In Spring 2020, worlwide measures to control the spread of the Corona virus became effective. These measures led to significant reductions in industrial activities as well as transportation, including air traffic. BLUESKY made use of this unprecedented situation and investigated the effects of anthropogenic emission by performing measurements in a far less perturbed atmosphere. The object was to analyze the impact of anthropogenic activities on atmospheric composition, aerosols, clouds and climate. The obtained results were compared with prior HALO campaigns which performed comparable measurements.

Two research aircrafts were deployed for these investigations. Beside HALO, the DLR Falcon performed scientific flights. From 16 May to 9 June 2020, the two research aircraft performed 20 flights over Europe and the North Atlantic. Satellite observartions and model studies complete the analyses.

One specific aspect of the mission was to investigate the effect of air traffic on cirrus clouds, as air traffic was reduced by 90%. For this aim, research flights took also place over the Atlantik Ocean in the vicinity of the flight corridor to North America.