Improving the ice sheet mass balance estimates for Antarctica using ICESat-2, GRACE/GRACE- FO, GPS and SMB models
Abstract
In recent decades, studies have shown an increased loss of ice mass from the Antarctic Ice Sheet. There are, however, discrepancies in cumulative mass loss magnitude and uncertainty among the three independent measuring methods: gravity measurement, altimetry, and mass budget for estimating the mass balance, especially in East Antarctica. As a result, ice sheet models are not well constrained in East Antarctica to make projections for the coming decades. Here, we employ an iterative algorithm combining altimetry, gravity, GPS and SMB models to refine the mass balance estimates based on the original algorithm of Wahr et al. (2000) and Velicogna et al. (2002). The algorithm iteratively solves for the best glacial isostatic adjustment, firn compaction and ice sheet mass balance that matches the gravity, altimetry, GPS and SMB record. The SMB record considers various alternatives such as RACMO2.3, MAR3.6 and MERRA-2. The results indicate a significant adjustment to the GIA and in turn to the mass balance estimates. We compare the results with a forward modeling of the GIA using a variety of viscosity and thickness parameters to identify a most plausible GIA correction that matches the GIA model and the GIA inferred from contemporaneous observational constraints. This work demonstrates a new approach to determine the GIA that does not rely solely on paleo climate records and a path forward to reconcile independent measurement techniques to offer a solution with reduced uncertainties.
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2020
- Bibcode:
- 2020AGUFMC028.0010L
- Keywords:
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- 0726 Ice sheets;
- CRYOSPHERE;
- 0750 Sea ice;
- CRYOSPHERE;
- 0758 Remote sensing;
- CRYOSPHERE;
- 0762 Mass balance;
- CRYOSPHERE