Surface conditions and error contribution to CryoSat-2 Low Rate Mode signal penetration across the Greenland Ice Sheet
Abstract
Greenland Ice Sheet surface heights contribute to estimates of ice volume and mass balance. The European Space Agency's CryoSat-2 Low Rate Mode measures the surface of the inland ice sheet using a radar altimeter. The CryoSat-2 mission accounts for altimeter errors due to satellite orbit and atmospheric conditions, but requires extensive ground validation to constrain errors due to signal penetration into the near-surface snow. The 2011 Greenland Inland Traverse (GrIT) provides kinematic GPS elevation measurements, near-surface density, and general surface observations across 1120km of northern Greenland. Initial comparisons between GrIT GPS elevations and CryoSat-2 Level-2 surface heights revealed a small but constant vertical offset. We examine contributions to this offset using CryoSat-2 Level-1b waveforms and GPS surface elevations improved by post-processing techniques. We use GrIT density and stratigraphy data from snowpits, shallow cores, and surface hardness measurements to investigate the impact of near-surface conditions on CryoSat-2 surface height error. GPS post-processing, Level-1b waveforms, and GrIT near-surface measurements improve understanding of surface height errors and CryoSat-2 signal penetration along the varying surface slopes and facies conditions crossed by the traverse route.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2013
- Bibcode:
- 2013AGUFM.C21D0661O
- Keywords:
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- 0726 CRYOSPHERE Ice sheets;
- 0758 CRYOSPHERE Remote sensing