Impact study of COVID-19 lockdown measures on air quality and climate (ICOVAC)

The global crisis due to the pandemic spread of the coronavirus COVID-19 that the humanity is facing since early 2020 led to unprecedented measures taken by different governments worldwide in order to limit as much as possible the number of impacted persons. Those measures include social distancing, banning of people gathering and travels, encouragement for teleworking, closings of schools, universities, restaurants, pubs and non-essential product shops, border closings,… All those measures have been implemented by the individual countries at different moments, depending mostly on the virus outbreak timing in each territory. Italy has been the first European country to be significantly impacted by the virus outbreak and to take lockdown measures in early March 2020. Most of the other European countries had to take similar decisions in the following weeks, almost all countries worldwide are impacted by the COVID-19.

All those measures impact significantly the anthropogenic emissions in the atmosphere as they lead to a drastic drop in road and air traffic and a strong reduction of industrial activities in non-essential sectors. On the other hand, other sectors might face increased demands, like domestic heating for example. Satellite measurements of nitrogen dioxide (NO2) tropospheric columns are a direct proxy for anthropogenic emissions. A decrease of the TROPOMI NO2 tropospheric columns in different parts of the world (e.g. China, Po Valley, US) during the respective lockdown periods has been reported in many press articles lately. Besides NO2, other atmospheric species such as CO, glyoxal, CO2,… originate, at least partly, from anthropogenic activity and might be impacted by the taken COVID-19 measures. It will be investigated during this work whether a COVID-19 footprint can be detected in available satellite and ground-based data sets for a number of pollutants. We will attempt to assess the potential impact of the lockdown measures on air quality and climate by deriving updated NOx and CO emissions but also on climate with the analysis of satellite greenhouse gas data products, such as XCO2 columns and/or via the use of the NOx emissions as a proxy to derive fossil fuel CO2 emissions.