FAQ

Frequently Asked Questions (FAQ)

Ice is stuck on the border of the domain (no fluxes), what can I do?

Set the parameter exclude_borders_from_iceflow to True.

I see some numerical artifacts (e.g., waves) occurring when modeling glacier evolution, what can I do?

Reduce the CFL parameter.

How to create/modify NetCDF files?

There are many ways to prepare NetCDF files (e.g., MATLAB, Python, GIS tools). The NCO toolkit allows easy operations via command lines, for example:

ncks -x -v thk file.nc file.nc              # Removes the variable 'thk' from file.nc
ncks -v usurf file.nc file.nc               # Extracts the variable 'usurf' from file.nc
ncap2 -h -O -s 'thk=0*thk' file.nc file.nc  # Performs operations on file.nc, here forcing zero 'thk'
ncrename -v apc,strflowctrl file.nc         # Renames variable 'apc' to 'strflowctrl' in file.nc

OGGM Shop produces an error on Windows

This is expected, as OGGM is not supported on Windows. However, modifying the tarfile.py file at line 2677 from name == member_name to name.replace(os.sep, '/') == member_name seems to fix the issue on Windows. Thanks to Alexi Morin for proposing this workaround.

GPU vs CPU

IGM works fine on CPUs for small computational domains (typically individual glaciers). In contrast, GPUs are highly advantageous for very large computational grids (e.g., large networks of glaciers), as IGM naturally benefits from parallelism. See this example.