North Atlantic Oscillation modulates total ozone winter trends

The North Atlantic Oscillation (NAO) is modulating the Earth's ozone shield such that the calculated anthropogenic total ozone decrease is enhanced over Europe whereas over the North Atlantic region it is reduced (for the last 30 years). Including the NAO in a statistical model suggests a more uniform chemical winter trend compared to the strong longitudinal variation reported earlier. At Arosa (Switzerland) the trend is reduced to −2.4% per decade compared to −3.2% and at Reykjavik (Iceland) it is enhanced to −3.8% compared to 0%. The revised trend is slightly below the predictions by 2D chemical models. Decadal ozone variability is linked to variations in the dynamical structure of the atmosphere, as reflected in the tropopause pressure. The latter varies in concert with the NAO index with a distinct geographical pattern.

[1]  L. Hood,et al.  Lower stratospheric stationary waves and the longitude dependence of ozone trends in winter , 1995 .

[2]  Siegfried Schubert,et al.  An Analysis of Tropopause Pressure and Total Ozone Correlations , 1987 .

[3]  Johannes Staehelin,et al.  Total ozone series at Arosa (Switzerland): Homogenization and data comparison , 1998 .

[4]  J. Ziemke,et al.  Dynamical proxies of column ozone with applications to global trend models , 1997 .

[5]  R. Stolarski,et al.  Measured Trends in Stratospheric Ozone , 1992, Science.

[6]  C. Appenzeller,et al.  Fragmentation of stratospheric intrusions , 1996 .

[7]  J. Hansen,et al.  Stratospheric aerosol optical depths, 1850–1990 , 1993 .

[8]  J. Hurrell.  Influence of variations in extratropical wintertime teleconnections on northern hemisphere temperature , 1996 .

[9]  J. Hurrell.  Decadal Trends in the North Atlantic Oscillation: Regional Temperatures and Precipitation , 1995, Science.

[10]  J. D. Price,et al.  On the relation between total ozone and meteorology , 1991 .

[11]  James B. Kerr,et al.  Trends in stratospheric and free tropospheric ozone , 1997 .

[12]  J. Wallace,et al.  The Arctic oscillation signature in the wintertime geopotential height and temperature fields , 1998 .

[13]  Ozonanomalie über der Nordatlantik-Europa Region im Januar: Längenabhängige dekadische Änderung des Gesamtozons während 1979-1992 , 1996 .

[14]  Johannes Staehelin,et al.  Trend analysis of the homogenized total ozone series of Arosa (Switzerland), 1926–1996 , 1998 .

[15]  J. Perlwitz,et al.  The statistical connection between tropospheric and stratospheric circulation of the northern hemisphere in winter , 1995 .

[16]  R. Reynolds,et al.  The NCEP/NCAR 40-Year Reanalysis Project , 1996, Renewable Energy.

[17]  S. Chandra,et al.  Past, present, and future modeled ozone trends with comparisons to observed trends , 1996 .

[18]  John M. Wallace,et al.  Annular Modes in the Extratropical Circulation. Part II: Trends , 2000 .

[19]  J. Wallace,et al.  Teleconnections in the Geopotential Height Field during the Northern Hemisphere Winter , 1981 .

[20]  Wolfgang Steinbrecht,et al.  Correlations between tropopause height and total ozone: Implications for long‐term changes , 1998 .