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GEOPHYSICAL RESEARCH LETTERS, VOL. 32, L03S11, doi:10.1029/2004GL021521, 2005

Observations of mesospheric ozone depletion during the October 28, 2003 solar proton event by OSIRIS

D. A. Degenstein

Institute of Space and Atmospheric Studies, Department of Physics and Engineering Physics, University of Saskatchewan, Saskatoon, Saskatchewan, Canada


N. D. Lloyd

Institute of Space and Atmospheric Studies, Department of Physics and Engineering Physics, University of Saskatchewan, Saskatoon, Saskatchewan, Canada


A. E. Bourassa

Institute of Space and Atmospheric Studies, Department of Physics and Engineering Physics, University of Saskatchewan, Saskatoon, Saskatchewan, Canada


R. L. Gattinger

Institute of Space and Atmospheric Studies, Department of Physics and Engineering Physics, University of Saskatchewan, Saskatoon, Saskatchewan, Canada


E. J. Llewellyn

Institute of Space and Atmospheric Studies, Department of Physics and Engineering Physics, University of Saskatchewan, Saskatoon, Saskatchewan, Canada


Abstract

One of the largest solar proton events in the past thirty years took place on October 28, 2003 and had a significant impact on the Earth's middle atmosphere. The incoming protons produce significant amounts of HOx constituents in the mesosphere and upper stratosphere that lead to ozone depletion. For 11 hours during the solar proton event the OSIRIS instrument on Odin measured high spatial resolution profiles of the oxygen infrared atmospheric band at 1.26 microns which under sunlit conditions can be used as a direct proxy for ozone. Ozone depletion is observed across the southern polar cap for the duration of the observations and extends to latitudes as far north as 45°S. OSIRIS observed significant ozone depletion between 50 and 80 km with a maximum value of 75% around 65 km. The actual maximum depletion could have been even greater as observations ceased while the depletion was still increasing.

Received 15 September 2004; accepted 5 November 2004; published 13 January 2005.

Index Terms: 0310 Atmospheric Composition and Structure: Airglow and aurora; 0340 Atmospheric Composition and Structure: Middle atmosphere: composition and chemistry; 0342 Atmospheric Composition and Structure: Middle atmosphere: energy deposition (3334).

Subscriber Access to Full Article (Nonsubscribers may purchase for $9.00, Includes print PDF, file size: 1320305 bytes)

Citation: Degenstein, D. A., N. D. Lloyd, A. E. Bourassa, R. L. Gattinger, and E. J. Llewellyn (2005), Observations of mesospheric ozone depletion during the October 28, 2003 solar proton event by OSIRIS, Geophys. Res. Lett., 32, L03S11, doi:10.1029/2004GL021521.