Hauke Schmidt, (Co-I of P4, Partner of P1 and P3), Dr., has worked on various aspects of dynamics and chemistry of the atmosphere from the surface to the thermosphere and has authored or co-authored about 40 scientific publications in this field. He is heading the research group on the “Middle and Upper Atmosphere” at MPI-M and is acting as deputy director of the department “Atmosphere in the Earth system”. He is coordinating the EU FP7 research project IMPLICC on geoengineering and has coordinated until 2011 the DFG-funded German ARTOS project on the “Atmospheric Response TO Solar variability”. His main interests are the response of the middle and upper atmosphere to natural and anthropogenic forcings, vertical coupling processes that link atmospheric layers, and the role of the middle atmosphere for tropospheric climate.