Impact of Coronavirus Outbreak on NO2 Pollution:
Assessed Using TROPOMI and OMI Observations

Spaceborne NO2 column observations from two high‐resolution instruments, Tropospheric Monitoring Instrument (TROPOMI) on board Sentinel‐5 Precursor and Ozone Monitoring Instrument (OMI) on Aura, reveal unprecedented NO2 decreases over China, South Korea, western Europe, and the United States as a result of public health measures enforced to contain the coronavirus disease outbreak (Covid‐19) in January–April 2020. The average NO2 column drop over all Chinese cities amounts to −40% relative to the same period in 2019 and reaches up to a factor of ~2 at heavily hit cities, for example, Wuhan, Jinan, while the decreases in western Europe and the United States are also significant (−20% to −38%). In contrast with this, although Iran is also strongly affected by the disease, the observations do not show evidence of lower emissions, reflecting more limited health measures.


Fig1 China

Fig. 1. TROPOMI NO2 columns over China (a) before and (b–e) after the lockdowns (shown by padlocks) due to Covid‐19. For comparison, columns over the same time periods are shown for 2019. The week of Chinese new year holiday is indicated by the red lantern shown inset panels (b) and (h). The New Year holiday covers 4–10 February in 2019 and 24–30 January in 2020 (exceptionally extended to 2 February because of Covid‐19). Partial loosening of the restrictions is suggested by the smaller padlock in panel (e). Gray areas indicate no valid data.



  • Bauwens, M., S. Compernolle, T. Stavrakou, J.-F. Müller, J. van Gent, H. Eskes, P. F. Levelt, R. van der A, J. P. Veefkind, J. Vlietinck, H. Yu, and C. Zehner: Impact of coronavirus outbreak on NO2 pollution assessed using TROPOMI and OMI observations, Geophys. Res. Lett., 47, e2020GL087978,, 2020.

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