乌鲁木齐重污染期NO_2浓度及扩散轨迹研究  

Research on Density and Diffusion Trajectory of NO_2 during Heavy Pollution Period in Urumqi

作　　者：刘岩[1,2] 李艳红[1,2] 侯小刚[3] 马雯[1,2] 

机构地区：[1]新疆师范大学地理科学与旅游学院,新疆乌鲁木齐830054 [2]新疆维吾尔自治区重点实验室新疆干旱区湖泊环境与资源实验室,新疆乌鲁木齐830054 [3]新疆维吾尔自治区气候中心,新疆乌鲁木齐830002

出　　处：《环境科学与技术》2017年第7期33-39,共7页Environmental Science & Technology

基　　金：国家自然科学地区基金项目(41161010);乌鲁木齐市科技计划项目(P161310004)

摘　　要：重污染天气频发,如何快速、有效地获取重污染天气下污染物的时空分布状况并分析其成因,对解决我国大气污染问题十分重要。该文基于车载多轴差分吸收光谱技术(MAX-DOAS),反演了乌鲁木齐2016年2-3月大气对流层NO_2垂直柱浓度(VCD),并结合气象因子与大气背景场进行了分析。结果表明:乌鲁木齐2016年2月16日对流层NO_2 VCDs的均值为26.89×10^(15)molec/cm^2,3月17日均值为21.21×10^(15)molec/cm^2,高值通常出现在高架桥等交通节点附近;2月NO_2排放通量平均值为1.11×10~3kg/h,3月NO_2排放通量平均值为0.73×10~3kg/h;重污染期间风速与NO_2 VCDs呈负相关的关系,2 m/s及以上风速与NO_2 VCDs的决定系数(R^2)为0.40,下风向NO_2浓度通常高于上风向,风向与地形要素的叠加,更容易产生NO_2浓度的差异;利用Hysplit模型反演扩散轨迹发现,乌鲁木齐重污染期间大气的污染物随气流从外地而来的占比例较少,以本地源为主,气流更多以搬运、稀释的方式影响本地污染物浓度。How to quickly and effectively obtain the temporal and spatial distribution of pollutants under heavy pollution and analyze its causes, is very important to solve the problem of air pollution in China. In this study, based on the multi axis differential optical absorption spectroscopy （MAX-DOAS）, inversion of the vertical column density （VCD） of tropospheric NO2 in Urumqi from February to March in 2016 was carried out, and the meteorological factors and atmospheric background field were analyzed. The results showed that the average tropospheric of NO2 VCDs on February 16th, 2016 in Urumqi was 26.89× 10^15 molec/cm^2 and it was 21.21×10^15 molec/cm^2 on March 17 th. High values were usually found near traffic nodes like viaducts. Average NO2 emission flux in February and March were 1.11×10^3 kg/h and 0.73×10^3 kg/h, respectively. There was a negative correlation between wind speed and NO2 VCDs during heavy pollution. 2 m/s and above wind speed and NO2 VCDs decision coefficient （Rz） is 0.40. And the downwind NO2 density was usually higher than the windward value. Wind direction and terrain elements of the superposition, are more likely to produce differences in NO2 concentration. The Hysplit model retrieved the diffusion trajectory and found that during heavy pollution period in Urumqi the atmospheric pollutants travelling with airflow from nonlocal areas were less than local sources, which were predominant. Airflow influenced local pollutant densities mainly by carrying and diluting.

关 键 词：重污染 车载MAX-DOAS 扩散轨迹 乌鲁木齐 

分 类 号：X831[环境科学与工程—环境工程]