polartoolkit.fetch.bedmap2

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polartoolkit.fetch.bedmap2#

bedmap2(layer, reference='eigen-gl04c', region=None, spacing=None, registration=None, fill_nans=False, **kwargs)[source]#

Load bedmap2 data as xarray.DataArrays from Fretwell et al.[1]. accessed from https://ramadda.data.bas.ac.uk/repository/entry/show?entryid=fa5d606c-dc95-47ee-9016-7a82e446f2f2.

All grids are by default referenced to the EIGEN-GL04C geoid. Use the reference=’ellipsoid’ to convert to the WGS-84 ellipsoid or reference=’eigen-6c4’ to convert to the EIGEN-6c4 geoid.

Unlike Bedmachine data, Bedmap2 surface and icethickness contain NaN’s over the ocean, instead of 0’s. To fill these NaN’s with 0’s, set fill_nans=True. Note, this only makes since if the reference is the geoid, therefore, if reference=’ellipsoid and fill_nans=True, the nan’s will be filled before converting the results to the geoid (just for surface, since thickness isn’t relative to anything).

Parameters:

  • layer (str) – choose which layer to fetch: “bed”, “coverage”, “grounded_bed_uncertainty”, “icemask_grounded_and_shelves”, “lakemask_vostok”, “rockmask”, “surface”, “ice_thickness”, “ice_thickness_uncertainty”, “gl04c_geiod_to_WGS84”, “icebase”, “water_thickness”

  • reference (str) – choose whether heights are referenced to the ‘eigen-6c4’ geoid, the WGS84 ellipsoid, ‘ellipsoid’, or by default the ‘eigen-gl04c’ geoid.

  • region (tuple[float, float, float, float] | None) – region to clip the loaded grid to, in format [xmin, xmax, ymin, ymax], by default doesn’t clip

  • spacing (float | None) – grid spacing to resample the loaded grid to, by default 1000m. If spacing >= 5000m, will resample the grid to 5km, and save it as a preprocessed grid, so future fetch calls are performed faster.

  • registration (str | None) – choose between ‘g’ (gridline) or ‘p’ (pixel) registration types, by default is the original type of the grid

  • fill_nans (bool) – choose whether to fill nans in ‘surface’ and ‘thickness’ with 0. If converting to reference to the geoid, will fill nan’s before conversion, by default is False

  • **kwargs (Any) – additional keyword arguments to pass to the resample_grid function

Returns:

Returns a loaded, and optional clip/resampled grid of Bedmap2.

Return type:

DataArray

References

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