应用区域空气质量模型系统(称为RAQMS)以及由WRF驱动的已开发的粉尘模型来综合研究排放,运输,沉积,预算,以及2021年3月10日至31日严重沙尘暴期间矿物粉尘的化学和辐射效应。模型结果在各种地面上进行了验证,垂直和卫星观测,在再现气象变量方面表现出普遍良好的模型能力,颗粒物和组合物,和气溶胶光学性质。第一次沙尘暴(DS1)这是自2010年以来最严重的一次,起源于3月14日蒙古南部的戈壁沙漠,粉尘排放通量达到2785μgm-2s-1,最大粉尘浓度超过18,000μgm-3。这场沙尘暴导致北京每小时的PM10观测值非常高,高达7506μgm-3、1887μgm-3和2704μgm-3,天津,石家庄3月15日,分别,并导致北京地表短波辐射最大减少313.4Wm-2(72%)。第二次沙尘暴(DS2)在蒙古东部的沙漠中爆发,粉尘排放量比第一个低。粉尘气溶胶对短波辐射的消光导致光解速率降低,因此华北平原(NCP)上的O3和二次气溶胶浓度降低,而在DS1期间,由于黄河中游和NCP地区灰尘表面的异质反应,硫酸盐和硝酸盐的总浓度不断增加。3月16日至17日,NCP中通过非均相反应形成的硫酸盐和硝酸盐在粉尘回流中平均增加了约18%和24%。非均相反应和矿物粉尘的光解速率降低共同导致硫酸盐的平均变化,硝酸盐,铵,二次有机气溶胶(SOA)浓度下降13.0%,13.5%,-12.3%,和-4.4%,分别,在DS1期间,NCP区域的变化大于长江三角洲(YRD)的变化。在顺风陆地和海洋区域,最大干沉积在7-11μm的尺寸范围内,而湿沉积在整个域中达到4.7-7μm尺寸范围的峰值。除粉尘源区外,湿沉降约为中国大陆干沉降的两倍。3月10日至31日,粉尘排放总量,干沉积和湿沉积估计为31.4Tg,13.78Tg和4.75Tg,分别,剩余的12.87Tg的粉尘气溶胶(占粉尘排放的41%)悬浮在大气中或输送到其他大陆和海洋。
A Regional Air Quality Model System (named RAQMS) coupled with a developed dust model driven by WRF was applied to synthetically investigate the emission, transport, deposition, budget, and chemical and radiative effects of mineral dust during the severe dust storm periods of 10-31 March 2021. Model results were validated against a variety of ground, vertical and satellite observations, which demonstrated a generally good model ability in reproducing meteorological variables, particulate matter and compositions, and aerosol optical properties. The first dust storm (DS1), which was the severest one since 2010 was originated from the Gobi Desert in southern Mongolia on 14 March, with the dust emission flux reaching 2785 μg m-2 s-1 and the maximum dust concentration exceeding 18,000 μg m-3 in the dust deflation region. This dust storm resulted in remarkably high hourly PM10 observations up to 7506 μg m-3, 1887 μg m-3, and 2704 μg m-3 in Beijing, Tianjin, and Shijiazhuang on 15 March, respectively, and led to a maximum decrease in surface shortwave radiation up to 313.4 W m-2 (72 %) in Beijing. The second dust storm (DS2) broke out in the deserts of eastern Mongolia, with lower dust emission than the first one. The extinction of shortwave radiation by dust aerosols led to a reduction in photolysis rate and consequently decreases in O3 and secondary aerosol concentrations over the North China Plain (NCP), whereas total sulfate and nitrate concentrations consistently increased due to heterogeneous reactions on dust surfaces over the middle reaches of the Yellow River and the NCP region during DS1. Sulfate and nitrate formation through heterogeneous reactions were enhanced in the dust backflow on 16-17 March by approximately 18 % and 24 % on average in the NCP. Heterogeneous reactions and photolysis rate reduction by mineral dust jointly led to average changes in sulfate, nitrate, ammonium, and secondary organic aerosol (SOA) concentrations by 13.0 %, 13.5 %, -12.3 %, and -4.4 %, respectively, in the NCP region during DS1, larger than the changes in the Yangtze River Delta (YRD). The maximum dry deposition settled in the 7-11 μm size range in downwind land and ocean areas, while wet deposition peaked in the 4.7-7 μm size range in the entire domain. Wet deposition was approximately twice the dry deposition over mainland China except for dust source regions. During 10-31 March, the total dust emission, dry and wet depositions were estimated to be 31.4 Tg, 13.78 Tg and 4.75 Tg, respectively, with remaining 12.87 Tg of dust aerosols (41 % of the dust emission) suspending in the atmosphere or transporting to other continents and oceans.