Since its first confirmed case in December 2019, coronavirus disease 2019 (COVID-19) has become a worldwide pandemic with more than 90 million confirmed cases by January 2021. Countries around the world have enforced lockdown measures to prevent the spread of the virus, introducing a temporal change of air pollutants such as nitrogen dioxide (NO₂) that are strongly related to transportation, industry, and energy. In this study, NO₂ variations over regions with strong responses to COVID-19 are analysed using datasets from the Global Ozone Monitoring Experiment-2 (GOME-2) sensor aboard the EUMETSAT Metop satellites and TROPOspheric Monitoring Instrument (TROPOMI) aboard the EU/ESA Sentinel-5 Precursor satellite. The global GOME-2 and TROPOMI NO₂ datasets are generated at the German Aerospace Center (DLR) using harmonized retrieval algorithms; potential influences of the long-term trend and seasonal cycle, as well as the short-term meteorological variation, are taken into account statistically. We present the application of the GOME-2 data to analyze the lockdown-related NO₂ variations for morning conditions. Consistent NO₂ variations are observed for the GOME-2 measurements and the early afternoon TROPOMI data: regions with strong social responses to COVID-19 in Asia, Europe, North America, and South America show strong NO₂ reductions of \(\sim \)30–50% on average due to restriction of social and economic activities, followed by a gradual rebound with lifted restriction measures.

自 2019 年 12 月出现首例确诊病例以来，2019 年冠状病毒病 (COVID-19) 已成为全球大流行病，到 2021 年 1 月确诊病例已超过 9000 万例。世界各国已实施封锁措施以防止病毒传播，引入与交通、工业和能源密切相关的二氧化氮 (NO _{2 ) 等空气污染物的时间变化。}在这项研究中，使用 EUMETSAT Metop 卫星上的全球臭氧监测实验 2 (GOME-2) 传感器和 EU/ 对流层监测仪器 (TROPOMI) 上的数据集分析了对 COVID-19 有强烈反应的地区的NO ₂变化。 ESA Sentinel-5 Precursor 卫星。全球 GOME-2 和 TROPOMI NO ₂数据集是在德国航空航天中心 (DLR) 使用统一检索算法生成的；在统计上考虑了长期趋势和季节周期以及短期气象变化的潜在影响。我们展示了应用 GOME-2 数据来分析早晨条件下与锁定相关的 NO ₂变化。在 GOME-2 测量和午后 TROPOMI 数据中观察到一致的 NO _{2变化：亚洲、欧洲、北美和南美对 COVID-19 有强烈社会反应的地区显示出强烈的 NO 2}减少\(\sim \ )由于社会和经济活动的限制，平均为 30-50%，随后随着限制措施的解除逐步反弹。