北京大兴国际机场不利气象条件下飞机尾气排放对大气环境影响的模拟研究

Simulation Study on Atmospheric Environmental Impact of Aircraft Emissions of Beijing Daxing International Airport Under Adverse Meteorological Conditions

北京大兴国际机场作为吞吐量巨大的超大型国际枢纽,其运营过程中飞机尾气排放量大,对机场周边地区大气环境的影响不容忽视。为研究不利气象条件下飞机尾气排放对大气环境的影响,根据北京市环境空气数据筛选出2020年度不利气象条件时段,基于北京大兴国际机场2025年规划相关基础数据,采用排放与扩散模型系统(EDMS)建立飞机尾气排放源清单,开展不利气象条件下大气污染扩散模拟预测分析。气象分析结果表明不利气象条件时段存在小静风、高湿、厚度薄而强度大的接地逆温等特征,该时段北京地区经历以PM_(2.5)为首要污染物的重污染过程,并伴随着低能见度天气。模式预测结果显示在不利气象条件下摩擦速度和混合层高度等参数均处于较小的水平,大气污染扩散条件较差,飞机尾气对周边环境产生较大程度的影响,且污染物落地浓度存在昼间较低、夜间较高的时间分布规律。分析不利气象条件下的污染气象特征和飞机尾气污染物落地浓度分布特征对开展机场大气污染控制措施研究工作具有一定的参考价值。

Beijing Daxing International Airport,as a super large international hub with huge throughput,has a large amount of aircraft exhaust emissions,which can impact the atmospheric environment around the airport greatly,and should not be ignored.In order to study the impact of aircraft exhaust emissions on the atmospheric environment under adverse meteorological conditions,the adverse meteorological conditions period in 2020 is selected based on the Beijing air quality data.According to the projected basic data of the 2025 planning of Daxing International Airport,the Emissions and Dispersion Modeling System(EDMS)is used to establish the list of exhaust emission sources of the airport and simulate the diffusion of air pollution.The results of pollution analysis show that there are meteorological characteristics such as light calm wind,high humidity and strong grounding temperature inversion with thin thickness during adverse meteorological conditions.Beijing has experienced heavy pollution processes,accompanied by the low visibility.Under the influence of adverse meteorological conditions,the parameters such as friction velocity and mixing layer height are at a lower level,indicating that the diffusion conditions of air pollution are poor.The model prediction results show that aircraft exhaust would have a great impact on the surrounding environment,and the ground concentration of pollutants might have the time distribution law of low in the daytime but high at night.Such characteristics of pollution meteorology and aircraft emission concentration distribution under adverse meteorological conditions could provide some references for the research on airport air pollution control measures.