气象科学2017，Vol.37Issue(6)：784-796,13.DOI:10.3969/2016jms.0077
海南岛不同强弱秋汛期暴雨的环流形势和动力特征分析
Comparative analysis of circulation feature and dynamic structure of the rainstorms with different intensity during the autumn flood season in Hainan island
摘要
Abstract
Daily precipitation data observed by 18 stations in Hainan and NCEP/NCAR reanalysis data are used to analyze the different intensity rainfall circulation characteristics during the autumnal flood season in Hainan.Results show that,there are many similarities in circulation configurations and precipitation distributions of the rainstorms with different intensity during autumnal flood season.The difference of the intensity and position of synoptic systems results in the precipitation discrepancy of the rainstorms during the autumnal flood season.In the strong rainstorm processes,the center of South Asia High (SAH) remain over Hainan Island,and its divergence intensity is about 2-3 times stronger than weaker rainstorm processes.At middle and lower level,Western North Pacific Subtropical High (WNPSH) is weaker and retreats from Asian continent,and tropical low-pressure system is stronger and more northern in the strong rainstorm cases.The presence of strong low-level jet in north central South China Sea(SCS) is the most significant feature of rainstorm case in autumnal flood season,but the distinct characteristics are also manifested mainly in the differentia of the shape and intensity of low level jet between different rainstorm cases.In the strong cases,the strength,length,thickness and speed gradient of jet core is much larger,and that horizontal wind circumvolve clockwise along with height,all facts are conductive to the maintenance and development of rainstorm.In addition,the jet cores of strong cases are stationary and stay over the sea near the eastern Hainan Island in the maximum precipitation day,and they fluctuate wildly in the vertical direction and wind speed.But when it comes to the weak cases,the situation is reversed,the jet cores change little in height and speed,and oscillate obviously in the east-west direction.The water vapor of the strong cases transports by three airflows:northeaster,easterly and southerly,but the vapor transportation of the weak cases is mainly due to the easterly wind.关键词
秋汛期/暴雨/环流特征/低空东风急流Key words
Autumnal flood season/Rainstorm/Circulation feature/Low-level easterly jet分类
天文与地球科学引用本文复制引用
冯文,吴俞,赵付竹,周玲丽..海南岛不同强弱秋汛期暴雨的环流形势和动力特征分析[J].气象科学,2017,37(6):784-796,13.基金项目
国家自然科学基金资助项目(41365004) （41365004）
海南省应用技术研发与示范推广专项(ZDXM2015106) （ZDXM2015106）
海南省自然科学基金项目(413132) （413132）
