A QUALITATIVE ASSESSMENT OF HEIGHT DEPENDENT INTERANNUAL VARIABILITY OF POLAR STRATOSPHERIC OZONE PART I : LONG-TERM VARIABILITY AND STRATOSPHERIC OZONE DEPLETION

Until now continuous balloon-borne observations of vertical ozone distributions in the Antarctic stratosphere for all seasons of a year do not well cover one solar cycle. Thus, long-term ozone variations in vertical and interannual patterns caused by dynamic and chemical processes of different scales cannot be analyzed by consistent data sets. Most regular Antarctic observations have been made for the months September and October since the beginning of ozone soundings at Syowa Station in 1966. An attempt is presented to assess long-term ozone variations by using monthly mean ozone data obtained at Syowa Station and additional data from Georg Forster Station and Neumayer Station. These ozone data together with monthly means of potential temperature and their standard deviations as observed at Syowa Station, as well as the monthly means of the QBO phase as observed at 10 hPa altitude in tropical latitudes, are used to discuss the long-term control of polar stratospheric ozone by atmospheric dynamics. Signals of the tropical QBO-phase can be found in polar stratospheric ozone variations at altitudes above the 20 hPa isobaric surface. It is suggested that inside the polar vortex chemically caused ozone reductions at 70 hPa are also controlled by dynamic processes. Significant impacts of volcanic aerosols on stratospheric ozone dominate at 150 hPa pressure level, showing additional severe ozone depletion