1. Delayed Antarctic sea-ice decline in high-resolution climate change simulations.
- Author
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Rackow, Thomas, Danilov, Sergey, Goessling, Helge F., Hellmer, Hartmut H., Sein, Dmitry V., Semmler, Tido, Sidorenko, Dmitry, and Jung, Thomas
- Subjects
CLIMATE change ,SEA ice ,MESOSCALE eddies ,OCEAN circulation ,GLOBAL warming ,ATMOSPHERIC models - Abstract
Despite global warming and Arctic sea-ice loss, on average the Antarctic sea-ice extent has not declined since 1979 when satellite data became available. In contrast, climate model simulations tend to exhibit strong negative sea-ice trends for the same period. This Antarctic sea-ice paradox leads to low confidence in 21st-century sea-ice projections. Here we present multi-resolution climate change projections that account for Southern Ocean mesoscale eddies. The high-resolution configuration simulates stable September Antarctic sea-ice extent that is not projected to decline until the mid-21st century. We argue that one reason for this finding is a more realistic ocean circulation that increases the equatorward heat transport response to global warming. As a result, the ocean becomes more efficient at moderating the anthropogenic warming around Antarctica and hence at delaying sea-ice decline. Our study suggests that explicitly simulating Southern Ocean eddies is necessary for providing Antarctic sea-ice projections with higher confidence. Delayed Antarctic sea-ice decline is linked to Southern Ocean eddies - and their explicit treatment in models is crucial. New multi-resolution climate change projections give a possible reason for low confidence in IPCC's current 21st-century Antarctic sea-ice projections. [ABSTRACT FROM AUTHOR]
- Published
- 2022
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