Midwinter Start to Antarctic Ozone Depletion: Evidence from Observations and Models

Measurements of total ozone at Faraday, Antarctica (65°S), by a visible spectrometer show a winter maximum. This new observation is consistent with the descent of air within the polar vortex during early winter, together with ozone depletion starting in midwinter. Chemical depletion at these latitud...

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Bibliographic Details
Published in:Science
Main Authors: Roscoe, H. K., Jones, A. E., Lee, A. M.
Format: Article in Journal/Newspaper
Language:English
Published: American Association for the Advancement of Science (AAAS) 1997
Subjects:
Online Access:http://dx.doi.org/10.1126/science.278.5335.93
https://syndication.highwire.org/content/doi/10.1126/science.278.5335.93
Description
Summary:Measurements of total ozone at Faraday, Antarctica (65°S), by a visible spectrometer show a winter maximum. This new observation is consistent with the descent of air within the polar vortex during early winter, together with ozone depletion starting in midwinter. Chemical depletion at these latitudes in midwinter is suggested by existing satellite observations of enhanced chlorine monoxide and reduced ozone above 100 hectapascals and by reduced ozone in sonde profiles. New three-dimensional model calculations for 1994 confirm that chemical ozone depletion started in June at the sunlit vortex edge and became substantial by late July. This would not have been observed by most previous techniques, which either could not operate in winter or were closer to the Pole.