重庆市一次严重雾霾过程的阶段性特征及成因

Analysis on the stage characteristics and causes of a severe fog-hazy process in Chongqing

针对2014年1月26日—2月3日重庆市主城区出现的一次严重雾霾过程,对污染物浓度、环流形势和气象要素进行综合分析。结果表明,雾霾强度变化与AQI指数、PM10和PM2.5浓度有比较好的对应关系,PM10和PM2.5是此次过程的首要污染物,SO2和NO2有明显的单峰型日变化,但对AQI指数的影响较小。高空持续稳定纬向环流和中低空西南暖湿气流,逆温层持续存在且低空风速小是有利于连续雾霾过程的背景条件。地面平均风速小,平均日温差小,相对湿度大于85%,能见度低使地面湍流活动弱,大气维持静稳状态,空气污染持续加重。

The pollutant concentration, circulation situation and meteorological elements during the fog-haze process of 26 Jan to 3 Feb 2014 in Chongqing metropolitan area were analyzed. The results show that there is a good correspondence between haze intensity and AQI index, PM 10 and PM 2.5 concentration. PM 10 and PM 2.5 are the primary pollutants in the process. SO 2 and NO 2 have obvious diurnal variation of single peak type. The continuous steady latitudinal circulation and the southwest warm and humid air, the existence of the inversion layer and the light low-level wind speed are favorable conditions for the severe fog-hazy process. The average wind speed in the ground is small, the average daily temperature difference is small, the relative humidity is more than 85%, which makes the ground turbulence weak, the atmosphere maintains static state, the visibility is reduced, and the air pollution continues to aggravate.