oggm.tasks.define_glacier_region(gdir, entity=None)[source]

Very first task: define the glacier’s local grid.

Defines the local projection (Transverse Mercator), centered on the glacier. There is some options to set the resolution of the local grid. It can be adapted depending on the size of the glacier with:

dx (m) = d1 * AREA (km) + d2 ; clipped to dmax

or be set to a fixed value. See params.cfg for setting these options. Default values of the adapted mode lead to a resolution of 50 m for Hintereisferner, which is approx. 8 km2 large. After defining the grid, the topography and the outlines of the glacier are transformed into the local projection. The default interpolation for the topography is cubic.


where to write the data


the glacier geometry to process


Files writen to the glacier directory:

A geotiff file containing the DEM (reprojected into the local grid).This DEM is not smoothed or gap filles, and is the closest to the original DEM source.


A salem.Grid handling the georeferencing of the local grid.


The glacier outlines in the local map projection (Transverse Mercator).