冬季北半球风暴轴的协同变化及其与大气环流的相互作用  

Coordinated variation of Northern Hemisphere storm tracks in winter and their interaction with atmospheric circulation

作　　者：祁春娟 朱伟军[1] 李欣 曹煜晨 QI Chunjuan;ZHU Weijun;LI Xin;CAO Yuchen(Key Laboratory of Meteorological Disaster,Ministry of Education(KLME)/Joint International Research Laboratory of Climate and Environment Change(ILCEC)/Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters(CIC-FEMD),Nanjing University of Information Science&Technology,Nanjing 210044,China;Xinzhou Meteorological Bureau,Shanxi Xinzhou 034000,China)

机构地区：[1]气象灾害教育部重点实验室/气候与环境变化国际合作联合实验室/气象灾害预报预警与评估协同创新中心,南京信息工程大学,南京210044 [2]忻州市气象局,山西忻州034000

出　　处：《气象科学》2020年第2期157-168,共12页Journal of the Meteorological Sciences

基　　金：国家自然科学基金资助项目(41575070,41075070);公益性行业(气象)科研专项(GYHY201306028);江苏高校优势学科建设工程(PAPD)。

摘　　要：基于1971—2016年NCEP/NCAR的逐日、逐月再分析资料,研究冬季北半球西伯利亚风暴轴(Siberian Storm Track,SIST)、北太平洋风暴轴(Pacific Storm Track,PST)和北大西洋风暴轴(Atlantic Storm Track,AST)的协同变化特征及其与大气环流的关系。结果表明:(1)三大风暴轴不仅各自的位置与强度变化存在显著相关性,风暴轴之间也存在一定的协同变化且年代际尺度上比年际尺度上更紧密。年际尺度上,SIST与AST的经度变化呈显著负相关,而PST和AST的协同性较差;年代际尺度上,SIST与PST的经、纬度变化均呈弱的负相关,SIST与AST的经度和强度变化均呈显著正相关,PST与AST的经、纬度变化均呈显著负相关。(2)由联合EOF分析得到北半球风暴轴的协同变化时空特征:在年际尺度上,第一模态主要表现为SIST偏弱(强),PST主体偏弱(强)、东南偏强(弱),AST略偏北(南)偏强(弱)但不显著的协同变化。PC1为正位相时,对应的大气环流异常为:500 hPa高度场上为太平洋北美(Pacific North America,PNA)型和欧亚(Eurasian,EU)型的正位相,东亚急流偏强且偏南;第二模态主要表现为SIST偏强(弱)且偏东(西),PST中东部偏南(北)、西部强度偏强(弱),AST偏强(弱)的协同变化。PC2为正位相时,对应的大气环流异常为:500 hPa高度场上为PNA型和大西洋东部(East Atlantic,EA)型的正位相,北美急流减弱;在年代际尺度上,第一模态主要表现为SIST偏西(东)且偏弱(强),PST偏东(西)且偏弱(强),AST偏西(东)且偏弱(强)的协同变化。PC1为正位相时,对应的大气环流异常为:500 hPa高度场上为西大西洋(West Atlantic,WA)型和EU型的正位相。第二模态主要表现为SIST偏强(弱)且偏北(南),PST偏南(北)且偏弱(强),AST北抬(南压)的协同变化。PC2为正位相时,对应的大气环流异常为:500 hPa高度场上为EU型和WA型的正位相,东亚急流强度加强且偏南,北美急流强度减弱。Based on the daily and monthly reanalysis data of NCEP/NCAR from 1971 to 2016,the coordinated variation characteristics of the Siberian Storm Track(SIST),North Pacific Storm Track(PST)and North Atlantic Storm Track(AST)and their relationship with atmospheric circulation in the Northern Hemisphere were investigated by using harmonic analysis,Empirical Orthogonal Function(EOF),regression analysis,etc.The results show that:(1)The three storm tracks not only have significant correlations between their respective positions and intensity changes,but have some coordinated variations between the storm tracks,and they are closer on the interdecadal scale than the interannual scale.On the interannual scale,there is a significant negative correlation between SIST and AST in their longitude changes,and the synergy between PST and AST is poor.On the interdecadal scale,SIST and PST are weakly negatively correlated in their latitude and longitude changes.SIST and AST are significantly positively correlated in their longitude and intensity changes.PST and AST are significantly negatively correlated in their latitude and longitude changes.(2)The temporal and spatial characteristics of the coordinated variations of the storm tracks at the Northern Hemisphere obtained by the EOF analysis include:on the interannual scale,the coordinated variation of the first order mode is mainly characterized that SIST is weak(strong);PST is weak(strong)at climatological position and strong(weak)in the southeast;AST is strong(weak)and northward(southward)but not significant.When PC1 is in the positive phase,corresponding atmospheric circulation anomalies include PNA and EU teleconnections are positive at the level of 500 hPa,and East Asia jet stream is strong and southward.The coordinated variation of the second order mode is mainly characterized that SIST is strong(weak)and eastward(westward);PST is southward(northward)in the middle east and strong(weak)in the west,and AST is strong(weak).When PC2 is in the positive phase,corresponding atmospheric

关 键 词：风暴轴 年际年代际 协同变化 大气环流 

分 类 号：P433[天文地球—大气科学及气象学]