基于后向轨迹模式下的合肥市大气污染来源研究

Investigation on the source of air pollutants in Hefei city based on backward trajectory model

利用HYSPLIT(hybrid single-particle Lagrangian integrated trajectory)-4后向轨迹模式和美国国家环境预报中心(NCEP)的全球资料同化系统(GDAS)气象数据,结合SO2、NO2、PM10和PM2.5等常规大气污染物的质量浓度数据,对安徽省合肥市2014年的大气污染输送过程进行了模拟,并通过聚类分析和轨迹分型确定大气污染传输路径及影响源区.结果表明:合肥市的气流后向轨迹季节变化明显;合肥市不同季节的污染物潜在源区不同.1月份西北方向气流占43%,城市间局地气流占57%,SO2、NO2、PM10、PM2.5各项污染物浓度都很大;4月份从长三角地区来的气流占58%,各项污染物浓度都很低;7月份城市间局地气流占48%,长三角地区来的气流占24%,PM10浓度较高,其他污染物浓度较低;10月份城市间局地气流占50%,北方气流占27%,长三角地区来的气流占23%,PM10浓度较高,其他污染物浓度较低.影响合肥市大气污染的来源主要有北方气流,长三角地区来的气流和城市间局地气流.

The transport process of air pollutants in Hefei in 2014 was simulated,using the HYSPLIT(hybrid single-particle Lagrangian integrated trajectory)-4 backward trajectory model and NCEP(National Centers for Environmental Prediction) reanalysis data,and the mass concentration data of conventional atmospheric pollutants such as SO2,NO 2,PM10 and PM2.5 were also used.The results showed that the air trajectories in Hefei had an obvious seasonal variation,and that the potential sources of pollutants in different seasons in Hefei were different.In January,the airflow in the northwest direction accounted for 43%,and the local airflow between cities accounted for 57%.The concentrations of SO2,NO 2,PM10,and PM2.5 were very large.In April,the airflow from the Yangtze River Delta region accounted for 58%.The concentrations of various pollutants were very low.In July,the local airflow between cities accounted for 48%,and the airflow from the Yangtze River Delta region accounted for 24%.The PM10 concentration was higher,and the concentrations of other pollutants were lower.In October,the local airflow between cities accounted for 50%,the northern airflow accounted for 27%,and the airflow from the Yangtze River Delta region accounted for 23%.The PM10 concentration was higher,and the concentrations of other pollutants were lower.The main sources of air pollution in Hefei were mainly from the northern air masses,the air masses in the Yangtze River Delta region,and the local urban air masses.