Atmospheric Chemistry and Physics Discussions www.atmos-chem-phys-discuss.net 1680-7367 1680-7375 4 6 2004 10.5194/acpd-4-7089-2004 http://www.atmos-chem-phys-discuss.net/4/7089/2004/ http://www.atmos-chem-phys-discuss.net/4/7089/2004/acpd-4-7089-2004.html http://www.atmos-chem-phys-discuss.net/4/7089/2004/acpd-4-7089-2004.pdf 7089 7120 2004-11-03 Ozone loss derived from balloon-borne tracer measurements and the SLIMCAT CTM A. D. Robinson adr22@cam.ac.uk G. A. Millard F. Danis M. Guirlet N. R. P. Harris A. M. Lee J. D. McIntyre J. A. Pyle J. Arvelius S. Dagnesjo S. Kirkwood H. Nilsson D. W. Toohey T. Deshler F. Goutail J.-P. Pommereau J. W. Elkins F. Moore E. Ray U. Schmidt A. Engel M. Mueller Centre for Atmospheric Science, Department of Chemistry, Cambridge University, Cambridge CB2 1EW, UK NCAS-ACMSU, Department of Chemistry, Cambridge University, Cambridge CB2 1EW, UK Swedish Institute of Space Physics (IRF), Kiruna Division, Box 812, SE-981 28 Kiruna, Sweden Program in Atmospheric and Oceanic Sciences, 311 UCB, University of Colorado, Boulder, CO 80309-0311, USA Department of Atmospheric Science, University of Wyoming, P.O. Box 3038, Laramie, WY 82071, USA Service d’Aeronomie, CNRS, Verrières le Buisson, France Climate Monitoring and Diagnostics Laboratory, NOAA, Boulder, Colorado University of Frankfurt, Germany Balloon-borne measurements of CFC-11 (on flights of the DIRAC <I>in&nbsp;situ</I> gas chromatograph and the DESCARTES grab sampler), ClO and O<sub>3</sub> were made during the 1999/2000 winter as part of the SOLVE-THESEO 2000 campaign. Here we present the CFC-11 data from nine flights and compare them first with data from other instruments which flew during the campaign and then with the vertical distributions calculated by the SLIMCAT 3-D CTM. We calculate ozone loss inside the Arctic vortex between late January and early March using the relation between CFC-11 and O<sub>3</sub> measured on the flights, the peak ozone loss (1200 ppbv) occurs in the 440&ndash;470 K region in early March in reasonable agreement with other published empirical estimates. There is also a good agreement between ozone losses derived from three independent balloon tracer data sets used here. The magnitude and vertical distribution of the loss derived from the measurements is in good agreement with the loss calculated from SLIMCAT over Kiruna for the same days.