华南后讯期降水的年际变化

ON INTERANNUAL VARIATION OF PRECIPITATION DURING THE SECOND RAINY SEASON IN SOUTH CHINA

本文研究了近30多年来(1951——1984)华南后讯期降水的年际变化。结果表明:(1)华南后讯期降水有3年周期变化和10年尺度的长期变化;(2)夏季西太平洋副热带高压轴线南北位置和西脊点西伸位置的年际变化与华南后讯期降水有密切联系。当副高位置偏北偏东时,华南后讯期降水偏多。反之,降水偏少。 利用1974—1983年的月平均OLR资料研究了热带辐合带对华南后讯期降水的影响。结果表明,华南后讯期降水多年和少年热带辐合带的位置和强度有显著差异。多雨年热带辐合带位置偏北强度偏弱,少雨年则相反,热带辐合带位置偏南强度偏强。

In this paper, the interannual variation of precipitation for 1951-1984 during the annually second rainy season in South China has been studied. The major results are as follows:1. There are 3-year perodic variation of precipitation and long-term variation of 10-year scale.2. There is a close relationship between preciptation and position of subtropical anticyclone over the western Pacific in summer during the second rainy season in South China . The rainfall amount is more when the position of subtropical anticyclone is located towards the north and towards the east or vice versa.3. The effect of ITCZ on the precipitation during the second rainy season in South China was investigated by using OLR data for 1974-1983. The results indicatae that The rainfall amount is more when position of ITCZ is located towards north and intensity of ITCZ is weaker or vice versa.