2014年10月太原市一次空气重污染过程分析  

Characteristics and formation mechanism of a serious pollution event in October 2014 in Taiyuan

作　　者：程兵芬 韩丽 程念亮[2] 罗锦洪 韩锋[3] 

机构地区：[1]山西省环境规划院,太原030002 [2]北京市环境保护监测中心,北京100048 [3]太原理工大学,太原030024

出　　处：《环境科学学报》2015年第12期4071-4080,共10页Acta Scientiae Circumstantiae

基　　金：环保公益性行业科研专项(No.201309071);国家科技支撑计划(No.2014BAC06B05);国家自然科学基金(No.41401222)~~

摘　　要：采用数值模拟(CAMx)与污染物、气象观测资料相结合的方式,对太原市及周边区域2014年10月6—12日一次典型空气重污染过程的大气环境背景、气象条件和形成原因进行了分析.结果表明:2014年10月8—10日太原ρ(PM_(2.5))日均值平均为175μg·m^(-3),太原城区约1460km^2的国土面积处于重度污染(ρ(PM_(2.5))>150μg·m^(-3))之下,而京津冀约20×104km2的国土面积达到重度污染水平;区域稳定的气象条件是形成重污染的主要原因,重污染过程中大气层结稳定,逆温明显(2.14℃/100m)、风速小(1.91 m·s^(-1))、湿度大(68.13%)、负变压(-0.74 h Pa)、正变温(0.92℃).模拟结果显示,8—10日重污染期间区域输送对太原PM_(2.5)的贡献率在17%~24%之间,太原市PM_(2.5)浓度以本地贡献为主;估算的2014年太原城区PM_(2.5)排放量是其大气环境容量的1.4倍,重污染期间大气环境容量的大幅降低又加剧了空气污染的程度.In this paper, atmospheric environmental background, weather conditions and formation mechanism of one typical air pollution episode in Taiyuan and the surrounding areas in October 2014 were all investigated by combining pollutants, metemvlogical observation data and numerical model of CAMx. Results showed that air pollution episode on October 8 -10th was the most serious with daily average PM2.5 concentration of 175 μg.m-3 in Taiyuan with heavily polluted land area （PM2.5 〉 150 μg. m-3） of about 1460 km2. Same episode led to about 20- 104 km2 pollution area in Beijing, Tianjin, and Hebei.The situation was mainly related to the regional meteorological conditions. Stable atmospheric circulation provided favorable environmental field for this heavy air pollution which was characterized by a stagnant atmospheric structure with average wind speed of 1.91 m. s-1 , high relative humidity of 68.13 %, large temperature inversion of 2.14℃ / 100m, negative pressure （ - 0.74 hPa） , and positive temperature （ 0.92 ℃ ） that were unfavorable to the dispersion of air pollutants. Modeling results showed that regional transport contributions to the receptor sites were between 17% - 24% during 8 - 10th October 2014 and the local emission was the dominated source of the surface PM2.5 in Taiyuan. The estimated PM2.5 emission was 1.4 times the capacity of the atmospheric environment in Taiyuan city in 2014. Sharply decreased atmospheric environmental capacity intensified the degree of air pollution on October 8 ~ 10 th episode.

关 键 词：PM_2.5 重污染 太原 区域输送 

分 类 号：X513[环境科学与工程—环境工程]