Tropospheric nitrogen dioxide (NO₂) poses a serious threat to the environmental quality and public health. Satellite NO₂ observations have been continuously used to monitor NO₂ variations and improve model performances. However, the accuracy of satellite NO₂ retrieval depends on the knowledge of aerosol optical properties, in particular for urban agglomerations accompanied by significant changes in aerosol characteristics. In this study, we investigate the impacts of aerosol composition on tropospheric NO₂ retrieval for an 18 year global data set from Global Ozone Monitoring Experiment (GOME)-series satellite sensors. With a focus on cloud-free scenes dominated by the presence of aerosols, individual aerosol composition affects the uncertainties of tropospheric NO₂ columns through impacts on the aerosol loading amount, relative vertical distribution of aerosol and NO₂, aerosol absorption properties, and surface albedo determination. Among aerosol compositions, secondary inorganic aerosol mostly dominates the NO₂ uncertainty by up to 43.5% in urban agglomerations, while organic aerosols contribute significantly to the NO₂ uncertainty by −8.9 to 37.3% during biomass burning seasons. The possible contrary influences from different aerosol species highlight the importance and complexity of aerosol correction on tropospheric NO₂ retrieval and indicate the need for a full picture of aerosol properties. This is of particular importance for interpreting seasonal variations or long-term trends of tropospheric NO₂ columns as well as for mitigating ozone and fine particulate matter pollution.

中文翻译：

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全球城市群气溶胶成分使卫星 NO2 反演变得复杂：季节变化和长期趋势（2001-2018）

对流层二氧化氮（NO ₂）对环境质量和公众健康构成严重威胁。卫星 NO ₂观测一直被用来监测 NO ₂变化并改进模型性能。然而，卫星NO ₂反演的准确性取决于对气溶胶光学性质的了解，特别是对于气溶胶特征发生显着变化的城市群。在这项研究中，我们利用全球臭氧监测实验 (GOME) 系列卫星传感器的 18 年全球数据集，研究了气溶胶成分对对流层 NO ₂反演的影响。重点关注以气溶胶存在为主的无云场景，单个气溶胶成分通过影响气溶胶负荷量、气溶胶和NO ₂的相对垂直分布、气溶胶吸收特性和表面反照率来影响对流层NO ₂柱的不确定性决心。在气溶胶成分中，次生无机气溶胶在城市群中主要主导NO ₂不确定性，高达43.5％，而有机气溶胶在生物质燃烧季节对NO ₂不确定性贡献显着，达-8.9％至37.3％。不同气溶胶种类可能产生的相反影响凸显了气溶胶校正对对流层 NO ₂反演的重要性和复杂性，并表明需要全面了解气溶胶特性。这对于解释对流层 NO ₂柱的季节变化或长期趋势以及减轻臭氧和细颗粒物污染特别重要。