NASA satellite measurements show that ozone reductions throughout the Northern Hemisphere (NH) free troposphere reported for spring-summer 2020 during the COronaVIrus Disease 2019 pandemic have occurred again in spring-summer 2021. The satellite measurements show that tropospheric column ozone (TCO) (mostly representative of the free troposphere) for 20°N–60°N during spring-summer for both 2020 and 2021 averaged ∼3 Dobson Units (DU) (or ∼7%–8%) below normal. These ozone reductions in 2020 and 2021 were the lowest in the 2005–2021 record. We also include satellite measurements of tropospheric NO₂ that exhibit reductions of ∼10%–20% in the NH in early spring-to-summer 2020 and 2021, suggesting that reduced pollution was the main cause for the low anomalies in NH TCO in 2020 and 2021. Reductions of TCO ∼2 DU (7%) are also measured in the Southern Hemisphere in austral summer but are not associated with reduced NO₂.

中文翻译：

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NASA 卫星测量显示，在 COVID-19 期间，2020 年和 2021 年全球范围内自由对流层臭氧的减少

NASA 卫星测量显示，2020 年春夏冠状病毒病 2019 大流行期间报告的整个北半球 (NH) 自由对流层的臭氧减少在 2021 年春夏再次发生。卫星测量显示，对流层柱臭氧 (TCO)（主要代表自由对流层）在 2020 年和 2021 年春夏期间 20°N–60°N 的平均水平低于正常水平 ∼3 多布森单位 (DU)（或 ∼7%–8%）。2020 年和 2021 年的这些臭氧减少量是 2005-2021 年记录中最低的。我们还包括对流层 NO _{2的卫星测量}2020 年春夏初夏和 2021 年 NH 减少 ∼10%–20%，表明污染减少是 2020 年和 2021 年 NH TCO 低异常的主要原因。 TCO 减少 ∼2 DU (7%) 也在南半球夏季的南半球进行了测量，但与 NO ₂减少无关。