海南岛登陆热带气旋频数异常成因分析

Abnormal Frequency of the tropical cyclone landing in Hainan Island

采用NCEP/NCAR再分析的月平均500hPa高度场、海温场(SST)资料,分析讨论了登陆海南岛热带气旋活动异常与大气环流、SST影响因子之间的关系,得到登陆海南岛热带气旋(TC)偏多、偏少年对应的大气环流、SST的概念模型。分析结果表明:(1)前一年11月500hPa亚洲大陆高纬位势高度偏低(高),则次年登陆海南岛TC偏多(少);(2)当年8、9月西太平洋和东亚大陆位势高度自北向南呈反相叠加,且中高纬度以经向(纬)向环流为主时,低纬度印度洋位势高度偏低(高),则当年登陆海南岛的TC偏多(少);(3)孟加拉湾SST对热带气旋的影响最稳定和最明显,当前一年9～12月孟加拉湾SST偏暖(冷)时,次年登陆的TC偏多(少),当年7～8月偏暖(冷),登陆TC偏多(少);(4)当年3～6月南海北部SST偏冷(暖)时,登陆TC偏多(少)。

Using NCAR/NCEP reanalysis data including 500hPa geopotential height and SST, the relationship between the abnormal action of tropical cyclones （TC） and air circulations was analyzed. The concept models corresponding to the landing TC abnormal action were also discussed. The results show that （1）While 500hPa potential height is low （high） Over the high latitudes of the Asian continent in November, landing TC is more （less） in the following year.（2）In Aug. and Sep., while the geopotential height of the Western Pacific and East Asia was overlay reversely from north to south, and the main cir- culation in mid-high latitudes was meridional （latitude）, landing TC is more （less） in this year.（3）TC was influenced by Bay of Bengal SST the most stably and obviously. When the Bay of Bengal SST is warm （cold） in the current Sep. to Dec. [July to Aug.], landing TC is more （less） in the following year [this year], （4） While the northern South China Sea SST is cold （warm） in the current Mar. to June, the landing TC is more （less） .