广东热带气旋降水年代际变化特征的分析

AN ANALYSIS ON INTERDECADAL VARIATION FEATURES OF TROPICAL CYCLONE PRECIPITATION IN GUANGDONG PROVINCE OF CHINA

采用1951—2005年热带气旋和广东省26个测站降水的观测资料,分析了广东热带气旋及其降水的年代际变化特征。结果表明:广东热带气旋降水存在峰值为25年左右的振荡周期,影响广东的热带气旋个数和西北太平洋上热带气旋的形成个数都存在峰值为23年左右的振荡周期;广东热带气旋降水的年代际变化与影响广东的热带气旋个数和西北太平洋上热带气旋的形成个数存在高度正相关;广东热带气旋降水的年代际变化与西太平洋部分区域的年平均SST的年代际变化和北太平洋中高纬部分地区的年平均500 hPa位势高度的年代际变化存在显著的负相关;广东热带气旋降水偏少时期与降水偏多时期相比,一般赤道中、东太平洋的平均SST相对较高,而北太平洋中纬度地区的平均SST相对较低,北太平洋上的东亚大槽相对较强。

The interdecadal variation features of tropical cyclone and its precipitation over Guangdong Province are investigated using the observational data of tropical cyclone and precipitation of 26 observational stations in Guangdong Province from 1951 to 2005. The results show that the tropical cyclone precipitation over Guangdong Province exists an oscillation with a peak value about 25-year, both the number of tropical cyclones that influenced Guangdong Province and of tropical cyclones formation in the western North Pacific exist an oscillation with a peak value about 23-year. There are high positive relationships between the interdecadal variation of tropical cyclone precipitation over Guangdong Province with the number of tropical cyclones that influenced Guangdong Province and the number of tropical cyclone formation in the western North Pacific. The interdecadal variation of tropical cyclone precipitation over Guangdong Province exists significant negative relationships with the interdecadal variation of annual mean SST in the partial area over the western North Pacific and the interdecadal variation of annual mean 500 hPa geopotential height in the middle and high latitude partial area over the North Pacific. In general, there is a high mean SST on the equator from central to eastern Pacific, a low mean SST in the middle and high latitude area over the North Pacific and a strong East Asian big trough over the North Pacific in the period of more tropical cyclone precipitation comparing with in the period of less tropical cyclone precipitation over Guangdong Province.