Question to creating sea-level fingerprints

nschuff3

I want to use the ISSM-SESAW tool to create sea-level fingerprints. Therefore I use the run me from the example SlrGRACE. Instead of the GRACE data, I use data including the forcing of ice height equivalent of melting ice, so the global mean sea level will increase 1 meter. The pattern for the sea level fingerprints fits only for big forcing areas and if the forcing has positive values. For forcings for a small area or with negative values it does not work. Does anybody has an idea how to improve it?

Lambert_Caron

Hi! Are you using the latest version of the code?
You are correct that negative ice thickness will not get taken into account by the model. That is because the masstransport core imposes a minimum thickness (by default 1m). That's ok because what you want is negative thickness change, and not negative thickness itself.
Here is the fix: Set md.geometry.thickness to a value that is larger than the changes you want (like 1000m everywhere). Then, set md.masstransport.spcthickness = md.geometry.thickness + thickness_change (your data) and the model should compute the pattern due to the difference.

I'm not sure what would cause the small elements to not contribute deformation though. Did you check that the ice and ocean levelsets look correct?
Lambert

nschuff3

Thanks so much. With adding some values to the md.geometry.thickness it is now working.