闽南地区酸雨特征与其影响天气系统的统计分析

THE ANALYSIS OF CONTRIBUTING WEATHER SYSTEMS AND ACID RAIN CHARACTERISTICS IN SOUTHERN FUJIAN PROVINCE

通过利用1991～2003年闽南地区的酸雨资料和天气图进行分析,结果表明:在闽南地区有近一半的降水出现酸雨。春冬季酸雨出现率大,秋季最小。与锋面伴随的850 hPa冷槽型、暖式切变型和冷式切变型,酸雨出现率大,倒槽型最小。在倒槽型的槽后酸雨出现率明显比槽前多出2倍多。pH值随降水等级的增大呈“U”型变化,酸雨出现率在暴雨出现之前随着雨量的增大而增大,大雨时的酸雨出现率最大。闽南地区在偏西风下的酸雨出现率大,东北风下最小。

Analyzing the acid rain data and synoptic charts in southern Fujian from 1991 to 2003 shows that about half of the precipitation is acid rain in the area. Acid rain frequency is larger in spring and winter than in autumn. The frequency is large with the types of cold troughs, warm shears and cold shears but small in the type of inverted troughs. The frequency of acid rain with the southeasterly airflow is twice as large as that with the northeasterly airflow in inverted troughs. The rainfall influences the pH value, which varies in a ＂U＂ pattern. The acid rain frequency is maximal with heavy rain and increases with rainfall intensity before torrential rain occurs. The frequency is large with the westerly wind but small with the northeasterly wind in southern Fujian.