6月西太平洋副高脊线的年际变化及其对华南降水的影响

THE INTERANNUAL VARIATIONS OF THE SUBTROPIC HIGH RIDGE POSITION OVER WESTERN PACIFIC IN JUNE AND ITS INFLUENCE ON PRECIPITATION IN SOUTH OF CHINA

用１９５１—１９９１年６月份５００ｈＰａ位势高度资料取得了西太平洋副热带高压脊线位置资料序列，分析了脊线位置的变化。分析结果发现副高脊线位置与５００ｈＰａ位势高度场、海面温度等关系密切。脊线位置具有显著的３２年、５．３年、３．２年和２．３年振荡周期。６月份副高脊线偏北（南）华南降水偏少（多）。

In this paper the interannual variations of subtropic high ridge position over western Pacific in June are investigated by using the data of the ridge based on 500 hPa height from 1951 to 1991. The results indicate that 41-year averaged ridge position is located in 20°N , the oscillations of the ridge position exhibit 32-year, 5. 3-year, 2-3year period and its variations are associated with 500 hPa height, SST of South China Sea and western Pacific. As the ridge locates more to the north (>20°N), there will be less precipitation in south of China, and as the ridge is more to south (<20°N), there will be much more precipitation.