广西春季降水变异成因分析

对广西 195 9- 2 0 0 0年春季 2～ 3月、 4月典型降水场的 5 0 0 h Pa高度差异场、及突变前后 10 a尺度 5 0 0 h Pa大气环流与海温场进行分析 ,得到 :2～ 3月与 4月降水典型年份高度场存在明显的差异 ,且中心位置、强度基本一致 ;10年尺度 5 0 0 h Pa高度异常变化是造成广西 2～ 3月份降水发生突变的主要原因。 10年尺度 5 0 0 h Pa高度场在北太平洋上的异常变化对 4月降水突变影响明显 ;北太平洋和 NINO海区海温突变前后发生了相反的变化 ,这种异常变化对春季降水突变影响明显

Analysis of Causes for Precipitation Variation in Spring of Guangxi

The analysis of 500hPa height differential field of the typical precipitaton field in Feb.~March and April during 1959~2000,the 500 atmospheric circulation and marine temperature in the 10 year scale before and after the sudden change shows that obvious difference exists in height fields of precipitation typical years in Feb.~March and April,and its center location and strength are basically the same.The abnormal change of 10 year scale 500 height field is the main cause for the sudden change of precipitation in Feb.~March in Guangxi.The effect of the abnormal change of 10 year scale 500 height field above the North Pacific on the precipitation in April is significant.Two kinds of opposite changes of temperature happens in North Pacific and NINO area before and after the sudden change,and this abnormal change has a significant effect of the precipitation in Spring.