SCIAMACHY VALIDATION BY MEASUREMENTS FROM AIRCRAFT PLATFORMS Gerhard Ehret (1) , Andreas Fix (1) , Manfred Gottwald (2) , Heinz Finkenzeller (3) , Harry Küllmann (4) , Andreas Richter (4) , John P. Burrows (4) , Thomas Wagner (5) , and Ulrich Platt (5) (1) DLR Institut für Physik der Atmosphäre, 82234 Wessling, Germany, Email: Gerhard.Ehret@dlr.de (1) DLR Institut für Physik der Atmosphäre, 82234 Wessling, Germany, Email: Andreas.Fix@dlr.de (2) DLR Deutsches Fernerkundungsdatenzentrum, 82234 Wessling, Germany, Email: Manfred.Gottwald@dlr.de (3) DLR Flugbetrieb, 82234 Wessling, Germany, Email: Heinz.Finkenzeller@dlr.de (4) Institut für Umweltphysik, Universität Bremen, Email:Harry.Küllmann@iup.physik.uni-bremen.de (4) Institut für Umweltphysik, Universität Bremen, Email:Andreas.Richter@iup.physik.uni-bremen.de (4) Institut für Umweltphysik, Universität Bremen, Email: Burrows@iup.physik.uni-bremen.de (5) Institut für Umweltphysik, Universität Heidelberg, Email:Thomas.Wagner@iup.uni-heidelberg.de (5) Institut für Umweltphysik, Universität Heidelberg, Email:Ulrich.Platt@ iup.uni-heidelberg.de ABSTRACT The first airborne main validation campaign has been successfully completed in September 2002 as part of the German Contribution to the Validation of SCIAMACHY level 2 and off-line data products. The three different remote sensing instruments, ASUR, AMAXDOAS, and OLEX aboard DLR's meteorological research aircraft Falcon 20, enabled simultaneous measurements of a number of important SCIAMACHY data products such as O 3 , NO 2 , N 2 O, NO, BrO, H 2 O, Aerosols and clouds for the first time. From extended latitudinal cross sections running from polar regions up to the tropics as well as longitudinal cross sections at polar latitudes at about 70°N, a unique data set has been generated which will enable detailed analysis of SCIAMACHY performances in different climates and at various geophysical locations. A second main validation campaign is planned to take place in February/March 2003. 1 INTRODUCTION SCIAMACHY (SCanning Imaging Absorption spectroMeter for Atmospheric CHartographY) is one of the 10 instruments aboard Europe’s research satellite ENVISAT, which aims at studying the composition of the earth’s atmosphere from space. It has been developed jointly by The Netherlands, Belgium and Germany as their national contribution to the ESA ENVISAT programme. SCIAMACHY measures electromagnetic radiation that is back scattered, reflected and transmitted from the atmosphere in the solar and near infrared spectral region in a variety of different viewing geometries. The measured spectrum contains the finger prints of absorbing and emitting species and, with this, information on the trace gas concentration of the atmosphere. Inversion of these measurements yields the amounts and distributions of stratospheric and tropospheric constituents. The SCIAMACHY instrument has many unique features: its limb measurements will provide global information about the mesosphere, stratosphere and upper troposphere, its nadir measurements will yield total column measurements of key tropospheric and stratospheric constituents, and the combination of limb and nadir sounding will yield measurements of important atmospheric constituents of the troposphere [1]. In order to assess the quality of the SCIAMACHY data, dedicated validation is essential. The large volume and high quality of the SCIAMACHY data will require strong validation efforts. Particular attention is needed for the validation of vertically resolved data products. For validation of vertical trace gas profiles measured by SCIAMACHY balloon-borne measurements are performed. __________________________________________________________________________________________________________ Proc. of Envisat Validation Workshop, Frascati, Italy, 9 – 13 December 2002 (ESA SP-531, August 2003)