【摘要】 利用中国环境监测总站的PM_2.5（Particulate Matter with aerodynamic≤2.5μm）数据、ERA-interim再分析资料等,结合混合单粒子拉格朗日综合轨迹模型（HYSPLIT4）,重点分析了华北地区PM_2.5的时空分布特征及该地区PM_2.5重污染对我国东北、长三角地区空气质量的影响。结果表明,华北地区是中国PM_2.5的高值区,2015、2016和2017年华北地区年平均PM_2.5质量浓度分别为62.1、59.5和56.8μg/m³,呈减小趋势。该地区冬季PM_2.5污染最严重,部分区域的平均浓度甚至超过110μg/m³。个例研究表明,来自华北的污染物可在大约48 h后输送至东北和长三角地区,分别占当地污染物总量的21%和71%;同时,在冬季弱高压系统和地形的共同影响下,华北地区42%的污染物不易扩散而局限在本地,15%的污染物向长三角方向输送,不易向东北方向输送。更多还原

【Abstract】 Using the PM_2.5（Particulate Matter with aerodynamic ≤2.5 μm）data from China Environmental Monitoring Center,ERA-interim reanalysis data and the Hybrid Single Particle Lagrangian Integrated Trajectory Model（HYSPLIT4）,the spatial and temporal distribution characteristics of PM_2.5 in North China were analyzed in this paper,furthermore,the impact of the heavy PM_2.5 pollution in North China on the air quality of Northeast China and the Yangtze River Delta were investigated.The results showed that North China was the high value area of PM_2.5 in China.The annual mean PM_2.5 concentrations in North China reached 62.1,59.5 and 56.8 μg/m³ in 2015,2016 and 2017,respectively,showing a decreasing trend.The PM_2.5 pollution in North China was most serious in winter with mean concentrations exceeding 110 μg/m³ in some region.Case studies showed that the pollutants could be transported from North China to Northeast China and the Yangtze River Delta in 48 hours,which accounted for 21% and 71% of local pollutants,respectively.Simultaneously,under the combined influence of weak-high-pressure system and topography,42% of the pollutants in North China were trapped locally and not easy to spread out;15% of the pollutants were transported to the Yangtze River Delta and hard to transport to Northeast China.更多还原