Impact of particulate nitrate photolysis on air quality over the Northern Hemisphere.
Impact of particulate nitrate photolysis on air quality over the Northern Hemisphere.
复制标题
颗粒硝酸盐光解对北半球空气质量的影响。
DOI：
10.1016/j.scitotenv.2024.170406
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发表时间：
2024
期刊：
影响因子：
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通讯作者：
Sarwar G
中科院分区：
文献类型：
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作者：
Sarwar G
摘要我们使用社区多尺度空气质量（CMAQv 5。4)模式，以研究颗粒硝酸盐（pN O 3−）光解对北方半球空气质量的潜在影响。我们通过缩放硝酸（HNO 3）的光解频率来估计pN O 3−的光解频率，增强因子在10到100之间变化，取决于pN O 3−和海盐气溶胶浓度，然后进行CMAQ模拟，没有和有pN O 3−光解，以量化对流层成分的影响范围。pN O 3−的光解在海水中产生气态亚硝酸（HONO）和二氧化氮（NO 2），从而增加了大气中HONO和NO 2的混合比例。HONO随后发生光解，产生羟基自由基（OH）。NO2和OH的增加改变了大气化学，提高了海水上空的大气臭氧（O3）混合比，随后被输送到下风向的大陆地区。没有pN O 3−光解的季节平均模式O 3垂直柱密度低于臭氧监测仪器（OMI）的反演，而有pN O 3−光解的柱密度与对流层O 3负担的OMI反演更好地吻合。我们将模型O3混合比与来自美国、日本、对流层臭氧评估报告第二阶段和OpenAQ的可用地面观测数据进行了比较;发现不含pN O3 −光解的模型低估了冬季和春季的观测数据，而含pN O3 −光解的模型改善了这两个季节的比较，在很大程度上纠正了春季的明显低估。与美国西部的测量结果相比，考虑pN O 3−光解的模型O 3混合比与所有月份的观测数据吻合得更好，这是因为在没有pN O 3−光解的情况下O 3的持续低估。与臭氧探空仪测量结果相比，考虑pN O 3−光解的模式O 3混合比也比不考虑pN O 3−光解的模式O 3更符合观测数据。
Abstract We use the Community Multiscale Air Quality (CMAQv5. 4) model to examine the potential impact of particulate nitrate (pN O 3−) photolysis on air quality over the Northern Hemisphere. We estimate the photolysis frequency of pN O 3− by scaling the photolysis frequency of nitric acid (HNO 3) with an enhancement factor that varies between 10 and 100 depending on pN O 3− and sea-salt aerosol concentrations and then perform CMAQ simulations without and with pN O 3− photolysis to quantify the range of impacts on tropospheric composition. The photolysis of pN O 3− produces gaseous nitrous acid (HONO) and nitrogen dioxide (NO 2) over seawater thereby increasing atmospheric HONO and NO 2 mixing ratios. HONO subsequently undergoes photolysis, producing hydroxyl radicals (OH). The increase in NO 2 and OH alters atmospheric chemistry and enhances the atmospheric ozone (O 3) mixing ratio over seawater, which is subsequently transported to downwind continental regions. Seasonal mean model O 3 vertical column densities without pN O 3− photolysis are lower than the Ozone Monitoring Instrument (OMI) retrievals, while the column densities with the pN O 3− photolysis agree better with the OMI retrievals of tropospheric O 3 burden. We compare model O 3 mixing ratios with available surface observed data from the US, Japan, the Tropospheric Ozone Assessment Report–Phase II, and OpenAQ; and find that the model without pN O 3− photolysis underestimates the observed data in winter and spring seasons and the model with pN O 3− photolysis improves the comparison in both seasons, largely rectifying the pronounced underestimation in spring. Compared to measurements from the western US, model O 3 mixing ratios with pN O 3− photolysis agree better with observed data in all months due to the persistent underestimation of O 3 without pN O 3− photolysis. Compared to the ozonesonde measurements, model O 3 mixing ratios with pN O 3− photolysis also agree better with observed data than the model O 3 without pN O 3− photolysis.