The Role of Ocean Dynamics in the Summer Retreat and Winter Expansion of Antarctic Sea-Ice in the Amundsen and Bellingshausen Seas since 1979
Abstract
According to modern satellite passive microwave data record (since late 1978), the Antarctic sea-ice extent has overall increased in all seasons, in stark contrast to the declining Arctic sea-ice extent. However, the upward trend of the Antarctic sea-ice extent is not homogeneous throughout the all longitudes and all seasons. In particular, the sea-ice extent has decreased substantially over the Amundsen and Bellingshausen Seas (150°W - 60°W) during warm seasons and over the Weddell Sea (60°W - 20E°) during cold seasons. The Antarctic sea-ice insulates the underlying ocean from the air-sea fluxes of heat, momentum, freshwater and carbon. Therefore, its multi-decadal trend may slow down or accelerate ocean warming, salinity stratification and ocean acidification, and thus modulate the Southern Ocean's response to the increasing anthropogenic greenhouse gases in the atmosphere. Hence, it is important to understand the atmosphere-ocean processes that caused the inhomogeneous trend of the Antarctic sea-ice extent. Various hypotheses have been proposed and tested to explain the spatially and seasonally inhomogeneous trend of the Antarctic sea-ice extent. However, many of the previous studies either neglected or did not fully incorporate the potential role of wind-driven ocean dynamics. Since both the atmosphere and ocean processes are involved in the seasonal formation and melting of the Antarctic sea-ice, it is very likely that regional ocean dynamics played an important role in shaping the spatially and seasonally inhomogeneous Antarctic sea-ice trend. Therefore, we would like to investigate how and to what extent the recent trends of Antarctic sea-ice fraction were affected by regional ocean dynamic processes. As a first step, here we mainly focus on the summer retreat and winter expansion of Antarctic sea-ice extent in the Amundsen and Bellingshausen Seas using both available observations and a surface-forced ocean-sea ice coupled model.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2016
- Bibcode:
- 2016AGUFM.C21C0707L
- 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