INVESTIGATION OF THE STATE OF THE OZONE LAYER IN THE WINTER AND SPRING OF 2000 USING BALLOON AND SURFACE OBSERVATIONS IN SIBERIA

V. A. Yushkov, H. Nakane, N. D. Tsvetkova, V. M. Dorokhov, V. I. Sitnikova, and A. N. Luk'yanov

Data of high-accuracy observations of total ozone and balloon ozone soundings at stations of Salekhard and Yakutsk are analyzed for the winter and spring of 2000. A brief description is given of the meteorological situation in the stratosphere at that period. The deficit of total ozone at these stations in February and March 2000 was 10—15% of the climatic norm. Estimates of the rate of chemical ozone destruction in the stratospheric cyclone are given for the 475 K potential temperature surface (18—19 km); they reach ~1% per day for February and March 2000. The total spring—winter reduction of the ozone mixing ratio at the indicated level due to chemical destruction was 2.1 ± 0.5 ppmv, or 60% of the cyclone averaged value at the beginning of January. This ozone deficiency was the largest in the entire period of balloon observations in Siberia since 1995.