Ziemke, Jerry R.Kramarova, Natalya A.Frith, Stacey M.Huang, Liang-KangHaffner, David P.Wargan, KrzysztofLamsal, LokLabow, Gordon J.McPeters, Richard D.Bhartia, Pawan K.2022-09-142022-09-142022-08-12Ziemke, J. R., Kramarova, N. A., Frith, S. M., Huang, L.-K., Haffner, D. P., Wargan, K., et al. (2022). NASA satellite measurements show global-scale reductions in free tropospheric ozone in 2020 and again in 2021 during COVID-19. Geophysical Research Letters, 49, e2022GL098712. https://doi.org/10.1029/2022GL098712https://doi.org/10.1029/2022GL098712http://hdl.handle.net/11603/25661NASA 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 NO28 pagesen-USThis work was written as part of one of the author's official duties as an Employee of the United States Government and is therefore a work of the United States Government. In accordance with 17 U.S.C. 105, no copyright protection is available for such works under U.S. Law.Public Domain Mark 1.0Text