IACS-cryo / Delineation-WG

Ice sheet and glacier boundaries and basins
https://cryosphericsciences.org/activities/delineation-of-glaciers-ice-sheets-and-ice-sheet-basins/
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[MASK]: Greenland Ice Sheet Modeling using ISSM #36

Open dfelikson opened 2 months ago

dfelikson commented 2 months ago

Overview

Upstream

Greenland Ice Mapping Project (GIMP) Ice and Ocean Mask

Howat, I.M., A. Negrete, B.E. Smith, 2014, The Greenland Ice Mapping Project (GIMP) land classification and surface elevation datasets, The Cryosphere, 8, 1509-1518, doi:10.5194/tc-8-1509-2014

NOTE that this is the original data product and it comes packaged with the BedMachine dataset for Greenland. I use it via BedMachine.

This mask is provided as part of the BedMachine dataset and is consistent with the bed and surface geometry in BedMachine, required for model initialization.

When initializing the model further back in time (e.g., in the 1980s or during the Little Ice Age), the mask has to be modified to extend ice further into outlet glacier fjords.

If the mask provides similar delineations (ice, ocean, land, etc.), and has a similar resolution, it would not be much effort to switch to the new mask.

I typically use this product for internal basins: https://earth.gsfc.nasa.gov/cryo/data/polar-altimetry/antarctic-and-greenland-drainage-systems

Zwally, H. Jay, Mario B. Giovinetto, Matthew A. Beckley, and Jack L. Saba, 2012, Antarctic and Greenland Drainage Systems, GSFC Cryospheric Sciences Laboratory

Sometimes subset to either (1) drainage basin using above or (2) individual glacier using catchment derived from ice sheet surface velocity observations

Downstream

Remove this section if no downstream output mask from your product

The model can simulate changes in the extent of the ice sheet (e.g., due to outlet glacier retreat). The model uses an unstructured mesh and a levelset method to track the ice extent. The value of the levelset is output at every mesh node at every model timestep and the ice extent can be directly calculated from the levelset.

Other notes