Ozone variation in the southern polar stratosphere

• Main Authors: Hartwig Gernandt, Andreas Herber, Peter Von der Gathen, Susumu Kaneto
• Format: Report
• Language: English
• Published: Alfred Wegener Institute for Polar and Marine Research, Research Unit Potsdam 1998
• Subjects: Arctic; Antarctic; Antarc*; Memoirs of National Institute of Polar Research; Polar Research
• Online Access: https://nipr.repo.nii.ac.jp/?action=repository_uri&item_id=2314; http://id.nii.ac.jp/1291/00002314/; https://nipr.repo.nii.ac.jp/?action=repository_action_common_download&item_id=2314&item_no=1&attribute_id=18&file_no=1

The objective of this study is to discuss the altitude dependent interannual variability of ozone inside the southern polar stratospheric vortex during spring. Trend of ozone mixing ratio as well as possible correlation to global forcing processes, and transient perturbations by volcanic aerosols are obtained by using balloon-borne ozone sonde data obtained at three Antarctic stations located at about 70°S between 30°E and 08°W. For the period 1966 to 1995 negative trend in ozone mixing ratio is statistically significant with 99% confidence between the 330K and 670K isentropic level. For the period 1985 to 1995 significant negative trends are recognized in three altitude ranges during spring. The interannual variability of ozone in the middle polar stratosphere is strongly affected by the El Nino Southern Oscillation (ENSO). For the period from 1985 to 1988 the pattern of year to year changes might be explained by a synergetic effect of ENSO and Quasi Biennial Oscillation of winds in the tropical stratosphere. Inside the polar vortex the impact of volcanic aerosols on vertical ozone distribution shows a similar altitude dependency as found for mid-latitudes but downward displaced by about 5km in altitude. In the lowest part of the polar stratosphere ozone is additionally removed when volcanic aerosol loading is extremely high. The intercomparison of balloon-borne ozone observations from Arctic and Antarctic stations shows significant differences in the recent mean annual pattern but also similarities in the seasonal behaviour.