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Response of surface ozone concentration to emission reduction and meteorology during the COVID-19 lockdown in Europe
  • +4
  • Adrien Deroubaix,
  • Guy Brasseur,
  • Benjamin Gaubert,
  • Inga Labuhn,
  • Laurent Menut,
  • Guillaume Siour,
  • Paolo Tuccella
Adrien Deroubaix
Max Planck Institute for Meteorology
Author Profile
Guy Brasseur
Atmospheric Chemistry Observations & Modeling Laboratory (ACOM), National Center for Atmospheric Research, Max Planck Institute for Meteorology
Benjamin Gaubert
Atmospheric Chemistry Observations & Modeling Laboratory (ACOM), National Center for Atmospheric Research
Inga Labuhn
Institute of Geography, University of Bremen
Laurent Menut
LMD/IPSL, Ecole Polytechnique, Université Paris Saclay, ENS, IPSL Research University, Sorbonne Université, CNRS
Guillaume Siour
Laboratoire Interuniversitaire des Systèmes Atmosphériques (LISA), UMR CNRS 7583, Université Paris Est Créteil et Université de Paris, Institut Pierre Simon Laplace
Paolo Tuccella
Departement of Physical and Chemical Sciences, University of L'Aquila


The lockdown period (March-May 2020) during the COVID-19 pandemics in Europe led to a reduction in the anthropogenic emissions of primary pollutants. For ¾ of over 1100 available monitoring stations, the average NO2 concentrations decreased by at least 2.7 µg.m-3 (or 25%) compared to the average concentrations recorded during the same period of the previous seven years. The O3 response differed spatially, with positive anomalies in northern Europe and negative anomalies in southwestern Europe. Reduced cloudiness and related enhanced radiation in northern Europe played a significant role in the increase of surface ozone concentrations by shifting the photochemical partitioning between NO2 and O3 toward more ozone. The level of total oxidant (Ox = O3 + NO2) remained unchanged except in southwestern Europe where it decreased. Several episodes lasting a few days of high level of total oxidants were observed in northern Europe. Our results illustrate the complexity of the atmospheric response to the unprecedented reduction in the emission of primary pollutants.

Peer review status:Published

May 2021Published in Meteorological Applications volume 28 issue 3. 10.1002/met.1990