Corrected the license on RGC_initialization.F90

  Corrected the license on RGC_initialization.F90 to refer to the same
LICENSE.md file as the rest of the MOM6 code, with the explicit written consent
of the contributors to this file.  Also changed the local variable "mod" into
"mdl" in this module to avoid some of the problems we had previously found with
some compilers from reusing an intrinsic function name for a variable name.  All
answers are bitwise identical.

src/user/RGC_initialization.F90

@@ -1,22 +1,9 @@
+!> Configures the models sponges for the Rotating Gravity Current (RGC) experiment.
 module RGC_initialization
+
+! This file is part of MOM6. See LICENSE.md for the license.
+
 !***********************************************************************
-!*                   GNU General Public License                        *
-!* This file is a part of MOM.                                         *
-!*                                                                     *
-!* MOM is free software; you can redistribute it and/or modify it and  *
-!* are expected to follow the terms of the GNU General Public License  *
-!* as published by the Free Software Foundation; either version 2 of   *
-!* the License, or (at your option) any later version.                 *
-!*                                                                     *
-!* MOM is distributed in the hope that it will be useful, but WITHOUT  *
-!* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY  *
-!* or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public    *
-!* License for more details.                                           *
-!*                                                                     *
-!* For the full text of the GNU General Public License,                *
-!* write to: Free Software Foundation, Inc.,                           *
-!*           675 Mass Ave, Cambridge, MA 02139, USA.                   *
-!* or see:   http://www.gnu.org/licenses/gpl.html                      *
 !* By Elizabeth Yankovsky, May 2018                                    *
 !***********************************************************************
 
@@ -39,9 +26,13 @@ module RGC_initialization
 
 #include <MOM_memory.h>
 
-character(len=40) :: mod = "RGC_initialization" ! This module's name.
 public RGC_initialize_sponges
 
+! A note on unit descriptions in comments: MOM6 uses units that can be rescaled for dimensional
+! consistency testing. These are noted in comments with units like Z, H, L, and T, along with
+! their mks counterparts with notation like "a velocity [Z T-1 ~> m s-1]".  If the units
+! vary with the Boussinesq approximation, the Boussinesq variant is given first.
+
 contains
 
 !> Sets up the the inverse restoration time, and the values towards which the interface heights,
@@ -86,7 +77,7 @@ subroutine RGC_initialize_sponges(G, GV, US, tv, u, v, depth_tot, PF, use_ALE, C
   character(len=40) :: filename, state_file
   character(len=40) :: temp_var, salt_var, eta_var, inputdir, h_var
 
-  character(len=40)  :: mod = "RGC_initialize_sponges" ! This subroutine's name.
+  character(len=40)  :: mdl = "RGC_initialize_sponges" ! This subroutine's name.
   integer, dimension(2) :: EOSdom ! The i-computational domain for the equation of state
   integer :: i, j, k, is, ie, js, je, isd, ied, jsd, jed, nz, iscB, iecB, jscB, jecB
 
@@ -95,31 +86,31 @@ subroutine RGC_initialize_sponges(G, GV, US, tv, u, v, depth_tot, PF, use_ALE, C
   iscB = G%iscB ; iecB = G%iecB; jscB = G%jscB ; jecB = G%jecB
 
   ! The variable min_thickness is unused, and can probably be eliminated.
-  call get_param(PF, mod,"MIN_THICKNESS", min_thickness, 'Minimum layer thickness', &
+  call get_param(PF, mdl, "MIN_THICKNESS", min_thickness, 'Minimum layer thickness', &
                  units='m', default=1.e-3, scale=GV%m_to_H)
 
-  call get_param(PF, mod, "RGC_TNUDG", TNUDG, 'Nudging time scale for sponge layers', &
+  call get_param(PF, mdl, "RGC_TNUDG", TNUDG, 'Nudging time scale for sponge layers', &
                  units='days', default=0.0, scale=86400.0*US%s_to_T)
 
-  call get_param(PF, mod, "LENLAT", lenlat, &
+  call get_param(PF, mdl, "LENLAT", lenlat, &
                   "The latitudinal or y-direction length of the domain", &
                  fail_if_missing=.true., do_not_log=.true.)
 
-  call get_param(PF, mod, "LENLON", lenlon, &
+  call get_param(PF, mdl, "LENLON", lenlon, &
                   "The longitudinal or x-direction length of the domain", &
                  fail_if_missing=.true., do_not_log=.true.)
 
-  call get_param(PF, mod, "LENSPONGE", lensponge, &
+  call get_param(PF, mdl, "LENSPONGE", lensponge, &
                  "The length of the sponge layer (km).", &
                  default=10.0)
 
-  call get_param(PF, mod, "SPONGE_UV", sponge_uv, &
+  call get_param(PF, mdl, "SPONGE_UV", sponge_uv, &
                  "Nudge velocities (u and v) towards zero in the sponge layer.", &
                  default=.false., do_not_log=.true.)
 
   T(:,:,:) = 0.0 ; S(:,:,:) = 0.0 ; Idamp(:,:) = 0.0
 
-  call get_param(PF, mod, "MINIMUM_DEPTH", min_depth, &
+  call get_param(PF, mdl, "MINIMUM_DEPTH", min_depth, &
                  "The minimum depth of the ocean.", units="m", default=0.0, scale=US%m_to_Z)
 
   if (associated(CSp)) call MOM_error(FATAL, &
@@ -145,21 +136,21 @@ subroutine RGC_initialize_sponges(G, GV, US, tv, u, v, depth_tot, PF, use_ALE, C
 
 
   ! 1) Read eta, salt and temp from IC file
-  call get_param(PF, mod, "INPUTDIR", inputdir, default=".")
+  call get_param(PF, mdl, "INPUTDIR", inputdir, default=".")
   inputdir = slasher(inputdir)
-  call get_param(PF, mod, "RGC_SPONGE_FILE", state_file, &
+  call get_param(PF, mdl, "RGC_SPONGE_FILE", state_file, &
               "The name of the file with temps., salts. and interfaces to \n"// &
               " damp toward.", fail_if_missing=.true.)
-  call get_param(PF, mod, "SPONGE_PTEMP_VAR", temp_var, &
+  call get_param(PF, mdl, "SPONGE_PTEMP_VAR", temp_var, &
               "The name of the potential temperature variable in \n"//&
               "SPONGE_STATE_FILE.", default="Temp")
-  call get_param(PF, mod, "SPONGE_SALT_VAR", salt_var, &
+  call get_param(PF, mdl, "SPONGE_SALT_VAR", salt_var, &
               "The name of the salinity variable in \n"//&
               "SPONGE_STATE_FILE.", default="Salt")
-  call get_param(PF, mod, "SPONGE_ETA_VAR", eta_var, &
+  call get_param(PF, mdl, "SPONGE_ETA_VAR", eta_var, &
               "The name of the interface height variable in \n"//&
               "SPONGE_STATE_FILE.", default="eta")
-  call get_param(PF, mod, "SPONGE_H_VAR", h_var, &
+  call get_param(PF, mdl, "SPONGE_H_VAR", h_var, &
               "The name of the layer thickness variable in \n"//&
               "SPONGE_STATE_FILE.", default="h")