BLUESKY – The Aircraft Mission on Atmospheric Composition Changes in Europe during the Corona Lockdown 2020

Abstract:

Worldwide regulations to control the COVID-19 pandemic caused significant reductions in ground and airborne transportation in spring 2020. This unprecedented situation provided a unique opportunity to directly investigate the relatively unperturbed atmosphere, notably near the tropopause, and derive the effects of anthropogenic emissions on atmospheric composition and climate.

The BLUESKY mission combined measurements by the high-altitude, long-range research aircraft HALO and the DLR Falcon with satellite observations and modeling to derive atmospheric composition changes during the Corona lockdown period. From 16 May to 9 June 2020, the two research aircraft performed in total 20 flights over Europe and the North Atlantic to investigate the effects of up to 90% reductions in air traffic on the composition of the upper troposphere and lower stratosphere. A major reduction of contrail cover has been derived from satellite observations and modelling. Aerosol and trace gases emitted by aviation at cruise exhibit reductions at various levels compared to aircraft observations in previous years. In addition, continental profiles of selected trace species and the pollution of the boundary layer below 2 km altitude were investigated. Here, we present the planning, objectives, implementation and first highlights of the BLUESKY mission.

The comprehensive data set acquired during the lockdown period allows better understanding and constraining the anthropogenic influence on the composition of the atmosphere and impacts on air quality and climate.