晋东南地区冬季PM2.5污染输送路径分析

利用2017~2019年晋城市和长治市冬季PM_2.5逐时浓度资料、地面风场数据等，结合HYSPLIT轨迹模型和中尺度数值模式WRFV4.2分析了晋东南地区冬季PM_2.5污染的特征和传输特点.结果表明，晋城市冬季PM_2.5污染程度高于长治市.受地形影响，晋城市地面盛行偏南风、偏北风和西北风，污染方向主要为偏南风和偏北风；长治市近地面盛行偏南风，该风向污染频率最高.影响晋城市和长治市污染的潜在源区主要分布在偏西、东北和东南方向，偏西气流来自陕西省中部，东北气流来自河北省西南部，东南气流来自河南省中东部.污染经过晋东南地区主要影响山西省中南部和北京南部.通过数值模拟流场，结合潜在源区和影响区域的分析结果，在均压场或高压后部的天气形势下，晋东南地区污染输送路径包括来自东北方向（河北省西南部一带）的气流，沿长治市东北部的滏口陉向晋东南地区输送污染物及沿太行山东麓向南在晋豫交界处的太行陉发生转折向晋东南地区输送污染物；来自东南方向（河南北部及东部）的气流输送和来自偏西方向（陕西中南部）的气流输送.污染物经过晋东南地区向北输送至山西省中南部，部分经过山西省中东部的井陉输送至北京南部.

Analysis of PM2.5 pollution transportation path in winter in Southeast Shanxi Province

Based on the hourly concentration data of PM_2.5 and surface wind field data in winter of Jincheng and Changzhi from 2017 to 2019, combined with HYSPLIT trajectory model and mesoscale numerical model WRFV4.2, the characteristics and transmission characteristics of PM_2.5 pollution in winter in Southeast Shanxi were analyzed. The results showed that the pollution degree of PM_2.5 in Jincheng in winter was higher than that in Changzhi. Affected by the terrain, southerly wind, northerly wind and northwest wind prevail on the ground in Jincheng, and the pollution direction was mainly southerly wind and northerly wind; The southerly wind prevails near the ground in Changzhi, and this wind direction had the highest frequency of pollution. The potential pollution source areas affecting Jincheng and Changzhi were mainly distributed in the west, northeast and southeast. The westward airflow came from central Shaanxi Province, the northeast airflow came from southwestern Hebei Province, and the southeast airflow came from central and eastern Henan Province. Pollution passing through the southeastern part of Shanxi mainly affected the central and southern parts of Shanxi Province and the southern part of Beijing. Through the numerical simulation of flow field, combined with the analysis results of potential source area and influence area, under the weather situation behind the pressure equalizing field or high pressure, the pollution transport path in the southeast of Shanxi included:Airflow from the Northeast (southwest of Hebei Province), transporting pollutants along the Fukou Xing in the northeast of Changzhi to the southeast of Shanxi, and the same northeast air flow continued southward along the eastern foot of the Taihang Mountain and then turned to the Taihang Xing at the junction of Shanxi and Henan to transport pollutants to the southeast of Shanxi; Airflow from the southeast (northern and east of Henan) transported pollutants; And airflow from the west (central and southern Shaanxi) transported pollutants. The pollutants were transported northward to the central and southern Shanxi Province through the southeast of Shanxi Province, and some were transported to the south of Beijing through Jingxing in the Middle East of Shanxi Province.