| Summary: | Radio-echo sounding data were collected in Greenland by the University of Kansas over several years for NASA's Program for Arctic Regional Climate Assessment (PARCA). Data from 1998, 1999, 2002 and 2003 have been analysed according to the method previously published by the author and Dr S P Gogineni, to determine the frozen or thawed state of the bed from the radio-echo signals. These four years provide broad coverage of the ice sheet, and it has been possible to map the bed state, as determined by this method, over a large fraction of the ice sheet area. The method is as published with the exception of finer-grained analysis of and adjustment for dielectric losses. The continuity of the bed state determination has been used to estimate the diameter of frozen or thawed regions, and then to derive the likely state at each point of a 1km grid over the ice sheet, centered at 74N, 40W. A map is provided in Matlab .fig format and as a .tiff image, and a file providing the bed state at each point of the grid, where data are available. The purpose of making these data available is to support numerical modelling efforts towards the prediction of future ice sheet behaviour. The analysis has been completed, taking account of known ground truth, but details are subject to continuing review.
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