Quality (philosophy)

Air pollution

2019-20 coronavirus outbreak

Linguistics

Climatology

Philosophy

Biology

Virology

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)

Outbreak

Environmental health

Geology

Coronavirus disease 2019 (COVID-19)

TRACE (psycholinguistics)

Environmental planning

Trace gas

Organic chemistry

Particulates

Geography

Epistemology

Atmospheric composition

Infectious disease (medical specialty)

Environmental science

Air quality index

Medicine

Chemistry

Meteorology

Atmosphere (unit)

Pandemic

Atmospheric sciences

Disease

Ozone

Pathology

The Science of The Total Environment

Recent studies based on observations have shown the impact of lockdown measures taken in various European countries to contain the Covid-19 pandemic on air quality. However, these studies are often limited to compare situations without and with lockdown measures, which correspond to different time periods and then under different meteorological conditions. We propose a modelling study with the WRF-CHIMERE modelling suite for March 2020, an approach allowing to compare atmospheric composition with and without lockdown measures without the biases of meteorological conditions. This study shows that the lockdown effect on atmospheric composition, in particular through massive traffic reductions, has been important for several short-lived atmospheric trace species, with a large reduction in NO2 concentrations, a lower reduction in Particulate Matter (PM) concentrations and a mitigated effect on ozone concentrations due to non-linear chemical effects.

Impact of lockdown measures to combat Covid-19 on air quality over western Europe