Classification of wintertime large-scale tilted ridges over the Eurasian continent and their influences on surface air temperature  

作　　者：Da-Wei LIN Cholaw BUEH Zuo-Wei XIE 

机构地区：[1]International Center for climate and Environment Sciences, Institute of Atmospheric Physics, Chinese Academy of Sciences [2]College of Earth Science, University of Chinese Academy of Sciences

出　　处：《Atmospheric and Oceanic Science Letters》2018年第5期404-411,共8页大气和海洋科学快报（英文版）

基　　金：jointly supported by the National Natural Science Foundation of China [grant number 41375064 and41675086];the National Key Technology Research and Development Program of the Ministry of Science and Technology of China [grant number 2015BAC03B03]

摘　　要：This study investigates the major patterns of large-scale tilted ridges(LSTRS)over the Eurasian continent and their connections with large-scale surface air temperature during boreal winter.A total number of 134 LSTR events with zonal extent exceeding 90°of longitude on the peak day are identified.Using self-organizing map(SOM),the LSTRs are classified into five clusters that are characterized by different spatial distributions and orientations.The leading two clusters are closely associated with extensive and persistent cold events over different places.Considering the first cluster,LSTRs extend from the Ural Mountains to Northeast Asia and are favorable for the amplification and southeastward extension of the Siberian high.Therefore,this cluster is closely associated with the occurrence of extensive and persistent cold events in china.In comparison with the first cluster,the LSTRs of second group are situated to the west,with starting points from the Kola Peninsula,and cause extensive and persistent cold events over Eastern Europe,central Asia,and central Siberia.The results suggest that the vertical coupling between LSTRs and the corresponding anomalous sea level pressure is crucial for the persistent cold temperature events associated with the leading two SOM clusters.本文研究了冬季欧亚大陆大型斜脊系统(LSTR)的类型及其对大范围持续性极端低温事件(EPECE)的影响。结果表明,依据斜脊位置和空间形态,LSTR可分为五类,其中前两类与欧亚大陆EPECE密切相关。第一类LSTR起于乌拉尔山,有利于我国EPECE的发生;第二类LSTR起于科拉半岛,位置偏西,有利于中欧至中西伯利亚一带EPECE的发生。LSTR与西伯利亚高压之间的垂直耦合作用是EPECE发生的重要原因。这些结论对我国EPECE的中期—延伸期预报有一定的指导意义。

关 键 词：Large-scale tilted ridges self-organizing map extensive and persistent cold event Siberian high 

分 类 号：P[天文地球]