• Archer, C. L., and K. Caldeira, 2008: Historical trends in the jet streams. Geophys. Res. Lett., 35, L08803, doi:10.1029/2008GL033614.

  • Baldwin, M. P., and T. J. Dunkerton, 2001: Stratospheric harbingers of anomalous weather regimes. Science, 244, 581584.

  • Baldwin, M. P., T. Hirooka, A. O’Neill, S. Yoden, A. J. Charlton, Y. Hio, W. A. Lahoz, and A. Mori, 2003a: Major stratospheric warming in the Southern Hemisphere in 2002: Dynamical aspects of the ozone hole split. SPARC Newsletter, No. 20, SPARC Office, Toronto, ON, Canada, 24–26.

  • Baldwin, M. P., D. B. Stephenson, D. W. J. Thompson, T. J. Dunkerton, A. J. Charlton, and A. O’Neill, 2003b: Stratospheric memory and skill of extended-range weather forecasts. Science, 301, 636640.

    • Search Google Scholar
    • Export Citation
  • Black, R. X., and B. A. McDaniel, 2007a: The dynamics of Northern Hemisphere stratospheric final warming events. J. Atmos. Sci., 64, 29322946.

    • Search Google Scholar
    • Export Citation
  • Black, R. X., and B. A. McDaniel, 2007b: Interannual variability in the Southern Hemisphere circulation organized by stratospheric final warming events. J. Atmos. Sci., 64, 29682974.

    • Search Google Scholar
    • Export Citation
  • Black, R. X., B. A. McDaniel, and W. A. Robinson, 2006: Stratosphere–troposphere coupling during spring onset. J. Climate, 19, 48914901.

    • Search Google Scholar
    • Export Citation
  • Fogt, R. L., J. Perlwitz, A. J. Monaghan, D. H. Bromwich, J. M. Jones, and J. G. Marshall, 2009: Historical SAM variability. Part II: Twentieth-century variability and trends from reconstructions, observations, and the IPCC AR4 models. J. Climate, 22, 53465365.

    • Search Google Scholar
    • Export Citation
  • Gerber, E. P., and L. M. Polvani, 2009: Stratosphere–troposphere coupling in a relatively simple AGCM: The importance of stratospheric variability. J. Climate, 22, 19201933.

    • Search Google Scholar
    • Export Citation
  • Gillett, N., and D. W. J. Thompson, 2003: Simulation of recent Southern Hemisphere climate change. Science, 302, 273275.

  • Krüger, K., B. Naujokat, and K. Labitzke, 2005: The unusual midwinter warming in the Southern Hemisphere stratosphere, 2002: A comparison to Northern Hemisphere phenomena. J. Atmos. Sci., 62, 603613.

    • Search Google Scholar
    • Export Citation
  • Kushner, P. J., and L. M. Polvani, 2006: Stratosphere–troposphere coupling in a relatively simple AGCM: Impact of the seasonal cycle. J. Climate, 19, 57215727.

    • Search Google Scholar
    • Export Citation
  • Newman, P. A., and E. R. Nash, 2005: The unusual Southern Hemisphere stratosphere winter of 2002. J. Atmos. Sci., 62, 614628.

  • Polvani, L. M., and P. J. Kushner, 2002: Tropospheric response to stratospheric perturbations in a relatively simple general circulation model. Geophys. Res. Lett., 29, 1114, doi:10.1029/2001GL014284.

    • Search Google Scholar
    • Export Citation
  • Polvani, L. M., D. W. Waugh, G. J. P. Correa, and S.-W. Son, 2011: Stratospheric ozone depletion: The main driver of twentieth-century atmospheric circulation changes in the Southern Hemisphere. J. Climate, 24, 795812.

    • Search Google Scholar
    • Export Citation
  • Thompson, D. W. J., and J. M. Wallace, 2000: Annular modes in the extratropical circulation. Part I: month-to-month variability. J. Climate, 13, 10001016.

    • Search Google Scholar
    • Export Citation
  • Thompson, D. W. J., and S. Solomon, 2002: Interpretation of recent Southern Hemisphere climate change. Science, 296, 895899.

  • Thompson, D. W. J., J. M. Wallace, and G. C. Hegerl, 2000: Annular modes in the extratropical circulation. Part II: Trends. J. Climate, 13, 10181036.

    • Search Google Scholar
    • Export Citation
  • Thompson, D. W. J., M. P. Baldwin, and S. Solomon, 2005: Stratosphere–troposphere coupling in the Southern Hemisphere. J. Atmos. Sci., 62, 708715.

    • Search Google Scholar
    • Export Citation
  • Thompson, D. W. J., S. Solomon, P. J. Kushner, M. H. England, K. M. Grise, and D. J. Karoly, 2011: Signatures of the Antarctic ozone hole in Southern Hemisphere surface climate change. Nat. Geosci., 4, 741749.

    • Search Google Scholar
    • Export Citation
  • Waugh, D. W., W. J. Randel, S. Pawson, P. A. Newman, and E. R. Nash, 1999: Persistence of the lower stratospheric polar vortices. J. Geophys. Res., 104 (D22), 27 19127 202.

    • Search Google Scholar
    • Export Citation
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Can the Delay in Antarctic Polar Vortex Breakup Explain Recent Trends in Surface Westerlies?

Aditi SheshadriDepartment of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts

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R. Alan PlumbDepartment of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts

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Daniela I. V. DomeisenDepartment of Earth and Atmospheric Sciences, Cornell University, Ithaca, New York

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Abstract

The authors test the hypothesis that recent observed trends in surface westerlies in the Southern Hemisphere are directly consequent on observed trends in the timing of stratospheric final warming events. The analysis begins by verifying that final warming events have an impact on tropospheric circulation in a simplified GCM driven by specified equilibrium temperature distributions. Seasonal variations are imposed in the stratosphere only. The model produces qualitatively realistic final warming events whose influence extends down to the surface, much like what has been reported in observational analyses. The authors then go on to study observed trends in surface westerlies composited with respect to the date of final warming events. If the considered hypothesis were correct, these trends would appear to be much weaker when composited with respect to the date of the final warming events. The authors find that this is not the case, and accordingly they conclude that the observed surface changes cannot be attributed simply to this shift toward later final warming events.

Current affiliation: Institute of Oceanography, University of Hamburg, Hamburg, Germany.

Corresponding author address: Aditi Sheshadri, 54-1515, Department of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA 02139. E-mail: aditi_s@mit.edu

Abstract

The authors test the hypothesis that recent observed trends in surface westerlies in the Southern Hemisphere are directly consequent on observed trends in the timing of stratospheric final warming events. The analysis begins by verifying that final warming events have an impact on tropospheric circulation in a simplified GCM driven by specified equilibrium temperature distributions. Seasonal variations are imposed in the stratosphere only. The model produces qualitatively realistic final warming events whose influence extends down to the surface, much like what has been reported in observational analyses. The authors then go on to study observed trends in surface westerlies composited with respect to the date of final warming events. If the considered hypothesis were correct, these trends would appear to be much weaker when composited with respect to the date of the final warming events. The authors find that this is not the case, and accordingly they conclude that the observed surface changes cannot be attributed simply to this shift toward later final warming events.

Current affiliation: Institute of Oceanography, University of Hamburg, Hamburg, Germany.

Corresponding author address: Aditi Sheshadri, 54-1515, Department of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA 02139. E-mail: aditi_s@mit.edu
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