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Abstract

The chemically induced ozone loss inside the Arctic vortex during the winter 2002/03 is currently quantified by an ozonesonde Match campaign. With this technique chemical depletion can be separated from dynamical effects through co-ordinated launches of over 500 ozonesondes from about 25 stations in the high and mid latitudes. During campaigns in former winters higher loss rates than can be explained by models have been found in cold Arctic Januaries. To address this issue we focus on conditions with high solar zenith angles and have started the measurements as early as November, which is the earliest start of a Match campaign ever. Temperatures (T_PSC) low enough for the formation of polar stratospheric clouds (PSC) show up already in the second half of November. The area (A_PSC) covered by temperatures lower than T_PSC showed record sizes in the beginning and mid of December with respect to the last 22 winters. Although a minor warming influenced the middle and upper stratosphere from mid December the lower stratosphere remained cold until mid January. Preliminary Match analysis suggests increasing ozone loss rates at 475 K, starting during the first 10 days of December and reaching about 5 ppbv / sunlit hour during the last 10 days of December. We will present the results of the whole campaign period in the vertical range 400 K - 550 K potential temperature. This research is part of the EC funded project "Quantitative Understanding of Ozone losses by Bipolar Investigations" (QUOBI).