北半球冬季欧亚中高纬大气季节内低频主模态的变化特征及其对环流背景场和气温的影响
投稿时间: 2018-03-05  最后修改时间: 2018-03-31  点此下载全文
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作者单位E-mail
陈栋杰 华东师范大学地理科学学院 975755513@qq.com 
史达伟 江苏省连云港市气象局 395158610@qq.com 
周放 国家气候中心  
基金项目:淮河流域气象开放基金(HRM201602)、江苏省气象局青年基金(KQ201802)
中文摘要:本文采用1979-2016年NCEP/DOE 2逐日再分析资料,分析了北半球冬半年(10月1日至次年3月31日)欧亚中高纬大气季节内振荡的主要模态特征及其与欧亚关键性环流系统的关系。结果表明: 欧亚大陆中高纬季节内振荡主要以20-40d周期为主,低频主模态呈现出位相一波型分布。位相合成和的结果表明,欧亚中高纬大气季节内振荡呈现出准正压结构,在整个对流层呈现出自东向西方向的传播特征,位相传播速度约为5-10经度/天。冬半年欧亚中高纬季节内低频活动与EU遥相关型,短波槽脊和西伯利亚高压等环流系统有着重要的联系,欧亚中高纬大气季节内低频振荡通过EU波列对对流层中层中高纬短波槽脊以及对流层低层西伯利亚高压的活动产生影响,进而影响欧亚地区气温的变化。
中文关键词:北半球冬季,欧亚中高纬地区,季节内振荡,EU遥相关型,短波槽脊,西伯利亚高压
 
Characteristics of Low Frequency Mode on an Intraseasonal Time Scale at Middle-high Latitudes over the Eurasia and Its Relations with Background Circulation and Air Temperature
Abstract:By using NCEP/DOE 2 daily reanalysis datasets, the characteristics of low frequency mode on an intraseasonal time scale at middle-high latitudes over Eurasia and their relations with background circulation and air temperature are analyzed. It shows that the intraseasonal oscillation at middle-high-latitudes over the Eurasia shows a significant tim e scale of about 20-40 days. The low frequency mode features a dipole mode at zonal direction. The phase composites shows that the intraseasonal oscillation at middle-high-latitudes over the Eurasia features a quasi-barotropic structure, and propagates from east to west in the whole troposphere with a speed of 5-10 degrees per day. The intraseasonal activity over the Eurasia during boreal winter is highly related with the EU teleconnection pattern, short wave ridge/trough, and the Siberia High. It shows that the intraseasonal oscillation at middle-high-latitudes over the Eurasia influences the short wave ridge/trough in the middle troposphere and Siberia High in the low troposphere through the EU wave, and further influence the air temperature in the Eurasia.
keywords:boreal winter, middle-high latitudes over the Eurasia, intraseasonal oscillation, EU pattern, Siberia high
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