Close relationship between the East Asian westerly jet and Russian far East surface air temperature in summer  

作　　者：LIN Xiao-Zhen LI Chao-Fan LIN Zhong-Da LU Ri-Yu 

机构地区：[1]State Key Laboratory of Numerical Modelling for Atmospheric Sciences and Geophysical Fluid Dynamics,Institute of Atmospheric Physics,Chinese Academy of Sciences [2]College of Earth Science,University of Chinese Academy of Sciences [3]Center for Monsoon System Research,Institute of Atmospheric Physics,Chinese Academy of Sciences

出　　处：《Atmospheric and Oceanic Science Letters》2018年第3期282-286,共5页大气和海洋科学快报（英文版）

基　　金：supported by the National Natural Science Foundation of China(Grant Nos.41320104007,41775062,41375086,U1502233,and 41775083)

摘　　要：The interannual variability of the east asian upper-tropospheric westerly jet（EAJ） in summer is characterized by the meridional displacement of its axis, or a seesaw pattern of zonal wind anomalies between the northern and southern flanks of the EAJ. This study reveals a close relationship between the surface air temperature in the russian far east and the northern flank of the EAJ. Related to a warmer surface in the russian far east, the westerly decelerates in the northern flank of the EAJ. The relationship can be explained by a positive feedback mechanism between the surface air temperature in the russian far east and the overhead circulation： the anticyclonic circulation anomaly related to a weakened westerly in the northern flank of the EAJ induces surface warming in the russian far east and the warmer surface can in turn act as a heat source and induces a local anticyclonic circulation anomaly in the upper troposphere, therefore decelerating the westerly in the northern flank of the EAJ. The result implies that a better description of the summer surface condition in the russian far east may benefit seasonal forecasts of the EAJ and, subsequently, east asian summer climate.本文研究了夏季东亚副热带高空西风急流的年际变化与俄罗斯远东地面温度的关系并揭示了二者的相互作用机制。结果表明:副热带西风急流北侧环流与俄罗斯远东地区地面温度关系密切,二者存在着正反馈机制。一方面,急流北侧西风减弱(增强)可以通过关联的反气旋(气旋)式环流引起下沉(上升)运动,使得俄罗斯远东地区地面增温(降温)。另一方面,俄罗斯远东地区地面温度也能作为热源(热汇)在高层激发出反气旋式(气旋式)环流,导致急流北侧西风减弱(增强),进而影响急流的南北移动。这些结果揭示了俄罗斯远东地区地表状况的重要性,有助于进一步认识和提高东亚夏季气候的季度预测水平。

关 键 词：East Asian westerly jet surface air temperature Russian far East 

分 类 号：P423[天文地球—大气科学及气象学] P434