The research group investigates physical and chemical processes in the atmosphere. The focus is on experimental research in the fields of clouds and aerosols, budgets of atmospheric trace gases and atmospheric transport. The basis of our research is the measurement of physical and chemical parameters in the atmosphere. Special priority are the EU funded projects coordinated in our group: Cloud-TRAIN (http://www.cloud-train.eu) and Eurohydros (http://www.meteor.uni-frankfurt.de/eurohydros), as well as the development of new instrumentation for the research aircraft HALO in the frame of DFG priority programme (http://www.halo.dlr.de) and the deployment of this instrumentation.