Merge pull request #1288 from jimmielin/hplin/geopotential_t_water_species

cam6_4_080: Derive new geopotential fields whenever water species are updated (not just water vapor)

Author: jimmielin

doc/ChangeLog

@@ -1,3 +1,64 @@
+===============================================================
+
+Tag name: cam6_4_080
+Originator(s): jimmielin
+Date: March 25, 2025
+One-line Summary: Derive new geopotential fields whenever water species are updated (not just water vapor)
+Github PR URL: https://github.com/ESCOMP/CAM/pull/1288
+
+Purpose of changes (include the issue number and title text for each relevant GitHub issue):
+- Fixes: geopotential_t should be recomputed if any water species are updated, not just water vapor (#1286)
+
+Describe any changes made to build system: N/A
+
+Describe any changes made to the namelist: N/A
+
+List any changes to the defaults for the boundary datasets: N/A
+
+Describe any substantial timing or memory changes: N/A
+
+Code reviewed by: PeterHjortLauritzen, cacraig
+
+List all files eliminated: N/A
+
+List all files added and what they do: N/A
+
+List all existing files that have been modified, and describe the changes:
+M       src/physics/cam/physics_types.F90
+  - call geopotential_t if any water species have tendencies, not just water vapor.
+
+If there were any failures reported from running test_driver.sh on any test
+platform, and checkin with these failures has been OK'd by the gatekeeper,
+then copy the lines from the td.*.status files for the failed tests to the
+appropriate machine below.  All failed tests must be justified.
+
+derecho/intel/aux_cam:
+  SMS_D_Ln9.ne16_ne16_mg17.QPX2000.derecho_intel.cam-outfrq9s_amie (Overall: DIFF) details:
+     - expected baseline change due to fix included in this PR
+
+  ERP_D_Ln9.ne30pg3_ne30pg3_mt232.QPC7.derecho_intel.cam-outfrq3s_cosp (Overall: FAIL) details:
+  ERS_Ln9.ne30pg3_ne30pg3_mg17.FHISTC_WXma.derecho_intel.cam-outfrq9s (Overall: FAIL) details:
+     - pre-existing failures: Two restart tests have answer changes due to moving mountain update in cam6_4_078 (#1284)
+
+  ERP_Ln9.f09_f09_mg17.FCSD_HCO.derecho_intel.cam-outfrq9s (Overall: FAIL) details:
+  SMS_Lh12.f09_f09_mg17.FCSD_HCO.derecho_intel.cam-outfrq3h (Overall: PASS) details:
+     - pre-existing failures due to HEMCO not having reproducible results (issues #1018 and #856)
+
+  SMS_D_Ln9_P1280x1.ne0CONUSne30x8_ne0CONUSne30x8_mt12.FCHIST.derecho_intel.cam-outfrq9s (Overall: FAIL) details:
+     - pre-existing failures due to build-namelist error requiring CLM/CTSM external update
+
+derecho/nvhpc/aux_cam: ALL PASS
+
+izumi/nag/aux_cam:
+  ERC_D_Ln9.ne16_ne16_mg17.QPC4.izumi_nag.cam-outfrq3s_usecase (Overall: DIFF) details:
+  ERC_D_Ln9.ne16pg3_ne16pg3_mg17.QPC4.izumi_nag.cam-outfrq3s_usecase (Overall: DIFF) details:
+  SMS_D_Ln3.ne5pg3_ne5pg3_mg37.QPX2000.izumi_nag.cam-outfrq3s (Overall: DIFF) details:
+  SMS_D_Ln6.ne5_ne5_mg37.QPWmaC4.izumi_nag.cam-outfrq3s_physgrid_tem (Overall: DIFF) details:
+    - expected baseline changes due to fix included in this PR
+
+izumi/gnu/aux_cam:
+  ERC_D_Ln9.ne5_ne5_mg37.QPC4.izumi_gnu.cam-outfrq3s_nudging_ne5_L26 (Overall: DIFF) details:
+    - expected baseline change due to fix included in this PR
 
 ===============================================================
 

src/physics/cam/physics_types.F90

@@ -211,7 +211,7 @@ subroutine physics_update(state, ptend, dt, tend)
     use scamMod,         only: scm_crm_mode, single_column
     use phys_control,    only: phys_getopts
     use cam_thermo,      only: cam_thermo_dry_air_update ! Routine which updates physconst variables (WACCM-X)
-    use air_composition, only: dry_air_species_num
+    use air_composition, only: dry_air_species_num, thermodynamic_active_species_num, thermodynamic_active_species_idx
     use qneg_module   ,  only: qneg3
 
 !------------------------------Arguments--------------------------------
@@ -231,6 +231,7 @@ subroutine physics_update(state, ptend, dt, tend)
     integer :: ixnumsnow, ixnumrain
     integer :: ncol                                ! number of columns
     integer :: ixh, ixh2    ! constituent indices for H, H2
+    logical :: derive_new_geopotential             ! derive new geopotential fields?
 
     real(r8) :: zvirv(state%psetcols,pver)  ! Local zvir array pointer
 
@@ -419,9 +420,23 @@ subroutine physics_update(state, ptend, dt, tend)
        end do
     end if
 
-    ! Derive new geopotential fields if heating or water tendency not 0.
+    ! Derive new geopotential fields if heating or water species tendency not 0.
+    derive_new_geopotential = .false.
+    if(ptend%ls) then
+        ! Heating tendency not 0
+        derive_new_geopotential = .true.
+    else
+        ! Check all water species and if there are nonzero tendencies
+        const_water_loop: do m = dry_air_species_num + 1, thermodynamic_active_species_num
+            if(ptend%lq(thermodynamic_active_species_idx(m))) then
+                ! does water species have tendency?
+                derive_new_geopotential = .true.
+                exit const_water_loop
+            endif
+        enddo const_water_loop
+    endif
 
-    if (ptend%ls .or. ptend%lq(1)) then
+    if (derive_new_geopotential) then
        call geopotential_t  (                                                                    &
             state%lnpint, state%lnpmid, state%pint  , state%pmid  , state%pdel  , state%rpdel  , &
             state%t     , state%q(:,:,:), rairv_loc(:,:), gravit  , zvirv              , &