南海西南季风异常与广东省汛期重要天气的关系

南海西南季风的活动直接影响广东省前、后汛期重要天气的异常,因此深入探索南海西南季风的活动规律及其与广东省各种重大天气异常的关系十分必要.利用合成分析和相关统计方法,探讨和分析了南海西南季风建立早晚、强弱与广东省前、后汛期降水量趋势,初、终台的早晚及登陆广东省的热带气旋个数等重要天气的关系.指出南海西南季风爆发早的年份,前汛期雨量以正常偏少为主、后汛期雨量以偏多为主、登陆广东热带气旋偏多;南海西南季风偏强的年份,后汛期雨量以偏多为主,登陆广东热带气旋以正常偏多为主.还分析了4～6月、7～9月以及前冬(12～2月)的海温场、500 hPa高度场与西南季风建立早晚、强弱的关系,初步探索了西南季风建立的早晚、强弱与广东省汛期重要天气气候异常的关系的一些机理,其结果可供短期气候业务预测参考.

THE RELATIONSHIP BETWEEN SOUTH CHINA SEA SOUTHWEST MONSOON ANOMALIES AND IMPORTANT WEATHER IN GUANGDONG PROVINCE DURING THE RAINING SEASON

The activity of South China Sea southwest monsoon has direct impact on the anomalies of important weather in Guangdong province during the raining season.So it is necessary to explore thoroughly the activity pattern of South China Sea southwest monsoon and the relationship between it and important weather anomalies in the province.In this paper,the methods of composite analysis and correlation statistics are used to study the relationship between onset date and intensity of South China Sea southwest monsoon and important weather,such as precipitation trends in Guangdong province during the annually first and second raining seasons,the timing of the annually first and last typhoon and the number of typhoons landing in Guangdong province.The results show that the rainfall is less than normal during the first raining season,but more than normal during the second raining season and the tropical cyclone landing in Guangdong province is more in the early onset years of South China Sea southwest monsoon.The rainfall is more than normal during the second raining season and the tropical cyclone landing in Guangdong province is more in the years of strong South China Sea southwest monsoon.The relationship between the SST of Apr.-Jun.,Jul.-Sep.and previous winter(Dec.-Feb.) and 500 hPa height and the onset date and intensity of South China Sea southwest monsoon is analyzed.Some mechanisms between onset dates and intensity of South China Sea southwest monsoon and important weather anomalies in Guangdong province are preliminarily explored.The results can be usedl in short-term climate forecast.