摘要
使用云南省中部玉溪站1971—2007年逐年雨季开始期资料和同期1—5月NCEP/NCAR再分析月平均气压场、高度场及风场资料,用相关分析、诊断分析和EOF等方法研究了滇中雨季开始期对冬、春季热带环流异常变化的响应关系,并利用太平洋东部副热带高压及大西洋亚速尔高压的平均气压与印尼和孟加拉湾地区的平均气压之差,定义了滇中雨季预测指数(MYRSPI)。结果表明:滇中雨季开始期对前期热带环流的异常变化会产生较强响应,当冬、春季热带高度场异常升高(降低)和MYRSPI为负(正)距平时,初夏500hPa西太平洋副热带高压偏强(偏弱)、偏西(偏东),滇中雨季偏晚(偏早)。统计表明,MYRSPI对滇中雨季早晚有较强的预测能力,可在实际业务中运用。
Using the NCEP/NCAR monthly mean data and the Yuxi rainy season onset data from 1971 to 2007, the response of the onset date of rainy seasons in the central area of Yunnan to precedent anomalous tropical circulation is analyzed using correlation analysis and EOF analysis. With the difference between the mean pressure of the subtropical high in the eastern Pacific and Azores high and the mean pressure in the Indonesian area and the Bay of Bengal, a rainy season prediction index for the central area of Yunnan （PICY） is defined. The results showed that the rainy season onset date in the central area of Yunnan highly responses to abnormal changes in precedent tropical circulation. When the geopotentiai height of the tropics is anomalously higher （lower） and the PICY is negatively （positively） anomalous in winter and spring, the west Pacific subtropical high at 500 hPa will be stronger （weaker） and extends westward （eastward） in early summer, and the onset date will be later （earlier） for the rainy season. Statistics indicates that the PICY is well capable of predicting the timing of the onset date for the rainy season in the central area of Yunnan and can be used in routine operation.
出处
《热带气象学报》
CSCD
北大核心
2009年第5期607-614,共8页
Journal of Tropical Meteorology
关键词
气候学
雨季早晚
响应关系
热带环流
Climatology
timing of rainy season onset
response relation
tropical circulation
