Atmospheric response in summer linked to recent Arctic sea ice loss
Atmospheric response in summer linked to recent Arctic sea ice loss
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DOI：
10.1002/qj.2502
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发表时间：
2015-07-01
影响因子：
8.9
通讯作者：
Sutton, R. T.
中科院分区：
文献类型：
--
作者：
Petrie, R. E.;Shaffrey, L. C.;Sutton, R. T.
自2007年以来，观察到北冰洋海冰大幅减少。在ERA中期再分析和HadGEM3气候模式试验中，研究了大尺度大气环流对这种下降的响应。在冬季，在北极、北大西洋和欧亚大陆观测到的2007年后环流异常与年际变化相比较小。在夏季，观测到的2007年后的环流以格陵兰上空的反气旋异常为主，具有较高的信噪比。由观测到的海温和海冰异常驱动的气候模型实验能够捕捉到观测到的环流异常的夏季模式，尽管其幅度是观测到的三分之一。实验表明，拉布拉多海的高海温和海冰减少导致对流层低层温度正异常，从而通过热风平衡减弱了北美上空的西风。实验还捕捉到了欧洲西北部的气旋异常，这与下游Rossby波的传播是一致的。
Since 2007 a large decline in Arctic sea ice has been observed. The large-scale atmospheric circulation response to this decline is investigated in ERA-Interim reanalyses and HadGEM3 climate model experiments. In winter, post-2007 observed circulation anomalies over the Arctic, North Atlantic and Eurasia are small compared to interannual variability. In summer, the post-2007 observed circulation is dominated by an anticyclonic anomaly over Greenland which has a large signal-to-noise ratio. Climate model experiments driven by observed SST and sea ice anomalies are able to capture the summertime pattern of observed circulation anomalies, although the magnitude is a third of that observed. The experiments suggest high SSTs and reduced sea ice in the Labrador Sea lead to positive temperature anomalies in the lower troposphere which weaken the westerlies over North America through thermal wind balance. The experiments also capture cyclonic anomalies over Northwest Europe, which are consistent with downstream Rossby wave propagation.