摘要
利用NCEP/NCARⅡ逐日再分析资料以及我国实测的降水资料,对2005年6月华南暴雨期间西太平洋副高的西伸过程进行了分析。结果表明:副高的东西进退可能与暴雨过程存在某种联系。分析指出副高中心的下沉气流主要是由副高南北两侧雨带中凝结潜热释放效应所致的上升气流在高空下沉而产生的,副高中心垂直运动的出现有利于副高的加强。而副高南北两侧雨带不但可以加强副高,同时又会激发正涡度增长,限制副高在南北方向上的活动,此时西侧印度季风雨带则会在副高西侧激发反气旋性涡度发展,即可诱使副高西伸。因此,华南强降水和印度季风区降水的共同作用使得副高加强西伸。
The NCEP/NCAR Ⅱ daily mean reanalysis data and observational precipitation data are employed to investigate the westward extension of the western Pacific subtropical high （WPSH） during the heavy rain period over the southern China in June 2005.Results show that there may exist a relationship between the shift of the WPSH in the east-west direction and the process of the southern China heavy rain. The analysis indicates that the vertical motion in the WPSH area is mainly caused by the latent heat release of monsoon rain-belts on its northern and southern sides. The vertical motion could cause the accumulation of air mass in the center and west of the WPSH, which leads to the strengthening of the WPSH. The appearance of the northern and southern monsoon rain-belts not only could enhance the WPSH by strengthening the descending draft, but also could excite the development of positive vorticity and restrict the WPSH＇s movement in the north-south direction. Moreover, the Indian monsoon rainfall to the west of the WPSH may excite the development of anticyclonic vorticity on its eastern side, which leads to the westward extension of the WPSH.
出处
《热带气象学报》
CSCD
北大核心
2008年第2期169-175,共7页
Journal of Tropical Meteorology
基金
国家重点基础研究发展规划“我国南方致洪暴雨检测与预测的理论和方法研究”项目(2004CB418304)资助
关键词
西太平洋副高
暴雨
垂直运动
凝结潜热释放
western pacific subtropical high
heavy rain
vertical motion
latent heat release
