1999年夏季青海多雨形势分析

Analyses on Qinghai Rainy Synoptic Situation Precipitation in Summer of 1999

利用１９５９－１９９９年降水、 气温、 高度场等资料分析得出： １９９９年夏季青海省多雨与乌拉尔山高压脊偏强、 西太平洋副热带高压位置偏北及西伸脊点位置偏东、 极涡强度偏强等因素有关。其中， 中高纬度地区乌拉尔山高压脊多次建立和稳定维持， 以及西太平洋副热带高压脊线位置异常偏北、 西伸脊点位置偏东是造成青海省夏季多雨的最关键因子．

According to the analyses of precipitation, temperature, upper circulation field, ocean temperature and other data( 1959－1999) , the main conclusions can be drawn that the more precipitation in summer of 1999 may relate to the following circulation situations, namely, the strong Ural high ridge, the far north position of west Pacific subtropical high ridge line, the far eastward extending west ridge point of it and the strong intensity of polar vortex. Among them, the first three situations are the key fectors that cause the rainy summers in Qinghai Province.