河南省汛期降水的天气季节特征

通过多年汛期逐日降水量场的ＥＯＦ分析，探讨了河南省汛期降水的天气季节特征。河南省主汛期出现在江淮梅汛之后，称暑汛较合适。暑汛期降水出现明显的南北与东西方向上的反相振荡；尤其是从小暑到大暑，季风雨带从沙河以南，北跃到黄河沿岸及其以北地区，是东亚季风重要的气候特征，表明梅雨结束后，中国东部的主要雨带不是一跃而至黄河以北，而是阶段性地逐次向北跳跃的。对暑汛降水气候的分析研究，有助于加深对东亚季风活动的认识

THE SYNOPTIC SEASONAL CHARACTERISTICS OF RAINFALL IN HENAN PROVINCE DURING THE RAINY SEASON

The synoptic seasonal characteristics of rainfall are studied by means of the analysis of EOF(Empirical Orthogonal Fuction) of the daily amounts of precipitation field in Henan Province during the rainy season,usually known as the flood season. The precipitation in the flood season is possessed of sameness in Henan which is hinterland of Huanghe Huaihe area. The main flood season occurs after the Meiyu period over Changjing Huaihe River Valley and is properly referred to as Shuxun period (flood season in the dog days). The oscillation of rainfall in Henan shows out of phase in the direction from north to south and from west to east obviously during the Shuxun period. Especially it is important property of monsoon climate over East Asia that the monsoon rain belt jumps from south of Shahe River to the littoral area and to the north of Huanghe River from Slight Heat (11th solar term) to Great Heat (12th solar term). This expresses that after the end of the meiyu period the main rain belt in the East Chain does not turn immediately to the north arear of Huanghe,but gradually, by stages. The analysis and reasearch of the precipitation climate in the Shuxun period are helpful to deepen our knowledge of the monsson motion in the eastern Asia.