diff --git a/.gitmodules b/.gitmodules
index 605b3f5a..86816841 100644
--- a/.gitmodules
+++ b/.gitmodules
@@ -20,7 +20,7 @@
 [submodule "ncar-physics"]
         path          = src/physics/ncar_ccpp
 	url           = https://github.com/ESCOMP/atmospheric_physics
-	fxtag         = 9865ef6a9384030233abe23e77acdc208abecdc3
+	fxtag         = d3dcffa8239e84bf6c251c7158d0246caf2caa6d
         fxrequired    = AlwaysRequired
         fxDONOTUSEurl = https://github.com/ESCOMP/atmospheric_physics
 [submodule "rrtmgp-data"]
diff --git a/src/data/generate_registry_data.py b/src/data/generate_registry_data.py
index a738fc78..a45d0b86 100755
--- a/src/data/generate_registry_data.py
+++ b/src/data/generate_registry_data.py
@@ -1950,5 +1950,5 @@ def main():
 
 ###############################################################################
 if __name__ == "__main__":
-    __RETCODE, _FILES, _IC_NAMES = main()
+    __RETCODE, *_ = main()
     sys.exit(__RETCODE)
diff --git a/src/data/registry.xml b/src/data/registry.xml
index 93266f68..3530022e 100644
--- a/src/data/registry.xml
+++ b/src/data/registry.xml
@@ -1046,16 +1046,16 @@
       <ic_file_input_names>bcphodry cam_out_bcphodry</ic_file_input_names>
     </variable>
     <variable local_name="co2diag"
-              standard_name="co2diag_tbd"
-              units="tbd" type="real" kind="kind_phys"
+              standard_name="diagnostic_volume_mixing_ratio_of_co2_to_coupler"
+              units="ppmv" type="real" kind="kind_phys"
               allocatable="allocatable">
       <dimensions>horizontal_dimension</dimensions>
       <initial_value>0.0_kind_phys</initial_value>
       <ic_file_input_names>co2diag cam_out_co2diag</ic_file_input_names>
     </variable>
     <variable local_name="co2prog"
-              standard_name="co2prog_tbd"
-              units="tbd" type="real" kind="kind_phys"
+              standard_name="prognostic_volume_mixing_ratio_of_co2_to_coupler"
+              units="ppmv" type="real" kind="kind_phys"
               allocatable="allocatable">
       <dimensions>horizontal_dimension</dimensions>
       <initial_value>0.0_kind_phys</initial_value>
@@ -1391,8 +1391,8 @@
        <data>dry_deposition_flux_of_hydrophilic_black_carbon_at_surface_to_coupler</data>
        <data>wet_deposition_flux_of_hydrophilic_black_carbon_at_surface_to_coupler</data>
        <data>dry_deposition_flux_of_hydrophobic_black_carbon_at_surface_to_coupler</data>
-       <data>co2diag_tbd</data>
-       <data>co2prog_tbd</data>
+       <data>diagnostic_volume_mixing_ratio_of_co2_to_coupler</data>
+       <data>prognostic_volume_mixing_ratio_of_co2_to_coupler</data>
        <data>dry_deposition_of_dust_bin1_at_surface_to_coupler</data>
        <data>dry_deposition_of_dust_bin2_at_surface_to_coupler</data>
        <data>dry_deposition_of_dust_bin3_at_surface_to_coupler</data>
diff --git a/src/physics/ncar_ccpp b/src/physics/ncar_ccpp
index 9865ef6a..d3dcffa8 160000
--- a/src/physics/ncar_ccpp
+++ b/src/physics/ncar_ccpp
@@ -1 +1 @@
-Subproject commit 9865ef6a9384030233abe23e77acdc208abecdc3
+Subproject commit d3dcffa8239e84bf6c251c7158d0246caf2caa6d