Atmos. Chem. Phys. Discuss., 10, 8623-8655, 2010
© Author(s) 2010. This work is distributed
under the Creative Commons Attribution 3.0 License.
Review Status
This discussion paper has been under review for the journal Atmospheric Chemistry and Physics (ACP). Please refer to the corresponding final paper in ACP.
Analysis of HCl and ClO time series in the upper stratosphere using satellite data sets
A. Jones1, J. Urban2, D. P. Murtagh2, C. Sanchez2, K. A. Walker1, L. Livesay3, L. Froidevaux3, and M. Santee3
1Department of Physics, Univ. of Toronto, Toronto, Canada
2Department of Radio and Space Science, Chalmers Univ. of Technology, Gothenburg, Sweden
3Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA, USA

Abstract. Previous analyses of satellite and ground-based measurements of hydrogen chloride (HCl) and chlorine monoxide (ClO) have suggested that total inorganic chlorine in the upper stratosphere is on the decline. We create HCl and ClO time series using satellite data sets with the intension of extending them to beyond November 2008 so that an update can be made on the long term evolution of these two species. We use the HALogen Occultation Experiment (HALOE) and the Atmospheric Chemistry Experiment Fourier Transform Spectrometer (ACE-FTS) data for the HCl analysis, and the Odin Sub-Millimetre Radiometer (SMR) and the Aura Microwave Limb Sounder (Aura-MLS) measurements for the study of ClO. Altitudes between 35 and 45 km and three latitude bands between 60° S–60° N for HCl, and 20° S–20° N for ClO are studied. HCl shows values to be reducing from peak 1997 values by −4.4% in the tropics and between −6.4% to −6.7% per decade in the mid-latitudes. Trend values are significantly different from a zero trend at the 2 sigma level. ClO is decreasing in the tropics by −7.1% ± 7.8%/decade based on measurements made from December 2001. As both of these species contribute most to the chlorine budget at these altitudes then HCl and ClO should decrease at similar rates. The results found here confirm how effective the 1987 Montreal protocol objectives and its amendments have been in reducing the total amount of inorganic chlorine.

Citation: Jones, A., Urban, J., Murtagh, D. P., Sanchez, C., Walker, K. A., Livesay, L., Froidevaux, L., and Santee, M.: Analysis of HCl and ClO time series in the upper stratosphere using satellite data sets, Atmos. Chem. Phys. Discuss., 10, 8623-8655, doi:10.5194/acpd-10-8623-2010, 2010.
Search ACPD
Discussion Paper
    Final Revised Paper