Merge branch 'hotfix-v8.3.1'

This merge corrects two issues in the MPAS-Atmosphere model:

 * Fix a bug in the vertical interpolation of humidity for LBCs when first-guess
   levels are given in top-to-bottom order. Incorrect logic in the
   init_atm_case_lbc routine previously assumed that first-guess levels would be
   given in bottom-to-top order when attempting to vertically extrapolate to
   model levels below the lowest first-guess level, resulting in a copy of the
   vertically interpolated relative humidity at level k+1 to level k if levels
   were given in top-to-bottom order. This bug resulted in an unreasonably low
   water vapor mixing ratio field (lbc_qv) in LBC files. (PR #1335)

   NB: This bug is present in most older releases of MPAS, and it should be
   possible to cherry-pick the fix onto any branch or release based on MPAS
   v7.0 or later.

 * Fix an issue with .F90 files in the src/core_atmosphere/physics/physics_mmm/
   directory not being re-compiled by updating the MMM-physics external tag to
   acquire a new Makefile.mpas file for MMM-physics. With the updated tag,
   compiling the atmosphere core, then making changes to any of the .F90 files
   in src/core_atmosphere/physics/physics_mmm/, then running make again (without
   first cleaning) leads to the modified .F90 files being correctly re-compiled.
   (PR #1337)

Author: mgduda

README.md

@@ -1,4 +1,4 @@
-MPAS-v8.3.0
+MPAS-v8.3.1
 ====
 
 The Model for Prediction Across Scales (MPAS) is a collaborative project for

src/core_atmosphere/Externals.cfg

@@ -2,7 +2,7 @@
 local_path = ./physics_mmm
 protocol = git
 repo_url = https://github.com/NCAR/MMM-physics.git
-tag = 20240626-MPASv8.2
+tag = 20250616-MPASv8.3
 required = True
 
 [GSL_UGWP]

src/core_atmosphere/Registry.xml

@@ -1,5 +1,5 @@
 <?xml version="1.0"?>
-<registry model="mpas" core="atmosphere" core_abbrev="atm" version="8.3.0">
+<registry model="mpas" core="atmosphere" core_abbrev="atm" version="8.3.1">
 
 <!-- **************************************************************************************** -->
 <!-- ************************************** Dimensions ************************************** -->

src/core_init_atmosphere/Registry.xml

@@ -1,5 +1,5 @@
 <?xml version="1.0"?>
-<registry model="mpas" core="init_atmosphere" core_abbrev="init_atm" version="8.3.0">
+<registry model="mpas" core="init_atmosphere" core_abbrev="init_atm" version="8.3.1">
 
 <!-- **************************************************************************************** -->
 <!-- ************************************** Dimensions ************************************** -->

src/core_init_atmosphere/mpas_init_atm_cases.F

@@ -5924,7 +5924,6 @@ subroutine init_atm_case_lbc(timestamp, block, mesh, nCells, nEdges, nVertLevels
             target_z = 0.5 * (zgrid(k,iCell) + zgrid(k+1,iCell))
             relhum(k,iCell) = vertical_interp(target_z, nfglevels_actual-1, &
                                        sorted_arr(:,1:nfglevels_actual-1), order=1, extrap=0)
-            if (target_z < z_fg(1,iCell) .and. k < nVertLevels) relhum(k,iCell) = relhum(k+1,iCell)
          end do
 
 
@@ -5942,7 +5941,6 @@ subroutine init_atm_case_lbc(timestamp, block, mesh, nCells, nEdges, nVertLevels
             target_z = 0.5 * (zgrid(k,iCell) + zgrid(k+1,iCell))
             spechum(k,iCell) = vertical_interp(target_z, nfglevels_actual-1, &
                                         sorted_arr(:,1:nfglevels_actual-1), order=1, extrap=0)
-            if (target_z < z_fg(1,iCell) .and. k < nVertLevels) spechum(k,iCell) = spechum(k+1,iCell)
          end do
 
 

src/core_landice/Registry.xml

@@ -1,5 +1,5 @@
 <?xml version="1.0"?>
-<registry model="mpas" core="landice" core_abbrev="li" version="8.3.0">
+<registry model="mpas" core="landice" core_abbrev="li" version="8.3.1">
 
 
 <!-- ======================================================================= -->

src/core_ocean/Registry.xml

@@ -1,5 +1,5 @@
 <?xml version="1.0"?>
-<registry model="mpas" core="ocean" core_abbrev="ocn" version="8.3.0">
+<registry model="mpas" core="ocean" core_abbrev="ocn" version="8.3.1">
 
 	<dims>
 		<dim name="nCells" units="unitless"

src/core_seaice/Registry.xml

@@ -1,5 +1,5 @@
 <?xml version="1.0"?>
-<registry model="mpas" core="seaice" core_abbrev="seaice" version="8.3.0">
+<registry model="mpas" core="seaice" core_abbrev="seaice" version="8.3.1">
 
 	<dims>
 		<dim name="nCells"

src/core_sw/Registry.xml

@@ -1,5 +1,5 @@
 <?xml version="1.0"?>
-<registry model="mpas" core="sw" core_abbrev="sw" version="8.3.0">
+<registry model="mpas" core="sw" core_abbrev="sw" version="8.3.1">
 	<dims>
 		<dim name="nCells"/>
 		<dim name="nEdges"/>

src/core_test/Registry.xml

@@ -1,5 +1,5 @@
 <?xml version="1.0"?>
-<registry model="mpas" core="test" core_abbrev="test" version="8.3.0">
+<registry model="mpas" core="test" core_abbrev="test" version="8.3.1">
 	<dims>
 		<dim name="nCells"/>
 		<dim name="nEdges"/>