate, endrun
       use cam_logfile,         only: iulog
       use spmd_utils,          only: masterproc
@@ -1182,55 +1209,54 @@ subroutine config_define_file(this, restart, logname, host, model_doi_url)
       ! Define the metadata for the file(s) for this volume
       ! Dummy arguments
       class(hist_file_t), intent(inout) :: this
-      logical,            intent(in)    :: restart
       character(len=*),   intent(in)    :: logname
       character(len=*),   intent(in)    :: host
       character(len=*),   intent(in)    :: model_doi_url
 
       ! Local variables
       integer :: amode, ierr
-      integer :: grid_index, split_file_index, field_index, idx, jdx
-      integer :: dtime              ! timestep size
+      integer :: split_file_index, idx
       integer :: yr, mon, day       ! year, month, day components of a date
       integer :: nbsec              ! time of day component of base date [seconds]
       integer :: nbdate             ! base date in yyyymmdd format
       integer :: nsbase = 0         ! seconds component of base time
       integer :: ndbase = 0         ! days component of base time
-      integer :: ncreal             ! real data type for output
-      integer :: grd
-      integer :: mdimsize, num_hdims, fdims
+      integer :: num_hdims
+      integer, allocatable :: fdims(:)
       integer :: num_patches
       integer, allocatable :: mdims(:)
 
       logical                  :: is_satfile
       logical                  :: is_initfile
       logical                  :: varid_set
-      character(len=16)        :: time_per_freq
-      character(len=max_chars) :: str       ! character temporary
+      logical                  :: restart, split_file
       character(len=max_chars) :: calendar  ! Calendar type
-      character(len=max_chars) :: cell_methods ! For cell_methods attribute
-      character(len=max_chars) :: fname_tmp ! local copy of field name
-      character(len=CM)        :: errmsg
-      type(var_desc_t)         :: varid
       ! NetCDF dimensions
       integer :: timdim             ! unlimited dimension id
       integer :: bnddim             ! bounds dimension id
       integer :: chardim            ! character dimension id
-      integer :: dimenchar(2)       ! character dimension ids
-      integer :: nacsdims(2)        ! dimension ids for nacs (used in restart file)
-      integer :: max_mdims          ! maximum number of middle dimensions
-      integer :: max_hdims          ! maximum number of grid dimensions
 
       integer, allocatable :: dimindex(:)    ! dimension ids for variable declaration
       ! A structure to hold the horizontal dimension and coordinate info
       type(cam_grid_header_info_t), allocatable :: header_info(:)
-      integer,          allocatable    :: mdimids(:)
-      integer,          parameter :: max_netcdf_len = 256
+      integer,        allocatable :: mdimids(:)
       character(len=*), parameter :: subname = 'config_define_file: '
 
       is_initfile = (this%hfile_type == hfile_type_init_value)
       is_satfile = (this%hfile_type == hfile_type_sat_track)
+
+      restart = .false.
+      split_file = .true.
+
+      ! Get date and calendar info
+      call get_ref_date(yr, mon, day, nbsec)
+      nbdate = yr*10000 + mon*100 + day
+      calendar = timemgr_get_calendar_cf()
       
+      ! v peverwhee - remove when patch output is set up
+      num_patches = 1
+      ! ^ peverwhee - remove when patch output is set up
+
       ! Log what we're doing
       if (masterproc) then
          if (this%has_accumulated) then
@@ -1257,20 +1283,209 @@ subroutine config_define_file(this, restart, logname, host, model_doi_url)
 
       this%files_open = .true.
 
-      allocate(header_info(size(this%grids)), stat=ierr)
+      call this%set_up_dimensions(num_patches, restart, header_info, dimindex, varid_set)
+
+      allocate(fdims(size(this%field_list)))
+      do split_file_index = 1, max_split_files
+         if (.not. pio_file_is_open(this%hist_files(split_file_index))) then
+            cycle
+         end if
+         ! Define the file dimensions
+         call this%define_dimensions(this%hist_files(split_file_index), restart, timdim, bnddim, chardim, mdimids)
+         ! Define the header information
+         call this%define_header_info(this%hist_files(split_file_index), timdim, bnddim, chardim, nbsec, nbdate, &
+                 calendar, logname, host, model_doi_url)
+
+         if (.not. is_satfile) then
+            call this%define_additional_header_info(this%hist_files(split_file_index), bnddim, timdim, chardim, &
+                    nbsec, nbdate, calendar)
+            if (split_file_index == instantaneous_file_index) then
+               call this%define_instantaneous_header_info(this%hist_files(split_file_index), timdim)
+            end if
+
+         end if ! .not. satfile
+
+         ! Create variables and attributes for field list
+         call this%define_fields(this%hist_files(split_file_index), split_file_index, split_file, restart, mdimids, &
+                   dimindex, timdim, num_patches, header_info, varid_set, num_hdims, fdims)
+
+         deallocate(mdimids)
+         ierr = pio_enddef(this%hist_files(split_file_index))
+         if (ierr /= PIO_NOERR) then
+            call endrun('config_define_file: ERROR exiting define mode in PIO', file=__FILE__, line=__LINE__)
+         end if
+         if(masterproc) then
+            write(iulog,*)'config_define_file: Successfully opened netcdf file '//trim(this%file_names(split_file_index))
+         end if
+
+         ! Write time-invariant portion of history header
+         if (.not. is_satfile) then
+            call this%write_invariant_header(this%hist_files(split_file_index), split_file_index, &
+                    ndbase, nsbase, nbdate, nbsec, restart)
+         end if
+
+      end do ! end loop over files
+
+      if (allocated(header_info)) then
+         do idx = 1, size(header_info)
+            call header_info(idx)%deallocate()
+         end do
+         deallocate(header_info)
+      end if
+
+      if (allocated(dimindex)) then
+         deallocate(dimindex)
+      end if
+
+   end subroutine config_define_file
+
+   ! ========================================================================
+
+   subroutine config_define_restart_file(this, logname, host, model_doi_url)
+      use time_manager,        only: timemgr_get_calendar_cf, get_ref_date
+      use spmd_utils,          only: masterproc
+      use cam_logfile,         only: iulog
+      use cam_history_support, only: max_chars, write_hist_coord_vars
+      use cam_pio_utils,       only: cam_pio_createfile
+      use pio,                 only: pio_clobber, pio_noerr, pio_enddef
+      use cam_grid_support,    only: cam_grid_header_info_t
+      use cam_abortutils,      only: endrun
+      ! Define the metadata for the history restart file (rhX)
+      ! Dummy arguments
+      class(hist_file_t), intent(inout) :: this
+      character(len=*),   intent(in)    :: logname
+      character(len=*),   intent(in)    :: host
+      character(len=*),   intent(in)    :: model_doi_url
+      ! Local variables
+      integer :: amode, ierr, idx
+      integer :: yr, mon, day
+      integer :: nbsec, nbdate
+      integer :: ndbase = 0
+      integer :: nsbase = 0
+      integer :: num_patches
+      integer :: num_hdims
+      integer, allocatable :: fdims(:)
+      integer :: timdim, bnddim, chardim
+      logical :: varid_set
+      logical :: restart, split_file
+      character(len=max_chars) :: calendar  ! Calendar type
+      integer, allocatable :: dimindex(:)    ! dimension ids for variable declaration
+      ! A structure to hold the horizontal dimension and coordinate info
+      type(cam_grid_header_info_t), allocatable :: header_info(:)
+      integer,        allocatable :: mdimids(:)
+
+      restart = .true.
+      split_file = .false.
+      ! Get date and calendar info
+      call get_ref_date(yr, mon, day, nbsec)
+      nbdate = yr*10000 + mon*100 + day
+      calendar = timemgr_get_calendar_cf()
+
+      ! v peverwhee - remove when patch output is set up
+      num_patches = 1
+      ! ^ peverwhee - remove when patch output is set up
+
+      ! Log what we're doing
+      if (masterproc) then
+         write(iulog,*) 'Opening history restart file to write, ', &
+                 trim(this%restart_file_name)
+      end if
+
+      amode = PIO_CLOBBER
+
+      ! Create the restart history file
+      call cam_pio_createfile(this%restart_file, this%restart_file_name, amode)
+
+      ! Deallocate file varids from history files (we don't need those anymore)
+      if (allocated(this%file_varids)) then
+         deallocate(this%file_varids)
+      end if
+
+      ! Set up data structures for dimension handling
+      call this%set_up_dimensions(num_patches, restart, header_info, dimindex, varid_set)
+
+      ! Begin header definition
+      !-- Define the file dimensions
+      call this%define_dimensions(this%restart_file, restart, timdim, bnddim, chardim, mdimids)
+      !-- Define the header information
+      call this%define_header_info(this%restart_file, timdim, bnddim, chardim, nbsec, nbdate, &
+              calendar, logname, host, model_doi_url)
+      call this%define_instantaneous_header_info(this%restart_file, timdim)
+      call this%define_additional_header_info(this%restart_file, bnddim, timdim, chardim, &
+              nbsec, nbdate, calendar)
+      ! End header definition
+
+      ! Create variables and attributes for field list
+      allocate(fdims(size(this%field_list)))
+      call this%define_fields(this%restart_file, 1, split_file, restart, mdimids, &
+                dimindex, timdim, num_patches, header_info, varid_set, num_hdims, fdims)
+      
+      ! Define additional restart fields
+      call this%define_restart_fields(num_patches, dimindex, num_hdims, fdims)
+
+      deallocate(mdimids)
+      ierr = pio_enddef(this%restart_file)
+      if (ierr /= PIO_NOERR) then
+         call endrun('config_define_restart_file: ERROR exiting define mode in PIO', file=__FILE__, line=__LINE__)
+      end if
+      if(masterproc) then
+         write(iulog,*)'config_define_restart_file: Successfully opened netcdf file '//trim(this%restart_file_name)
+      end if
+
+      ! Write time-invariant header info
+      call this%write_invariant_header(this%restart_file, restart_file_index, ndbase, nsbase, nbdate, nbsec, restart)
+
+      ! Clean up
+      if (allocated(header_info)) then
+         do idx = 1, size(header_info)
+            call header_info(idx)%deallocate()
+         end do
+         deallocate(header_info)
+      end if
+
+   end subroutine config_define_restart_file
+
+   ! ========================================================================
+
+   subroutine config_set_up_dimensions(this, num_patches, restart, header_info, dimindex, varid_set)
+      use cam_grid_support, only: cam_grid_header_info_t, cam_grid_write_attr
+      use cam_abortutils,   only: check_allocate
+      use pio,              only: pio_file_is_open
+      ! Dummy arguments
+      class(hist_file_t),                      intent(inout) :: this
+      integer,                                    intent(in) :: num_patches
+      logical,                                    intent(in) :: restart
+      type(cam_grid_header_info_t), allocatable, intent(out) :: header_info(:)
+      integer,                      allocatable, intent(out) :: dimindex(:)
+      logical,                                   intent(out) :: varid_set
+      ! Local variables
+      integer :: ierr
+      integer :: grid_index, field_index, split_file_index
+      integer :: max_hdims, max_mdims
+      character(len=512) :: errmsg
+      character(len=*), parameter :: subname = 'config_set_up_dimensions: '
+
+      allocate(header_info(size(this%grids)), stat=ierr, errmsg=errmsg)
       call check_allocate(ierr, subname, 'header_info',             &
-           file=__FILE__, line=__LINE__-1)
+           file=__FILE__, line=__LINE__-1, errmsg=errmsg)
 
       max_hdims = 0
       do grid_index = 1, size(this%grids)
-         do split_file_index = 1, max_split_files
-            if (pio_file_is_open(this%hist_files(split_file_index))) then
-               call cam_grid_write_attr(this%hist_files(split_file_index), &
-                  this%grids(grid_index), header_info(grid_index),         &
-                  file_index=split_file_index)
-               max_hdims = max(max_hdims, header_info(grid_index)%num_hdims())
+         if (restart) then
+            if (pio_file_is_open(this%restart_file)) then
+               call cam_grid_write_attr(this%restart_file, this%grids(grid_index), &
+                       header_info(grid_index), file_index=restart_file_index)
             end if
-         end do
+         else
+            do split_file_index = 1, max_split_files
+               if (pio_file_is_open(this%hist_files(split_file_index))) then
+                  call cam_grid_write_attr(this%hist_files(split_file_index), &
+                     this%grids(grid_index), header_info(grid_index),         &
+                     file_index=split_file_index)
+                  max_hdims = max(max_hdims, header_info(grid_index)%num_hdims())
+               end if
+            end do
+         end if
       end do
       ! Determine the maximum number of dimensions
       max_mdims = 0
@@ -1278,369 +1493,639 @@ subroutine config_define_file(this, restart, logname, host, model_doi_url)
          max_mdims = max(max_mdims, size(this%field_list(field_index)%dimensions()))
       end do
       ! Allocate dimindex to the maximum possible dimensions (plus 1 for time)
-      allocate(dimindex(max_hdims + max_mdims + 1), stat=ierr)
-      call check_allocate(ierr, subname, 'dimindex', file=__FILE__, line=__LINE__-1)
+      allocate(dimindex(max_hdims + max_mdims + 1), stat=ierr, errmsg=errmsg)
+      call check_allocate(ierr, subname, 'dimindex', file=__FILE__, line=__LINE__-1, &
+              errmsg=errmsg)
 
-      call get_ref_date(yr, mon, day, nbsec)
-      nbdate = yr*10000 + mon*100 + day
-      calendar = timemgr_get_calendar_cf()
-      dtime = get_step_size()
-      ! v peverwhee - remove when patch output is set up
-      num_patches = 1
-      ! ^ peverwhee - remove when patch output is set up
       varid_set = .true.
       ! Allocate the varid array
       if (.not. allocated(this%file_varids)) then
-         allocate(this%file_varids(size(this%field_list), num_patches), stat=ierr)
+         allocate(this%file_varids(size(this%field_list), num_patches), stat=ierr, errmsg=errmsg)
          call check_allocate(ierr, subname, 'this%file_varids',             &
-              file=__FILE__, line=__LINE__-1)
+              file=__FILE__, line=__LINE__-1, errmsg=errmsg)
          varid_set = .false.
       end if
 
+   end subroutine config_set_up_dimensions
+
+   ! ========================================================================
+
+   subroutine config_define_dimensions(this, hist_file, restart, timdim, &
+                   bnddim, chardim, mdimids)
+      use cam_pio_utils,       only: cam_pio_def_dim
+      use pio,                 only: pio_unlimited
+      use cam_history_support, only: write_hist_coord_attrs
+      ! Dummy arguments
+      class(hist_file_t), intent(inout) :: this
+      type(file_desc_t),  intent(inout) :: hist_file
+      logical,            intent(in)    :: restart
+      integer,            intent(out)   :: timdim     ! unlimited dimension id
+      integer,            intent(out)   :: bnddim     ! bounds dimension id
+      integer,            intent(out)   :: chardim    ! character dimension id
+      integer, allocatable, intent(out) :: mdimids(:) ! mdim ids
+
+      ! Define the unlimited time dim
+      call cam_pio_def_dim(hist_file, 'time', pio_unlimited, timdim)
+      call cam_pio_def_dim(hist_file, 'nbnd', 2, bnddim, existOK=.true.)
+      call cam_pio_def_dim(hist_file, 'chars', 8, chardim)
+      ! Populate the history coordinate (well, mdims anyway) attributes
+      ! This routine also allocates the mdimids array
+      call write_hist_coord_attrs(hist_file, bnddim, mdimids, restart)
+
+   end subroutine config_define_dimensions
+
+   ! ========================================================================
+
+   subroutine config_define_header_info(this, hist_file, timdim, bnddim, chardim, &
+                   nbsec, nbdate, calendar, logname, host, model_doi_url)
+      use pio,                 only: pio_def_var, pio_double, pio_int, pio_put_att, PIO_GLOBAL
+      use cam_pio_utils,       only: cam_pio_handle_error
+      use string_utils,        only: date2yyyymmdd, sec2hms
+      use cam_history_support, only: max_chars
+      use cam_control_mod,     only: caseid
+      use cam_initfiles,       only: ncdata, bnd_topo
+      ! Dummy arguments
+      class(hist_file_t), intent(inout) :: this
+      type(file_desc_t),  intent(inout) :: hist_file
+      integer,            intent(in)    :: timdim    ! unlimited dimension id
+      integer,            intent(in)    :: bnddim    ! bounds dimension id
+      integer,            intent(in)    :: chardim   ! character dimension id
+      integer,            intent(in)    :: nbsec     ! time of day component of base date [seconds]
+      integer,            intent(in)    :: nbdate    ! base date in yyyymmdd format
+      character(len=*),   intent(in)    :: calendar  ! Calendar type
+      character(len=*),   intent(in)    :: logname
+      character(len=*),   intent(in)    :: host
+      character(len=*),   intent(in)    :: model_doi_url
+      ! Local variables
+      integer :: ierr
+      character(len=max_chars) :: str       ! character temporary
+      character(len=16)        :: time_per_freq
+
       ! Format frequency
       write(time_per_freq,999) trim(this%output_freq_type), '_', this%output_freq_mult
 999   format(2a,i0)
 
-      do split_file_index = 1, max_split_files
-         if (.not. pio_file_is_open(this%hist_files(split_file_index))) then
-            cycle
-         end if
-         ! Define the unlimited time dim
-         call cam_pio_def_dim(this%hist_files(split_file_index), 'time', pio_unlimited, timdim)
-         call cam_pio_def_dim(this%hist_files(split_file_index), 'nbnd', 2, bnddim, existOK=.true.)
-         call cam_pio_def_dim(this%hist_files(split_file_index), 'chars', 8, chardim)
-         ! Populate the history coordinate (well, mdims anyway) attributes
-         ! This routine also allocates the mdimids array
-         call write_hist_coord_attrs(this%hist_files(split_file_index), bnddim, mdimids, restart)
-         ! Define time variable
-         ierr=pio_def_var (this%hist_files(split_file_index),'time',pio_double,(/timdim/),this%timeid)
-         call cam_pio_handle_error(ierr, 'config_define_file: failed to define "time" variable')
-         ierr=pio_put_att (this%hist_files(split_file_index), this%timeid, 'long_name', 'time')
-         call cam_pio_handle_error(ierr, 'config_define_file: failed to add "long_name" attribute to "time" variable')
-         str = 'days since ' // date2yyyymmdd(nbdate) // ' ' // sec2hms(nbsec)
-         ierr=pio_put_att (this%hist_files(split_file_index), this%timeid, 'units', trim(str))
-         call cam_pio_handle_error(ierr, 'config_define_file: failed to add "units" attribtue to "time" variable')
-         ierr=pio_put_att (this%hist_files(split_file_index), this%timeid, 'calendar', trim(calendar))
-         call cam_pio_handle_error(ierr, 'config_define_file: failed to add "calendar" attribute to "time" variable')
-
-         ! Define date variable
-         ierr=pio_def_var (this%hist_files(split_file_index),'date    ',pio_int,(/timdim/),this%dateid)
-         call cam_pio_handle_error(ierr, 'config_define_file: failed to define "date" variable')
-         str = 'current date (YYYYMMDD)'
-         ierr=pio_put_att (this%hist_files(split_file_index), this%dateid, 'long_name', trim(str))
-         call cam_pio_handle_error(ierr, 'config_define_file: failed to add "long_name" attribute to "date" variable')
-
-         ! Define datesec variable
-         ierr=pio_def_var (this%hist_files(split_file_index),'datesec ',pio_int,(/timdim/), this%datesecid)
-         call cam_pio_handle_error(ierr, 'config_define_file: failed to define "datesec" variable')
-         str = 'current seconds of current date'
-         ierr=pio_put_att (this%hist_files(split_file_index), this%datesecid, 'long_name', trim(str))
-         call cam_pio_handle_error(ierr, 'config_define_file: failed to add "long_name" attribute to "datesec" variable')
+      ! Define time variable
+      ierr=pio_def_var (hist_file,'time',pio_double,(/timdim/),this%timeid)
+      call cam_pio_handle_error(ierr, 'config_define_header_info: failed to define "time" variable')
+      ierr=pio_put_att (hist_file, this%timeid, 'long_name', 'time')
+      call cam_pio_handle_error(ierr, 'config_define_header_info: failed to add "long_name" attribute to "time" variable')
+      str = 'days since ' // date2yyyymmdd(nbdate) // ' ' // sec2hms(nbsec)
+      ierr=pio_put_att (hist_file, this%timeid, 'units', trim(str))
+      call cam_pio_handle_error(ierr, 'config_define_header_info: failed to add "units" attribtue to "time" variable')
+      ierr=pio_put_att (hist_file, this%timeid, 'calendar', trim(calendar))
+      call cam_pio_handle_error(ierr, 'config_define_header_info: failed to add "calendar" attribute to "time" variable')
+
+      ! Define date variable
+      ierr=pio_def_var (hist_file,'date    ',pio_int,(/timdim/),this%dateid)
+      call cam_pio_handle_error(ierr, 'config_define_header_info: failed to define "date" variable')
+      str = 'current date (YYYYMMDD)'
+      ierr=pio_put_att (hist_file, this%dateid, 'long_name', trim(str))
+      call cam_pio_handle_error(ierr, 'config_define_header_info: failed to add "long_name" attribute to "date" variable')
+
+      ! Define datesec variable
+      ierr=pio_def_var (hist_file,'datesec ',pio_int,(/timdim/), this%datesecid)
+      call cam_pio_handle_error(ierr, 'config_define_header_info: failed to define "datesec" variable')
+      str = 'current seconds of current date'
+      ierr=pio_put_att (hist_file, this%datesecid, 'long_name', trim(str))
+      call cam_pio_handle_error(ierr, 'config_define_header_info: failed to add "long_name" attribute to "datesec" variable')
+      !
+      ! Character header information
+      !
+      str = 'CF-1.0'
+      ierr=pio_put_att (hist_file, PIO_GLOBAL, 'Conventions', trim(str))
+      call cam_pio_handle_error(ierr, 'config_define_header_info: failed to add "Conventions" attribtue to file')
+      ierr=pio_put_att (hist_file, PIO_GLOBAL, 'source', 'CAM-SIMA')
+      call cam_pio_handle_error(ierr, 'config_define_header_info: failed to add "source" attribute to file')
+      ierr=pio_put_att (hist_file, PIO_GLOBAL, 'case', caseid)
+      call cam_pio_handle_error(ierr, 'config_define_header_info: failed to add "case" attribute to file')
+      ierr=pio_put_att (hist_file, PIO_GLOBAL, 'logname',trim(logname))
+      call cam_pio_handle_error(ierr, 'config_define_header_info: failed to add "logname" attribute to file')
+      ierr=pio_put_att (hist_file, PIO_GLOBAL, 'host', trim(host))
+      call cam_pio_handle_error(ierr, 'config_define_header_info: failed to add "host" attribute to file')
+
+      ierr=pio_put_att (hist_file, PIO_GLOBAL, 'initial_file', ncdata)
+      call cam_pio_handle_error(ierr, 'config_define_header_info: failed to add "initial_file" attribute to file')
+      ierr=pio_put_att (hist_file, PIO_GLOBAL, 'topography_file', bnd_topo)
+      call cam_pio_handle_error(ierr, 'config_define_header_info: failed to add "topography_file" attribute to file')
+      if (len_trim(model_doi_url) > 0) then
+         ierr=pio_put_att (hist_file, PIO_GLOBAL, 'model_doi_url', model_doi_url)
+         call cam_pio_handle_error(ierr, 'config_define_header_info: failed to add "model_doi_url" attribute to file')
+      end if
+      ierr=pio_put_att (hist_file, PIO_GLOBAL, 'time_period_freq', trim(time_per_freq))
+      call cam_pio_handle_error(ierr, 'config_define_header_info: failed to add "time_period_freq" attribute to file')
+   end subroutine config_define_header_info
 
-         !
-         ! Character header information
-         !
-         str = 'CF-1.0'
-         ierr=pio_put_att (this%hist_files(split_file_index), PIO_GLOBAL, 'Conventions', trim(str))
-         call cam_pio_handle_error(ierr, 'config_define_file: failed to add "Conventions" attribtue to file')
-         ierr=pio_put_att (this%hist_files(split_file_index), PIO_GLOBAL, 'source', 'CAM-SIMA')
-         call cam_pio_handle_error(ierr, 'config_define_file: failed to add "source" attribute to file')
-         ierr=pio_put_att (this%hist_files(split_file_index), PIO_GLOBAL, 'case', caseid)
-         call cam_pio_handle_error(ierr, 'config_define_file: failed to add "case" attribute to file')
-         ierr=pio_put_att (this%hist_files(split_file_index), PIO_GLOBAL, 'logname',trim(logname))
-         call cam_pio_handle_error(ierr, 'config_define_file: failed to add "logname" attribute to file')
-         ierr=pio_put_att (this%hist_files(split_file_index), PIO_GLOBAL, 'host', trim(host))
-         call cam_pio_handle_error(ierr, 'config_define_file: failed to add "host" attribute to file')
-
-         ierr=pio_put_att (this%hist_files(split_file_index), PIO_GLOBAL, 'initial_file', ncdata)
-         call cam_pio_handle_error(ierr, 'config_define_file: failed to add "initial_file" attribute to file')
-         ierr=pio_put_att (this%hist_files(split_file_index), PIO_GLOBAL, 'topography_file', bnd_topo)
-         call cam_pio_handle_error(ierr, 'config_define_file: failed to add "topography_file" attribute to file')
-         if (len_trim(model_doi_url) > 0) then
-            ierr=pio_put_att (this%hist_files(split_file_index), PIO_GLOBAL, 'model_doi_url', model_doi_url)
-            call cam_pio_handle_error(ierr, 'config_define_file: failed to add "model_doi_url" attribute to file')
-         end if
+   ! ========================================================================
+
+   subroutine config_define_instantaneous_header_info(this, hist_file, timdim)
+      use pio,                 only: pio_def_var, pio_int, pio_put_att
+      use cam_pio_utils,       only: cam_pio_handle_error
+      use cam_history_support, only: max_chars
+      ! Dummy arguments
+      class(hist_file_t), intent(inout) :: this
+      type(file_desc_t),  intent(inout) :: hist_file
+      integer,            intent(in)    :: timdim    ! unlimited dimension id
+      ! Local variables
+      integer :: ierr
+      character(len=max_chars) :: str ! Temporary string
+
+      ierr=pio_def_var (hist_file,'ndcur   ',pio_int,(/timdim/),this%ndcurid)
+      call cam_pio_handle_error(ierr, 'config_define_instantaneous_header_info: failed to define "ndcur" variable')
+      str = 'current day (from base day)'
+      ierr=pio_put_att (hist_file, this%ndcurid, 'long_name', trim(str))
+      call cam_pio_handle_error(ierr, 'config_define_instantaneous_header_info: failed to add "long_name" attribute to "ndcur" variable')
+
+      ierr=pio_def_var (hist_file,'nscur   ',pio_int,(/timdim/),this%nscurid)
+      call cam_pio_handle_error(ierr, 'config_define_instantaneous_header_info: failed to define "nscur" variable')
+      str = 'current seconds of current day'
+      ierr=pio_put_att (hist_file, this%nscurid, 'long_name', trim(str))
+      call cam_pio_handle_error(ierr, 'config_define_instantaneous_header_info: failed to add "long_name" attribute to "nscur" variable')
+      ierr=pio_def_var (hist_file,'nsteph',pio_int,(/timdim/),this%nstephid)
+      call cam_pio_handle_error(ierr, 'config_define_instantaneous_header_info: failed to define "nsteph" variable')
+      str = 'current timestep'
+      ierr=pio_put_att (hist_file, this%nstephid, 'long_name', trim(str))
+      call cam_pio_handle_error(ierr, 'config_define_instantaneous_header_info: failed to add "long_name" attribute to "nsteph" variable')
+
+   end subroutine config_define_instantaneous_header_info
 
-         ierr=pio_put_att (this%hist_files(split_file_index), PIO_GLOBAL, 'time_period_freq', trim(time_per_freq))
-         call cam_pio_handle_error(ierr, 'config_define_file: failed to add "time_period_freq" attribute to file')
+   ! ========================================================================
 
-         if (.not. is_satfile) then
-            ! Define time_bounds variable
-            ierr=pio_put_att (this%hist_files(split_file_index), this%timeid, 'bounds', 'time_bounds')
-            call cam_pio_handle_error(ierr, 'config_define_file: failed to add "bounds" attribute to file')
-            ierr=pio_def_var (this%hist_files(split_file_index),'time_bounds',pio_double,(/bnddim,timdim/),this%tbndid)
-            call cam_pio_handle_error(ierr, 'config_define_file: failed to define "time_bounds" variable')
-            ierr=pio_put_att (this%hist_files(split_file_index), this%tbndid, 'long_name', 'time interval endpoints')
-            call cam_pio_handle_error(ierr, 'config_define_file: failed to add "long_name" attribute to "time_bounds" variable')
-            str = 'days since ' // date2yyyymmdd(nbdate) // ' ' // sec2hms(nbsec)
-            ierr=pio_put_att (this%hist_files(split_file_index), this%tbndid, 'units', trim(str))
-            call cam_pio_handle_error(ierr, 'config_define_file: failed to add "units" attribute to "time_bounds" variable')
-            ierr=pio_put_att (this%hist_files(split_file_index), this%tbndid, 'calendar', trim(calendar))
-            call cam_pio_handle_error(ierr, 'config_define_file: failed to add "calendar" attribute to "time_bounds" variable')
-
-            !
-            ! Character
-            !
-            dimenchar(1) = chardim
-            dimenchar(2) = timdim
-            ierr=pio_def_var (this%hist_files(split_file_index),'date_written',pio_char,dimenchar,this%date_writtenid)
-            call cam_pio_handle_error(ierr, 'config_define_file: failed to define "date_written" variable')
-            ierr=pio_def_var (this%hist_files(split_file_index),'time_written',pio_char,dimenchar,this%time_writtenid)
-            call cam_pio_handle_error(ierr, 'config_define_file: failed to define "time_written" variable')
-
-            !
-            ! Integer header
-            !
-            ! Define base day variables
-            ierr=pio_def_var (this%hist_files(split_file_index),'ndbase',PIO_INT,this%ndbaseid)
-            call cam_pio_handle_error(ierr, 'config_define_file: failed to define "ndbase" variable')
-            str = 'base day'
-            ierr=pio_put_att (this%hist_files(split_file_index), this%ndbaseid, 'long_name', trim(str))
-            call cam_pio_handle_error(ierr, 'config_define_file: failed to add "long_name" attribute to "ndbase" variable')
-
-            ierr=pio_def_var (this%hist_files(split_file_index),'nsbase',PIO_INT,this%nsbaseid)
-            call cam_pio_handle_error(ierr, 'config_define_file: failed to define "nsbase" variable')
-            str = 'seconds of base day'
-            ierr=pio_put_att (this%hist_files(split_file_index), this%nsbaseid, 'long_name', trim(str))
-            call cam_pio_handle_error(ierr, 'config_define_file: failed to add "long_name" attribute to "nsbase" variable')
-
-            ierr=pio_def_var (this%hist_files(split_file_index),'nbdate',PIO_INT,this%nbdateid)
-            call cam_pio_handle_error(ierr, 'config_define_file: failed to define "nbdate" variable')
-            str = 'base date (YYYYMMDD)'
-            ierr=pio_put_att (this%hist_files(split_file_index), this%nbdateid, 'long_name', trim(str))
-            call cam_pio_handle_error(ierr, 'config_define_file: failed to add "long_name" attribtue to "nbdate" variable')
-
-            ierr=pio_def_var (this%hist_files(split_file_index),'nbsec',PIO_INT,this%nbsecid)
-            call cam_pio_handle_error(ierr, 'config_define_file: failed to define "nbsec" variable')
-            str = 'seconds of base date'
-            ierr=pio_put_att (this%hist_files(split_file_index), this%nbsecid, 'long_name', trim(str))
-            call cam_pio_handle_error(ierr, 'config_define_file: failed to add "long_name" attribute to "nbsec" variable')
-
-            ierr=pio_def_var (this%hist_files(split_file_index),'mdt',PIO_INT,this%mdtid)
-            call cam_pio_handle_error(ierr, 'config_define_file: failed to define "mdt" variable')
-            ierr=pio_put_att (this%hist_files(split_file_index), this%mdtid, 'long_name', 'timestep')
-            call cam_pio_handle_error(ierr, 'config_define_file: failed to add "long_name" attribute to "mdt" variable')
-            ierr=pio_put_att (this%hist_files(split_file_index), this%mdtid, 'units', 's')
-            call cam_pio_handle_error(ierr, 'config_define_file: failed to add "units" attribute to "mdt" variable')
-
-            !
-            ! Create variables for model timing and header information
-            !
-            if (split_file_index == instantaneous_file_index) then
-               ierr=pio_def_var (this%hist_files(split_file_index),'ndcur   ',pio_int,(/timdim/),this%ndcurid)
-               call cam_pio_handle_error(ierr, 'config_define_file: failed to define "ndcur" variable')
-               str = 'current day (from base day)'
-               ierr=pio_put_att (this%hist_files(split_file_index), this%ndcurid, 'long_name', trim(str))
-               call cam_pio_handle_error(ierr, 'config_define_file: failed to add "long_name" attribute to "ndcur" variable')
-
-               ierr=pio_def_var (this%hist_files(split_file_index),'nscur   ',pio_int,(/timdim/),this%nscurid)
-               call cam_pio_handle_error(ierr, 'config_define_file: failed to define "nscur" variable')
-               str = 'current seconds of current day'
-               ierr=pio_put_att (this%hist_files(split_file_index), this%nscurid, 'long_name', trim(str))
-               call cam_pio_handle_error(ierr, 'config_define_file: failed to add "long_name" attribute to "nscur" variable')
-               ierr=pio_def_var (this%hist_files(split_file_index),'nsteph',pio_int,(/timdim/),this%nstephid)
-               call cam_pio_handle_error(ierr, 'config_define_file: failed to define "nsteph" variable')
-               str = 'current timestep'
-               ierr=pio_put_att (this%hist_files(split_file_index), this%nstephid, 'long_name', trim(str))
-               call cam_pio_handle_error(ierr, 'config_define_file: failed to add "long_name" attribute to "nsteph" variable')
+   subroutine config_define_additional_header_info(this, hist_file, bnddim, timdim, chardim, &
+                    nbsec, nbdate, calendar)
+      use pio,                 only: pio_def_var, pio_double, pio_put_att, pio_char, pio_int
+      use cam_pio_utils,       only: cam_pio_handle_error
+      use string_utils,        only: date2yyyymmdd, sec2hms
+      use cam_history_support, only: max_chars
+      ! Dummy arguments
+      class(hist_file_t), intent(inout) :: this
+      type(file_desc_t),  intent(inout) :: hist_file
+      integer,            intent(in)    :: timdim    ! unlimited dimension id
+      integer,            intent(in)    :: bnddim    ! bounds dimension id
+      integer,            intent(in)    :: chardim   ! character dimension id
+      integer,            intent(in)    :: nbsec     ! time of day component of base date [seconds]
+      integer,            intent(in)    :: nbdate    ! base date in yyyymmdd format
+      character(len=*),   intent(in)    :: calendar  ! Calendar type
+      ! Local variables
+      integer :: dimenchar(2), ierr
+      character(len=max_chars) :: str       ! character temporary
+
+      dimenchar(1) = chardim
+      dimenchar(2) = timdim
+      ! Define time_bounds variable
+      ierr=pio_put_att (hist_file, this%timeid, 'bounds', 'time_bounds')
+      call cam_pio_handle_error(ierr, 'config_define_additional_header_info: failed to add "bounds" attribute to file')
+      ierr=pio_def_var (hist_file,'time_bounds',pio_double,(/bnddim,timdim/),this%tbndid)
+      call cam_pio_handle_error(ierr, 'config_define_additional_header_info: failed to define "time_bounds" variable')
+      ierr=pio_put_att (hist_file, this%tbndid, 'long_name', 'time interval endpoints')
+      call cam_pio_handle_error(ierr, 'config_define_additional_header_info: failed to add "long_name" attribute to "time_bounds" variable')
+      str = 'days since ' // date2yyyymmdd(nbdate) // ' ' // sec2hms(nbsec)
+      ierr=pio_put_att (hist_file, this%tbndid, 'units', trim(str))
+      call cam_pio_handle_error(ierr, 'config_define_additional_header_info: failed to add "units" attribute to "time_bounds" variable')
+      ierr=pio_put_att (hist_file, this%tbndid, 'calendar', trim(calendar))
+      call cam_pio_handle_error(ierr, 'config_define_additional_header_info: failed to add "calendar" attribute to "time_bounds" variable')
+
+      !
+      ! Character
+      !
+      ierr=pio_def_var (hist_file,'date_written',pio_char,dimenchar,this%date_writtenid)
+      call cam_pio_handle_error(ierr, 'config_define_additional_header_info: failed to define "date_written" variable')
+      ierr=pio_def_var (hist_file,'time_written',pio_char,dimenchar,this%time_writtenid)
+      call cam_pio_handle_error(ierr, 'config_define_additional_header_info: failed to define "time_written" variable')
+      !
+      ! Integer header
+      !
+      ! Define base day variables
+      ierr=pio_def_var (hist_file,'ndbase',PIO_INT,this%ndbaseid)
+      call cam_pio_handle_error(ierr, 'config_define_additional_header_info: failed to define "ndbase" variable')
+      str = 'base day'
+      ierr=pio_put_att (hist_file, this%ndbaseid, 'long_name', trim(str))
+      call cam_pio_handle_error(ierr, 'config_define_additional_header_info: failed to add "long_name" attribute to "ndbase" variable')
+
+      ierr=pio_def_var (hist_file,'nsbase',PIO_INT,this%nsbaseid)
+      call cam_pio_handle_error(ierr, 'config_define_additional_header_info: failed to define "nsbase" variable')
+      str = 'seconds of base day'
+      ierr=pio_put_att (hist_file, this%nsbaseid, 'long_name', trim(str))
+      call cam_pio_handle_error(ierr, 'config_define_additional_header_info: failed to add "long_name" attribute to "nsbase" variable')
+
+      ierr=pio_def_var (hist_file,'nbdate',PIO_INT,this%nbdateid)
+      call cam_pio_handle_error(ierr, 'config_define_additional_header_info: failed to define "nbdate" variable')
+      str = 'base date (YYYYMMDD)'
+      ierr=pio_put_att (hist_file, this%nbdateid, 'long_name', trim(str))
+      call cam_pio_handle_error(ierr, 'config_define_additional_header_info: failed to add "long_name" attribtue to "nbdate" variable')
+
+      ierr=pio_def_var (hist_file,'nbsec',PIO_INT,this%nbsecid)
+      call cam_pio_handle_error(ierr, 'config_define_additional_header_info: failed to define "nbsec" variable')
+      str = 'seconds of base date'
+      ierr=pio_put_att (hist_file, this%nbsecid, 'long_name', trim(str))
+      call cam_pio_handle_error(ierr, 'config_define_additional_header_info: failed to add "long_name" attribute to "nbsec" variable')
+
+      ierr=pio_def_var (hist_file,'mdt',PIO_INT,this%mdtid)
+      call cam_pio_handle_error(ierr, 'config_define_additional_header_info: failed to define "mdt" variable')
+      ierr=pio_put_att (hist_file, this%mdtid, 'long_name', 'timestep')
+      call cam_pio_handle_error(ierr, 'config_define_additional_header_info: failed to add "long_name" attribute to "mdt" variable')
+      ierr=pio_put_att (hist_file, this%mdtid, 'units', 's')
+      call cam_pio_handle_error(ierr, 'config_define_additional_header_info: failed to add "units" attribute to "mdt" variable')
+
+   end subroutine config_define_additional_header_info
+
+   ! ========================================================================
+
+   subroutine config_define_fields(this, hist_file, file_index, split_file, restart, mdimids, &
+                   dimindex, timdim, num_patches, header_info, varid_set, num_hdims, fdims)
+      use string_utils,        only: stringify
+      use pio,                 only: pio_def_var, pio_double, pio_real, pio_int, pio_put_att
+      use cam_pio_utils,       only: cam_pio_handle_error, cam_pio_def_var
+      use cam_history_support, only: max_chars
+      use cam_abortutils,      only: endrun
+      use cam_grid_support,    only: cam_grid_header_info_t
+      use shr_kind_mod,        only: r4 => shr_kind_r4
+      ! Dummy arguments
+      class(hist_file_t),           intent(inout) :: this
+      type(file_desc_t),            intent(inout) :: hist_file
+      integer,                      intent(in)    :: file_index
+      logical,                      intent(in)    :: split_file
+      logical,                      intent(in)    :: restart
+      integer,                      intent(in)    :: mdimids(:)
+      integer,                      intent(inout) :: dimindex(:)
+      integer,                      intent(in)    :: timdim
+      integer,                      intent(in)    :: num_patches
+      logical,                      intent(in)    :: varid_set
+      type(cam_grid_header_info_t), allocatable, intent(in) :: header_info(:)
+      integer,                      intent(out)   :: num_hdims
+      integer,                      intent(out)   :: fdims(:)
+
+      ! Local variables
+      type(var_desc_t) :: varid
+      integer :: dimenchar(2)
+      integer :: ierr
+      integer :: field_index, idx, jdx
+      integer :: ncreal
+      integer :: grd
+      integer :: mdimsize
+      integer, allocatable :: mdims(:)
+      integer,   parameter :: max_netcdf_len = 256
+      integer              :: nacsdims(2)   ! dimension ids for nacs (used in restart file)
+      character(len=max_chars) :: str       ! character temporary
+      character(len=512)       :: errmsg
+      character(len=max_chars) :: fname_tmp ! local copy of field name
+      character(len=max_chars) :: cell_methods
+
+      do field_index = 1, size(this%field_list)
+         if (split_file) then
+            if (file_index == accumulated_file_index) then
+               ! this is the accumulated file of a potentially split
+               ! history tape - skip instantaneous fields
+               if (this%field_list(field_index)%accumulate_type() == 'lst') then
+                  cycle
+               end if
+            else
+               ! this is the instantaneous file of a potentially split
+               ! history tape - skip accumulated fields
+               if (this%field_list(field_index)%accumulate_type() /= 'lst') then
+                  cycle
+               end if
             end if
+         end if
 
-         end if ! .not. satfile
+         ! Don't write instantaneous fields to the restart history file
+         if (restart .and. this%field_list(field_index)%accumulate_type() == 'lst') then
+            cycle
+         end if
 
-         !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
+         if (this%precision() == 'REAL32') then
+            ncreal = pio_real
+         else if (this%precision() == 'REAL64') then
+            ncreal = pio_double
+         end if
+         mdims = this%field_list(field_index)%dimensions()
+         mdimsize = size(mdims)
+         fname_tmp = strip_suffix(this%field_list(field_index)%diag_name())
+         ! Ensure that fname_tmp is not longer than the maximum length for a
+         !  netcdf file
+         if (len_trim(fname_tmp) > max_netcdf_len) then
+            ! Endrun if the name is too long
+            write(errmsg, *) 'config_define_fields: variable name ', trim(fname_tmp), &
+               ' too long for NetCDF file (len=', stringify((/len(trim(fname_tmp))/)), ' > ', &
+               stringify((/max_netcdf_len/)), ')'
+            call endrun(errmsg, file=__FILE__, line=__LINE__)
+         end if
          !
-         ! Create variables and attributes for field list
+         !  Create variables and atributes for fields written out as columns
          !
-         !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
-
-         do field_index = 1, size(this%field_list)
-            if (.not. is_satfile .and. .not. restart .and. .not. is_initfile) then
-               if (split_file_index == accumulated_file_index) then
-                  ! this is the accumulated file of a potentially split
-                  ! history tape - skip instantaneous fields
-                  if (this%field_list(field_index)%accumulate_type() == 'lst') then
-                     cycle
-                  end if
-               else
-                  ! this is the instantaneous file of a potentially split
-                  ! history tape - skip accumulated fields
-                  if (this%field_list(field_index)%accumulate_type() /= 'lst') then
-                     cycle
-                  end if
-               end if
+         !  Find appropriate grid in header_info
+         if (.not. allocated(header_info)) then
+            ! Safety check
+            call endrun('config_define_fields: header_info not allocated', file=__FILE__, line=__LINE__)
+         end if
+         grd = -1
+         do idx = 1, size(header_info)
+           if (header_info(idx)%get_gridid() == this%field_list(field_index)%decomp()) then
+              grd = idx
+              exit
+           end if
+         end do
+         if (grd < 0) then
+            write(errmsg, '(a,i0,2a)') 'grid, ',this%field_list(field_index)%decomp(),', not found for ', &
+               trim(fname_tmp)
+            call endrun('config_define_fields: '//errmsg, file=__FILE__, line=__LINE__)
+         end if
+         num_hdims = header_info(grd)%num_hdims()
+         do idx = 1, num_hdims
+            dimindex(idx) = header_info(grd)%get_hdimid(idx)
+            if (restart) then
+                nacsdims(idx) = header_info(grd)%get_hdimid(idx)
             end if
-
-            if (this%precision() == 'REAL32') then
-               ncreal = pio_real
-            else if (this%precision() == 'REAL64') then
-               ncreal = pio_double
+         end do
+         do idx = 1, num_patches
+            varid = this%file_varids(field_index, idx)
+            ! Figure the dimension ID array for this field
+            ! We have defined the horizontal grid dimensions in dimindex
+            fdims(field_index) = num_hdims
+            do jdx = 1, mdimsize
+               fdims(field_index) = fdims(field_index) + 1
+               dimindex(fdims(field_index)) = mdimids(mdims(jdx))
+            end do
+            if(.not. restart) then
+               ! Only add time dimension if this is not a restart history tape
+               fdims(field_index) = fdims(field_index) + 1
+               dimindex(fdims(field_index)) = timdim
             end if
-            mdims = this%field_list(field_index)%dimensions()
-            mdimsize = size(mdims)
-            fname_tmp = strip_suffix(this%field_list(field_index)%diag_name())
-            ! Ensure that fname_tmp is not longer than the maximum length for a
-            !  netcdf file
-            if (len_trim(fname_tmp) > max_netcdf_len) then
-               ! Endrun if the name is too long
-               write(errmsg, *) 'config_define_file: variable name ', trim(fname_tmp), &
-                  ' too long for NetCDF file (len=', stringify((/len(trim(fname_tmp))/)), ' > ', &
-                  stringify((/max_netcdf_len/)), ')'
-               call endrun(errmsg, file=__FILE__, line=__LINE__)
+            ! peverwhee - TODO: enable patch output
+            ! Define the variable
+            call cam_pio_def_var(hist_file, trim(fname_tmp), ncreal,           &
+                 dimindex(1:fdims(field_index)), varid)
+            if (.not. varid_set) then
+               this%file_varids(field_index, idx) = varid
             end if
-            !
-            !  Create variables and atributes for fields written out as columns
-            !
-            !  Find appropriate grid in header_info
-            if (.not. allocated(header_info)) then
-               ! Safety check
-               call endrun('config_define_file: header_info not allocated', file=__FILE__, line=__LINE__)
+
+            if (mdimsize > 0) then
+               ierr = pio_put_att(hist_file, varid, 'mdims', mdims(1:mdimsize))
+               call cam_pio_handle_error(ierr, 'config_define_fields: cannot define mdims for '//trim(fname_tmp))
             end if
-            grd = -1
-            do idx = 1, size(header_info)
-              if (header_info(idx)%get_gridid() == this%field_list(field_index)%decomp()) then
-                 grd = idx
-                 exit
-              end if
-            end do
-            if (grd < 0) then
-               write(errmsg, '(a,i0,2a)') 'grid, ',this%field_list(field_index)%decomp(),', not found for ', &
-                  trim(fname_tmp)
-               call endrun('config_define_file: '//errmsg, file=__FILE__, line=__LINE__)
+            str = this%field_list(field_index)%sampling_sequence()
+            if (len_trim(str) > 0) then
+               ierr = pio_put_att(hist_file, varid, 'Sampling_Sequence', trim(str))
+               call cam_pio_handle_error(ierr, 'config_define_fields: cannot define Sampling_Sequence for '//trim(fname_tmp))
             end if
-            num_hdims = header_info(grd)%num_hdims()
-            do idx = 1, num_hdims
-               dimindex(idx) = header_info(grd)%get_hdimid(idx)
-               nacsdims(idx) = header_info(grd)%get_hdimid(idx)
-            end do
-            do idx = 1, num_patches
-               varid = this%file_varids(field_index, idx)
-               ! Figure the dimension ID array for this field
-               ! We have defined the horizontal grid dimensions in dimindex
-               fdims = num_hdims
-               do jdx = 1, mdimsize
-                  fdims = fdims + 1
-                  dimindex(fdims) = mdimids(mdims(jdx))
-               end do
-               if(.not. restart) then
-                  ! Only add time dimension if this is not a restart history tape
-                  fdims = fdims + 1
-                  dimindex(fdims) = timdim
-               end if
-               ! peverwhee - TODO: enable patch output
-               ! Define the variable
-               call cam_pio_def_var(this%hist_files(split_file_index), trim(fname_tmp), ncreal,           &
-                    dimindex(1:fdims), varid)
-               if (.not. varid_set) then
-                  this%file_varids(field_index, idx) = varid
-               end if
-               if (mdimsize > 0) then
-                  ierr = pio_put_att(this%hist_files(split_file_index), varid, 'mdims', mdims(1:mdimsize))
-                  call cam_pio_handle_error(ierr, 'config_define_file: cannot define mdims for '//trim(fname_tmp))
-               end if
-               str = this%field_list(field_index)%sampling_sequence()
-               if (len_trim(str) > 0) then
-                  ierr = pio_put_att(this%hist_files(split_file_index), varid, 'Sampling_Sequence', trim(str))
-                  call cam_pio_handle_error(ierr, 'config_define_file: cannot define Sampling_Sequence for '//trim(fname_tmp))
-               end if
-               if (this%field_list(field_index)%flag_xyfill()) then
-                  ! Write _FillValue and missing_value attributes so that
-                  ! netCDF-aware tools (ncview, ncdump, etc.) recognise fill
-                  ! values.  The attribute type must match the variable type.
-                  if (ncreal == pio_double) then
-                     ierr = pio_put_att(this%hist_files(split_file_index), varid, '_FillValue', this%field_list(field_index)%fill_value())
-                     call cam_pio_handle_error(ierr, subname//'cannot define _FillValue for '//trim(fname_tmp))
-                     ierr = pio_put_att(this%hist_files(split_file_index), varid, 'missing_value', this%field_list(field_index)%fill_value())
-                     call cam_pio_handle_error(ierr, subname//'cannot define missing_value for '//trim(fname_tmp))
-                  else
-                     ierr = pio_put_att(this%hist_files(split_file_index), varid, '_FillValue', real(this%field_list(field_index)%fill_value(), r4))
-                     call cam_pio_handle_error(ierr, subname//'cannot define _FillValue for '//trim(fname_tmp))
-                     ierr = pio_put_att(this%hist_files(split_file_index), varid, 'missing_value', real(this%field_list(field_index)%fill_value(), r4))
-                     call cam_pio_handle_error(ierr, subname//'cannot define missing_value for '//trim(fname_tmp))
-                  end if
-               end if
-               str = this%field_list(field_index)%units()
-               if (len_trim(str) > 0) then
-                  ierr=pio_put_att (this%hist_files(split_file_index), varid, 'units', trim(str))
-                  call cam_pio_handle_error(ierr, 'config_define_file: cannot define units for '//trim(fname_tmp))
-               end if
-               str = this%field_list(field_index)%mixing_ratio()
-               if (len_trim(str) > 0) then
-                  ierr=pio_put_att (this%hist_files(split_file_index), varid, 'mixing_ratio', trim(str))
-                  call cam_pio_handle_error(ierr, 'config_define_file: cannot define mixing_ratio for '//trim(fname_tmp))
+            if (this%field_list(field_index)%flag_xyfill()) then
+               ! Write _FillValue and missing_value attributes so that
+               ! netCDF-aware tools (ncview, ncdump, etc.) recognise fill
+               ! values.  The attribute type must match the variable type.
+               if (ncreal == pio_double) then
+                  ierr = pio_put_att(hist_file, varid, '_FillValue', this%field_list(field_index)%fill_value())
+                  call cam_pio_handle_error(ierr, 'config_define_fields: cannot define _FillValue for '//trim(fname_tmp))
+                  ierr = pio_put_att(hist_file, varid, 'missing_value', this%field_list(field_index)%fill_value())
+                  call cam_pio_handle_error(ierr, 'config_define_fields: cannot define missing_value for '//trim(fname_tmp))
+               else
+                  ierr = pio_put_att(hist_file, varid, '_FillValue', real(this%field_list(field_index)%fill_value(), r4))
+                  call cam_pio_handle_error(ierr, 'config_define_fields: cannot define _FillValue for '//trim(fname_tmp))
+                  ierr = pio_put_att(hist_file, varid, 'missing_value', real(this%field_list(field_index)%fill_value(), r4))
+                  call cam_pio_handle_error(ierr, 'config_define_fields: cannot define missing_value for '//trim(fname_tmp))
                end if
-               str = this%field_list(field_index)%long_name()
-               ierr=pio_put_att (this%hist_files(split_file_index), varid, 'long_name', trim(str))
-               call cam_pio_handle_error(ierr, 'config_define_file: cannot define long_name for '//trim(fname_tmp))
-               ! Assign field attributes defining valid levels and averaging info
-               cell_methods = ''
-               if (len_trim(this%field_list(field_index)%cell_methods()) > 0) then
-                  if (len_trim(cell_methods) > 0) then
-                     cell_methods = trim(cell_methods)//' '//trim(this%field_list(field_index)%cell_methods())
-                  else
-                     cell_methods = trim(this%field_list(field_index)%cell_methods())
-                  end if
+            end if
+            str = this%field_list(field_index)%units()
+            if (len_trim(str) > 0) then
+               ierr=pio_put_att (hist_file, varid, 'units', trim(str))
+               call cam_pio_handle_error(ierr, 'config_define_fields: cannot define units for '//trim(fname_tmp))
+            end if
+            str = this%field_list(field_index)%mixing_ratio()
+            if (len_trim(str) > 0) then
+               ierr=pio_put_att (hist_file, varid, 'mixing_ratio', trim(str))
+               call cam_pio_handle_error(ierr, 'config_define_fields: cannot define mixing_ratio for '//trim(fname_tmp))
+            end if
+            str = this%field_list(field_index)%long_name()
+            ierr=pio_put_att (hist_file, varid, 'long_name', trim(str))
+            call cam_pio_handle_error(ierr, 'config_define_fields: cannot define long_name for '//trim(fname_tmp))
+            ! Assign field attributes defining valid levels and averaging info
+            cell_methods = ''
+            if (len_trim(this%field_list(field_index)%cell_methods()) > 0) then
+               if (len_trim(cell_methods) > 0) then
+                  cell_methods = trim(cell_methods)//' '//trim(this%field_list(field_index)%cell_methods())
+               else
+                  cell_methods = trim(this%field_list(field_index)%cell_methods())
                end if
-               ! Time cell methods is after field method because time averaging is
-               ! applied later (just before output) than field method which is applied
-               ! before outfld call.
-               call AvgflagToString(this%field_list(field_index)%accumulate_type(), str)
-               cell_methods = adjustl(trim(cell_methods)//' '//'time: '//str)
-               ierr = pio_put_att(this%hist_files(split_file_index), varid, 'cell_methods', trim(cell_methods))
-               call cam_pio_handle_error(ierr, 'config_define_file: cannot define cell_methods for '//trim(fname_tmp))
-            end do ! end loop over patches
-            deallocate(mdims)
-         end do ! end loop over fields
-         deallocate(mdimids)
-         ierr = pio_enddef(this%hist_files(split_file_index))
-         if (ierr /= PIO_NOERR) then
-            call endrun('config_define_file: ERROR exiting define mode in PIO', file=__FILE__, line=__LINE__)
+            end if
+            ! Time cell methods is after field method because time averaging is
+            ! applied later (just before output) than field method which is applied
+            ! before outfld call.
+            call AvgflagToString(this%field_list(field_index)%accumulate_type(), str)
+            cell_methods = adjustl(trim(cell_methods)//' '//'time: '//str)
+            ierr = pio_put_att(hist_file, varid, 'cell_methods', trim(cell_methods))
+            call cam_pio_handle_error(ierr, 'config_define_fields: cannot define cell_methods for '//trim(fname_tmp))
+         end do ! end loop over patches
+         deallocate(mdims)
+      end do ! end loop over fields
+
+   end subroutine config_define_fields
+
+   ! ========================================================================
+
+   subroutine config_define_restart_fields(this, num_patches, dimindex, num_hdims, fdims)
+      use cam_history_support, only: max_chars
+      use cam_pio_utils,       only: cam_pio_def_var
+      use pio,                 only: pio_int, pio_double
+      use cam_abortutils,      only: endrun
+      class(hist_file_t), intent(inout) :: this
+      integer,               intent(in) :: num_patches
+      integer,               intent(in) :: dimindex(:)
+      integer,               intent(in) :: num_hdims
+      integer,               intent(in) :: fdims(:)
+      ! Local variables
+      integer :: ierr, field_index, idx
+      integer :: nstdev, stdev_index
+      character(len=512) :: errmsg
+      character(len=max_chars) :: str
+      type(var_desc_t) :: varid
+
+      ! Determine how many standard deviation fields we have
+      nstdev = 0
+      stdev_index = 1
+      do field_index = 1, size(this%field_list)
+         if (this%field_list(field_index)%accumulate_type() == 'var') then
+            nstdev = nstdev + 1
          end if
-         if(masterproc) then
-            write(iulog,*)'config_define_file: Successfully opened netcdf file '//trim(this%file_names(split_file_index))
+      end do
+
+      if (.not. allocated(this%nacs_varids)) then
+         allocate(this%nacs_varids(size(this%field_list), num_patches), stat=ierr, errmsg=errmsg)
+         if (ierr /= 0) then
+            call endrun('config_define_restart_fields: failed to allocate this%nacs_varids; errmsg = '//trim(errmsg))
+         end if
+         allocate(this%varbuff_varids(nstdev, num_patches), stat=ierr, errmsg=errmsg)
+         if (ierr /= 0) then
+            call endrun('config_define_restart_fields: failed to allocate this%varbuff_varids; errmsg = '//trim(errmsg))
          end if
+      end if
+      do field_index = 1, size(this%field_list)
+         do idx = 1, num_patches
+            if (this%field_list(field_index)%accumulate_type() == 'lst') then
+               cycle
+            end if
+            ! Define "number of samples" variable per field
+            str = trim(this%field_list(field_index)%diag_name()) // '_nacs'
+            call cam_pio_def_var(this%restart_file, trim(str), pio_int,      &
+                     dimindex(1:num_hdims), varid)
+            this%nacs_varids(field_index, idx) = varid
+            ! Define standard deviation buffer variable where relevant
+            if (this%field_list(field_index)%accumulate_type() == 'var') then
+               str = trim(this%field_list(field_index)%diag_name()) // '_var_buffer'
+               call cam_pio_def_var(this%restart_file, trim(str), pio_double, &
+                     dimindex(1:fdims(field_index)), varid)
+               this%varbuff_varids(stdev_index, idx) = varid
+               stdev_index = stdev_index + 1
+            end if
+         end do
+      end do
 
-         !
-         ! Write time-invariant portion of history header
+   end subroutine config_define_restart_fields
 
-         if (.not. is_satfile) then
-            do idx = 1, size(this%grids)
-               call cam_grid_write_var(this%hist_files(split_file_index), this%grids(idx), &
-                  file_index=split_file_index)
-            end do
-            ierr = pio_put_var(this%hist_files(split_file_index), this%mdtid, (/dtime/))
-            call cam_pio_handle_error(ierr, 'config_define_file: cannot put mdt')
-
-            !
-            ! Model date info
-            !
-            ierr = pio_put_var(this%hist_files(split_file_index), this%ndbaseid, (/ndbase/))
-            call cam_pio_handle_error(ierr, 'config_define_file: cannot put ndbase')
-            ierr = pio_put_var(this%hist_files(split_file_index), this%nsbaseid, (/nsbase/))
-            call cam_pio_handle_error(ierr, 'config_define_file: cannot put nsbase')
-
-            ierr = pio_put_var(this%hist_files(split_file_index), this%nbdateid, (/nbdate/))
-            call cam_pio_handle_error(ierr, 'config_define_file: cannot put nbdate')
-            ierr = pio_put_var(this%hist_files(split_file_index), this%nbsecid, (/nbsec/))
-            call cam_pio_handle_error(ierr, 'config_define_file: cannot put nbsec')
-         end if
+   ! ========================================================================
 
-         ! Write the mdim variable data
-         call write_hist_coord_vars(this%hist_files(split_file_index), restart)
+   subroutine config_write_invariant_header(this, hist_file, file_index, ndbase, &
+                    nsbase, nbdate, nbsec, restart)
+      use pio,                 only: pio_put_var
+      use cam_pio_utils,       only: cam_pio_handle_error
+      use cam_grid_support,    only: cam_grid_write_var
+      use time_manager,        only: get_step_size
+      use cam_history_support, only: write_hist_coord_vars
+      ! Dummy arguments
+      class(hist_file_t),           intent(inout) :: this
+      type(file_desc_t),            intent(inout) :: hist_file
+      integer,                      intent(in)    :: file_index
+      integer,                      intent(in)    :: ndbase
+      integer,                      intent(in)    :: nsbase
+      integer,                      intent(in)    :: nbdate
+      integer,                      intent(in)    :: nbsec
+      logical,                      intent(in)    :: restart
+      ! Local variables
+      integer :: idx, ierr
+      integer :: dtime
 
-      end do ! end loop over files
+      dtime = get_step_size()
 
-      if (allocated(header_info)) then
-         do idx = 1, size(header_info)
-            call header_info(idx)%deallocate()
-         end do
-         deallocate(header_info)
-      end if
+      do idx = 1, size(this%grids)
+         call cam_grid_write_var(hist_file, this%grids(idx), &
+            file_index=file_index)
+      end do
+      ierr = pio_put_var(hist_file, this%mdtid, (/dtime/))
+      call cam_pio_handle_error(ierr, 'config_write_invariant_header: cannot put mdt')
 
-   end subroutine config_define_file
+      !
+      ! Model date info
+      !
+      ierr = pio_put_var(hist_file, this%ndbaseid, (/ndbase/))
+      call cam_pio_handle_error(ierr, 'config_write_invariant_header: cannot put ndbase')
+      ierr = pio_put_var(hist_file, this%nsbaseid, (/nsbase/))
+      call cam_pio_handle_error(ierr, 'config_write_invariant_header: cannot put nsbase')
+
+      ierr = pio_put_var(hist_file, this%nbdateid, (/nbdate/))
+      call cam_pio_handle_error(ierr, 'config_write_invariant_header: cannot put nbdate')
+      ierr = pio_put_var(hist_file, this%nbsecid, (/nbsec/))
+      call cam_pio_handle_error(ierr, 'config_write_invariant_header: cannot put nbsec')
+
+      ! Write the mdim variable data
+      call write_hist_coord_vars(hist_file, restart)
+
+   end subroutine config_write_invariant_header
 
    ! ========================================================================
 
-   subroutine config_write_time_dependent_variables(this, restart)
+   subroutine config_write_restart_file(this)
+      use pio,           only: pio_put_var, pio_file_is_open
+      use time_manager,  only: get_nstep, get_curr_date, get_curr_time
+      use time_manager,  only: set_date_from_time_float, get_step_size
+      use datetime_mod,  only: datetime
+      use spmd_utils,    only: masterproc
+      use cam_logfile,   only: iulog
+      use perf_mod,      only: t_startf, t_stopf
+      use cam_pio_utils, only: cam_pio_handle_error
+      ! Dummy arguments
+      class(hist_file_t), intent(inout) :: this
+      ! Local variables
+      integer :: ierr
+      integer :: field_index, var_buffer_idx
+      integer :: yr, mon, day    ! year, month, and day components of a date
+      integer :: nstep
+      integer :: ncdate
+      integer :: ncsec
+      integer :: ndcur
+      integer :: nscur
+      integer :: start, count1
+      integer :: startc(2)         ! start values required by nf_put_vara (character)
+      integer :: countc(2)         ! count values required by nf_put_vara (character)
+      real(r8) :: time             ! current (or midpoint) time
+      real(r8) :: time_interval(2) ! time interval boundaries
+      logical :: accumulate        ! flag for write_field to indicate whether to do accumulation or not
+      logical :: write_var_buffer
+      character(len=8) :: cdate    ! system date
+      character(len=8) :: ctime    ! system time
+
+      accumulate = .false.
+      nstep = get_nstep()
+      call get_curr_date(yr, mon, day, ncsec)
+      ncdate = yr*10000 + mon*100 + day
+      call get_curr_time(ndcur, nscur)
+      time = ndcur + nscur/86400._r8
+      time_interval(1) = this%beg_time
+      time_interval(2) = time
+
+      start = 1
+      count1 = 1
+      startc(1) = 1
+      startc(2) = start
+      countc(2) = 1
+
+      call datetime (cdate, ctime)
+     
+      ierr = pio_put_var (this%restart_file,this%ndcurid,(/start/),(/count1/),(/ndcur/))
+      call cam_pio_handle_error(ierr, 'config_write_restart_file: cannot write "ndcur" variable')
+      ierr = pio_put_var (this%restart_file,this%nscurid,(/start/),(/count1/),(/nscur/))
+      call cam_pio_handle_error(ierr, 'config_write_restart_file: cannot write "nscur" variable')
+      ierr = pio_put_var (this%restart_file,this%nstephid,(/start/),(/count1/),(/nstep/))
+      call cam_pio_handle_error(ierr, 'config_write_restart_file: cannot write "nstephid" variable')
+
+      ierr = pio_put_var (this%restart_file,this%dateid,(/start/),(/count1/),(/ncdate/))
+      call cam_pio_handle_error(ierr, 'config_write_restart_file: cannot write "ncdate" variable')
+      ierr = pio_put_var (this%restart_file,this%datesecid,(/start/),(/count1/),(/ncsec/))
+      call cam_pio_handle_error(ierr, 'config_write_restart_file: cannot write "ncsec" variable')
+      countc(1) = 2
+
+      ierr=pio_put_var (this%restart_file, this%timeid, (/start/),(/count1/),(/time/))
+      call cam_pio_handle_error(ierr, 'config_write_restart_file: cannot write instantaneous "time" variable')
+      ierr=pio_put_var (this%restart_file, this%tbndid, startc, countc, time_interval)
+      call cam_pio_handle_error(ierr, 'config_write_restart_file: cannot write "time_bounds" variable')
+      countc(1) = 8
+      ierr = pio_put_var (this%restart_file, this%date_writtenid, startc, countc, (/cdate/))
+      call cam_pio_handle_error(ierr, 'config_write_restart_file: cannot write "cdate" variable')
+      ierr = pio_put_var (this%restart_file, this%time_writtenid, startc, countc, (/ctime/))
+      call cam_pio_handle_error(ierr, 'config_write_restart_file: cannot write "ctime" variable')
+
+      var_buffer_idx = 0
+
+      do field_index = 1, size(this%field_list)
+         if (this%field_list(field_index)%accumulate_type() == 'lst') then
+            cycle
+         end if
+         call this%write_field(this%restart_file, this%field_list(field_index), start, field_index, &
+            this%precision(), accumulate)
+         if (this%field_list(field_index)%accumulate_type() == 'var') then
+            write_var_buffer = .true.
+            var_buffer_idx = var_buffer_idx + 1
+         else
+            write_var_buffer = .false.
+         end if
+         call this%write_restart_fields(this%restart_file, this%field_list(field_index), field_index, write_var_buffer, &
+            var_buffer_idx)
+         ! Clear the buffers
+         call this%field_list(field_index)%clear_buffers()
+      end do
+
+   end subroutine config_write_restart_file
+
+   ! ========================================================================
+
+   subroutine config_write_time_dependent_variables(this)
       use pio,           only: pio_put_var, pio_file_is_open
       use time_manager,  only: get_nstep, get_curr_date, get_curr_time
       use time_manager,  only: set_date_from_time_float, get_step_size
@@ -1651,7 +2136,6 @@ subroutine config_write_time_dependent_variables(this, restart)
       use cam_pio_utils, only: cam_pio_handle_error
       ! Dummy arguments
       class(hist_file_t), intent(inout) :: this
-      logical,            intent(in)    :: restart
 
       ! Local variables
       integer :: yr, mon, day      ! year, month, and day components of a date
@@ -1668,10 +2152,12 @@ subroutine config_write_time_dependent_variables(this, restart)
       integer :: start, count1
       integer :: startc(2)          ! start values required by nf_put_vara (character)
       integer :: countc(2)          ! count values required by nf_put_vara (character)
+      logical :: accumulate         ! flag for write_field to indicate whether to do accumulation or not
       logical :: is_initfile, is_satfile
       character(len=8) :: cdate  ! system date
       character(len=8) :: ctime  ! system time
 
+      accumulate = .true.
       nstep = get_nstep()
       call get_curr_date(yr, mon, day, ncsec(instantaneous_file_index))
       ncdate(instantaneous_file_index) = yr*10000 + mon*100 + day
@@ -1696,7 +2182,7 @@ subroutine config_write_time_dependent_variables(this, restart)
       startc(2) = start
       countc(2) = 1
 
-      if(.not.restart) this%beg_time = time  ! update beginning time of next interval
+      this%beg_time = time  ! update beginning time of next interval
       call datetime (cdate, ctime)
 
       ! peverwhee - TODO handle composed fields
@@ -1728,7 +2214,7 @@ subroutine config_write_time_dependent_variables(this, restart)
          ierr = pio_put_var (this%hist_files(split_file_index),this%datesecid,(/start/),(/count1/),(/ncsec(split_file_index)/))
          call cam_pio_handle_error(ierr, 'config_write_time_dependent_variables: cannot write "ncsec" variable')
          countc(1) = 2
-         if (split_file_index == accumulated_file_index .and. .not. restart .and. .not. is_initfile) then
+         if (split_file_index == accumulated_file_index .and. .not. is_initfile) then
             ! accumulated tape - time is midpoint of time_bounds
 
             ierr=pio_put_var (this%hist_files(split_file_index), this%timeid, (/start/),(/count1/), &
@@ -1750,14 +2236,16 @@ subroutine config_write_time_dependent_variables(this, restart)
             ! we may have a history split, conditionally skip fields that are
             ! for the other file
             if ((this%field_list(field_idx)%accumulate_type() .eq. 'lst') .and. &
-               split_file_index == accumulated_file_index .and. .not. restart) then
+               split_file_index == accumulated_file_index) then
                cycle
             else if ((this%field_list(field_idx)%accumulate_type() .ne. 'lst') .and. &
-               split_file_index == instantaneous_file_index .and. .not. restart) then
+               split_file_index == instantaneous_file_index) then
                cycle
             end if
-            call this%write_field(this%field_list(field_idx), split_file_index, restart, start, field_idx, &
-               this%precision())
+            call this%write_field(this%hist_files(split_file_index), this%field_list(field_idx), start, field_idx, &
+               this%precision(), accumulate)
+            ! Clear the buffers
+            call this%field_list(field_idx)%clear_buffers()
          end do
       end do
       call t_stopf  ('write_field')
@@ -1766,10 +2254,11 @@ end subroutine config_write_time_dependent_variables
 
    ! ========================================================================
 
-   subroutine config_write_field(this, field, split_file_index, restart, &
-      sample_index, field_index, field_precision)
+   subroutine config_write_field(this, hist_file, field, sample_index, field_index, field_precision, &
+                   accumulate)
       use pio,                 only: PIO_OFFSET_KIND, pio_setframe
       use hist_api,            only: hist_field_norm_value
+      use hist_api,            only: hist_field_value
       use cam_grid_support,    only: cam_grid_write_dist_array
       use cam_abortutils,      only: check_allocate, endrun
       use hist_field,          only: hist_field_info_t
@@ -1778,12 +2267,12 @@ subroutine config_write_field(this, field, split_file_index, restart, &
       use cam_logfile,         only: iulog
       ! Dummy arguments
       class(hist_file_t),      intent(inout) :: this
+      type(file_desc_t),       intent(inout) :: hist_file
       type(hist_field_info_t), intent(inout) :: field
-      integer,                 intent(in)    :: split_file_index
-      logical,                 intent(in)    :: restart
       integer,                 intent(in)    :: sample_index
       integer,                 intent(in)    :: field_index
       character(len=*),        intent(in)    :: field_precision
+      logical,                 intent(in)    :: accumulate
 
       ! Local variables
       integer, allocatable           :: field_shape(:) ! Field file dim sizes
@@ -1829,45 +2318,133 @@ subroutine config_write_field(this, field, split_file_index, restart, &
 
       do patch_idx = 1, num_patches
          varid = this%file_varids(field_index, patch_idx)
-         call pio_setframe(this%hist_files(split_file_index), varid, int(sample_index,kind=PIO_OFFSET_KIND))
+         call pio_setframe(hist_file, varid, int(sample_index,kind=PIO_OFFSET_KIND))
          if (frank == 1) then
-            call hist_field_norm_value(field, field_data(:,1), logger=errors)
+            if (accumulate) then
+               call hist_field_norm_value(field, field_data(:,1), logger=errors)
+            else
+               call hist_field_value(field, field_data(:,1), logger=errors)
+            end if
             if (errors%num_errors() > 0) then
                call errors%output(iulog)
                write(errmsg, *) subname, 'ERROR writing field "', trim(field%diag_name()), '"'
                call endrun(errmsg)
             end if
             if (trim(field_precision) == 'REAL32') then
-               call cam_grid_write_dist_array(this%hist_files(split_file_index), field_decomp, (/dim_sizes(1)/), &
+               call cam_grid_write_dist_array(hist_file, field_decomp, (/dim_sizes(1)/), &
                     field_shape, real(field_data(:,1), r4), varid)
             else
-               call cam_grid_write_dist_array(this%hist_files(split_file_index), field_decomp, (/dim_sizes(1)/), &
+               call cam_grid_write_dist_array(hist_file, field_decomp, (/dim_sizes(1)/), &
                     field_shape, field_data(:,1), varid)
             end if
          else
-            call hist_field_norm_value(field, field_data, logger=errors)
+            if (accumulate) then
+               call hist_field_norm_value(field, field_data, logger=errors)
+            else
+               call hist_field_value(field, field_data, logger=errors)
+            end if
             if (errors%num_errors() > 0) then
                call errors%output(iulog)
                write(errmsg, *) subname, 'ERROR writing field "', trim(field%diag_name()), '"'
                call endrun(errmsg)
             end if
             if (trim(field_precision) == 'REAL32') then
-               call cam_grid_write_dist_array(this%hist_files(split_file_index), field_decomp, dim_sizes(1:frank), &
+               call cam_grid_write_dist_array(hist_file, field_decomp, dim_sizes(1:frank), &
                     field_shape, real(field_data, r4), varid)
             else
-               call cam_grid_write_dist_array(this%hist_files(split_file_index), field_decomp, dim_sizes(1:frank), &
+               call cam_grid_write_dist_array(hist_file, field_decomp, dim_sizes(1:frank), &
                     field_shape, field_data, varid)
             end if
          end if
       end do
 
-      ! Clear the buffers after writing
-      call field%clear_buffers(logger=errors)
-
    end subroutine config_write_field
 
    ! ========================================================================
 
+   subroutine config_write_restart_fields(this, hist_file, field, field_index, write_var_buffer, &
+                   var_buff_idx)
+      use hist_field,       only: hist_field_info_t
+      use hist_api,         only: hist_field_samples
+      use hist_api,         only: hist_field_var_buffer
+      use cam_abortutils,   only: check_allocate
+      use pio,              only: var_desc_t
+      use cam_grid_support, only: cam_grid_write_dist_array
+      ! Dummy arguments
+      class(hist_file_t),      intent(inout) :: this
+      type(file_desc_t),       intent(inout) :: hist_file
+      type(hist_field_info_t), intent(inout) :: field
+      integer,                 intent(in)    :: field_index
+      integer,                 intent(in)    :: var_buff_idx
+      logical,                 intent(in)    :: write_var_buffer
+      ! Local variables
+      integer, allocatable :: num_samples(:)
+      integer, allocatable :: beg_dims(:)
+      integer, allocatable :: end_dims(:)
+      integer, allocatable :: dimind(:)
+      integer, allocatable :: dim_sizes(:)
+      integer, allocatable :: field_shape(:)
+      real(r8), allocatable :: var_buffer(:,:)
+      type(var_desc_t)     :: varid
+      integer              :: idx, patch_index
+      integer              :: field_decomp
+      integer              :: num_patches, ierr, rank
+      character(len=512)   :: errmsg
+      character(len=*), parameter :: subname = 'config_write_restart_fields: '
+
+      beg_dims = field%beg_dims()
+      end_dims = field%end_dims()
+      field_shape = field%shape()
+      rank = size(field_shape)
+
+      allocate(num_samples(end_dims(1) - beg_dims(1) + 1), stat=ierr, errmsg=errmsg)
+      call check_allocate(ierr, subname, 'num_samples', file=__FILE__, line=__LINE__-1, errmsg=errmsg)
+
+      if (rank == 1) then
+         allocate(var_buffer(end_dims(1) - beg_dims(1) + 1, 1), stat=ierr, errmsg=errmsg)
+         call check_allocate(ierr, subname, 'var_buffer', file=__FILE__, line=__LINE__-1, errmsg=errmsg)
+      else
+         allocate(var_buffer(end_dims(1) - beg_dims(1) + 1, field_shape(2)), stat=ierr, errmsg=errmsg)
+         call check_allocate(ierr, subname, 'var_buffer', file=__FILE__, line=__LINE__-1, errmsg=errmsg)
+      end if
+
+      ! Shape of array
+      dimind = field%dimensions()
+
+      allocate(dim_sizes(size(beg_dims)), stat=ierr)
+      call check_allocate(ierr, subname, 'dim_sizes', file=__FILE__, line=__LINE__-1)
+      do idx = 1, size(beg_dims)
+         dim_sizes(idx) = end_dims(idx) - beg_dims(idx) + 1
+      end do
+
+      field_decomp = field%decomp()
+
+      num_patches = 1
+
+      do patch_index = 1, num_patches
+         varid = this%nacs_varids(field_index, patch_index)
+         call hist_field_samples(field, num_samples)
+         call cam_grid_write_dist_array(hist_file, field_decomp, (/dim_sizes(1)/), &
+                    (/field_shape(1)/), num_samples, varid)
+         if (write_var_buffer) then
+            varid = this%varbuff_varids(var_buff_idx, patch_index)
+            if (rank == 1) then
+               call hist_field_var_buffer(field, var_buffer(:,1))
+               call cam_grid_write_dist_array(hist_file, field_decomp, (/dim_sizes(1)/), &
+                       (/field_shape(1)/), var_buffer(:,1), varid)
+            else
+               call hist_field_var_buffer(field, var_buffer)
+               call cam_grid_write_dist_array(hist_file, field_decomp, dim_sizes(1:rank), &
+                       field_shape, var_buffer, varid)
+            end if
+         end if
+      end do
+
+      
+   end subroutine config_write_restart_fields
+
+   ! ========================================================================
+
    subroutine config_close_files(this)
       use pio,           only: pio_file_is_open
       use cam_pio_utils, only: cam_pio_closefile
@@ -1879,16 +2456,16 @@ subroutine config_close_files(this)
       ! Local variables
       integer :: split_file_index
 
-      if(pio_file_is_open(this%hist_files(accumulated_file_index)) .or. &
-                 pio_file_is_open(this%hist_files(instantaneous_file_index))) then
-         deallocate(this%file_varids)
-      end if
+!      if(pio_file_is_open(this%hist_files(accumulated_file_index)) .or. &
+!                 pio_file_is_open(this%hist_files(instantaneous_file_index))) then
+!         deallocate(this%file_varids)
+!      end if
 
       do split_file_index = 1, max_split_files
          if (pio_file_is_open(this%hist_files(split_file_index))) then
             if (masterproc) then
                write(iulog,*)'config_close_files: nf_close(', trim(this%volume),')=',&
-                  this%file_names(split_file_index)
+                  trim(this%file_names(split_file_index))
             end if
             call cam_pio_closefile(this%hist_files(split_file_index))
          end if
@@ -1903,6 +2480,26 @@ end subroutine config_close_files
 
    ! ========================================================================
 
+   subroutine config_close_restart_file(this)
+      use cam_pio_utils, only: cam_pio_closefile
+      use pio,           only: pio_file_is_open
+      use spmd_utils,    only: masterproc
+      use cam_logfile,   only: iulog
+      ! Dummy arguments
+      class(hist_file_t), intent(inout) :: this
+
+      if (pio_file_is_open(this%restart_file)) then
+         if (masterproc) then
+            write(iulog,*) 'config_close_restart_file: nf_close(', trim(this%volume), ')=', &
+                    trim(this%restart_file_name)
+         end if
+         call cam_pio_closefile(this%restart_file)
+      end if
+
+   end subroutine config_close_restart_file
+
+   ! ========================================================================
+
    subroutine config_clear_buffers(this)
       use hist_msg_handler,    only: hist_log_messages
       use spmd_utils,          only: masterproc
diff --git a/src/history/cam_hist_restart.F90 b/src/history/cam_hist_restart.F90
index 9685f14d6..42057da28 100644
--- a/src/history/cam_hist_restart.F90
+++ b/src/history/cam_hist_restart.F90
@@ -31,7 +31,7 @@ module cam_hist_restart
     !
     !   The size of these parameters should match the assignments in restart_vars_setnames and restart_dims_setnames below
     !
-    integer, parameter :: num_restart_vars = 20
+    integer, parameter :: num_restart_vars = 21
     integer, parameter :: num_restart_dims =  9
     type(restart_variable_t)  :: restart_vars(num_restart_vars)
     type(restart_dimension_t) :: restart_dims(num_restart_dims)
@@ -120,7 +120,9 @@ subroutine hist_restart_write(restart_file, hist_configs, max_num_fields, just_w
       character(len=max_chars) :: long_name(max_num_fields, size(hist_configs))
       character(len=max_chars) :: cell_methods(max_num_fields, size(hist_configs))
       character(len=max_chars) :: units(max_num_fields, size(hist_configs))
+      character(len=max_chars) :: volume(size(hist_configs))
       character(len=max_hcoordname_len) :: dim_names(registeredmdims)
+      character(len=max_string_len) :: restart_file_paths(size(hist_configs))
       real(r8) :: beg_time(size(hist_configs))
       real(r8) :: fill_value(max_num_fields, size(hist_configs))
       logical :: has_accum
@@ -136,6 +138,7 @@ subroutine hist_restart_write(restart_file, hist_configs, max_num_fields, just_w
       fill_flag = 0
       fill_value = 0
       dimensions = 0
+      restart_file_paths = ''
       ! Compile all the necessary info for the restart file from the hist_configs array
       do idx = 1, size(hist_configs)
           ! Grab the field list
@@ -145,7 +148,9 @@ subroutine hist_restart_write(restart_file, hist_configs, max_num_fields, just_w
           ! Determine whether or not there will be an rh file
           if (hist_configs(idx)%has_accumulated_fields() .and. .not. just_written(idx)) then
              has_rh_int(idx) = 1
+             restart_file_paths(idx) = hist_configs(idx)%get_restart_filename()
           end if
+          volume(idx) = hist_configs(idx)%get_volume()
           ! Get the output frequency
           output_freq(idx) = hist_configs(idx)%output_freq()
           ! Get the number of samples written to the hist file
@@ -189,7 +194,9 @@ subroutine hist_restart_write(restart_file, hist_configs, max_num_fields, just_w
       do idx = 1, num_restart_vars
          select case(trim(restart_vars(idx)%var_name))
          case ('has_rh_file')
-            ierr = pio_put_var(restart_file, restart_vars(idx)%vdesc, has_rh_int)            
+            ierr = pio_put_var(restart_file, restart_vars(idx)%vdesc, has_rh_int)
+         case ('volume')
+            ierr = pio_put_var(restart_file, restart_vars(idx)%vdesc, volume)
          case ('output_frequency')
             ierr = pio_put_var(restart_file, restart_vars(idx)%vdesc, output_freq)
          case ('field_list')
@@ -226,8 +233,8 @@ subroutine hist_restart_write(restart_file, hist_configs, max_num_fields, just_w
             ierr = pio_put_var(restart_file, restart_vars(idx)%vdesc, dimensions)
          case ('dimension_names')
             ierr = pio_put_var(restart_file, restart_vars(idx)%vdesc, dim_names)
-         case ('history_restart_path')
-            ! PEVERWHEE Needs accumulated fields to properly implement
+         case ('rh_file_path')
+            ierr = pio_put_var(restart_file, restart_vars(idx)%vdesc, restart_file_paths)
          case default
          end select
          if (ierr /= 0) then
@@ -253,6 +260,13 @@ subroutine set_restart_variable_names()
       restart_vars(rvar_index)%dimension_ids(1) = max_chars_dim_ind
       restart_vars(rvar_index)%dimension_ids(2) = num_configs_dim_ind
 
+      rvar_index = rvar_index + 1
+      restart_vars(rvar_index)%var_name = 'volume'
+      restart_vars(rvar_index)%var_type = pio_char
+      restart_vars(rvar_index)%number_of_dimensions = 2
+      restart_vars(rvar_index)%dimension_ids(1) = max_chars_dim_ind
+      restart_vars(rvar_index)%dimension_ids(2) = num_configs_dim_ind
+
       rvar_index = rvar_index + 1
       restart_vars(rvar_index)%var_name = 'field_list'
       restart_vars(rvar_index)%var_type = pio_char
@@ -382,7 +396,7 @@ subroutine set_restart_variable_names()
       restart_vars(rvar_index)%dimension_ids(2) = registeredmdims_dim_ind
 
       rvar_index = rvar_index + 1
-      restart_vars(rvar_index)%var_name = 'history_restart_path'
+      restart_vars(rvar_index)%var_name = 'rh_file_path'
       restart_vars(rvar_index)%var_type = pio_char
       restart_vars(rvar_index)%number_of_dimensions = 2
       restart_vars(rvar_index)%dimension_ids(1) = max_string_len_dim_ind
diff --git a/src/history/cam_history.F90 b/src/history/cam_history.F90
index b4c15f590..789756f26 100644
--- a/src/history/cam_history.F90
+++ b/src/history/cam_history.F90
@@ -227,9 +227,9 @@ subroutine history_write_files()
                   end if
                end do
             end do
-            call hist_configs(file_idx)%define_file(restart, logname, host, model_doi_url)
+            call hist_configs(file_idx)%define_file(logname, host, model_doi_url)
          end if
-         call hist_configs(file_idx)%write_time_dependent_variables(restart)
+         call hist_configs(file_idx)%write_time_dependent_variables()
          if (nstep == 0) then
              ! Reset samples if nstep0 was written
              call hist_configs(file_idx)%reset_samples()
@@ -687,6 +687,8 @@ subroutine history_out_field_1d(diagnostic_name, field_values)
             cycle
          end if
          ! Field is active on this file - accumulate!
+         write(iulog,*) 'peverwhee - accumulate'
+         write(iulog,*) field_info%diag_name()
          call hist_field_accumulate(field_info, field_values, 1, logger=logger)
          if (masterproc) then
             call logger%output(iulog)
@@ -904,15 +906,26 @@ end subroutine history_wrap_up
    subroutine history_restart_init(restart_file)
       use cam_hist_restart, only: hist_restart_init
       use pio,              only: file_desc_t
+      ! Dummy variables
       type(file_desc_t), intent(inout) :: restart_file
+      ! Local variables
+      integer :: config_idx
 
+      ! Set up history restart variables in the restart file
+      ! We can skip this if we have no output for this run
       if (max_num_fields > 0) then
          call hist_restart_init(restart_file, size(hist_configs), max_num_fields)
       end if
 
-      ! Create restart files for history tapes if necessary (.rhX.)
+      ! Create restart files for history configs if necessary (.rhX.)
+      do config_idx = 1, size(hist_configs)
+         ! Only write the rhX file if it has accumulated fields and has not just been written
+         if (.not. hist_configs(config_idx)%has_accumulated_fields() .or. just_written(config_idx)) then
+            cycle
+         end if
+         call hist_configs(config_idx)%define_restart_file(logname, host, model_doi_url)
+      end do
 
-      ! Add history restart variables to overall restart file (.r.)
    end subroutine history_restart_init
 
 !#######################################################################
@@ -920,15 +933,28 @@ end subroutine history_restart_init
    subroutine history_restart_write(restart_file)
       use pio,              only: file_desc_t
       use cam_hist_restart, only: hist_restart_write
-!      use cam_hist_file, only: hist_file_restart_write
+      ! Dummy variables
       type(file_desc_t), intent(inout) :: restart_file
+      ! Local variables
+      integer :: config_idx
 
       if (max_num_fields == 0) then
          ! Don't do anything if there aren't any history fields
          return
       end if
+
       call hist_restart_write(restart_file, hist_configs, max_num_fields, just_written)
 
+      ! Write restart files for history configs if necessary (.rhX.)
+      do config_idx = 1, size(hist_configs)
+         ! Only write the rhX file if it has accumulated fields and has not just been written
+         if (.not. hist_configs(config_idx)%has_accumulated_fields() .or. just_written(config_idx)) then
+            cycle
+         end if
+         call hist_configs(config_idx)%write_restart_file()
+         call hist_configs(config_idx)%close_restart_file()
+      end do
+
    end subroutine history_restart_write
 !#######################################################################
 
diff --git a/src/history/cam_history_support.F90 b/src/history/cam_history_support.F90
index 06a948ef2..5aea98c70 100644
--- a/src/history/cam_history_support.F90
+++ b/src/history/cam_history_support.F90
@@ -174,8 +174,6 @@ function get_hist_coord_names() result(mdimnames)
      if (ierr /= 0) then
         call endrun('get_hist_coord_names: failed to allocate mdimnames; errmsg = '//trim(errmsg))
      end if
-     write(iulog,*) "peverwhee - num hist coords"
-     write(iulog,*) registeredmdims
      do idx = 1, registeredmdims
         mdimnames(idx) = hist_coords(idx)%name
      end do
diff --git a/src/utils/cam_grid_support.F90 b/src/utils/cam_grid_support.F90
index 1e4fc9666..478d23a7a 100644
--- a/src/utils/cam_grid_support.F90
+++ b/src/utils/cam_grid_support.F90
@@ -17,6 +17,7 @@ module cam_grid_support
 
    integer, parameter, public :: max_hcoordname_len   = 16
    integer, parameter, public :: max_split_files      = 2
+   integer, parameter         :: max_files = max_split_files + 1 ! Split files plus restart
 
    type, public :: vardesc_ptr_t
       type(var_desc_t), pointer :: p => NULL()
@@ -41,8 +42,8 @@ module cam_grid_support
       integer(iMap),    pointer :: map(:) => NULL()  ! map (dof) for dist. coord
       logical                   :: latitude          ! .false. means longitude
       real(r8),         pointer :: bnds(:,:) => NULL() ! bounds, if present
-      type(vardesc_ptr_t)       :: vardesc(max_split_files) ! If we are to write coord
-      type(vardesc_ptr_t)       :: bndsvdesc(max_split_files) ! Set to write bounds
+      type(vardesc_ptr_t)       :: vardesc(max_files) ! If we are to write coord
+      type(vardesc_ptr_t)       :: bndsvdesc(max_files) ! Set to write bounds
    contains
       procedure                 :: get_coord_len  => horiz_coord_len
       procedure                 :: num_elem       => horiz_coord_num_elem
@@ -63,7 +64,7 @@ module cam_grid_support
    type, abstract :: cam_grid_attribute_t
       character(len=max_hcoordname_len)    :: name = ''      ! attribute name
       character(len=max_chars)             :: long_name = '' ! attr long_name
-      type(vardesc_ptr_t)                  :: vardesc(max_split_files)
+      type(vardesc_ptr_t)                  :: vardesc(max_files)
       ! We aren't going to use this until we sort out PGI issues
       class(cam_grid_attribute_t), pointer :: next => NULL()
    contains
@@ -165,7 +166,7 @@ module cam_grid_support
       type(horiz_coord_t), pointer       :: lon_coord => NULL() ! Longitude
       logical                            :: unstructured  ! Is this needed?
       logical                            :: block_indexed ! .false. for lon/lat
-      logical                            :: attrs_defined(max_split_files) = .false.
+      logical                            :: attrs_defined(max_files) = .false.
       logical                            :: zonal_grid    = .false.
       type(cam_filemap_t),       pointer :: map => null() ! global dim map (dof)
       type(cam_grid_attr_ptr_t), pointer :: attributes => NULL()
@@ -191,6 +192,7 @@ module cam_grid_support
       procedure :: read_darray_3d_double  => cam_grid_read_darray_3d_double
       procedure :: read_darray_2d_real    => cam_grid_read_darray_2d_real
       procedure :: read_darray_3d_real    => cam_grid_read_darray_3d_real
+      procedure :: write_darray_1d_int    => cam_grid_write_darray_1d_int
       procedure :: write_darray_2d_int    => cam_grid_write_darray_2d_int
       procedure :: write_darray_3d_int    => cam_grid_write_darray_3d_int
       procedure :: write_darray_1d_double => cam_grid_write_darray_1d_double
@@ -352,6 +354,7 @@ end subroutine print_attr_spec
    end interface cam_grid_read_dist_array
 
    interface cam_grid_write_dist_array
+      module procedure cam_grid_write_dist_array_1d_int
       module procedure cam_grid_write_dist_array_2d_int
       module procedure cam_grid_write_dist_array_3d_int
       module procedure cam_grid_write_dist_array_1d_double
@@ -1322,6 +1325,41 @@ subroutine cam_grid_read_dist_array_3d_real(File, id, adims, fdims,        &
 
    end subroutine cam_grid_read_dist_array_3d_real
 
+   !------------------------------------------------------------------------
+   !
+   !  cam_grid_write_dist_array_1d_int
+   !
+   !  Interface function for the grid%write_darray_1d_int method
+   !
+   !------------------------------------------------------------------------
+   subroutine cam_grid_write_dist_array_1d_int(File, id, adims, fdims,        &
+        hbuf, varid)
+      use pio, only: file_desc_t
+
+      ! Dummy arguments
+      type(file_desc_t),         intent(inout) :: File ! PIO file handle
+      integer,                   intent(in)    :: id
+      integer,                   intent(in)    :: adims(:)
+      integer,                   intent(in)    :: fdims(:)
+      integer,                   intent(in)    :: hbuf(:)
+      type(var_desc_t),          intent(inout) :: varid
+
+      ! Local variable
+      integer                                  :: gridid
+      character(len=shr_kind_cm)               :: errormsg
+
+      gridid = get_cam_grid_index(id)
+      if (gridid > 0) then
+         call cam_grids(gridid)%write_darray_1d_int(File, adims, fdims,       &
+              hbuf, varid)
+      else
+         write(errormsg, *)                                                   &
+              'cam_grid_write_dist_array_1d_int: Bad grid ID, ', id
+         call endrun(errormsg)
+      end if
+
+   end subroutine cam_grid_write_dist_array_1d_int
+
    !------------------------------------------------------------------------
    !
    !  cam_grid_write_dist_array_2d_int
@@ -3589,6 +3627,36 @@ subroutine cam_grid_read_darray_3d_real(this, File, adims, fdims,          &
       call cam_pio_handle_error(ierr, subname//': Error reading variable')
    end subroutine cam_grid_read_darray_3d_real
 
+   !------------------------------------------------------------------------
+   !
+   !  cam_grid_write_darray_1d_int: Write a variable defined on this grid
+   !
+   !------------------------------------------------------------------------
+   subroutine cam_grid_write_darray_1d_int(this, File, adims, fdims,          &
+        hbuf, varid)
+      use pio,           only: file_desc_t, io_desc_t
+      use pio,           only: pio_write_darray, PIO_INT
+
+      use cam_pio_utils, only: cam_pio_get_decomp
+
+      ! Dummy arguments
+      class(cam_grid_t)                        :: this
+      type(file_desc_t),         intent(inout) :: File  ! PIO file handle
+      integer,                   intent(in)    :: adims(:)
+      integer,                   intent(in)    :: fdims(:)
+      integer,                   intent(in)    :: hbuf(:)
+      type(var_desc_t),          intent(inout) :: varid
+
+      ! Local variables
+      type(io_desc_t),  pointer   :: iodesc
+      integer                     :: ierr
+      character(len=*), parameter :: subname = 'cam_grid_write_darray_1d_int'
+
+      call cam_pio_get_decomp(iodesc, adims, fdims, PIO_INT, this%map)
+      call pio_write_darray(File, varid, iodesc, hbuf, ierr)
+      call cam_pio_handle_error(ierr, subname//': Error writing variable')
+   end subroutine cam_grid_write_darray_1d_int
+
    !------------------------------------------------------------------------
    !
    !  cam_grid_write_darray_2d_int: Write a variable defined on this grid

From b4a466f872d746c4a29118a10a0efffcd519797c Mon Sep 17 00:00:00 2001
From: peverwhee <courtneyp@ucar.edu>
Date: Thu, 18 Jun 2026 17:00:37 -0600
Subject: [PATCH 14/19] update hist hash

---
 .gitmodules         | 4 ++--
 src/history/buffers | 2 +-
 2 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/.gitmodules b/.gitmodules
index b9f977e0f..ec4e1c4cc 100644
--- a/.gitmodules
+++ b/.gitmodules
@@ -6,8 +6,8 @@
 	fxDONOTUSEurl = https://github.com/NCAR/ccpp-framework
 [submodule "history"]
 	path          = src/history/buffers
-	url           = https://github.com/ESMCI/history_output
-	fxtag         = history01_01
+	url           = https://github.com/peverwhee/history_output
+	fxtag         = 61536e9012bcc336f03495d718d1f046ca302195
 	fxrequired    = AlwaysRequired
 	fxDONOTUSEurl = https://github.com/ESMCI/history_output
 [submodule "mpas"]
diff --git a/src/history/buffers b/src/history/buffers
index dc000fe06..61536e901 160000
--- a/src/history/buffers
+++ b/src/history/buffers
@@ -1 +1 @@
-Subproject commit dc000fe064e10e60baa9263fbc60eccd1bc84309
+Subproject commit 61536e9012bcc336f03495d718d1f046ca302195

From 8113e4be2d308411d6b08087b4f61241babfa904 Mon Sep 17 00:00:00 2001
From: peverwhee <courtneyp@ucar.edu>
Date: Tue, 23 Jun 2026 15:26:59 -0600
Subject: [PATCH 15/19] all parts of restart write now working

---
 .gitmodules                            |  2 +-
 src/control/cam_restart.F90            | 62 +++++++++++++++++++++++---
 src/dynamics/mpas/restart_dynamics.F90 | 50 +++++++++++++++++++++
 src/history/buffers                    |  2 +-
 src/history/cam_history.F90            |  2 -
 5 files changed, 108 insertions(+), 10 deletions(-)
 create mode 100644 src/dynamics/mpas/restart_dynamics.F90

diff --git a/.gitmodules b/.gitmodules
index ec4e1c4cc..d9259c5cd 100644
--- a/.gitmodules
+++ b/.gitmodules
@@ -7,7 +7,7 @@
 [submodule "history"]
 	path          = src/history/buffers
 	url           = https://github.com/peverwhee/history_output
-	fxtag         = 61536e9012bcc336f03495d718d1f046ca302195
+	fxtag         = a8e4bf4ffd69e1332aebab7f5d34ddf2ffb228fd
 	fxrequired    = AlwaysRequired
 	fxDONOTUSEurl = https://github.com/ESMCI/history_output
 [submodule "mpas"]
diff --git a/src/control/cam_restart.F90 b/src/control/cam_restart.F90
index 81858720b..359b730d6 100644
--- a/src/control/cam_restart.F90
+++ b/src/control/cam_restart.F90
@@ -21,8 +21,9 @@ subroutine cam_write_restart(dyn_out, yr_spec, mon_spec, day_spec, sec_spec)
     use physics_grid,     only: phys_decomp, num_global_phys_cols
     use dyn_comp,         only: dyn_export_t
     use cam_control_mod,  only: caseid
-    use cam_abortutils,   only: endrun, check_allocate
+    use cam_abortutils,   only: endrun
     use shr_kind_mod,     only: cl=>shr_kind_cl
+    use runtime_obj,      only: cam_runtime_opts
 
     ! Arguments
     type(dyn_export_t),      intent(in) :: dyn_out
@@ -67,8 +68,14 @@ subroutine cam_write_restart(dyn_out, yr_spec, mon_spec, day_spec, sec_spec)
     call history_restart_init(fh)
 
     ierr = pio_put_att(fh, pio_global, 'caseid', caseid)
-    ierr = pio_enddef(fh)
 
+    ! The MPAS dycore will end the definition phase for us
+    if (cam_runtime_opts%get_dycore() /= 'mpas') then
+       ierr = pio_enddef(fh)
+    end if
+
+    ! Restart dynamics must come first in write phase
+    ! because MPAS restart write includes the definitions
     call write_restart_dynamics(fh, dyn_out)
 
     ! TODO: write ionosphere restart
@@ -82,18 +89,61 @@ subroutine cam_write_restart(dyn_out, yr_spec, mon_spec, day_spec, sec_spec)
        call endrun(errmsg)
     end if
 
-!    call write_restart_history(fh, yr_spec=yr_spec, mon_spec=mon_spec, &
-!            day_spec=day_spec, sec_spec= sec_spec )
     call history_restart_write(fh)
 
     ! Close the primary restart file
     call pio_closefile(fh)
 
     ! Update the restart pointer file
-!    call write_rest_pfile(fname, yr_spec=yr_spec, mon_spec=mon_spec, &
-!                          day_spec=day_spec, sec_spec= sec_spec )
+    call write_rest_pfile(fname, yr_spec=yr_spec, mon_spec=mon_spec, &
+                          day_spec=day_spec, sec_spec= sec_spec )
 
 
   end subroutine cam_write_restart
 
+!========================================================================================
+
+  subroutine write_rest_pfile(restart_file, yr_spec, mon_spec, day_spec, sec_spec)
+
+     ! Write the restart pointer file
+     use cam_instance,     only: inst_suffix
+     use cam_filenames,    only: interpret_filename_spec
+     use shr_kind_mod,     only: cl=>shr_kind_cl
+     use spmd_utils,       only: masterproc
+     use cam_logfile,      only: iulog
+     use cam_abortutils,   only: endrun
+     use ioFileMod,        only: cam_open_file
+
+     character(len=*),        intent(in) :: restart_file
+     integer,       optional, intent(in) :: yr_spec         ! Simulation year
+     integer,       optional, intent(in) :: mon_spec        ! Simulation month
+     integer,       optional, intent(in) :: day_spec        ! Simulation day
+     integer,       optional, intent(in) :: sec_spec        ! Seconds into current simulation day
+
+     integer :: ierr, unitn
+     character(len=CL) :: rest_pfile
+     character(len=*), parameter :: sub='write_rest_pfile'
+     !---------------------------------------------------------------------------
+
+     if (masterproc) then
+        rest_pfile = interpret_filename_spec('rpointer.cam'//trim(inst_suffix)//'.'//'%y-%m-%d-%s',&
+             yr_spec=yr_spec, mon_spec=mon_spec, day_spec=day_spec, sec_spec= sec_spec )
+        call cam_open_file(rest_pfile, unitn, 'f', status="unknown")
+        rewind unitn
+        write(unitn, '(a)', iostat=ierr) trim(restart_file)
+        if (ierr /= 0) then
+           call endrun(sub//': ERROR: writing rpointer file')
+        end if
+        close(unitn)
+
+        write(iulog,*)'(WRITE_REST_PFILE): successfully wrote local restart pointer file ',&
+           trim(rest_pfile)
+        write(iulog,'("---------------------------------------")')
+     end if
+
+  end subroutine write_rest_pfile
+
+!========================================================================================
+
+
 end module cam_restart
diff --git a/src/dynamics/mpas/restart_dynamics.F90 b/src/dynamics/mpas/restart_dynamics.F90
new file mode 100644
index 000000000..1babfac8a
--- /dev/null
+++ b/src/dynamics/mpas/restart_dynamics.F90
@@ -0,0 +1,50 @@
+module restart_dynamics
+
+! Writing and reading grid and dynamics state information to/from restart files is
+! delegated to MPAS utility code.  This module provides the CAM interfaces for the
+! restart functionality.  CAM just provides MPAS with the PIO filehandle to the
+! restart file.
+
+use dyn_comp,           only: dyn_export_t, mpas_dynamical_core
+use pio,                only: file_desc_t
+
+implicit none
+private
+save
+
+public :: &
+   init_restart_dynamics,  &
+   write_restart_dynamics
+
+!=========================================================================================
+contains
+!=========================================================================================
+
+subroutine init_restart_dynamics(file, dyn_out)
+
+   ! arguments
+   type(file_desc_t),  target     :: File
+   type(dyn_export_t), intent(in) :: dyn_out
+   !----------------------------------------------------------------------------
+   
+   ! STUB-ROUTINE
+
+end subroutine init_restart_dynamics
+
+!=========================================================================================
+
+subroutine write_restart_dynamics(File, dyn_out)
+
+   ! arguments
+   type(File_desc_t), target :: File
+   type(dyn_export_t), intent(in)  :: dyn_out
+   type(file_desc_t), pointer :: file_ptr
+   !----------------------------------------------------------------------------
+
+   file_ptr => File
+
+   call mpas_dynamical_core % read_write_stream(File, 'w', 'invariant+restart+input')
+
+end subroutine write_restart_dynamics
+
+end module restart_dynamics
diff --git a/src/history/buffers b/src/history/buffers
index 61536e901..a8e4bf4ff 160000
--- a/src/history/buffers
+++ b/src/history/buffers
@@ -1 +1 @@
-Subproject commit 61536e9012bcc336f03495d718d1f046ca302195
+Subproject commit a8e4bf4ffd69e1332aebab7f5d34ddf2ffb228fd
diff --git a/src/history/cam_history.F90 b/src/history/cam_history.F90
index 789756f26..3f8d9481b 100644
--- a/src/history/cam_history.F90
+++ b/src/history/cam_history.F90
@@ -687,8 +687,6 @@ subroutine history_out_field_1d(diagnostic_name, field_values)
             cycle
          end if
          ! Field is active on this file - accumulate!
-         write(iulog,*) 'peverwhee - accumulate'
-         write(iulog,*) field_info%diag_name()
          call hist_field_accumulate(field_info, field_values, 1, logger=logger)
          if (masterproc) then
             call logger%output(iulog)

From 49e2fc5fba0b9c0afed5e49b29fa25764c8e4652 Mon Sep 17 00:00:00 2001
From: peverwhee <courtneyp@ucar.edu>
Date: Mon, 29 Jun 2026 14:19:21 -0600
Subject: [PATCH 16/19] fix build cache

---
 cime_config/cam_autogen.py     |  2 +-
 cime_config/cam_build_cache.py | 23 +++++++++++++++++++++++
 2 files changed, 24 insertions(+), 1 deletion(-)

diff --git a/cime_config/cam_autogen.py b/cime_config/cam_autogen.py
index b30a60fb1..6711652fc 100644
--- a/cime_config/cam_autogen.py
+++ b/cime_config/cam_autogen.py
@@ -835,7 +835,7 @@ def generate_restart_routines(build_cache, bldroot, force_ccpp, force_restart,
         else:
             #If not, then check cache to see if actual
             #"restart_physics.py" was modified:
-            do_gen_restart = build_cache.init_write_mismatch(gen_restart_file)
+            do_gen_restart = build_cache.restart_write_mismatch(gen_restart_file)
     else:
         #If no directory exists, then one will need
         # to create new routines:
diff --git a/cime_config/cam_build_cache.py b/cime_config/cam_build_cache.py
index f9d66b65c..94f2b0d51 100644
--- a/cime_config/cam_build_cache.py
+++ b/cime_config/cam_build_cache.py
@@ -213,6 +213,7 @@ def __init__(self, build_cache):
         # Set empty values sure to trigger processing
         self.__gen_reg_file = None
         self.__gen_init_file = None
+        self.__gen_restart_file = None
         self.__registry_files = {}
         self.__dycore = None
         self.__sdfs = {}
@@ -241,6 +242,9 @@ def __init__(self, build_cache):
                         elif item.tag == 'generate_init_file':
                             new_entry = new_entry_from_xml(item)
                             self.__gen_init_file = new_entry
+                        elif item.tag == 'generate_restart_file':
+                            new_entry = new_entry_from_xml(item)
+                            self.__gen_restart_file = new_entry
                         elif item.tag == 'registry_file':
                             new_entry = new_entry_from_xml(item)
                             self.__registry_files[new_entry.key] = new_entry
@@ -409,6 +413,9 @@ def write(self):
         new_xml_entry(registry, 'generate_registry_file',
                       self.__gen_reg_file.file_path,
                       self.__gen_reg_file.file_hash)
+        new_xml_entry(registry, 'generate_restart_file',
+                      self.__gen_restart_file.file_path,
+                      self.__gen_restart_file.file_hash)
         for rfile in self.__registry_files.values():
             new_xml_entry(registry, 'registry_file',
                           rfile.file_path, rfile.file_hash)
@@ -623,6 +630,22 @@ def init_write_mismatch(self, gen_init_file):
         #Return mismatch logical:
         return mismatch
 
+    def restart_write_mismatch(self, gen_restart_file):
+        """
+        Determine if the restart_files writer (write_restart_files.py)
+            differs from the data stored in our cache. Return True
+            if the data differs.
+        """
+
+        # Initialize variable
+        mismatch = False
+
+        # Check file hash to see if mis-match exists:
+        mismatch = self.__gen_restart_file.hash_mismatch(gen_restart_file)
+
+        # Return mismatch logical:
+        return mismatch
+
     def scheme_nl_metadata(self):
         """Return the stored list of scheme namelist metadata files"""
         return self.__scheme_nl_metadata

From c3a739166ddac9527c4bde6de6bacb8bed8e3137 Mon Sep 17 00:00:00 2001
From: peverwhee <courtneyp@ucar.edu>
Date: Mon, 29 Jun 2026 14:19:38 -0600
Subject: [PATCH 17/19] handle no restart physics variables

---
 src/data/write_restart_physics.py | 11 ++++++++++-
 1 file changed, 10 insertions(+), 1 deletion(-)

diff --git a/src/data/write_restart_physics.py b/src/data/write_restart_physics.py
index 305449f4f..9936f7f57 100644
--- a/src/data/write_restart_physics.py
+++ b/src/data/write_restart_physics.py
@@ -337,6 +337,12 @@ def write_restart_physics_write(outfile, required_vars, constituent_dimmed_vars,
     outfile.write("integer                          :: constituent_idx", 2)
     outfile.write("type(ccpp_constituent_prop_ptr_t), pointer :: const_props(:)", 2)
 
+    # Just exit if we don't have any variables!
+    if len(required_vars) == 0 and len(constituent_dimmed_vars) == 0:
+        outfile.write("end subroutine restart_physics_write", 1)
+        return
+    # end if
+
     outfile.comment("Grab physics grid", 2)
     outfile.write("grid_decomp = cam_grid_id('physgrid')", 2)
     outfile.write("dims(1) = columns_on_task", 2)
@@ -515,7 +521,10 @@ def gather_required_restart_variables(all_req_vars, registry_constituents, resta
 def write_use_statements(outfile, use_stmts, indent):
     """Output Fortran module use (import) statements listed in <use_stmts>.
     """
-
+    # Don't do anything if we don't have use statements!
+    if len(use_stmts) == 0:
+        return
+    # end if
     # The plus one is for a comma
     max_modname = max(len(x[0]) for x in use_stmts) + 1
     # max_modspace is the max chars of the module plus other 'use' statement

From 783a41a86f9067a9017cd5e36c4360cf5d3c4c2e Mon Sep 17 00:00:00 2001
From: peverwhee <courtneyp@ucar.edu>
Date: Mon, 29 Jun 2026 14:20:07 -0600
Subject: [PATCH 18/19] add restart stubs for null dycore

---
 src/dynamics/none/restart_dynamics.F90 | 41 ++++++++++++++++++++++++++
 1 file changed, 41 insertions(+)
 create mode 100644 src/dynamics/none/restart_dynamics.F90

diff --git a/src/dynamics/none/restart_dynamics.F90 b/src/dynamics/none/restart_dynamics.F90
new file mode 100644
index 000000000..db2a6c19b
--- /dev/null
+++ b/src/dynamics/none/restart_dynamics.F90
@@ -0,0 +1,41 @@
+module restart_dynamics
+
+use dyn_comp,           only: dyn_export_t
+use pio,                only: file_desc_t
+
+implicit none
+private
+save
+
+public :: &
+   init_restart_dynamics,  &
+   write_restart_dynamics
+
+!=========================================================================================
+contains
+!=========================================================================================
+
+subroutine init_restart_dynamics(file, dyn_out)
+
+   ! arguments
+   type(file_desc_t),  target     :: File
+   type(dyn_export_t), intent(in) :: dyn_out
+   !----------------------------------------------------------------------------
+   
+   ! STUB-ROUTINE
+
+end subroutine init_restart_dynamics
+
+!=========================================================================================
+
+subroutine write_restart_dynamics(File, dyn_out)
+
+   ! arguments
+   type(File_desc_t), target :: File
+   type(dyn_export_t), intent(in)  :: dyn_out
+   !----------------------------------------------------------------------------
+
+   ! STUB-ROUTINE
+end subroutine write_restart_dynamics
+
+end module restart_dynamics

From 36cb08a1d6fbd40f0e380d50715b88e33eebb75d Mon Sep 17 00:00:00 2001
From: peverwhee <courtneyp@ucar.edu>
Date: Tue, 30 Jun 2026 09:35:15 -0600
Subject: [PATCH 19/19] remove hard-coded dimensions

---
 src/data/write_restart_physics.py | 20 +++++++++++++-------
 1 file changed, 13 insertions(+), 7 deletions(-)

diff --git a/src/data/write_restart_physics.py b/src/data/write_restart_physics.py
index 9936f7f57..7b2c4a772 100644
--- a/src/data/write_restart_physics.py
+++ b/src/data/write_restart_physics.py
@@ -117,11 +117,11 @@ def write_restart_physics(cap_database, ic_names, registry_constituents,
 
         # Write the restart init subroutine
         outfile.blank_line()
-        dim_use_stmts = write_restart_physics_init(outfile, required_restart_vars, constituent_dimmed_vars, host_dict)
+        dim_use_stmts, dims = write_restart_physics_init(outfile, required_restart_vars, constituent_dimmed_vars, host_dict)
 
         # Write the restart write subroutine
         outfile.blank_line()
-        write_restart_physics_write(outfile, required_restart_vars, constituent_dimmed_vars, used_vars, dim_use_stmts)
+        write_restart_physics_write(outfile, required_restart_vars, constituent_dimmed_vars, used_vars, dim_use_stmts, dims)
 
         # Write the restart read subroutine
         outfile.blank_line()
@@ -181,11 +181,13 @@ def write_restart_physics_init(outfile, required_vars, constituent_dimmed_vars,
 
     # Gather up dimension imports
     dim_use_stmts = []
+    dims = []
     for key, value in dim_use_stmt_dict.items():
         imports = []
         dim_use_stmt = []
         for var_import in value:
             imports.append(f"{var_import}")
+            dims.append(f"{var_import}")
         # end for
         dim_use_stmt.append(key)
         dim_use_stmt.append(imports)
@@ -299,9 +301,9 @@ def write_restart_physics_init(outfile, required_vars, constituent_dimmed_vars,
     # end if
 
     outfile.write("end subroutine restart_physics_init", 1)
-    return dim_use_stmts
+    return dim_use_stmts, dims
 
-def write_restart_physics_write(outfile, required_vars, constituent_dimmed_vars, used_vars, dim_use_stmts):
+def write_restart_physics_write(outfile, required_vars, constituent_dimmed_vars, used_vars, dim_use_stmts, dims):
     """
     Write the 'write' routine for the physics restart variables. This
     routine writes the physics fields to the restart (cam.r) file
@@ -317,6 +319,7 @@ def write_restart_physics_write(outfile, required_vars, constituent_dimmed_vars,
 
     write_use_statements(outfile, use_stmts, 2)
     write_use_statements(outfile, dim_use_stmts, 2)
+
     for var in used_vars:
         outfile.write(f"use physics_types, only: {var}", 2)
     # end for
@@ -330,7 +333,7 @@ def write_restart_physics_write(outfile, required_vars, constituent_dimmed_vars,
     outfile.blank_line()
 
     outfile.comment("Local variables", 2)
-    outfile.write("integer                          :: dims(2)",   2)
+    outfile.write(f"integer                         :: dims({len(dims)})", 2)
     outfile.write("integer                          :: grid_decomp", 2)
     outfile.write("integer                          :: grid_dims(2)", 2)
     outfile.write("integer                          :: field_shape(2)", 2)
@@ -345,8 +348,11 @@ def write_restart_physics_write(outfile, required_vars, constituent_dimmed_vars,
 
     outfile.comment("Grab physics grid", 2)
     outfile.write("grid_decomp = cam_grid_id('physgrid')", 2)
-    outfile.write("dims(1) = columns_on_task", 2)
-    outfile.write("dims(2) = pver", 2)
+    dim_index = 1
+    for dim in dims:
+        outfile.write(f"dims({dim_index}) = {dim}", 2)
+        dim_index = dim_index + 1
+    # end if
     outfile.comment("Write required restart variables to the restart file", 2)
     for key, value in required_vars.items():
         desc_name = f"{value['diag_name'].lower()}_desc"