Abstract: In order to investigate the condition of acid rain and its relationship with atmospheric environment, statistic and correlation analysis and numerical simulation have been used. The results showed that，among 352 samples, average of which was 4.5; 8% of the samples was not acid rain with pH value larger than 5.6, in the left 92% (which is acid rain), severe acid rain was amount to 67%. Annual average variations of pH were slight, while there was monthly and seasonal difference. Conductivity K changed sharply between 11.9 and 284 μS·cm-1, which meant there was a severe variation of total ion content in atmospheric precipitation. Different precipitation pointed to different pH value and K value: acid heavy rain and rain storm corresponded to pH value less than 5.6, light and medium rainfall corresponded to pH value over 5.6; K value decreased with the increasing of precipitation, which illustrated there was a stronger adsorption of small rain drops to pollutants. There was a negative relationship between pH value and mass concentration of air pollutants. Model simulation for a case analysis of acid rain in March 22 of 2010 demonstrated air pollutant could propagate over long distance, and the high content of ion in sand dust led to increase of K value in precipitation. 

Key words: Acid rain, pH, K, Atmospheric environment, Numerical simulation