Variability of the North Atlantic eddy-driven jet stream
Variability of the North Atlantic eddy-driven jet stream
复制标题
DOI：
10.1002/qj.625
复制
发表时间：
2010-04-01
影响因子：
8.9
通讯作者：
Hoskins, Brian
中科院分区：
文献类型：
--
作者：
Woollings, Tim;Hannachi, Abdel;Hoskins, Brian
北大西洋部分的大部分大气变化与纬向流的涡动驱动分量的变化有关。在这里，我们提出了一个简单的方法来具体诊断这一部分的流动使用低层风场（925-700百帕）。我们在ERA-40再分析中关注北大西洋冬季。诊断的纬度和速度的涡驱动的急流进行了比较，与传统的诊断北大西洋涛动（NAO）和东大西洋（EA）模式。这表明NAO和EA都描述了急流的纬度和速度的综合变化。因此，有必要，但并不总是足够的，同时考虑NAO和EA在确定急流的变化。急流分析表明，有三个首选的纬度位置的北大西洋涡驱动急流在冬季。这一结果是非常好的协议与应用程序的统计混合模型的NAO和EA定义的二维状态空间。这些结果是一致的，与其他几项研究，确定四个欧洲/大西洋制度，包括三个急流模式加上欧洲阻塞事件。版权所有（C）2010皇家气象学会
Much of the atmospheric variability in the North Atlantic sector is associated with variations in the eddy-driven component of the zonal flow. Here we present a simple method to specifically diagnose this component of the flow using the low-level wind field (925-700 hPa). We focus on the North Atlantic winter season in the ERA-40 reanalysis. Diagnostics of the latitude and speed of the eddy-driven jet stream are compared with conventional diagnostics of the North Atlantic Oscillation (NAO) and the East Atlantic (EA) pattern. This shows that the NAO and the EA both describe combined changes in the latitude and speed of the jet stream. It is therefore necessary, but not always sufficient, to consider both the NAO and the EA in identifying changes in the jet stream.The jet stream analysis suggests that there are three preferred latitudinal positions of the North Atlantic eddy-driven jet stream in winter. This result is in very good agreement with the application of a statistical mixture model to the two-dimensional state space defined by the NAO and the EA. These results are consistent with several other studies which identify four European/Atlantic regimes, comprising three jet stream patterns plus European blocking events. Copyright (C) 2010 Royal Meteorological Society