中文摘要：

利用昆明市13 a的酸雨资料及气象资料进行分析,结果表明年酸雨频率有前期较少后期呈上升的趋势,汛期期间酸雨频率较高,9月最高,干季较低;强酸雨频率与酸雨基本一致,日酸雨次数夜间多于白天,最少次数出现在19时,SO2含量在超前7 h时对酸雨有指示作用,年酸雨和强酸雨与温度、湿度、雾日、霜日和风等要素相关较好;而月酸雨和强酸雨均与雷暴日数呈正相关;极端酸雨的出现与空气中酸性物质的堆积有关,在酸雨出现之前有持续时间较长的连续无雨日或强降水.

英文摘要：

The acid rain data of Kunming City for 13 years and meteorological data have been used to analyze the characteristic of acid rain. The results show that the trend of annual acid rain frequency has descended in the early stage and then raised, with the higher frequency of acid rain in flood period, the tallest in September, and the lower in dry season ; the trend of severe acid rain frequency is consistent with of the acid rain ; the times of acid rain in one day emerges more in night than in daytime with the minimum of times appearing at 19：00; there has the indication of SO2 contents to acid rain before 7 hours; annual acid rain and severe acid rain have better relationship to temperature, humidity, fog day, frost day and wind, but monthly acid rain and severe acid rain all have positive correlation to thunder day. The emergence of the extreme acid rain has relationship to the pile - up of acid material in the air, with longer continuous rainless days or heavy rain before the acid rain appearing.