Atmospheric Chemistry and Physics Discussions www.atmos-chem-phys-discuss.net 1680-7367 1680-7375 5 6 2005 10.5194/acpd-5-13011-2005 http://www.atmos-chem-phys-discuss.net/5/13011/2005/ http://www.atmos-chem-phys-discuss.net/5/13011/2005/acpd-5-13011-2005.html http://www.atmos-chem-phys-discuss.net/5/13011/2005/acpd-5-13011-2005.pdf 13011 13052 2005-12-19 Balloon-borne stratospheric BrO measurements: comparison with Envisat/SCIAMACHY BrO limb profiles M. Dorf marcel.dorf@iup.uni-heidelberg.de H. Bösch A. Butz C. Camy-Peyret M. P. Chipperfield A. Engel F. Goutail K. Grunow F. Hendrick S. Hrechanyy B. Naujokat J.-P. Pommereau M. Van Roozendael C. Sioris F. Stroh F. Weidner K. Pfeilsticker Institut für Umweltphysik, University of Heidelberg, Heidelberg, Germany Forschungszentrum Jülich GmbH, Institut für Chemie und Dynamik der Geosphäre ICG-I: Stratosphäre, Jülich, Germany Laboratoire de Physique Moléculaire pour l’Atmosphère et l’Astrophysique (LPMAA), Université Pierre et Marie Curie, Paris, France Harvard-Smithsonian Center for Astrophysics, Cambridge, USA Institute for Atmospheric Science, School of Earth and Environment, University of Leeds, Leeds, UK Meteorologisches Institut, Freie Universität Berlin, Berlin, Germany Service d’Aeronomie du CNRS, Verrières le Buisson, France Belgian Institute for Space Aeronomy (BIRA-IASB), Brussels, Belgium Institute for Atmosphere and Environment, J. W. Goethe University Frankfurt, Frankfurt, Germany now at: Jet Propulsion Laboratory (JPL), Pasadena, USA For the first time, results of all four existing stratospheric BrO profiling instruments, are presented and compared with reference to the SLIMCAT 3-dimensional chemical transport model (3-D CTM). Model calculations are used to infer a BrO profile validation set, measured by 3 different balloon sensors, for the new Envisat/SCIAMACHY (ENVIronment SATellite/SCanning Imaging Absorption spectroMeter for Atmospheric CHartographY) satellite instrument. The balloon observations include (a) balloon-borne in situ resonance fluorescence detection of BrO, (b) balloon-borne solar occultation DOAS measurements (Differential Optical Absorption Spectroscopy) of BrO in the UV, and (c) BrO profiling from the solar occultation SAOZ (Systeme d'Analyse par Observation Zenithale) balloon instrument. Since stratospheric BrO is subject to considerable diurnal variation and none of the measurements are performed close enough in time and space for a direct comparison, all balloon observations are considered with reference to outputs from the 3-D CTM. The referencing is performed by forward and backward air mass trajectory calculations to match the balloon with the satellite observations. The diurnal variation of BrO is considered by 1-D photochemical model calculation along the trajectories. The 1-D photochemical model is initialised with output data of the 3-D model with additional constraints on the vertical transport, the total amount and photochemistry of stratospheric bromine as given by the various balloon observations. Total [Br_y]=(20.1±2.8)pptv obtained from DOAS BrO observations at mid-latitudes in 2003, serves as an upper limit of the comparison. Most of the balloon observations agree with the photochemical model predictions within their given error estimates. First retrieval exercises of BrO limb profiling from the SCIAMACHY satellite instrument agree to <±50% with the photochemically-corrected balloon observations, and tend to show less agreement below 20 km.