| VOCs源强不确定性对臭氧生成及污染防治影响的模拟分析 |
| 摘要点击 1956 全文点击 585 投稿时间：2021-03-22 修订日期：2021-05-27 |
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| 中文关键词 挥发性有机化合物(VOCs) 源强不确定性 臭氧(O3) WRF-Chem模式 调控对策 |
| 英文关键词 volatile organic compounds(VOCs) uncertainty in VOCs emissions ozone(O3) WRF-Chem model control strategies |
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| 中文摘要 |
| 本文基于三维区域空气质量模式WRF-Chem，通过修改模式化学模块，量化输出过程量和诊断量，提供了一种定量分析挥发性有机化合物（VOCs）源强不确定性对O3生成影响的方法.为无法定量计算VOCs源强导致的臭氧生成率[P（O3）]偏差，以及由此对O3体积分数分布和污染控制相关联的VOCs敏感区和NOx敏感区分布的误判提供了方法参考.采用标准统计参数对WRF-Chem模式的气象场与污染场模拟性能进行了评估，相关指标均优于前人结果.以INTEX-B（intercontinental chemical transport experiment-phase B）人为源、FINNv1（fire inventory from NCAR version 1）生物质燃烧源和MEGAN（model of emissions of gases and aerosols from nature）生物源作为基准源，并以卫星观测数据作为约束，对排放源进行改进，评估了源改进前后臭氧生成率[P（O3）]、O3体积分数和O3控制敏感区指标（Ln/Q）的变化情况.仅人为VOCs（AVOCs）源增加68%后，P（O3）模拟峰值增升比例达13%~82%，以北京观测站点为例，P（O3）模拟月均峰值增加42%（22.5×10-9 h-1）.对P（O3）形成贡献比例最大的主要化学反应是HO2+NO（占比约68%），AVOCs源增加68%后，该反应贡献比例下降至65%.在改进源下，P（O3）普遍增加达到2×10-9~4×10-9 h-1，O3各季节增幅较大的区域均主要集中在京津冀、长三角和珠三角中心城市及周边区域，与我国大型城市区基本都是VOCs敏感区的结论一致.整体而言，VOCs源强改进后，NOx敏感区O3体积分数增加幅度不大，不超过4×10-9，而部分VOCs敏感区增幅超过20×10-9.VOCs源强的不确定性会影响O3形成过程中NOx和VOCs敏感区的判断，特别是VOCs源强明显低估会夸大VOCs敏感区的范围，从而降低O3调控对策的有效性. |
| 英文摘要 |
| This study utilized the WRF-Chem model, with modified chemical modules that were added as diagnostic variables. This facilitated the evaluation of the impacts of uncertainty in VOC emissions on ozone formation and control strategies that few studies have investigated in China. The performance metrics of WRF-Chem meteorology simulations and O3 and NO2 simulations were evaluated. The results indicated that some metrics were far superior to those from previous studies. We used the bottom-up VOC emission inventories of intercontinental chemical transport experiment-phase B (INTEX-B) for anthropogenic sources, the fire inventory from NCAR version 1 (FINNv1) for biomass burning sources, and the model of emissions of gases and aerosols from nature (MEGAN) for biogenic sources. We evaluated the changes in the ozone production rate[P(O3)], ozone concentration, and the indicator of Ln/Q while the emission inventories were improved by the satellite observation data as a constraint. It produced 13%-82% increases in the P(O3) peaks in Beijing and resulted in a 42%(22.5×10-9 h-1) enhancement in the P(O3) monthly average, with 68% increases in AVOC emissions. The predominant contribution to P(O3) was the reaction of HO2+NO, which accounted for 68% in Beijing. A 68% increase in AVOC emissions reduced the reaction to 65%. Under the improvement source, P(O3) generally increased to 2×10-9-4×10-9 h-1. The areas with large seasonal increases in O3 were mainly concentrated in the Beijing-Tianjin-Hebei, Yangtze River Delta, and Pearl River Delta central cities and surrounding areas and large cities in China. The conclusion that these areas are basically VOC-sensitive areas is consistent with those of previous studies. Overall, after the source of VOCs is improved, the increase in O3 concentration in NOx-sensitive areas is minor, not exceeding 4×10-9, whereas the increase in some VOC-sensitive areas exceeds 20×10-9. Changes in the source strength of VOCs will affect the determination of NOx-and VOC-sensitive areas during the formation of O3. In particular, a significant underestimation of the source strength of VOCs will exaggerate the range of VOC-sensitive areas, thereby reducing the effectiveness of O3 control strategies. |
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