Merge pull request #456 from yuanjianz/bugfix/gchp-advection-small-nu…

…merical-bugs

Fix GCHPctmEnv small numerical bugs

CHANGELOG.md

@@ -13,6 +13,10 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 ### Added
 - Added code to `src/CMakeLists.txt` to build & install the KPP standalone executable when `fullchem` or `custom` mechanisms are selected
 
+### Fixed
+- Fixed dry mass flux derivation in GCHPctmEnv when using mass flux imports
+- Fixed UpwardsMassFlux sign to make positive represent upwards direction
+
 ## [14.5.0] - 2024-11-08
 ### Added
 - Added documentation about GEOS convection change affecting meteorology starting June 1, 2020

src/GCHP_GridComp/GCHPctmEnv_GridComp/GCHPctmEnv_GridCompMod.F90

@@ -871,15 +871,15 @@ subroutine prepare_massflux_exports(IMPORT, EXPORT, PLE, dt, RC)
          call MAPL_GetPointer(IMPORT, temp3d_r4, 'MFXC',  RC=STATUS)
          _VERIFY(STATUS)
          if ( correct_mass_flux_for_humidity > 0 ) then
-            MFX_EXPORT = dble(temp3d_r4) / ( 1.d0 - SPHU0_EXPORT )
+            MFX_EXPORT = dble(temp3d_r4) * ( 1.d0 - SPHU0_EXPORT )
          else
             MFX_EXPORT = dble(temp3d_r4)
          endif
 
          call MAPL_GetPointer(IMPORT, temp3d_r4, 'MFYC',  RC=STATUS)
          _VERIFY(STATUS)
          if ( correct_mass_flux_for_humidity > 0 ) then
-            MFY_EXPORT = dble(temp3d_r4) / ( 1.d0 - SPHU0_EXPORT )
+            MFY_EXPORT = dble(temp3d_r4) * ( 1.d0 - SPHU0_EXPORT )
          else
             MFY_EXPORT = dble(temp3d_r4)
          endif
@@ -953,8 +953,9 @@ subroutine prepare_massflux_exports(IMPORT, EXPORT, PLE, dt, RC)
          ! Get vertical mass flux
          call fv_getVerticalMassFlux(MFX_EXPORT, MFY_EXPORT, UpwardsMassFlux, dt)
 
-         ! Flip vertical so that GCHP diagnostic is positive="up"
-         UpwardsMassFlux(:,:,:) = UpwardsMassFlux(:,:,LM:0:-1)/dt
+         ! Flip vertical so that GCHP diagnostic level is following GEOS-Chem convention
+         ! Add negative sign to make positive = "up"
+         UpwardsMassFlux(:,:,:) = -UpwardsMassFlux(:,:,LM:0:-1)/dt
       end if
 
       ! nullify pointers