The following notes document the process used to create
mksrf_GlacierRegion_10x10min_nomask_c160122.nc

The 10' resolution was chosen somewhat arbitrarily, but considerations were: (a)
wanted to use a resolution for which we already have at least one raw data file,
so that no new mapping files would be needed, and (b) wanted to use a high
enough resolution, without going to higher resolution than is really needed for
this purpose.

Short summary: The Greenland mask was generated based on the CISM grid, using
tools in the CISM tools directory: any point within the CISM grid file is
classified as Greenland, because CISM could potentially evolve the Greenland ice
sheet to include these points. The Antarctica mask was generated by assuming
that any grid cell south of 60 deg S is Antarctica.

(1) Created ESMF mapping file between the 5-km Greenland grid and the 10' grid:

From cime4.4.1: tools/mapping/gen_mapping_files/gen_ESMF_mapping_file

Used SCRIP grid file that had already been created for the 5-km Greenland grid
(by Jeremy Fyke, using a different method than the one documented in the CISM
tools directory).

Used the following batch script:

   #!/bin/bash
   #
   #
   # Batch script to submit to create ESMF mapping file
   #
   # Set up for yellowstone
   # 
   # yellowstone-specific batch commands:
   #BSUB -P P93300601        # project number
   #BSUB -n 8               # number of processors
   #BSUB -R "span[ptile=16]" 
   #BSUB -W 1:00             # wall-clock limit
   #BSUB -q caldera            # queue
   #BSUB -o regrid.%J.out    # ouput filename
   #BSUB -e regrid.%J.err    # error filename
   #BSUB -J create_ESMF_map  # job name
   #BSUB -N                  # send email upon job completion

   #----------------------------------------------------------------------

   #----------------------------------------------------------------------
   # Set user-defined parameters here
   #----------------------------------------------------------------------

   filesrc="$CESMDATAROOT/inputdata/lnd/clm2/mappingdata/grids/SCRIPgrid_10x10min_nomask_c110228.nc"
   filedst="/glade/p/cesmdata/cseg/inputdata/glc/cism/griddata/SCRIPgrid_gland_5km_c150511.nc"

   namesrc='10x10min'
   namedst='gland5km'

   typesrc='global'
   typedst='regional'
   maptype='aave'

   #----------------------------------------------------------------------
   # Done setting user-defined parameters
   #----------------------------------------------------------------------

   #----------------------------------------------------------------------
   # Stuff done in a machine-specific way
   #----------------------------------------------------------------------

   # Determine number of processors we're running on
   host_array=($LSB_HOSTS)
   REGRID_PROC=${#host_array[@]}

   #----------------------------------------------------------------------
   # Begin general script
   #----------------------------------------------------------------------

   cmdargs="--filesrc $filesrc --filedst $filedst --namesrc $namesrc --namedst $namedst --typesrc $typesrc --typedst $typedst --maptype $maptype --batch"
   env REGRID_PROC=$REGRID_PROC ./create_ESMF_map.sh $cmdargs

(2) Created a glcmask-like file

From https://svn-ccsm-models.cgd.ucar.edu/glc/trunk_tags/cism2_1_10 : tools

with these diffs:

   Index: scrip2CLMoverlap.ncl
   ===================================================================
   --- scrip2CLMoverlap.ncl	(revision 76273)
   +++ scrip2CLMoverlap.ncl	(working copy)
   @@ -11,7 +11,7 @@
    ; must contain regrid information from a CLM grid to a GLC grid
    ; -------------------------------------------------------------
    
   -infileS = addfile("map_fv0.9x1.25_TO_gland_aave.141105.nc","r")
   +infileS = addfile("map_10x10min_TO_gland5km_aave.160122.nc","r")
    
    ; ---------------------------------------
    ; read in corresponding CLM fracdata file
   @@ -19,7 +19,8 @@
    
    ; infileF    = addfile ("$CESMDATAROOT/inputdata/lnd/clm2/griddata/fracdata_48x96_gx3v7_c090915.nc","r")
    ; infileF    = addfile ("$CESMDATAROOT/inputdata/lnd/clm2/griddata/fracdata_1.9x2.5_gx1v6_c090206.nc","r")
   -infileF    = addfile ("$CESMDATAROOT/inputdata/lnd/clm2/griddata/fracdata_0.9x1.25_gx1v6_c090317.nc","r")
   +; infileF    = addfile ("$CESMDATAROOT/inputdata/lnd/clm2/griddata/fracdata_0.9x1.25_gx1v6_c090317.nc","r")
   +infileF    = addfile("/glade/p/cesmdata/cseg/inputdata/lnd/clm2/griddata/fracdata_10min_USGS_071205.nc","r")
    
    ; ------------------------------------------------
    ; read in necessary information from the two files


Renamed the resulting file to mksrf_GlacierRegion_10x10min_nomask_c160122.nc

(3) Renamed GLCMASK to GLACIER_REGION:

ncrename -v GLCMASK,GLACIER_REGION mksrf_GlacierRegion_10x10min_nomask_c160122.nc

(4) Modified the resulting file so that points in Antarctica are given a
GLACIER_REGION of 2 rather than 0

In python (using netCDF4):

dat = Dataset('mksrf_GlacierRegion_10x10min_nomask_c160122.nc', 'a')
antarctica = np.where(dat.variables['LATIXY'][:] <= -60)
dat.variables['GLACIER_REGION'][antarctica] = 2
dat.close()