Responses of the East Asian Jet Stream to the North Pacific Subtropical Front in Spring

作     者：Leying ZHANG Haiming XU Ning SHI Jiechun DENG 

作者机构：Collaborative Innovation Center on Forecast and Evaluation of Meteorological DisastersKey Laboratory of Meteorological DisasterMinistry of Education Joint International Research Laboratory of Climate and Environment ChangeNanjing University of Information Science and TechnologyNanjing 210044China College of Atmospheric ScienceNanjing University of Information Science and TechnologyNanjing 210044China 

出 版 物：《Advances in Atmospheric Sciences》 (大气科学进展（英文版）)

年 卷 期：2017年第34卷第2期

页      面：144-156页

核心收录：

学科分类：07[理学] 070601[理学-气象学] 0706[理学-大气科学] 0816[工学-测绘科学与技术] 0825[工学-航空宇航科学与技术] 

基　　金：jointly supported by the Ministry of Science and Technology of China,through the National Basic Research Program of China(Grant No.2012CB955602) the National Natural Science Foundation of China(Grant Nos.41575077,41490643 and 41275094) a project funded by the PAPD(Priority Academic Program Development of Jiangsu Higher Education Institutions) supported by the Innovation Project for Graduate Student of Jiangsu Province(Grant No.KYLX15-0860) 

主　　题：North Pacific subtropical front East Asian jet stream transient eddy activity atmospheric heat source 

摘      要：This study concerns atmospheric responses to the North Pacific subtropical front （NPSTF） in boreal spring over the period 1982-2014. Statistical results show that a strong NPSTF in spring can significantly enhance the East Asian jet stream （EAJS）. Both transient eddy activity and the atmospheric heat source play important roles in this process. The enhanced atmospheric temperature gradient due to a strong NPSTF increases atmospheric baroclinicity, resulting in an intensification of transient eddy and convection activities. On the one hand, the enhanced transient eddy activities can excite an anomalous cyclonic circulation with a quasi-baraotropical structure in the troposphere to the north of the NPSTF. Accordingly, the related westerly wind anomalies around 30°N can intensify the component of the EAJS over the Northeast Pacific. On the other hand, an enhanced atmospheric heat source over the NPSTF, which is related to increased rainfall, acts to excite an anomalous cyclonic circulation system in the troposphere to the northwest of the NPSTF, which can explain the enhanced component of the EAJS over the Northwest Pacific. The two mechanisms may combine to enhance the EAJS.