高原地区高速路-森林接触带光化学臭氧形成机制研究

Study on photochemical formation mechanism of ozone at contact area of highway-forest in plateau

基于大气氮氧化物(NO和NO_2)和总挥发性有机化合物(TVOCs)在太阳辐射条件下生成大气臭氧(O_3)这一反应原理,选取云贵高原地区高速路-森林接触带生态系统开展大气臭氧污染特征及生成机制研究,并以昆明城区大气臭氧污染特征为对照,采集大气臭氧、氮氧化物及挥发性有机物样品,分析高速路-森林接触带大气污染物浓度时空分布特征及受气象条件的影响.结果表明,在夏季高速路-森林接触带存在强烈的大气光化学反应,臭氧质量浓度为91.83μg/m^3,高于其他季节,气温及太阳紫外指数与其浓度变化显著正相关;高速路-森林接触带大气O_3生成对周边NO_2浓度变化最为敏感,说明减少机动车尾气中NO_x排放将有利于此区域臭氧污染的控制.

Based on photochemical formation mechanism of O3 with NOx and VOCs under the solar radiation, pollution characteristic and formation mechanism of O3 were studied at contact area of highway-forest in the Yun- nan-Guizhou plateau.The characteristics of atmospheric O3 in Kunming was used to as a comparison, atmospheric O3, NOx and VOCs samples were collected in highway-forest contact area, and temporal and spatial distribution of their concentrations and influence of weather conditions were analyzed.The results showed that the strongest at- mospheric photochemical reaction of ozone at contact area of highway-forest had happened in summer ,the con- centration of O3 was up to 91.83 μg/ma, which was higher than that in other seasons;Positively relationships were found among O3 ,temperatures and ultraviolet indexes;The formation sensitivity of O3 was closely related to the concentration changing of NO2,which suggested that reducing NOx from vehicles exhaust would be conducive to control the concentration of O3 at contact area of highway-forest.