Seasonal dynamics of North Greenland ice shelves
Abstract
Seasonal changes in ice velocity of north Greenland glaciers are observed in the satellite data record, but it is unclear what physical mechanism is controlling these changes. Subglacial hydrology and ocean forcing are both important factors in ice dynamics and have been suggested as possible causes for the seasonal speed up. However, it remains undetermined if either is responsible for the observed seasonal pattern. Here we use a combination of modeling techniques and remote sensing data to address the question of seasonal variability in the ice flow of glaciers in northern Greenland. The potential for calving, grounding line location, basal melting, and surface melting to cause seasonal changes in glacier velocity is examined using the Ice Sheet System Model (ISSM). Grounding line positions are obtained from synthetic aperture radar (SAR) double difference interferometry. The Sentinel-1 satellite pair has a repeat cycle of 6 days which has allowed for the examination of grounding line migration over short time scales. Surface melt has been reconstructed across the Greenland Ice Sheet by the Regional Atmospheric Climate Model, RACMO2.3. These data are used to test the sensitivity of glaciers in northern Greenland to ocean forcings and subglacial hydrology on seasonal time scales. Understanding what drives seasonal changes in ice flow dynamics will further the development of a comprehensive framework describing how ice sheets respond to changes in climate forcings. Being able to model the response of northern Greenland glaciers to increasing atmospheric and ocean temperatures is important for projecting climate change induced sea level rise.
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2019
- Bibcode:
- 2019AGUFM.C23D1584E
- Keywords:
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- 3349 Polar meteorology;
- ATMOSPHERIC PROCESSES;
- 0456 Life in extreme environments;
- BIOGEOSCIENCES;
- 0750 Sea ice;
- CRYOSPHERE;
- 1620 Climate dynamics;
- GLOBAL CHANGE;
- 1621 Cryospheric change;
- GLOBAL CHANGE;
- 1622 Earth system modeling;
- GLOBAL CHANGE;
- 1694 Instruments and techniques;
- GLOBAL CHANGE;
- 4207 Arctic and Antarctic oceanography;
- OCEANOGRAPHY: GENERAL