1.  summary:		conservative mappings between gx3v5 and T31

2.  created by:		Steve Yeager
 
3.  date and time:	December 05, 2003

4.  created on: 	dataproc
 
5.  dataset format: 	nc
 
6.  endian:		n/a
 
7.  archival copy location:
 
8.  creation summary:
 
The following is a description of how the netcdf mapping files 
between gx3v5 and T31 grids were produced.

run /fs/cgd/data0/yeager/POP_GRIDS/gx3v5.012/mk_remap.csh

This generates the following output from scrip (/home/dataproc/yeager/scrip1.4):

 	Using lat/lon boxes to restrict search.
  	Computing remappings between: gx3v5, Present DP x3
                           and  T31 Gaussian Grid
 	grid1 sweep 
 	grid2 sweep 
 	Total number of links =  22527
 	Map 1 weight > 1  9751,  4513,  299.9154912313067
 	Map 2 weight < 0  9751,  4513,  332.71640138563134

The erroneous weights between 9751->4513 are simply deleted from the mapping
files using:

/fs/cgd/data0/yeager/POP_GRIDS/idl_tools/correct_map_errors.run


The script mk_remap.csh takes care of all the following:

--------------------------------
-- Scrip Grid File Generation --
--------------------------------

Note: As of November 2001 we are not using the standard scrip1.4
version of convertPOPT, but have nonstandard code to use the
ccsm_pop/cice calculation of T-grid cell center locations.  The code used
here was /home/dataproc/yeager/scrip1.4/create_grids/myconvertPOPT.f (NOTE!
this is a different code from that used for gx3v4 grids, 
/fs/cgd/home0/hecht/csm/fortran/SCRIP/scrip1.4/grids/convertPOPT.f, see
/fs/cgd/csm/mapping/grids/gx3v4_020513.readme)


-------------------------------------
-- Scrip Remapping File Generation --
-------------------------------------

The scrip_in used is:

&remap_inputs
    num_maps = 2
    grid1_file = '/ptmp/yeager/gx3v5/gx3v5.nc'
    grid2_file = '/fs/cgd/csm/mapping/grids/T31.nc'
    interp_file1 = '/ptmp/yeager/gx3v5/map_gx3v5_to_T31_aave_da.nc'
    interp_file2 = '/ptmp/yeager/gx3v5/map_T31_to_gx3v5_aave_da.nc'
    map1_name = 'gx3v5 to T31 Mapping'
    map2_name = 'T31 to gx3v5 Mapping'
    map_method = 'conservative'
    normalize_opt = 'destarea'
    output_opt = 'ncar-csm'
    restrict_type = 'latlon'
    num_srch_bins = 10 
    luse_grid1_area = .false.
    luse_grid2_area = .false.
/