气候动力学-4-大气环流的遥相关.pdf

《气候动力学》 大气环流的遥相关 大气环流的遥相关  Teleconnection首次出现在文献上(Bjerknes, 1969) Teleconnections  AMS Glossary defines: teleconnection  1. A linkage between weather changes occurring in widely separated regions of the globe. 2. A significant positive or negative correlation in the fluctuations of a field at widely separated points. Most commonly applied to variability on monthly and longer timescales, the name refers to the fact that such correlations suggest that information is propagating between the distant points through the atmosphere. Cited2288，2015.3 Cited1430 ，2009.3 SLP H500 南方涛动 （SO ） 地面气压场的遥相关 • 南方涛动（SO） • 北大西洋涛动（NAO） • 北太平洋涛动（NPO） North Atlantic Oscillation (NAO) North Atlantic Oscillation (NAO) NAO Pattern From NOAA CPC North Atlantic Oscillation NAO + NAO - • Azores High strong • Azores high weak • Icelandic Low deep • Icelandic Low shallow • westerlies strong • westerlies weak • wind and rain • clear and still • mild conditions in NW Europe • cold and dry in NW Europe • dry conditions in Mediterranean • wet conditions in Mediterranean •Correlation with North Atlantic SST (tripole pattern) From: /NAO Classic NAO is defined as the SLP pressure difference between two stations representing the Icelandic Low and the Azores High, respectively Mechanisms of NAO  Internal dynamics: Wave-mean flow interactions Synoptic eddy forcing et al.  External forcing: North Atlantic SST Sea ice QBO et al. NAO and North Atlantic SST Graf and Walter,