2015-2018年淮北市冬半年重污染天气大气环流分型研究

Research on atmospheric synoptic classification of heavy pollution weatherduring winter half year from 2015 to 2018 in Huaibei city

选用2015—2018年安徽省淮北市6种主要污染物浓度月变化数据,利用聚类分析、潜在源分析(PSCF、CWT)、T-mode斜交旋转分解(PCT)等方法,分析淮北市冬半年重污染的传输通道、潜在源区,重污染天气不同阶段(形成、维持和结束)的大气环流类型。结果表明:淮北市冬半年PM_(2.5)、PM_(10)、CO、NO_(2)和SO_(2)的月均质量浓度较高。短距离轨迹为当地冬半年重污染的主要输送轨迹,山东西部、江苏中北部是淮北市重污染的重要潜在源区。持续性重污染形成、维持及结束期间的环流场存在异同点,共同点为3阶段均存在占比不同的均压场,不同点为大气环流分型、气压值、气压梯度、风向风速等存在差异。持续性重污染形成期间,大气环流可分为5种类型,其总次数的90%与均压场有关;持续性重污染维持期间6种大气环流类型均与均压场有关,但范围明显大于形成时期,气压值与形成时期相近,风速普遍为静风;持续性重污染结束期间淮北市多处于冷高压前沿,均压场仅占15%,气压梯度、海平面气压值及风速均显著增大。

Using cluster analysis,potential source analysis(PSCF,CWT)and obliquely rotated T-mode principal component analysis(PCT)method,the transmission channels and potential source areas were studied,and the prone circulation patterns was revealed for different stages(formation,maintenance and dissipation)of heavy air pollution in Huaibei in winter half year,based on the data of the monthly variation of six types of air pollutants from 2015 to 2018.The results show that monthly average mass concentrations of the main air pollutants,i.e.PM_(2.5),PM_(10),CO,NO_(2)and SO_(2)are higher in winter half year.For heavy pollution in Huaibei,short distance trajectory is dominant,and the important potential sources include the southeast of west of Shandong province and north central of Jiangsu province.There are similarities and difference during the different stages(formation,maintenance,and dissipation)of heavy air pollution.The common point is that there are uniform pressure field with different proportions in the three stages.The differences among the three stages are mainly expressed in circulation type,pressure value,pressure gradient,wind direction and wind speed.In the formation stage of persistent heavy pollution,circulation patterns are divided into five types and more than 90%of them are related to uniform pressure field.In the maintenance stage,six circulation patterns are related to uniform pressure field,but the control range of uniform pressure field is significantly larger than that in the formation stage.The pressure value was close to the formation stage and the wind speed was mostly static.In the dissipation stage of persistent heavy pollution,Huaibei city was mostly in the front of cold high pressure,with the uniform pressure field just accounting for 15%.The pressure gradient,sea-level pressure,and wind speed increased significantly.