Regional and hemispheric circulation patterns in the northern hemisphere winter, or the NAO and the AO
Regional and hemispheric circulation patterns in the northern hemisphere winter, or the NAO and the AO
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DOI：
10.1029/2003gl017290
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发表时间：
2003-09-20
影响因子：
5.2
通讯作者：
Kuroda, Y
中科院分区：
文献类型：
--
作者：
Kodera, K;Kuroda, Y
[ 1]冬季欧洲-大西洋地区存在两种不同尺度的遥相关型。一个是冰岛和亚速尔群岛之间的区域跷跷板，另一个是地中海和极地-西伯利亚地区之间的半球跷跷板。北大西洋涛动（NAO）和北极涛动（AO）指数对这两种模态都很敏感，尽管NAO指数反映的是更区域性的模态。在波浪强迫的驱动下，极地对流层垂直风场的变化是造成地面气压呈半球跷跷板状变化的主要过程。极地地区的上升运动在近地面，特别是在挪威海和白令海峡附近诱发了涡旋流，这在表面压力中诱发了波浪图案。区分这两种模式在了解最近的趋势的重要性也得到了解决。
[ 1] Two different scales of teleconnection patterns are found over the Euro- Atlantic region during the winter. One is a regional seesaw between Iceland and the Azores, and the other is a hemispheric seesaw between the Mediterranean and the polar- Siberia region. The North Atlantic Oscillation ( NAO) and the Arctic Oscillation ( AO) indices are sensitive to both modes, although the NAO index reflects the more regional one. The principal process producing a hemispheric seesaw pattern in the surface pressure is changing in vertical winds in the polar troposphere driven by wave forcings. Upward motion in the polar region induces meridional flows near the surface, especially around the Norwegian Sea and Bering Strait, which induce wavy patterns in the surface pressure. The importance of distinguishing the two modes in understanding recent trends is also addressed.