add_lake_20200810: Update sfc_climo_gen to work with

model points that can be partial land.

References ufs-community#111

sorc/sfc_climo_gen.fd/model_grid.F90

@@ -334,7 +334,7 @@ subroutine get_model_info(orog_file, mask, lat2d, lon2d, idim, jdim)
  real(esmf_kind_r4), intent(out)    :: lat2d(idim,jdim)
  real(esmf_kind_r4), intent(out)    :: lon2d(idim,jdim)
 
- integer                            :: error, lat, lon
+ integer                            :: error, lat, lon, i, j
  integer                            :: ncid, id_dim, id_var
 
  real(kind=4), allocatable          :: dummy(:,:)
@@ -365,12 +365,37 @@ subroutine get_model_info(orog_file, mask, lat2d, lon2d, idim, jdim)
 
  allocate(dummy(idim,jdim))
 
- print*,"- READ LAND MASK"
- error=nf90_inq_varid(ncid, 'slmsk', id_var)
- call netcdf_err(error, "READING SLMSK ID")
- error=nf90_get_var(ncid, id_var, dummy)
- call netcdf_err(error, "READING SLMSK")
- mask = nint(dummy)
+!-----------------------------------------------------------------------
+! If the lake maker was used, there will be a 'lake_frac' record.
+! In that case, land/non-land is determined by 'land_frac'.
+!
+! If the lake maker was not used, use 'slmsk', which is defined
+! as the nint(land_frac).
+!-----------------------------------------------------------------------
+
+ error=nf90_inq_varid(ncid, 'lake_frac', id_var)
+ if (error /= 0) then
+   print*,"- READ LAND MASK (SLMSK)"
+   error=nf90_inq_varid(ncid, 'slmsk', id_var)
+   call netcdf_err(error, "READING SLMSK ID")
+   error=nf90_get_var(ncid, id_var, dummy)
+   call netcdf_err(error, "READING SLMSK")
+   mask = nint(dummy)
+ else
+   print*,"- READ LAND FRACTION"
+   error=nf90_inq_varid(ncid, 'land_frac', id_var)
+   call netcdf_err(error, "READING LAND_FRAC ID")
+   error=nf90_get_var(ncid, id_var, dummy)
+   call netcdf_err(error, "READING LAND_FRAC")
+   mask = 0
+   do j = 1, lat
+   do i = 1, lon
+     if (dummy(i,j) > 0.0) then
+       mask(i,j) = 1
+     endif
+   enddo
+   enddo
+ endif
 
  print*,"- READ LATITUDE"
  error=nf90_inq_varid(ncid, 'geolat', id_var)