SIMA patch for energy bug in physics-dynamics coupling

src/data/registry.xml

@@ -575,8 +575,21 @@
               standard_name="specific_heat_of_air_used_in_dycore"
               units="J kg-1 K-1" type="real" kind="kind_phys"
               allocatable="allocatable">
-      <long_name>specific heat of air used in the dynamical core (enthalpy for pressure-based dynamical cores and internal energy for z-based dynamical cores)</long_name>
+      <long_name>specific heat of air used in the dynamical core (enthalpy for pressure-based dynamical cores and internal energy for z-based dynamical cores), updated mid-physics for post-mass-adjustment total energy diagnostics</long_name>
       <dimensions>horizontal_dimension vertical_layer_dimension</dimensions>
+      <initial_value>0._kind_phys</initial_value>
+    </variable>
+    <variable local_name="cp_or_cv_dycore_at_start_of_physics_timestep"
+              standard_name="specific_heat_of_air_used_in_dycore_at_start_of_physics_timestep"
+              units="J kg-1 K-1" type="real" kind="kind_phys"
+              allocatable="allocatable">
+      <long_name>Specific heat of air used in the dynamical core (enthalpy for pressure-based dynamical cores and internal energy for z-based dynamical cores), at start of physics timestep, for energy-consistency scaling and energy checker</long_name>
+      <dimensions>horizontal_dimension vertical_layer_dimension</dimensions>
+      <!-- Note: this quantity is read from CAM snapshot from the dycore value
+           since the CAM fix in cam6_4_173 (CAM#1554) restores the mid-physics update
+           value (for total energy diagnostics) to the start of physics timestep
+           (d_p_coupling) value. It is used for running the energy checker for
+           individual physics scheme tests. -->
       <ic_file_input_names>cp_or_cv_dycore</ic_file_input_names>
     </variable>
 

src/dynamics/mpas/dyn_coupling_impl.F90

@@ -507,7 +507,8 @@ subroutine set_physics_state_external()
             use dyn_comp, only: advected_constituent_index, mpas_dynamical_core
             use dyn_procedures, only: exner_function
             use dynconst, only: constant_g => gravit
-            use physics_types, only: cappav, cp_or_cv_dycore, cpairv, lagrangian_vertical, phys_state, rairv, zvirv
+            use physics_types, only: cappav, cp_or_cv_dycore, cp_or_cv_dycore_at_start_of_physics_timestep, &
+                                     cpairv, lagrangian_vertical, phys_state, rairv, zvirv
             use runtime_obj, only: cam_runtime_opts
             use string_utils, only: stringify
             use vert_coord, only: pver, pverp
@@ -565,6 +566,8 @@ subroutine set_physics_state_external()
             call cam_thermo_water_update( &
                 constituents, ncells_solve, pver, energy_formula_dycore_mpas, cp_or_cv_dycore)
 
+            cp_or_cv_dycore_at_start_of_physics_timestep(:, :) = cp_or_cv_dycore(:, :)
+
             ! This variable name is really misleading. It actually represents the reciprocal of Exner function
             ! with respect to surface pressure. This definition is sometimes used for boundary layer work. See
             ! the paragraph below equation 1.5.1c in doi:10.1007/978-94-009-3027-8.

src/dynamics/se/dp_coupling.F90

@@ -588,6 +588,7 @@ subroutine derived_phys_dry(cam_runtime_opts, phys_state, phys_tend)
    use air_composition,   only: dry_air_species_num
    use physics_types,     only: cpairv, rairv, zvirv, cappav
    use physics_types,     only: cp_or_cv_dycore
+   use physics_types,     only: cp_or_cv_dycore_at_start_of_physics_timestep
    use physics_grid,      only: columns_on_task
    use geopotential_temp, only: geopotential_temp_run
    use static_energy,     only: update_dry_static_energy_run
@@ -807,6 +808,8 @@ subroutine derived_phys_dry(cam_runtime_opts, phys_state, phys_tend)
         cp_or_cv_dycore = cp_or_cv_dycore           &
    )
 
+   cp_or_cv_dycore_at_start_of_physics_timestep(:,:) = cp_or_cv_dycore(:,:)
+
    !$omp parallel do num_threads(horz_num_threads) private (k, i)
    do k = 1, nlev
       do i = 1, pcols

tools/stdnames_to_inputnames_dictionary.xml

@@ -196,7 +196,7 @@
       <ic_file_input_name>state_tw_cur</ic_file_input_name>
     </ic_file_input_names>
   </entry>
-  <entry stdname="specific_heat_of_air_used_in_dycore">
+  <entry stdname="specific_heat_of_air_used_in_dycore_at_start_of_physics_timestep">
     <ic_file_input_names>
       <ic_file_input_name>cp_or_cv_dycore</ic_file_input_name>
     </ic_file_input_names>