Antarctic ozone scenario As of 27 July, the winter polar vortex at Rothera, Halley and Vernadsky/Faraday stations was in place with high ozone values, exceeding 400 DU in places outside the vortex. Inside the vortex, ozone values were around 250 DU. Owing to the cold temperature of the ozone layer, stratospheric clouds have formed. Some areas of Antarctica saw ozone values down to ozone hole levels (less than 220 DU) in mid-June, suggesting the possibility of early chemical depletion, combined with some dynamic processes. In mid-July the minimum temperature of the Antarctic stratosphere at 70 and 50 hectopascal (hPa) was near the normal, although that at 30 hPa was below the normal, suggesting the likelihood of another strong ozone hole year. Source: www.antarctica.ac.uk New clues to ozone depletion Large quantities of ozone-depleting chemicals have been discovered in the Antarctic atmosphere by researchers from the University of Leeds, the University of East Anglia and the British Antarctic Survey. The atmospheric chemists carried out an 18-month study of the make-up of the lowest part of the earth’s atmosphere on the Brunt Ice Shelf, about 20 km from the Weddell Sea. They found high concentrations of halogens – bromine and iodine oxides – which persist throughout the period when there is sunlight in Antarctica (August through May). Using hi-tech equipment, a beam of light was projected across the ice shelf and the spectrum of the reflected light analysed and chemical levels measured. The work was carried out in a new atmospheric observatory at Halley Station, operated by the British Antarctic Survey, and was supported by funding from the United Kingdom’s Natural Environment Research Council. An unexpected finding was the large quantities of iodine oxide, since this chemical has not been detected in the Arctic. The iodine oxides form tiny particles (a few nanometres in size) which can grow to form ice clouds, with a consequent impact on the local climate. Recent satellite observations by one of the team, Dr. Alfonso Saiz-Lopez, have affirmed that iodine oxides are widespread throughout coastal Antarctica. Source: www.sciencedaily.com