(*)+Use RHO_KV_CONVERT to set nonBous GV%H_to_m

  Use RHO_KV_CONVERT instead of RHO_0 to set the non-Boussinesq version of
GV%m_to_H, so that there is a mechanism for testing the independence of the
fully non-Boussinesq mode from the Boussinesq reference density.  With this
change, GV%Z_to_H is not guaranteed to be equal to (GV%Z_to_m*GV%m_to_H), with
the latter expression preferred when setting parameters. By default the two
parameters are the same, and they will probably only ever differ in testing the
code.  All Boussinesq solutions are bitwise identical, but there are differences
in the description of RHO_KV_CONVERT that will appear in MOM_parameter_doc
files.

src/core/MOM_verticalGrid.F90

@@ -138,8 +138,12 @@ subroutine verticalGridInit( param_file, GV, US )
                  default=.true., do_not_log=GV%Boussinesq)
   if (GV%Boussinesq) GV%semi_Boussinesq = .true.
   call get_param(param_file, mdl, "RHO_KV_CONVERT", Rho_Kv, &
-                 "The density used to convert input kinematic viscosities into dynamic "//&
-                 "viscosities in non-BOUSSINESQ mode, and similarly for vertical diffusivities.", &
+                 "The density used to convert input vertical distances into thickesses in "//&
+                 "non-BOUSSINESQ mode, and to convert kinematic viscosities into dynamic "//&
+                 "viscosities and similarly for vertical diffusivities.  GV%m_to_H is set "//&
+                 "using this value, whereas GV%Z_to_H is set using RHO_0.  The default is "//&
+                 "RHO_0, but this can be set separately to demonstrate the independence of the "//&
+                 "non-Boussinesq solutions of the value of RHO_0.", &
                  units="kg m-3", default=GV%Rho0*US%R_to_kg_m3, scale=US%kg_m3_to_R, &
                  do_not_log=GV%Boussinesq)
   call get_param(param_file, mdl, "ANGSTROM", GV%Angstrom_Z, &
@@ -186,18 +190,22 @@ subroutine verticalGridInit( param_file, GV, US )
     GV%m_to_H = 1.0 / GV%H_to_m
     GV%H_to_MKS = GV%H_to_m
     GV%m2_s_to_HZ_T = GV%m_to_H * US%m_to_Z * US%T_to_s
+
+    GV%H_to_Z = GV%H_to_m * US%m_to_Z
+    GV%Z_to_H = US%Z_to_m * GV%m_to_H
   else
     GV%kg_m2_to_H = 1.0 / GV%H_to_kg_m2
-    GV%m_to_H = US%R_to_kg_m3*GV%Rho0 * GV%kg_m2_to_H
-    GV%H_to_m = GV%H_to_kg_m2 / (US%R_to_kg_m3*GV%Rho0)
+    !  GV%m_to_H = US%R_to_kg_m3*GV%Rho0 * GV%kg_m2_to_H
+    GV%m_to_H = US%R_to_kg_m3*rho_Kv * GV%kg_m2_to_H
     GV%H_to_MKS = GV%H_to_kg_m2
     GV%m2_s_to_HZ_T = US%R_to_kg_m3*rho_Kv * GV%kg_m2_to_H * US%m_to_Z * US%T_to_s
-  endif
+    GV%H_to_m = 1.0 / GV%m_to_H
 
-  GV%H_to_Z = GV%H_to_m * US%m_to_Z
-  GV%Z_to_H = US%Z_to_m * GV%m_to_H
+    GV%H_to_Z = US%m_to_Z * ( GV%H_to_kg_m2 / (US%R_to_kg_m3*GV%Rho0) )
+    GV%Z_to_H = US%Z_to_m * ( US%R_to_kg_m3*GV%Rho0 * GV%kg_m2_to_H )
+  endif
 
-  GV%Angstrom_H = GV%Z_to_H * GV%Angstrom_Z
+  GV%Angstrom_H = (US%Z_to_m * GV%m_to_H) * GV%Angstrom_Z
   GV%Angstrom_m = US%Z_to_m * GV%Angstrom_Z
 
   GV%H_subroundoff = 1e-20 * max(GV%Angstrom_H, GV%m_to_H*1e-17)