Yesterday we completed our campaign with the 24th successful flight. HALO turned a 4,5 h round through Germany. Besides the important turbulence calibration of the nose boom (where the manoeuvers rendered some of the crew with pale faces), we sampled HALO’s own exhaust plume, this time without a visible contrail. A profile from the ground to high altitude was measured for valuable information on the distribution of aerosol particles in the tropospheric column.
In the evening we concluded the day with the present staff in typical Bavarian manner in a restaurant at the Wörthsee.
All of us participants, but also our colleagues, employers and funding agencies are glad that we could complete this campaign in these challenging times, obeying all the health rules that protect us. This could not be taken for granted before, but after several delays and re-evaluation of operational and scientific concepts, we now possess a wealth of interesting data and many contributors are now willing to analyse them in the following months and years. This way we expect to contribute to answering the questions and better understand the properties and behaviour of cirrus and the impact of aviation on the atmosphere.