峨眉山酸雨的垂直观测

本文为了解降水酸度在垂直方向上的变化规律,自峨眉山金顶(3077m)至山脚的西南交大(约500m)在高差约2500m的垂直方向,设立了五个酸雨观测站,1985年10月5—20日联合观测期间共测了三次降水过程,结果得出:(1)天气形势对降水酸度起决定性作用,不同天气形势所引起的降水酸度变化,大大超过降水酸度的垂直变化梯度;(2)同一天气形势下,降水酸度随海拔高度的降低无明显的线性相关,但在三次降水过程中,降水酸度在垂直方向上的变化趋势是较为一致的。作为影响峨眉山降水酸度垂直变化的因子,云水酸度和山顶至山脚大气中硫化物等污染物的垂直分布,也与天气过程密切相关。

Vertical observation of acid rain in Emei Mountain

In order to know variations of rain's acidity in a vertical direction , five observation posts of acid rain from the Gold Top (3077m) of Emei Mountain to Southwest Communications University (about 500m) located near the foot of Emei Mountain were built. The longest distance between two posts is about 2500m in the vertical direction. During the joint period from 5 to 20 October 1985 , three weather processes of precipitation were observed . The results show : (1) weather situation is a decisive factor effecting precipitation's acidity . The variations of pre -cipitation's acidity caused by different weather situations are much more than the gradient changes of precipitation's acidity in the vertical direction; (2) in the same weather situation, precipitation's acidities do not obviously show linear change with decrease of sea level elevation, but in the three weather situations, precipitation's acidities are of the same changing trend in the vertical direction .The acidity of cloud water and the vertical distribution (from the top to the foot of the mountain) of some pollution gases , such as SO2, are considered as the factors to effect the vertical change of precipitation's acidities in Emei Mountain , and also have direct bearing on the weather processes.