Spatial and temporal variations in radar backscatter in Antarctica as detected by CryoSat-2
Abstract
Satellite radar altimetry over the Antarctic ice-sheet provides time series of elevation change used as primary inputs in determining mass balance. Ice-sheet elevation estimates obtained from altimetry are affected by spatial and temporal variability in the backscattering properties of the illuminated snowpack. Temporally correlated fluctuations in elevation and power observed in Antarctica are known to introduce spurious signals in elevation change. As a result two different elevation estimates can be retrieved from the same geographical location over time, despite there being no real change in surface elevation. We use a backscatter model which retrieves estimates of the depth distribution of radar backscatter from Low Resolution Mode CryoSat-2 waveforms. With this dataset we map the spatial pattern of surface and sub-surface scattering and its evolution over time, demonstrating a seasonal increase in the strength of surface backscatter from the West and East Antarctic ice divides in the austral summer months. We compare results from threshold and Offset Centre-of-Gravity retrackers in order to investigate the effects of the observed changes in surface and sub-surface scattering on CryoSat-2 elevation estimates.
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2016
- Bibcode:
- 2016AGUFM.C11A0754S
- Keywords:
-
- 0758 Remote sensing;
- CRYOSPHEREDE: 0799 General or miscellaneous;
- CRYOSPHEREDE: 1240 Satellite geodesy: results;
- GEODESY AND GRAVITYDE: 1241 Satellite geodesy: technical issues;
- GEODESY AND GRAVITY