延庆城区空气质量特征与气象条件关系分析

Analysis of the Relationship between Air Quality Characteristics and Meteorological Conditions in Yanqing Urban Area

摘要: 选取2018和2019年延庆城区环境空气颗粒物(PM₁₀, PM_2.5)质量浓度(夏都公园站)，并结合同期气象观测数据(延庆站)，对延庆城区的空气质量特征与气象条件相关性进行分析。进一步了解延庆空气污染状况、传输特征以及空气质量与气象要素的关系，为建立定量化空气污染气象条件预报模型积累经验，为本地空气污染防治提供科学依据。结果表明：从近两年来看，延庆城区主导风向为东北偏东风，占总风向频率的14.5%，在近地面吹北风时，PM₁₀质量浓度最高，偏东风能够明显增加PM_2.5质量浓度，日平均风速处于1.1~2.0米/秒时，颗粒物污染日数占比达到最大值，日平均相对湿度在40%~60%区间时，污染日数占比相对比较集中。能见度随PM2.5增加呈幂指数降低，在80 ≤ RH < 90湿度条件下，大气能见度与颗粒物相关性最强，当延庆城区PM_2.5质量浓度低于69 μg/m³时，能够大幅提高能见度。

Abstract: Taking the mass concentrations of ambient air particles (PM₁₀, PM_2.5) in Yanqing urban area in 2018 and 2019 (Xiadu park station), combining with the meteorological observation data of the same period (Yanqing station). The air quality characteristics and meteorological conditions in Yanqing urban area were analyzed. The purpose is to explore the air pollution situation and transmission characteristics in Yanqing, as well as the relationship between air quality and meteorological elements. We need to gain experience for the establishment of quantitatively meteorological prediction model of air pollution, and provide scientific basis for the prevention and control of local air pollution. The results showed that: from the point of the past two years, leading the direction of the wind for Yanqing urban area is east northeast wind. It accounts for 14.5% of the total wind direction frequency. The highest quality of PM₁₀ concentration appeared when the north wind blowing in close to the ground. PM_2.5 mass concentration can be dramatically increased when easterly winds appear. When the daily average wind speed was 1.1 - 2.0 m/s, maximum of partic-ulate matter pollution days accounted. When daily average relative humidity is within the range of 40% - 60%, pollution days’ proportion is relatively concentrated. Visibility decreases exponentially with the increase of PM_2.5. Under the condition of 80 ≤ RH < 90 humidity, atmospheric visibility has the strongest correlation with particulate matter. When the PM_2.5 mass concentration in Yanqing urban area is lower than 69 μg/mm³, visibility can be significantly improved.