基于CMAQ源同化反演方法的京津冀局地污染源动态变化特征模拟研究

Spatial-temporal variations of pollutant emission sources inversed by adaptive nudging scheme over Beijing-Tianjin-Hebei region based on the CMAQ model

利用"Nudging"源同化技术反演了京津冀地区2014年1、3、7、11月SO_2、NO_x的局地动态污染源,并分析其排放源强、特征及地理分布,对比其与初始源的差异,同时检验了反演源的模拟效果.结果表明,SO_2、NO_x污染源存在明显的季节变化,冬季或采暖期排放强度最大.由唐山、北京、天津、廊坊、保定、石家庄、邢台、邯郸构成东北-西南走向的带状污染物高排放区,最高排放中心主要集中在太行山、燕山山前区域,且排放具有典型的"城市化"特征,即各个城市市区及附近强度最大,周边郊县稍弱.与初始源模拟结果相比,采用反演源更能反映出污染物的时空变化特征,模拟值与实测值较接近,而且对于重污染过程亦具有较好的模拟效果.

The pollutant source assimilation of nudging inversion method was applied to simulate the local sources of SO2 and NOxin Beijing-Tianjin-Hebei region during January,March,July and November 2014. The strengths,patterns,and geographical distribution of SO2 and NOxsources were compared with the original sources and the performance of inversed-source-based modeling was evaluated. The results showed that the sources of SO2 and NOxpresent obvious seasonal variations and is the strongest in winter or heating period. A high pollutant emission zone in the direction of northeast-southwest wasdiscovered along Tangshan,Beijing,Tianjin,Langfang,Baoding,Shijiazhuang,Xingtai and Handan in the front of the Taihang and Yan mountains. The pollutant emissions exhibit a typical＂urbanization＂effect,i.e. SO2 and NOxsources are high in the urban area and its surroundings and weak in the rural area. Compared with the initial-emission-based modeling,the inversed-emission-based simulation could better capture the spatial-temporal variations of air pollutants,especially during high pollution periods.