CAFE-EU/BLUESKY (Chemistry of the atmosphere: Field Experiment in Europe) is a HALO mission that took place in May/June 2020 over Europe. Its aim was to study the chemical composition of the atmosphere during the Corona lockdown. Various instruments were installed on board the research aircraft HALO and FALCON, measuring physical and meteorological parameters (temperature, pressure, radiation etc.), chemical trace gases (VOCs, sulphuric acid, OH, ozone etc.), and aerosol particle concentration and composition. The campaign was coordinated by DLR (German Aerospace Center) and Max Planck Institute for Chemistry Mainz, accompanied by research groups of KIT (Karlsruhe Institute of Technologie), Goethe University Frankfurt and Research Center Jülich.  The mission’s base was Oberpfaffenhofen airport in Bavaria.

During the mission, we conducted eight measurement flights over Europe, covering an area between the South of Spain up to the North Atlantic Flight Corridor off the coast of Ireland. We took vertical profiles above metropolitan areas (60 m to 14 km altitude), and took samples of the outflow of cumulonimbus clouds (thunder clouds).

For the first time, we successfully employed the CI-APi-TOF mass spectrometer on board the research aircraft HALO. We measured sulphuric acid, methanesulphonic acid, and C₂ amines (dimethylamine and ethylamine) in Chemical Ionisation mode, among others. Additionally, we measured ambient ions in APi mode (Atmospheric Pressure interface). The results of the measurement campaign give unique insights into the concentration profiles of the mentioned chemical species in the troposphere and lower stratosphere.

The subsequent mission with the CI-APi-TOF – CAFE-Brazil -  took place in winter 2022/23 in over the Amazon rainforest in Brazil. For the upcoming campaign, CAFE-Pacific, the aircraft will be stationed in Cairns, Australia.

More information on BLUESKY you can find in this press release (in English) and in this and this TV report (both in German).