1330号台风“海燕”路径北翘的原因及其对华南的影响

Abstract

利用常规气象观测资料、间隔为6小时的1˚ × 1˚NCEP再分析资料和卫星云图，对1330号“海燕”台风路径北翘东移的原因，以及其对华南地区所带来的强降水过程进行分析。结果表明：台风的路径和西太平洋副高的强度及位置演变密切相关，副高西伸加强时，台风位于副高南侧，受东风气流引导向西行，10日起，台风位于海南省南部，受冷空气影响，副高减弱东退，台风逐渐调整至副高西侧，10日20时，台风受南风气流引导而转向北行。台风登陆前，受台风倒槽影响，我国华南地区有充沛的水汽和强烈的上升运动，降水与850 hPa涡度场、散度场有较好的对应关系，强降水过程中有明显的水汽输送带和水汽辐合与动力条件相配合。台风登陆后，螺旋雨带降水逐渐减弱，广西东南部云系再生，从而产生又一波降水过程。 Based on the conventional meteorological observation data and the 1˚ × 1˚ NCEP reanalysis data and satellite cloud images with a time interval of 6 hours, the reason for the eastward migration of typhoon trail of “Haiyan” No. 1330 was analyzed. And the impact of typhoon in southern China which led to strong precipitation was also analyzed. The results show that the typhoon path is closely related to the intensity and position evolution of the western Pacific subtropical high. When the subtropical high is strengthened, the typhoon is located on the south side of the subtropical high, guided by the east wind flow westward. From 10 onwards, the typhoon is located in the south of Hainan Province, the typhoon is affected by cold air, subtropical high weakened eastward, and the typhoon gradually adjusts to the west side of the subtropical high. At 20 o’clock on the 10th, the typhoon was led by the south wind and turned northbound. Before typhoon landing, by the typhoon inverted trough, China’s southern region has abundant water vapor and a strong upward movement; precipitation and 850 hPa vorticity field, divergence field has a good correspondence. During the heavy rainfall, there is obvious water vapor conveyor belt, water vapor convergence and dynamic condition. When typhoon landed, the spiral rain gradually reduced and the southeastern Guangxi cloud regenerated, resulting in another wave of precipitation process.