中国西南典型地区酸雨形成过程研究

本文根据云水和雨水化学特性的观测和雨水酸化模式的模拟计算，研究了中国西南地区酸雨的形成过程。结果表明:在重庆和贵阳等重污染城市，云下过程对雨水的酸化起主要作用，在污染较轻的中小城镇和乡村地区，雨水酸度主要决定于云内过程。 但是云下过程对雨水中的主要酸碱离子浓度都有不可忽视的明显影响。雨水的酸化主要是由于SO2与H2O2和O3的氧化，气溶胶起较弱的缓冲碱化作用。在重庆和贵阳等地，当地SO2浓度已高达饱和，其值增减50％，都不会对该地雨水酸度有明显影响，起控制作用的是氧化剂浓度。

A Study on the Formation Processes of Acid Rain inSome Areas of Southwest China

Based on the observations on chemical characteristics of cloud water and rain water and the modelling calculations of rain water acidification, the formation processes of acid rain in the southwestern area of China were studied in this paper. The results show that in the seriously polluted cities like Chongqing and Guiyang, the below-cloud process plays a major role in rain water avodification, and in slightly polluted towns and rural areas, the acidification of rain water are determined predominantly by in-cloud processes. However, below-colid processes a ways have an evident influence on the concentrations of main acid and basic ions in rain water. The acidification results are mainly from the oxidization of SO2 with H2O2 and O3. Atmospheric aerosols only play a weaker buffer and basifiothon role. In the areas of Chongqing, Guiyang and so on, local SO2 concentrations have got a saturation state, therefore variations with 50% of their values do not have any obvious impacts on local rain water acidity, in this case, the concentrations of oxidizers become the most impotent control factor.