Cornelis. E. Blom, IMK-FZK, Karlsruhe, Germany

1. Forschungszentrum KarlsruheTechnik und Umwelt Cornelis. E. Blom, IMK-FZK, Karlsruhe, Germany Bruno Carli and Ugo Cortesi, IROE-CNR, Firenze, Italy Gianluca Redaelli, University of L’Aquila, L’Aquila, Italy Martyn P. Chipperfield, University of Leeds, Leeds, United Kingdom APE-GAIA: Airborne Polar Experiment - Geophysica Aircraft In Antarctica Abstract We report about the field campaign APE-GAIA conducted by the high altitude research aircraft M55-Geophysica in the Antarctic region, to study chemical and dynamical processes related to stratospheric ozone depletion. An overview of the mission objectives and a summary of the scientific flights is presented, along with preliminary results. Fig. 2: Altitude, latitude and in-situ measurements of minor constituents acquired during the flight of 23rd September 1999. The measurements are preliminary. Fig. 3: The volume mixing ratio [pptv] of ClO as a function of altitude and latitude from SAFIRE-A measurements on two legs of the flight of 23rd September 1999. Fig. 4: The volume mixing ratio [ppmv] of nitric acid as a function of altitude and latitude from MIPAS-STR measurements on two legs of the flight of 23rd September 1999. The 2-dimensional distribution is obtained from about 50 individual profiles. Fig. 1: Map of the test flight and the five scientific flights performed by the M55-Geophysica from the base of Ushuaia (Argentina) during the APE-GAIA mission Juli 2000