Extreme Cold Winter Temperatures in Europe under the Influence of North Atlantic Atmospheric Blocking
Extreme Cold Winter Temperatures in Europe under the Influence of North Atlantic Atmospheric Blocking
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DOI：
10.1175/2011jcli4075.1
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发表时间：
2011-11-15
影响因子：
4.9
通讯作者：
Katz, Richard W.
中科院分区：
文献类型：
--
作者：
Sillmann, Jana;Croci-Maspoli, Mischa;Katz, Richard W.
北大西洋大气阻塞条件解释了欧洲冬季气候变化的部分原因，这与异常寒冷的冬季温度有关。本文用ECHAM5/MPI-OM全球气候模式模拟和ECMWF再分析产品ERA-40得到的欧洲冬季6小时最低气温的月最低值与广义极值(GeV)分布进行了拟合，协变量为大气阻塞条件指标。结果表明，将GeV分布的位置和尺度参数与大气阻塞联系起来，可以改善对欧洲大片地区极端最低温度的拟合。在当前气候条件下(1961-2000年)，气候模式模拟结果与ERA-40符合得很好。在大气阻塞的影响下，0.95℃的降幅可以区分出极端最低气温。然而，由于阻塞位置的转移，大气阻塞的这种冷却效应在未来的气候模拟中会减弱，从而降低了欧洲东北部地区冬季非常寒冷的可能性。
North Atlantic atmospheric blocking conditions explain part of the winter climate variability in Europe, being associated with anomalous cold winter temperatures. In this study, the generalized extreme value (GEV) distribution is fitted to monthly minima of European winter 6-hourly minimum temperatures from the ECHAM5/MPI-OM global climate model simulations and the ECMWF reanalysis product known as ERA-40, with an indicator for atmospheric blocking conditions being used as covariate. It is demonstrated that relating the location and scale parameter of the GEV distribution to atmospheric blocking improves the fit to extreme minimum temperatures in large areas of Europe. The climate model simulations agree reasonably with ERA-40 in the present climate (1961-2000). Under the influence of atmospheric blocking, a decrease in the 0.95th (pantiles of extreme minimum temperatures can be distinguished. This cooling effect of atmospheric blocking is, however, diminished in future climate simulations because of a shift in blocking location, and thus reduces the chances of very cold winters in northeastern parts of Europe.