中文摘要：

亚洲夏季风爆发始于孟加拉湾,然后向中国南海和印度次大陆扩展,其过程约持续1个月。各地区夏季风爆发时间呈明显的年际变化。利用热带气旋资料和气象再分析资料,统计了1951—2010年孟加拉湾和中国南海夏季风爆发前后西北太平洋热带气旋、孟加拉湾气旋风暴活动和夏季风爆发的关系。结果表明,在孟加拉湾夏季风爆发过程中,共有36a出现孟加拉湾气旋风暴,并且夏季风爆发偏早年出现风暴的几率最高,为80%。在孟加拉湾夏季风爆发偏早、正常和偏晚3种类型中,孟加拉湾风暴活动频率高峰期多出现在夏季风爆发前后几天内。并且在孟加拉湾风暴活动频率高峰出现前期,西北太平洋热带气旋最先出现活动频率高峰。孟加拉湾夏季风爆发前有40%—50%的年份西北太平洋出现热带气旋活动,其中,夏季风爆发偏早年,爆发前西北太平洋热带气旋活跃的时间偏早（4月第2候）,且多活动在中国南海和菲律宾附近;爆发正常年,西北太平洋热带气旋活跃的时间为4月第4候,多活动在略偏东的海域;爆发偏晚年,西北太平洋热带气旋活跃的时间为5月初,活动区域最偏东。中国南海夏季风爆发过程中,60a中共有29a西北太平出现热带气旋,其中爆发偏早和正常年出现热带气旋的频率较高,并且热带气旋多出现在爆发当日和爆发后一段时间。整体来看,亚洲夏季风爆发前,西北太平洋热带气旋活动频率最先开始增强,然后孟加拉湾风暴开始活跃并伴随着孟加拉湾夏季风爆发,夏季风爆发偏早和正常年,孟加拉湾夏季风爆发后,西北太平洋热带气旋再次增强,中国南海夏季风爆发。

英文摘要：

Climatologically,the Asian summer monsoon（ASM）onset first occurs at the Bay of Bengal（BOB）and then spreads to the South China Sea（SCS）and Indian subcontinent.The onset usually lasts for about one month.The summer monsoon onsets in different areas show apparent inter-annual variations.The relationship between the tropical cyclone（storm）over the northwestern Pacific and BOB during the ASM onset is analyzed using the datasets from 1951 to 2010.Results show that there are tropical storm activities over the BOB during the BOB summer monsoon onset in 36 a.The earlier onset years are coincident with years of higher probability of up to 80%for tropical storm occurrence.For the three types of the BOB summer monsoon onset（early,normal and late）,the high frequency of the BOB tropical storm appears several days before the BOB summer monsoon onset,and the tropical cyclones over the northwestern Pacific become active before the high frequency occurrence of the BOB tropical storm.For the early BOB summer monsoon onset years,tropical cyclones occur in about 40%-50% of the years over the northwestern Pacific,and the tropical cyclones usually occur over the SCS and near the Philippines in the second pentad of April.When the BOB summer monsoon onset is normal,the tropical cyclones usually occur to the east of the Philippines in the fourth pentad of April.When the BOB summer monsoon onset is late,the tropical cyclones most likely occur over the Pacific,which is the easternmost among the areas of tropical cyclone occurrence corresponding to the three types of monsoon onset in early May.During the SCS summer monsoon onsets from 1951 to 2010,there are tropical cyclone activities over the northwestern Pacific in 29 a.In the early and normal SCS summer monsoon onset years,the frequency of tropical cyclone activities is high.The tropical cyclone over the northwestern Pacific usually becomes active on the SCS summer monsoon onset date or several days later.That is,the tropical cyclone activity over the northwestern Paci