Ozone depletion studied in the Antarctic

London -- British scientists have found naturally occurring chemicals in the Antarctic atmosphere deplete most of that atmosphere's ozone from August through May.

The 18-month collaborative study involving the British Antarctic Survey, the University of Leeds and the University of East Anglia was conducted on the Brunt Ice Shelf, 12 miles from the Weddell Sea.

In the atmosphere above the ice shelf, researchers found surprisingly high concentrations of bromine and iodine oxides. Both chemicals remove ozone from the atmosphere.

The bromine is naturally produced by sea salt and the iodine by algae forming on the underside of sea ice, the scientists said. Since ozone helps remove harmful compounds from the atmosphere, ozone depletion harms the atmosphere's ability to clean itself and might contribute to climate change.

The research was conducted at a new atmospheric observatory operated by the British Antarctic Survey and was supported by funding from Britain's Natural Environment Research Council.

The scientists, who reported the study in the journal Science, plan to assess what impact the chemicals have on the local environment.

Copyright 2007 by United Press International.