The early twentieth century warming and winter Arctic sea ice
The early twentieth century warming and winter Arctic sea ice
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二十世纪初期变暖和冬季北极海冰
DOI：
10.5194/tc-6-1231-2012
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发表时间：
2012
期刊：
影响因子：
--
通讯作者：
M. Latif
中科院分区：
文献类型：
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作者：
V. Semenov;M. Latif
近几十年来，北极的地表变暖是地球仪上最强烈的，气温上升的同时，海冰范围迅速缩小。然而，人们对1920-1940年世纪初变暖（ETCW）期间北极海冰的变化知之甚少，这也是全球和北极强烈地表变暖的时期。在这里，我们调查的敏感性北极冬季表面空气温度（SAT）海冰在1875-2008年期间通过模拟与大气环流模式（AGCM）被迫估计观测到的海表温度（SST）和海冰浓度。自20世纪60年代以来，北极变暖的趋势很好地再现了模型。相比之下，北极的ETCW几乎没有被捕获。这与强迫数据中海冰范围在ETCW期间没有强烈变化的事实是一致的。AGCM模拟观测到的SST，但固定的海冰揭示了冬季SAT海冰范围的强烈依赖。特别是，近几十年来的变暖被严重低估的模型，如果海冰范围不下降，只是季节性变化。这表明，北极海冰范围的显着减少也可能伴随着20世纪初的变暖，指向异常海冰范围和北极表面温度变化之间的重要联系。
The Arctic featured the strongest surface warming over the globe during the recent decades, and the temperature increase was accompanied by a rapid decline in sea ice extent. However, little is known about Arctic sea ice change during the Early Twentieth Century Warming (ETCW) during 1920–1940, also a period of a strong surface warming, both globally and in the Arctic. Here, we investigate the sensitivity of Arctic winter surface air temperature (SAT) to sea ice during 1875–2008 by means of simulations with an atmospheric general circulation model (AGCM) forced by estimates of the observed sea surface temperature (SST) and sea ice concentration. The Arctic warming trend since the 1960s is very well reproduced by the model. In contrast, ETCW in the Arctic is hardly captured. This is consistent with the fact that the sea ice extent in the forcing data does not strongly vary during ETCW. AGCM simulations with observed SST but fixed sea ice reveal a strong dependence of winter SAT on sea ice extent. In particular, the warming during the recent decades is strongly underestimated by the model, if the sea ice extent does not decline and varies only seasonally. This suggests that a significant reduction of Arctic sea ice extent may have also accompanied the Early Twentieth Century Warming, pointing toward an important link between anomalous sea ice extent and Arctic surface temperature variability.