• Andrews, D. G., J. R. Holton, and C. B. Leovy, 1987: Middle Atmosphere Dynamics. Academic Press, 489 pp.

  • Baldwin, M. P., and T. J. Dunkerton, 1989: The stratospheric major warming of early December 1987. J. Atmos. Sci., 46, 28632884.

  • Birner, T., and P. D. Williams, 2008: Sudden stratospheric warmings as noise-induced transitions. J. Atmos. Sci., 65, 33373343.

  • Chao, W. C., 1985: Sudden stratospheric warmings as catastrophes. J. Atmos. Sci., 42, 16311646.

  • Charlton, A. J., and L. M. Polvani, 2007: A new look at stratospheric sudden warmings. Part I: Climatology and modeling benchmarks. J. Climate, 20, 449469; Corrigendum, 24, 5951.

    • Search Google Scholar
    • Export Citation
  • Christiansen, B., 2000: Chaos, quasiperiodicity, and interannual veriability: Studies of a stratospheric vacillation model. J. Atmos. Sci., 57, 31613173.

    • Search Google Scholar
    • Export Citation
  • Geisler, J. E., 1974: A numerical model of the sudden stratospheric warming mechanism. J. Geophys. Res., 79, 49894999.

  • Hardiman, S. C., and P. H. Haynes, 2008: Dynamical sensitivity of the stratospheric circulation and downward influence of upper level perturbations. J. Geophys. Res., 113, D23103, doi:10.1029/2008JD010168.

    • Search Google Scholar
    • Export Citation
  • Harnik, N., 2009: Observed stratospheric downward reflection and its relation to upward pulses of wave activity. J. Geophys. Res., 114, D08120, doi:10.1029/2008JD010493.

    • Search Google Scholar
    • Export Citation
  • Held, I. M., 2005: The gap between simulation and understanding in climate modeling. Bull. Amer. Meteor. Soc., 86, 16091614.

  • Holton, J. R., 1976: A semi-spectral numerical model for wave-mean flow interactions in the stratosphere: Application to sudden stratospheric warmings. J. Atmos. Sci., 33, 16391649.

    • Search Google Scholar
    • Export Citation
  • Holton, J. R., and C. Mass, 1976: Stratospheric vacillation cycles. J. Atmos. Sci., 33, 22182225.

  • Kuroda, Y., 2002: Relationship between the polar-night jet oscillation and the annular mode. Geophys. Res. Lett., 29, 1240, doi:10.1029/2001GL013933.

    • Search Google Scholar
    • Export Citation
  • Martius, O., L. M. Polvani, and H. C. Davies, 2009: Blocking precursors to stratospheric sudden warming events. Geophys. Res. Lett., 36, L14806, doi:10.1029/2009GL038776.

    • Search Google Scholar
    • Export Citation
  • Matsuno, T., 1971: A dynamical model of the sudden stratospheric warming. J. Atmos. Sci., 28, 14791494.

  • Newman, P. A., and E. R. Nash, 2000: Quantifying the wave driving of the stratosphere. J. Geophys. Res., 105, 12 48512 497.

  • Newman, P. A., E. R. Nash, and J. Rosenfield, 2001: What controls the temperature of the Arctic stratosphere during the spring? J. Geophys. Res., 106, 19 99920 010.

    • Search Google Scholar
    • Export Citation
  • Plumb, R. A., and K. Semeniuk, 2003: Downward migration of extratropical zonal wind anomalies. J. Geophys. Res., 108, 4223, doi:10.1029/2002JD002773.

    • Search Google Scholar
    • Export Citation
  • Polvani, L. M., and D. W. Waugh, 2004: Upward wave activity flux as a precursor to extreme stratospheric events and subsequent anomalous surface weather regimes. J. Climate, 17, 35483554.

    • Search Google Scholar
    • Export Citation
  • Randel, W. J., D. E. Stevens, and J. L. Stanford, 1987: A study of planetary waves in the southern winter troposphere and stratosphere. Part II: Life cycles. J. Atmos. Sci., 44, 936949.

    • Search Google Scholar
    • Export Citation
  • Ruzmaikin, A., J. Lawrence, and C. Cadavid, 2003: A simple model of stratospheric dynamics including solar variability. J. Climate, 16, 15931600.

    • Search Google Scholar
    • Export Citation
  • Scherhag, R., 1952: Die explosionsartigen Stratosphärenerwärmungen des Spätwinters 1951–52. Ber. Dtsch. Wetterdienstes, 6, 5163.

    • Search Google Scholar
    • Export Citation
  • Scott, R. K., and L. M. Polvani, 2004: Stratospheric control of upward wave flux near the tropopause. Geophys. Res. Lett., 31, L02115, doi:10.1029/2003GL017965.

    • Search Google Scholar
    • Export Citation
  • Scott, R. K., and L. M. Polvani, 2006: Internal variability of the winter stratosphere. Part I: Time-independent forcing. J. Atmos. Sci., 63, 27582776.

    • Search Google Scholar
    • Export Citation
  • Scott, R. K., L. M. Polvani, and D. W. Waugh, 2008: Internal variability of the winter stratosphere. Part II: Time-dependent forcing. J. Atmos. Sci., 65, 23752388.

    • Search Google Scholar
    • Export Citation
  • Sjoberg, J. P., 2010: Low-order models of sudden stratospheric warmings. M.S. thesis, Department of Atmospheric Science, Colorado State University, 89 pp.

  • Yoden, S., 1987: Bifurcation properties of a stratospheric vacillation model. J. Atmos. Sci., 44, 17231733.

All Time Past Year Past 30 Days
Abstract Views 0 0 0
Full Text Views 135 91 3
PDF Downloads 70 42 2

Transient Tropospheric Forcing of Sudden Stratospheric Warmings

View More View Less
  • 1 Colorado State University, Fort Collins, Colorado
Restricted access

Abstract

The amplitude of upward-propagating tropospherically forced planetary waves is known to be of first-order importance in producing sudden stratospheric warmings (SSWs). This forcing amplitude is observed to undergo strong temporal fluctuations. Characteristics of the resulting transient forcing leading to SSWs are studied in reanalysis data and in highly truncated simple models of stratospheric wave–mean flow interaction. It is found in both the reanalysis data and the simple models that SSWs are preferentially generated by transient forcing of sufficiently long time scales (on the order of 1 week or longer). The time scale of the transient forcing is found to play a stronger role in producing SSWs than the strength of the forcing. In the simple models it is possible to fix the amplitude of the tropospheric forcing but to vary the time scale of the forcing. The resulting frequency of occurrence of SSWs shows dramatic reductions for decreasing forcing time scales.

Corresponding author address: Jeremiah P. Sjoberg, Colorado State University, 1371 Campus Delivery, Fort Collins, CO 80521. E-mail: jeremiah@atmos.colostate.edu

Abstract

The amplitude of upward-propagating tropospherically forced planetary waves is known to be of first-order importance in producing sudden stratospheric warmings (SSWs). This forcing amplitude is observed to undergo strong temporal fluctuations. Characteristics of the resulting transient forcing leading to SSWs are studied in reanalysis data and in highly truncated simple models of stratospheric wave–mean flow interaction. It is found in both the reanalysis data and the simple models that SSWs are preferentially generated by transient forcing of sufficiently long time scales (on the order of 1 week or longer). The time scale of the transient forcing is found to play a stronger role in producing SSWs than the strength of the forcing. In the simple models it is possible to fix the amplitude of the tropospheric forcing but to vary the time scale of the forcing. The resulting frequency of occurrence of SSWs shows dramatic reductions for decreasing forcing time scales.

Corresponding author address: Jeremiah P. Sjoberg, Colorado State University, 1371 Campus Delivery, Fort Collins, CO 80521. E-mail: jeremiah@atmos.colostate.edu
Save