Merge branch 'mpas_16pt_init' into develop (PR #1303)

This merge changes the horizontal interpolation from a four-point bilinear
interpolation to a sixteen point overlapping parabolic interpolation for both
initialization of the state variables from an existing analysis (e.g. GFS, ERA5,
etc; case 7 for init_atmosphere) and for interpolating lateral boundary values
for the regional MPAS-A configuration (case 9 for init_atmosphere).

Author: mgduda

src/core_init_atmosphere/mpas_init_atm_cases.F

@@ -3485,7 +3485,8 @@ subroutine init_atm_case_gfs(block, mesh, nCells, nEdges, nVertLevels, fg, state
 
       do while (istatus == 0)
 
-         interp_list(1) = FOUR_POINT
+         ! interp_list(1) = FOUR_POINT
+         interp_list(1) = SIXTEEN_POINT
          interp_list(2) = SEARCH
          interp_list(3) = 0
 
@@ -5277,7 +5278,8 @@ subroutine init_atm_case_lbc(timestamp, block, mesh, nCells, nEdges, nVertLevels
 
       do while (istatus == 0)
 
-         interp_list(1) = FOUR_POINT
+         ! interp_list(1) = FOUR_POINT
+         interp_list(1) = SIXTEEN_POINT
          interp_list(2) = SEARCH
          interp_list(3) = 0