cam6_4_070: Pertlim fix for MPAS

cime_config/testdefs/testlist_cam.xml

@@ -1404,6 +1404,15 @@
     </options>
   </test>
 
+  <test compset="F2000climo" grid="mpasa480_mpasa480" name="ERS_D_Ln9" testmods="cam/outfrq9s_mpasa480_pertlim">
+    <machines>
+      <machine name="derecho" compiler="intel" category="aux_cam"/>
+    </machines>
+    <options>
+      <option name="wallclock">00:45:00</option>
+    </options>
+  </test>
+
   <test compset="FHS94" grid="mpasa480z32_mpasa480" name="ERC_D_Ln9" testmods="cam/outfrq3s_usecase">
     <machines>
       <machine name="derecho" compiler="intel" category="prealpha"/>

cime_config/testdefs/testmods_dirs/cam/outfrq9s_mpasa480_pertlim/shell_commands

@@ -0,0 +1,2 @@
+./xmlchange ROF_NCPL=\$ATM_NCPL
+./xmlchange GLC_NCPL=\$ATM_NCPL

cime_config/testdefs/testmods_dirs/cam/outfrq9s_mpasa480_pertlim/user_nl_cam

@@ -0,0 +1,7 @@
+mfilt=1,1,1,1,1,1
+ndens=1,1,1,1,1,1
+nhtfrq=9,9,9,9,9,9
+inithist='ENDOFRUN'
+mpas_cam_coef=1.0D0
+mpas_cam_damping_levels=3
+pertlim = 1.e-14

cime_config/testdefs/testmods_dirs/cam/outfrq9s_mpasa480_pertlim/user_nl_clm

@@ -0,0 +1,3 @@
+hist_nhtfrq = 9
+hist_mfilt  = 1
+hist_ndens  = 1

doc/ChangeLog

@@ -1,5 +1,74 @@
 ===============================================================
 
+Tag name: cam6_4_070
+Originator(s): patcal, nusbaume
+Date: 22 February 2025
+One-line Summary: Pertlim fix for MPAS
+Github PR URL: https://github.com/ESCOMP/CAM/pull/1114
+
+Purpose of changes (include the issue number and title text for each relevant GitHub issue):
+
+Closes #1109 - MPAS-A Pertlim usage is only implemented for ideal initial states
+
+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: jtruesdal
+
+List all files eliminated: N/A
+
+List all files added and what they do:
+
+A       cime_config/testdefs/testmods_dirs/cam/outfrq9s_mpasa480_pertlim/shell_commands
+A       cime_config/testdefs/testmods_dirs/cam/outfrq9s_mpasa480_pertlim/user_nl_cam
+A       cime_config/testdefs/testmods_dirs/cam/outfrq9s_mpasa480_pertlim/user_nl_clm
+ - Add new MPAS pertlim regression test files.
+
+List all existing files that have been modified, and describe the changes:
+
+M       src/dynamics/mpas/dyn_comp.F90
+ - Allow initial state perturbations with MPAS when reading from the ncdata file.
+
+M       cime_config/testdefs/testlist_cam.xml
+ - Add new MPAS pertlim regression test files.
+
+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:
+
+ERP_Ln9.f09_f09_mg17.FCSD_HCO.derecho_intel.cam-outfrq9s (Overall: FAIL)
+SMS_Ld1.f09_f09_mg17.FCHIST_GC.derecho_intel.cam-outfrq1d (Overall: DIFF)
+ - pre-existing failures due to HEMCO not having reproducible results (issues #1018 and #856)
+
+ERS_D_Ln9.mpasa480_mpasa480.F2000climo.derecho_intel.cam-outfrq9s_mpasa480_pertlim (Overall: DIFF)
+ - New test (so no baselines yet)
+
+SMS_D_Ln9.f19_f19_mg17.FXHIST.derecho_intel.cam-outfrq9s_amie (Overall: FAIL)
+SMS_D_Ln9_P1280x1.ne0CONUSne30x8_ne0CONUSne30x8_mt12.FCHIST.derecho_intel.cam-outfrq9s (Overall: FAIL)
+ - pre-existing failures due to build-namelist error requiring CLM/CTSM external update
+
+derecho/nvhpc/aux_cam: ALL PASS
+
+izumi/nag/aux_cam: ALL PASS
+
+izumi/gnu/aux_cam: ALL PASS
+
+CAM tag used for the baseline comparison tests if different than previous
+tag:
+
+Summarize any changes to answers: b4b
+
+===============================================================
+===============================================================
+
 Tag name: cam6_4_069
 Originator(s): peverwhee
 Date: 20 February 2025
@@ -29,7 +98,7 @@ List all files added and what they do: none
 List all existing files that have been modified, and describe the changes:
 
 .github/workflows/fleximod_test.yaml
- - update fleximod workflow to include check that the checked out externals 
+ - update fleximod workflow to include check that the checked out externals
    match what is expected
 
 .gitmodules
@@ -218,7 +287,7 @@ cime_config/config_compsets.xml
   all FSCAM* compsets
 . remove FDABIP04 (_CAM%DABIP04_)
 . In the future new tests will be added for FSCAM* compsets using SE
-  dycore. 
+  dycore.
 
 cime_config/config_component.xml
 . remove eul as valid value for CAM_DYCORE
@@ -338,7 +407,7 @@ Resolve #1171 - Remove SP-CAM from cam_development
 Describe any changes made to build system:
 . remove spcam build options
 
-Describe any changes made to the namelist: 
+Describe any changes made to the namelist:
 . remove spcam namelist options
 
 List any changes to the defaults for the boundary datasets: none

src/dynamics/mpas/dyn_comp.F90

@@ -11,7 +11,7 @@ module dyn_comp
 use const_init,         only: cnst_init_default
 
 use cam_control_mod,    only: initial_run
-use cam_initfiles,      only: initial_file_get_id, topo_file_get_id
+use cam_initfiles,      only: initial_file_get_id, topo_file_get_id, pertlim
 
 use cam_grid_support,   only: cam_grid_id, &
                               cam_grid_get_latvals, cam_grid_get_lonvals
@@ -813,6 +813,11 @@ subroutine read_inidat(dyn_in)
 
    logical  :: readvar
 
+   integer                          :: rndm_seed_sz
+   integer, allocatable             :: rndm_seed(:)
+   real(r8)                         :: pertval
+   integer                          :: nc
+
    character(len=shr_kind_cx) :: str
 
    type(mpas_pool_type), pointer :: mesh_pool
@@ -1083,6 +1088,29 @@ subroutine read_inidat(dyn_in)
          call endrun(subname//': failed to read theta from initial file')
       end if
 
+      ! optionally introduce random perturbations to theta values
+      if (pertlim.ne.0.0_r8) then
+         if (masterproc) then
+            write(iulog,*) trim(subname), ': Adding random perturbation bounded', &
+               'by +/- ', pertlim, ' to initial theta field'
+         end if
+
+         call random_seed(size=rndm_seed_sz)
+         allocate(rndm_seed(rndm_seed_sz))
+
+         do nc = 1,nCellsSolve
+            rndm_seed = glob_ind(nc)
+            call random_seed(put=rndm_seed)
+            do kk = 1,plev
+               call random_number(pertval)
+               pertval = 2.0_r8*pertlim*(0.5_r8 - pertval)
+               theta(kk,nc) = theta(kk,nc)*(1.0_r8 + pertval)
+            end do
+         end do
+
+         deallocate(rndm_seed)
+      end if
+
       ! read rho
       call infld('rho', fh_ini, 'lev', 'nCells', 1, plev, 1, nCellsSolve, 1, 1, &
                  mpas3d, readvar, gridname='mpas_cell')