1Japan Meteorological Agency, Aerological Observatory, Tsukuba, Ibaraki, 305-0052, Japan
2Cooperative Institute for Research in Environmental Sciences, University of Colorado, Boulder Colorado, USA
3NOAA/OAR/ESRL Climate Monitoring Division, 325 Broadway, Boulder, Colorado, USA
4NOAA/NWS/NCEP/Climate Prediction Center, College Park, MD, USA
5Wyle ST&E, Houston, TX, USA
6NorthWest Research Associates, Socorro, NM, USA
7New Mexico Institute of Mining and Technology, Socorro, NM, USA
8Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA, USA
Received: 09 Nov 2012 – Discussion started: 07 Jan 2013
Abstract. Analyses of stratospheric ozone data determined from Dobson–Umkehr measurements since 1977 at the Syowa (69.0° S, 39.6° E), Antarctica, station show a significant decrease in ozone at altitudes higher than that of the 4 hPa pressure level during the 1980s and 1990s. Ozone values over Syowa have remained low since 2001. The time series of upper stratospheric ozone from the homogenized NOAA SBUV (Solar Backscatter Ultraviolet Instrument)(/2) 8.6 overpass data (±4°, 24 h) are in qualitative agreement with those from the Syowa station data. Ozone recovery during the austral spring over the Syowa station appears to be slower than predicted by the equivalent effective stratospheric chlorine (EESC) curve. The long-term changes in the station's equivalent latitude (indicative of vortex size/position in winter and spring) are derived from MERRA (Modern Era Retrospective-analysis for Research and Applications) reanalyses at ~ 2 and ~ 50 hPa. These data are used to attribute some of the upper and middle stratospheric ozone changes to the changes in vortex position relative to the station's location. In addition, high correlation of the Southern Hemisphere annular mode (SAM) with polar upper stratospheric ozone during years of maximum solar activity points toward a strong relationship between the strength of the Brewer–Dobson circulation and the polar stratospheric ozone recovery. In the lower stratosphere, ozone recovery attributable to CFCs (chlorofluorocarbons) is still not definitive, whereas the recovery of the upper stratosphere is slower than predicted. Further research indicates that dynamical and other chemical changes in the atmosphere are delaying detection of recovery over this station.
Revised: 12 Feb 2014 – Accepted: 28 Feb 2014 – Published: 17 Apr 2014
Miyagawa, K., Petropavlovskikh, I., Evans, R. D., Long, C., Wild, J., Manney, G. L., and Daffer, W. H.: Long-term changes in the upper stratospheric ozone at Syowa, Antarctica, Atmos. Chem. Phys., 14, 3945-3968, doi:10.5194/acp-14-3945-2014, 2014.