Which climate effects do clouds have? Under what conditions do they warm or cool the atmosphere? The research aircraft HALO (High Altitude and Long Range Research Aircraft) is measuring vertical profiles of all components of atmospheric water such as vapor, liquid, and ice in both cloud and precipitation forms, as well as the aerosol particles upon which cloud droplets form. The aircraft, equipped with a large amount of advanced technology, is an initiative by German climate and environmental research institutions.

The Belly Pod under the hull of the HALO aircraft contains radiometers, radar, and a laser. (DLR)

The flight will provide scientists with more detailed information on the constitution of tropical clouds. The collected data will contribute to a better understanding of cloud and precipitation processes and will help to reduce uncertainties in climate models.

Remote sensing instruments, located in the "Belly Pod" underneath the aircraft´s hull, will detect vertical profiles of temperature and humidity and the distribution of droplets and aerosols. Additionally, dropsondes will be released during the flight. These radiosondes usually ascend from Earth with the help of a weather balloon and perform measurements on their way through the atmosphere. This time, they will be dropped by parachute and will glide back to the ground.