Articles | Volume 14, issue 8
Atmos. Chem. Phys., 14, 3945–3968, 2014

Special issue: Changes in the vertical distribution of ozone – the SI2N report...

Atmos. Chem. Phys., 14, 3945–3968, 2014

Research article 17 Apr 2014

Research article | 17 Apr 2014

Long-term changes in the upper stratospheric ozone at Syowa, Antarctica

K. Miyagawa1, I. Petropavlovskikh2, R. D. Evans3, C. Long4, J. Wild4,5, G. L. Manney6,7, and W. H. Daffer8 K. Miyagawa et al.
  • 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

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.

Final-revised paper