RAPID VARIATIONS OF OZONE ALTITUDE PROFILE OBSERVED WITH THE TUNABLE DIODE LASER HETERODYNE SPECTROMETER AT SYOWA STATION IN 1994

摘要

With the improved tunable diode laser heterodyne spectrometer (TDLHS-3), we observed stratospheric ozone, nitrous oxide, methane and nitric acid at Syowa Station (69.0′S, 39.6′E) from August 1994 to January 1995. From the analysis of observed ozone and nitrous oxide spectra, their altitude profiles in the lower to middle stratosphere were retrieved with a time resolution of 10min. On September 26 and October 14,1994,rapid variations of ozone altitude profiles were obtained. To investigate the causes of these rapid variations, we made potential vorticity maps over the Antarctic using objective data provided by the Japan Meteorological Agency. Such maps clearly showed that the polar vortex had fine structures, and that the rapid variations of ozone were caused by the wavy structures of the polar vortex. Especially, when Syowa Station was located almost just under the polar vortex boundary on October 14,1994,an eastward-moving wavy structure with a wavelength of about 1000km passed above Syowa Station, moving very fast (40-50m/s wave propagation velocity). On September 26,a similar wavy structure was seen near Syowa Station, though the polar vortex was still covering the entire Antarctic. The observed rapid ozone variations on this day could be due to penetration of air from outside of the polar vortex to inside.