春季沙尘对关中地区PM2.5 浓度影响的多尺度模拟研究

“一带一路”建设让古代丝绸之路的起点——西安成为世界焦点,西安的空气质量也是政府和公众关注的焦点。以2017年5月我国北方的一次强沙尘过程为例,首次利用中国科学院大气物理研究所气溶胶和大气化学模式系统IAP-AACM（Aerosol and Atmospheric Chemistry Model of the Institute of Atmospheric Physics）模拟关中地区细颗粒物（PM_2.5）的时空分布,并结合地面逐小时PM_2.5观测数据对沙尘气溶胶和PM_2.5模拟的关系进行深入探究。结果表明:加入沙尘组分对模拟关中地区PM_2.5时空变化特征作用显著,相关性可提升0.4～0.6,并且可以很好地再现强沙尘时段PM_2.5浓度骤增的过程;在强沙尘时段和一般时段,沙尘组分对PM_2.5的贡献分别为60%～80%和10%～30%;0.11°×0.11°高分辨率模拟有助于提升模式捕捉污染物时空变化的能力。

Multi-scale Simulation of the Influence of Spring Dust on PM2.5 Concentration in Central Shaanxi Area, China

The implement of"one belt and one road"program has made the starting station of the Silk Road Xi'an become the focus of the world.The air quality in Xi'an also attracts attention from the government and the public.Taking a strong dust period in northern China in May 2017 as a case,we firstly used the aerosol and atmospheric chemistry model developed by the Institute of Atmospheric Physics(IAP-AACM)to simulate the spatial and temporal distribution of fine particulate matter(PM2.5)in the Central Shaanxi area.Combined with hourly surface PM2.5 observation data,we explored the relationship between dust aerosol and the PM2.5 simulation.Results show that adding the dust component to anthropogenic PM2.5 significantly improves simulation accuracy,through which the correlation can be elevated by 0.4-0.6,and the sudden increase of PM2.5 during the strong dust period can be well reproduced.During strong dust and general periods,the contribution of dust aerosol to PM2.5 ranges from 60%-80%and 10%-30%,respectively.Highresolution simulations improve the model’s ability to capture the spatiotemporal changes of the pollutants.