Basal slipperiness and englacial rate factor of the Antarctic Ice Sheet

The data set contains values of basal slipperiness (C) and the rate factor (A) for the whole of the Antarctic Ice Sheet.

The slipperiness was estimated through model inversion from measurements of surface velocities (1) and ice thickness (2) using the ice-flow model Ua (3).

The ice was assumed to deform according to Glen's flow law with a stress exponent n=3.

Basal sliding was assumed to follow Weertman sliding law with m=3, with u_b = C tau^m, where u_b is the basal sliding velocity and tau the (tangential) basal traction.

The columns in the data file are:

lat lon x y A C

where x and y are coordinates in polar stereographic projection corresponding to the lat lon values in the first two columns.

A and C are the values at location (lat,lon) and (x,y).

References :

1. Rignot, E., Mouginot, J., Scheuchl, B. Ice flow of the Antarctic ice sheet. Science 333, 1427-1430 (2011). DOI:10.1126/science.1208336
2. Fretwell, P. et al. Bedmap2: Improved ice bed, surface and thickness datasets for Antarctica. Cryosphere 7, 375-393 (2013). DOI:10.5194/tc-7-375-2013
3. Gudmundsson, G. H. Ice-shelf buttressing and the stability of marine ice sheets. Cryosph. 7, 647-655 (2013). DOI:10.1073/pnas.1512482112