Tropical Cyclone Formation Associated with Monsoon *** Ⅰ:Observational Analysis
会议名称：《强化科技基础 推进气象现代化——第29届中国气象学会年会》
会议日期：2012年
学科分类：07[理学] 070601[理学-气象学] 0706[理学-大气科学]
基 金：supported by the typhoon research project(2009CB421503)of the National Basic Research Program of China the National Natural Science Foundation of China(NSFC grant No.40875038) the social commonweal research program of the Ministry of Science and Technology of the People’s Republic of China(GYHY200806009)
摘 要：Large-scale monsoon gyres and the involved tropical cyclone formation over the western North Pacific have been documented in previous *** study is aimed to understand how monsoon gyres affect tropical cyclone *** the first part of this study,an observational study is conducted on monsoon gyres during the period 2000-2010,with a focus on their structures and the associated tropical cyclone formation.A total of 36 monsoon gyres are identified in May-October during 2000-2010,among which 31 monsoon gyres are accompanied with the formation of 43 tropical cyclones,accounting for 20.3% of the total tropical cyclone *** gyres generally are found on the poleward side of the climatological monsoon trough with a peak occurrence in *** about 1000 km outward from the center in at lower levels,the cyclonic circulation of the composited monsoon gyre shrinks with height and is replaced with negative relative vorticity above 200 *** maximum winds of the composited monsoon gyre appear 500-800 km away from the gyre center with a magnitude of 8-13 m s-1 at 850 *** agreement with previous studies,the composited monsoon gyre shows enhanced southwesterly flows and convection on the south-southeast side due to Rossby wave energy *** of tropical cyclones associated with monsoon gyres are found to form near the centers of monsoon gyres and the northeast end of the enhanced southwesterly flows,accompanying with weak vertical wind shear.