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

Abstract

Spaceborne NO₂ column observations from two high‐resolution instruments, TROPOMI onboard Sentinel‐5 Precursor and OMI on Aura, reveal unprecedented NO₂ decreases over China, South Korea, Western Europe and the U.S. 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, e.g. Wuhan, Jinan, while the decreases in Western Europe and the U.S. 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.