Modeling future mass balance of glaciers in Alaska using Python Glacier Evolution Model
Abstract
In recent decades, glaciers in Alaska have been losing mass and retreating in response to increases in temperature. This glacial change has implications for global sea-level rise as well as freshwater availability. In this investigation we simulated the mass balance of a subset of 116 of Alaska's largest glaciers (>36,000 km2, and 43% of the glacier area in Alaska) using the Python Glacier Evolution Model (PyGEM) from 1960 to 2100. These simulations were forced by monthly air temperature and precipitation using ERA-Interim reanalysis climate data from 1980-2017 (hindcast), 10 different General Circulation Models (GCMs), and 3 different Representative Concentration Pathways (RCPs): RCP 2.6, RCP 4.5, and RCP 8.5. The model was calibrated for each of the 116 glaciers individually using geodetic mass balance observations. The 116 glaciers are projected to lose between 21.9% ± 8.2% and 33.8% ± 10.1% of their mass by 2100 relative to 2017, depending on choice of RCP. We analyze the changes in the individual components of the mass budget. Results indicate a strong increase in specific mass loss due to melt and frontal ablation with time for RCP 8.5, while specific accumulation stays relatively constant.
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2019
- Bibcode:
- 2019AGUFM.C31B1504S
- Keywords:
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- 0720 Glaciers;
- CRYOSPHERE;
- 0758 Remote sensing;
- CRYOSPHERE;
- 0762 Mass balance;
- CRYOSPHERE;
- 0776 Glaciology;
- CRYOSPHERE