基于CMAQ模式的自适应“nudging”源反演方法的中国主要污染区排放特征分析

Air pollutant emission characteristics over major pollution areas in China based on adaptive “nudging” method with CMAQ model

中国中东部地区的空气污染主要集中在京津冀、长三角、珠三角、东北地区及汾渭平原等区域,各区域的污染排放特征各异.本文应用基于CMAQ(The Community Multiscale Air Quality)模式的自适应“nudging”源反演方法,反演中国中东部地区2016年12月—2017年1月逐日NOx污染源,分析上述主要污染区的污染物排放强度空间分布特征,并与2016年MEIC(The Multi-resolution emission inventory for China)排放源进行比较,检验反演源的可靠性.结果表明,2016年冬季各个区域反演源NOx排放强度空间分布特征与2016年MEIC排放源基本一致.京津冀地区高强度排放区域形成沿山前区域东北-西南走向的NOx高强度排放带;长三角地区NOx高强度排放区域位于常州、苏州、上海和湖州等城市构成的城市群;珠三角地区NOx高强度排放区域位于以广州为中心的大范围城市群且排放强度呈现向四周逐渐降低的放射状分布;东北地区NOx高强度排放区域空间分布特征呈现以城市为中心且稀疏分布;汾渭平原排放区域呈现以城市为中心且向峡谷中间集中分布,排放区域轮廓与汾渭平原狭长的新月状相符.

Severe haze events occur frequently in central-eastern China,where air pollution is mainly concentrated in the Beijing-Tianjin-Hebei,Yangtze River Delta,Pearl River Delta,Northeast China,and Fen-Wei Plains with the different emission characteristics over each region.Based on the adaptive“nudging”method with CMAQ(The Community Multiscale Air Quality)model,this study inversed the NOx pollution sources from December 2016 to January 2017 in central-eastern China,and analyzed the spatial distribution of pollutant emission intensities in the above-mentioned major polluted regions,and compared with the 2016 MEIC emission sources to verify the reliability of the inversion source.The results showed that the spatial distributions of NOx emission intensity of each region in the winter of 2016 are basically consistent with the 2016 MEIC emission sources.The NOx high intensity emission area in the Beijing-Tianjin-Hebei region forms a high-intensity NOx emission zone along the northeast-southwest direction of the piedmont area.The NOx high-intensity emission area in the Yangtze River Delta region is located in the urban agglomerations of cities such as Changzhou,Suzhou,Shanghai and Huzhou.The NOx high-intensity emission area in the Pearl River Delta region is located in a large urban agglomeration in Guangzhou and exhibits a radial distribution with the gradually decreasing toward the periphery.The NOx high-intensity emissions in Northeast China are distributed over the urban area.The air pollutant emissions over the Fen-Wei Plain are centered on the urban area and in the middle of the canyon.The outline of air pollutant emission area is consistent with the crescent shape of the narrow plain.