generate-ismip7-grid-files-py

Python scripts to generate ISMIP7 grid description files used for CDO regridding.
(The grids did not change since ISMIP6)
See also old matlab version of scripts

Setup

Needs a python3 environment with
numpy, netCDF4

Usage

The scripts can generate 3 different types of files for Greenland and Antarctica

grid description files (e.g. used for CDO regridding)

grid_ISMIP7_g?_IS_res.nc

xy coordinates

xy_ISMIP7_g?_IS_res.nc

area factors

af2_ISMIP7_g?_IS_res.nc

All files are produced for the diagnostic grid g1 (ice thickness, SMB, ..)
The scripts can also generate files for a staggered grid g0, where e.g. CISM defines horizontal velocities.

ISMIP7_AIS_multigrid_generator_nc.py
ISMIP7_GrIS_multigrid_generator_nc.py

using

polar_stereo.py
wnc.py

New text-based grid description files

In new versions of CDO, the grid description can be provided per text files that specify the projection information. These files are much smaller in size and can be produced with the following scripts.

make_GDF_AIS.py
make_GDF_GrIS.py

Example of CDO regridding

Conservative remapping (here from 16 km to 8 km grid)
remapycon,gdf_.. specifies the output grid
-setgrid,gdf_.. specifies the input grid

cdo -v remapycon,gdf_ISMIP7_AIS_08000m.txt -setgrid,gdf_ISMIP7_AIS_16000m.txt lithk_AIS_16000m.nc lithk_AIS_08000m.nc

See examples/ for more.