Climatically-driven changes of Antarctic sea ice
Abstract
While Arctic sea ice is melting at a record pace, observations show that sea ice surrounding Antarctica has been slowly expanding since 1979. Increased melt rates of the Antarctic ice sheet and changes in atmospheric dynamics and winds are both considered to be key drivers of sea ice trends. We present a sensitivity study with an eddy-permitting global NEMO sea ice-ocean model (forced with ERA-Interim atmospheric reanalysis) that aims to investigate how modifications of regional climate conditions (mass loss of the Antarctic ice sheet and atmospheric forcing) can affect Antarctic sea ice variability and in turn how these changes might impact on-shelf water properties and ocean circulation. First, we performed a set of numerical simulations with additional fresh water supply at the Antarctic ocean surface. Our results confirm that enhanced freshwater inputs can increase the sea ice extent. However, a very strong freshwater discharge might eventually invert the trend. The freshwater spatial distribution plays a key role in our simulations. It affects sea ice dynamics and can strongly alter regional sea ice concentration and thickness. We find that additional coastal runoff generally leads to fresher and warmer dense shelf waters. Then, we performed and compared numerical simulations where wind velocities in the ERA-Interim reanalysis data are simply manipulated. Preliminary results on how idealized wind intensifications (in both zonal and meridional components) impact regional properties of sea ice are shown.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2016
- Bibcode:
- 2016AGUFM.C21C0704I
- Keywords:
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- 3349 Polar meteorology;
- ATMOSPHERIC PROCESSESDE: 0750 Sea ice;
- CRYOSPHEREDE: 4207 Arctic and Antarctic oceanography;
- OCEANOGRAPHY: GENERALDE: 4540 Ice mechanics and air/sea/ice exchange processes;
- OCEANOGRAPHY: PHYSICAL