The HALO (High Altitude and LOng Range Research Aircraft) mission POLSTRACC (Polar Stratosphere in a Changing Climate) aims at providing new scientific knowledge on the structure, composition and evolution of the Arctic upper troposphere and lower stratosphere in a changing climate. The POLSTRACC field campaign is scheduled for the arctic winter 2015/16 in Kiruna, Sweden. POLSTRACC will be coordinated with the ROMIC Project GW-LCYCLE (Investigation of the life cycle of gravity waves) and the SALSA Project (Seasonality of Air mass transport and origin in the Lowermost Stratosphere using the HALO Aircraft).