In the TACTS atmospheric mission, scientists are investigating seasonal changes in the structure of the tropopause region, especially during the shift from summer to autumn. Located between the troposphere and the stratosphere, it is especially important for the radiation budget of the atmosphere and hence for our climate.

To this end HALO is set to carry out a number of measurement flights to the Cape Verde islands and back at intervals of 2 to 3 weeks. Both the large range of HALO and the maximum flight altitude of 15 kilometres are necessary for this, as the researchers will be measuring the tropopause region from the mid-latitudes to the subtropics. During the flight, highly specialised measurement equipment will be used to measure the chemical composition of the tropopause region at latitudes between 50 and 10 degrees north, enabling conclusions to be drawn on the atmospheric transport process. In this way TACTS is expected to improve our understanding of the dominant atmospheric transport processes and so contribute to a better understanding of the atmospheric models that will be used for future projections of the development of Earth’s atmosphere and the climate as the chemical composition changes.