2018年沈阳市一次空气重污染过程分析

采用数值模拟与观测资料相结合的方式，对沈阳市2018年1—3月发生的1次重污染过程的气象条件、天气形势和潜在来源进行初步分析。结果表明:重污染过程与当地的气象条件密切相关，沈阳市重污染期间的PM_2.5和PM₁₀浓度与风速和气温呈负相关，与气压和相对湿度呈正相关。中度、重度及以上污染主要集中于相对湿度为50%~70%条件下；重污染主要在高压、高湿、低风速、近地层逆温的天气形势下，污染物不易扩散。高空若有暖平流、受槽前脊后暖平流的影响也会导致区域空气质量下降。潜在来源分析表明，沈阳市的气团共有4条运输路线，其中来自内蒙古的轨迹携带了大量的PM₁₀；属于簇团2（34.72%）的内蒙古自治区中东部，属于簇团3（21.94%）的河北省以及属于簇团4（13.06%）的吉林省西部地区对沈阳市的污染贡献比较高。

ANALYSIS OF A HEAVY AIR POLLUTION PROCESS IN SHENYANG IN 2018

The meteorological conditions, weather situation and potential sources of a heavy pollution process that occurred in Shenyang from January to March 2018 were analyzed by combining numerical model and observation data. The results showed that the heavy pollution process was closely related to the local meteorological conditions. The concentration of PM_2.5 and PM₁₀ during the heavy pollution period in Shenyang had a negative correlation with wind speed and temperature. During heavy pollution, northeast wind and northeast wind prevail, and the wind speed was relatively low, which had a positive correlation with air pressure and relative humidity. Moderate, severe and above polluting weather was mainly concentrated in the weather with relative humidity between 50% and 70%; while heavy pollution mainly under the weather conditions of high pressure, high humidity, low wind speed, and near-surface temperature inversion, pollutants were not easy to spread; if there was warm advection at high altitude, the influence of warm advection after the front ridge of the trough would also cause regional air quality to decline. There were 4 transportation routes in the air mass in Shenyang:cluster 1 in the north-northwest direction accounted for 30.28% of the total trajectory; cluster 2 in the northwest direction accounted for 34.72%, compared with 21.94% of cluster 3, and 13.06% of cluster 4; the trajectory from Inner Mongolia carried a large amount of PM₁₀. The central and eastern Inner Mongolia Autonomous Region (cluster 2), Hebei province (cluster 3) and the western Jilin province (cluster 4) had a relatively higher contribution to the pollution in Shenyang.