两次秸秆焚烧污染过程的气象条件对比分析

Comparative Analysis on Meteorological Condition for Two Air Pollution Events from Crop Residue Burning

利用常规气象资料、卫星遥感监测资料、污染物浓度资料和NECP/NCAR再分析资料,结合气流后向轨迹模拟,对比分析了南京地区2011年6月10和13日两次由于秸秆焚烧而引起的严重空气污染事件的天气条件、大气边界层特征以及污染物的来源和输送路径等。结果表明:两次污染过程中PM_(2.5)浓度均出现陡升陡降,由秸秆焚烧而产生的细粒子贡献显著。13日高污染的持续时间和强度都高于10日,10日的高低空形势配置和物理量场有利于降水的产生,对污染物有一定的冲刷作用,而13日的高低空形势配置和物理量场则有利于污染物在边界层堆积。两次污染过程的边界层逆温均不明显。气流后向轨迹模拟表明,两次过程都是由区域污染输送造成的,都主要来源于苏中、苏北地区,13日的污染源可能还有苏南和安徽地区。

Based on the conventional observational data, satellite remote sensing data, main pollutants monitoring data and NCEP/NCAR reanalysis data, together with the airflow backward trajectory simulation method, comparative analysis is conducted on the atmospheric conditions, planetary boundary layer features, air pollutant sources and transport paths of the two serious air pollution events which respectively took place on 10 and 13 June 2011. The results show that the concentrations of PM2.5 display a more significant peak valley variation during the two air pollution events, which result from crop residue burning. The event seen on 13 June has a longer duration and a stronger intensity than the event on 10 June. The weather situation and the physical quantity field of the event on 10 June are favourable for the rainfall, which plays a role in flushing the pollutants. However, the weather conditions on 13 June are conducive to accumulation of pollutants. Both of the boundary inversion layers are not obvious. Air mass backward trajectory simulation show that two air pollution events are caused by the transport of regional pollution due to crop residue burning in the central and north parts of Jiangsu Province. Moreover, the pollution sources for the event on 13 June probably include the south part of Jiangsu Province and part of Anhui Province additional as well.