ACP Atmospheric Chemistry and Physics ACP 1680-7324 Copernicus GmbH Göttingen, Germany 10.5194/acp-8-6199-2008 Validation of ACE-FTS v2.2 measurements of HCl, HF, CCl<sub>3</sub>F and CCl<sub>2</sub>F<sub>2</sub> using space-, balloon- and ground-based instrument observations Mahieu E. 1 Duchatelet P. 1 Demoulin P. 1 Walker K. A. 2 3 Dupuy E. 3 Froidevaux L. 4 Randall C. 5 Catoire V. 6 Strong K. 2 Boone C. D. 3 Bernath P. F. 7 Blavier J.-F. 4 Blumenstock T. 8 Coffey M. 9 De Mazière M. 10 Griffith D. 11 Hannigan J. 9 Hase F. 8 Jones N. 11 Jucks K. W. 12 Kagawa A. 13 Kasai Y. 13 Mebarki Y. 6 Mikuteit S. 8 Nassar R. 14 Notholt J. 15 Rinsland C. P. 16 Robert C. 6 Schrems O. 17 Senten C. 10 Smale D. 18 Taylor J. 2 Tétard C. 19 Toon G. C. 4 Warneke T. 15 Wood S. W. 18 Zander R. 1 Servais C. 1 Groupe Infra-Rouge de Physique Atmosphérique et Solaire (GIRPAS), Institute of Astrophysics and Geophysics, University of Liège, Liège, Belgium Department of Physics, University of Toronto, 60 St. George Street, Toronto, Ontario, M5S 1A7, Canada Department of Chemistry, University of Waterloo, 200 University Avenue West, Waterloo, Ontario, N2L 3G1, Canada Jet Propulsion Laboratory, California Institute of Technology , Pasadena, CA, USA University of Colorado, CO, USA Lab. de Physique et Chimie de l'Environnement, CNRS – Univ. d'Orléans (UMR 6115), 45071 Orléans Cedex 2, France Department of Chemistry, University of York, Heslington, York, YO10 5DD, UK Institute for Meterorology and Climate Research (IMK), Forschungszentrum Karlsruhe and University of Karlsruhe, Karlsruhe, Germany National Center for Atmospheric Research, CO, USA Belgian Institute for Space Aeronomy, Brussels, Belgium University of Wollongong, Australia Harvard-Smithsonian Center for Astrophysics, Cambridge, MA, USA National Institute of Communications and Information Technology, 4-2-1 Nukui-kita, Koganei, Tokyo 184-8795, Japan Harvard University, Cambridge, MA, USA Institute of Environmental Physics, University of Bremen, Germany Langley Research Center, VA, USA Alfred Wegener Insitute for Polar and Marine Research, Bremerhaven, Germany National Institute of Water and Atmospheric Research Ltd, Lauder,Central Otago, New Zealand Laboratoire d'Optique Atmosphérique, Université des sciences et technologies de Lille (UMR 8518), 59655 Villeneuve d'Ascq, France 27 10 2008 8 20 6199 6221 This is an open-access article ditributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. This article is available from http://www.atmos-chem-phys.net/8/6199/2008/acp-8-6199-2008.html The full text article is available as a PDF file from http://www.atmos-chem-phys.net/8/6199/2008/acp-8-6199-2008.pdf

Hydrogen chloride (HCl) and hydrogen fluoride (HF) are respectively the main chlorine and fluorine reservoirs in the Earth's stratosphere. Their buildup resulted from the intensive use of man-made halogenated source gases, in particular CFC-11 (CCl<sub>3</sub>F) and CFC-12 (CCl<sub>2</sub>F<sub>2</sub>), during the second half of the 20th century. It is important to continue monitoring the evolution of these source gases and reservoirs, in support of the Montreal Protocol and also indirectly of the Kyoto Protocol. The Atmospheric Chemistry Experiment Fourier Transform Spectrometer (ACE-FTS) is a space-based instrument that has been performing regular solar occultation measurements of over 30 atmospheric gases since early 2004. In this validation paper, the HCl, HF, CFC-11 and CFC-12 version 2.2 profile data products retrieved from ACE-FTS measurements are evaluated. Volume mixing ratio profiles have been compared to observations made from space by MLS and HALOE, and from stratospheric balloons by SPIRALE, FIRS-2 and Mark-IV. Partial columns derived from the ACE-FTS data were also compared to column measurements from ground-based Fourier transform instruments operated at 12 sites. ACE-FTS data recorded from March 2004 to August 2007 have been used for the comparisons. These data are representative of a variety of atmospheric and chemical situations, with sounded air masses extending from the winter vortex to summer sub-tropical conditions. Typically, the ACE-FTS products are available in the 10–50 km altitude range for HCl and HF, and in the 7–20 and 7–25 km ranges for CFC-11 and -12, respectively. For both reservoirs, comparison results indicate an agreement generally better than 5–10% above 20 km altitude, when accounting for the known offset affecting HALOE measurements of HCl and HF. Larger positive differences are however found for comparisons with single profiles from FIRS-2 and SPIRALE. For CFCs, the few coincident measurements available suggest that the differences probably remain within &plusmn;20%.

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