摘要
文中用500hPa信号场研究了长江中游地区暴雨发生的气候异常环境,并提出用信号场合成图的检验方法来分析暴雨规律。结果表明,暴雨过程与无雨过程在500hPa信号场中异常信号显著区的出现及分布形势有明显不同。分析14次暴雨过程的合成图,发现在发生暴雨过程第1天,正异常区常常出现在贝加尔湖附近地区(40°～50°N,80°～100°E)和中国华南地区(20°～25°N,100°～130°E),负异常区出现在中国长江中游北部地区。暴雨过程出现的主要特征是在110°E附近,形成南北向的“+-+”分布形势和波列。
The signal field of 500 hPa anomalies for the heavy rainfall events was analysed over the Middle Reaches of Yangtze River, China. A t-test for the composite signal field has been developed. The analysis of the 1977-1999 observational data implies that the appearance and distribution of anomaly in the 500 hPa signal field is an important precursory signal of heavy rainfall. The analysis of the composite signal field of 14 heavy rainfall cases indicates that on the first day of a heavy rainfall event, a positive anomaly occurred over the northwest of China (40°-50°N, 80°-100°E), and another over the south of China (20°-25°N, 100°-130°E), while a negative anomaly occurred over the area northern of the Middle Reaches of Yangtze, i.e., (30°-50°N, 100-150°E). Thus, a wave pattern +-+has been identified from the northwest to the southeast in China.
出处
《气象学报》
CAS
CSCD
北大核心
2005年第3期333-341,共9页
Acta Meteorologica Sinica
基金
中国科学院海外知名学者基金(2002102)
国家基金委项目(40035010)
