利用气象与化学模块在线耦合的模式WRF-Chem V3. 5(Weather Research and Forecasting Model coupled to Chemistry Version 3. 5)对2016年11月3-6日的一次京津冀污染过程展开了数值模拟,设计进行了包含人为排放源的实验,运用有效的模拟结果对过程进行分析。结果表明:大气稳定度指数能有效量化反映污染过程中的大气稳定状况,且K指数和TT指数相较其他两种指数的指示效果更为准确,是讨论雾霾发生发展原因的有力依据。本次污染高值中心有三个,分别为北京天津一带、河北东北部以及河北南部。PM2. 5、PM10以及SO2污染物水平分布有明显日变化特征,CO和NO2则变化不明显,污染从3日开始发展至6日结束,除NO2外各项污染物都明显受到冷空气的影响,在6日浓度骤降。北京和天津地区的污染是主要来源于河北南部的工业和交通排放的外源型污染,而河北东北部和河北南部的污染则是主要受本地排放影响的内源型污染。污染物主要化学成分为CO,污染物颗粒PM2. 5和PM10量级相当且浓度差别不大,均对本次污染有较大贡献。
To investigate the pollution process from 3 to 6 in November 2016 in Beijing,Tianjin and Hebei region,a simulations with anthropogenic emissions are conducted by using WRF-Chem V3. 5( Weather Research and Forecasting Model coupled to Chemistry Version 3. 5). The effective simulated results shows that the atmospheric stability index can effectively quantify the atmospheric stable status in the process of pollution,both the K index and the TT index are more accurate than the other two indices. It is a powerful basis for discussing the causes of the occurrence and development of haze. There are three high value centers of pollution. They are Beijing Tianjin area,northeast Hebei and southern Hebei. The horizontal distribution of PM2. 5,PM10 and SO2 pollutants has a more obvious diurnal variation,while CO and NO2 are not changed obviously. The pollution begin on 3 and end on 6 in November,all pollutants are obviously affected by the cold air except NO2,and the concentration suddenly drops on 6 in November. The pollution in Beijing and Tianjin is mainly derived from the external pollution of industry and transport in southern Hebei,while the pollution in the northeast of Hebei and southern Hebei is an endogenous pollution mainly affected by local emissions. With the classification of chemical composition,the main pollutants are CO,and with the classification of the particle size of the pollutants,the size of PM2. 5 and PM10 are similar and their concentration is not very different,all of which have great contribution to the pollution.