The Contributions of Winter Cloud Anomalies in 2011 to the Summer Sea-Ice Rebound in 2012 in the Antarctic
Unlike the rapid decline of Arctic sea ice in the warming climate, Antarctic sea-ice extent exhibits a modest positive trend in the period of near four decades. In recent years, the fluctuation in Antarctic sea ice has been strengthened, including a decrease toward the lowest sea-ice extent in Febru...
Published in: | Journal of Geophysical Research: Atmospheres |
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Main Authors: | , , , , , , |
Format: | Report |
Language: | English |
Published: |
AMER GEOPHYSICAL UNION
2019
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Subjects: | |
Online Access: | http://ir.qdio.ac.cn/handle/337002/161124 https://doi.org/10.1029/2018JD029435 |
Summary: | Unlike the rapid decline of Arctic sea ice in the warming climate, Antarctic sea-ice extent exhibits a modest positive trend in the period of near four decades. In recent years, the fluctuation in Antarctic sea ice has been strengthened, including a decrease toward the lowest sea-ice extent in February 2011 for the period of 1978-2016 and a strong rebound in the summer of 2012. The sea-ice recovery mainly occurs in the Weddell Sea, Bellingshausen Sea, Amundsen Sea, southern Ross Sea, and the eastern Somov Sea. This study offers a new mechanism for this summertime sea-ice rebound. We demonstrate that cloud-fraction anomalies in winter 2011 contributed to the positive Antarctic sea-ice anomaly in summer 2012. The results show that the negative cloud-fraction anomalies in winter 2011 related to the large-scale atmospheric circulation resulted in a substantial negative surface-radiation budget, which cooled the surface and promoted more sea-ice growth. The sea-ice growth anomalies due to the negative cloud forcing propagated by sea-ice motion vectors from September 2011 to January 2012. The distribution of the sea-ice anomalies corresponded well with the sea-ice concentration anomalies in February 2012 in the Weddell Sea and eastern Somov Sea. Thus, negative cloud-fraction anomalies in winter can play a vital role in the following summer sea-ice distribution. |
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