秸秆焚烧导致南京及周边地区一次严重空气污染过程的分析

2008年10月28～29日南京及周边地区发生了一次严重的空气污染事件,PM10、CO、SO2等大气污染物浓度急剧增高.本文综合利用地面空气污染监测资料、卫星遥感火点监测资料、气象观测和NCAR/NCEP再分析资料及气流后向轨迹模拟,分析了该次污染事件发生的天气条件和大气边界层特征以及大气污染物的来源、输送路径.结果表明,苏中、苏北地区秸秆焚烧产生的大气污染物向南京及周边地区输送,并结合不利于污染物扩散的天气形势和边界层条件,即:均压场结构、500hPa以下弱的垂直速度、涡度和散度、较低的边界层高度及逆温层的存在,以及地形因素是导致这次大气污染事件的主要原因.

Analysis of a serious air pollution event resulting from crop residue burning over Nanjing and surrounding regions

During the time period between Oct.28 to Oct.29,2008,a serious air pollution event took place in Nanjing and surrounding regions,accompanying with sharply increasing of PM10,CO and SO2 in the air.Satellite remote sensing data,surface meteorological observations,air pollution index and the NCEP reanalysis dam were used to investigate the atmospheric conditions and planetary boundary layer(PBL)features.Air mass backward trajectory simulation method was employed to analyzethe airpollutants sources and transport paths of this event.The results showed that the transport of gas pollutants releasing from crop residue burning in the central and north parts of Jiangsu Province,combining with unfavorable weather condition,which was the dominating reason of this air pollution episode.It was found there was a high-pressure system with relative uniform pressure pattern,weak vertical velocity,vorticity and divergence below 500hPa,which prevented atmospheric ventilation.The inversion temperature,low mixing height and topographical forcing winds in the PBL was also not favor for the air pollutants diffusion.