• Allen, D. R., , R. M. Bevilacqua, , G. E. Neboluha, , C. E. Randall, , and G. L. Manney, 2003: Unusual stratospheric transport and mixing during the 2002 Antarctic winter. Geophys. Res. Lett.,30, 1599, doi:10.1029/2003GL017117.

    • Search Google Scholar
    • Export Citation
  • Arai, M., , and H. Mukougawa, 2002: On the effectiveness of the eddy straining mechanism for the maintenance of blocking flows. J. Meteor. Soc. Japan, 80 , 10891102.

    • Search Google Scholar
    • Export Citation
  • Beersma, J. J., , K. M. Rider, , G. J. Komen, , E. Kass, , and V. V. Kharin, 1997: An analysis of extra-tropical storms in the North Atlantic region as simulated in a control and 2 × CO2 times slice experiment with a high resolution atmospheric model. Tellus, 49A , 347361.

    • Search Google Scholar
    • Export Citation
  • Blackmon, M. L., 1976: A climatological spectral study of the 500 mb geopotential height of the Northern Hemisphere. J. Atmos. Sci, 33 , 16071623.

    • Search Google Scholar
    • Export Citation
  • Cai, W., , P. H. Whetton, , and D. J. Karoly, 2003: The response of the Antarctic Oscillation to increasing and stabilized atmospheric CO2. J. Climate, 16 , 15251538.

    • Search Google Scholar
    • Export Citation
  • Carnell, R. E., , and C. A. Senior, 1998: Changes in mid-latitude variability due to increasing greenhouse gases and sulfate aerosols. Climate Dyn, 14 , 369383.

    • Search Google Scholar
    • Export Citation
  • Christoph, M., , U. Ulbrich, , and U. Haak, 1995: Faster determination of the intraseasonal variability of storm tracks using Murakami's recursive filter. Mon. Wea. Rev, 123 , 578581.

    • Search Google Scholar
    • Export Citation
  • Dole, R. M., , and N. D. Gordon, 1983: Persistent anomalies of the extra-tropical Northern Hemisphere wintertime circulation: Geographical distribution and regional persistence characteristics. Mon. Wea. Rev, 111 , 15671586.

    • Search Google Scholar
    • Export Citation
  • ECMWF, cited 1997: The description of the ECMWF Re-analysis Global Atmospheric Data Archive. [Available online at http:// www.ecmwf.int/products/data/archive/index.html.].

    • Search Google Scholar
    • Export Citation
  • Feldstein, S. B., 2002: The recent trend and variance increase of the annular mode. J. Climate, 15 , 8894.

  • Frauenfeld, O. W., , and R. E. Davis, 2003: Northern Hemisphere circumpolar vortex trends and climate change implications. J. Geophys. Res.,108, 4423, doi:10.1029/2002JD002958.

    • Search Google Scholar
    • Export Citation
  • Fyfe, J. C., 2003: Extratropical Southern Hemisphere cyclones: Harbingers of climate change? J. Climate, 16 , 28022805.

  • Fyfe, J. C., , G. J. Boer, , and G. M. Flato, 1999: The Arctic and Antarctic Oscillations and their projected changes under global warming. Geophys. Res. Lett, 26 , 16011604.

    • Search Google Scholar
    • Export Citation
  • Geng, Q., , and M. Sugi, 2003: Possible change of extratropical cyclone activity due to enhanced greenhouse gases and sulfate aerosols— Study with a high-resolution AGCM. J. Climate, 16 , 22622274.

    • Search Google Scholar
    • Export Citation
  • Gillett, N. P., , and M. R. Allen, 2002: The role of stratospheric resolution in simulating the Arctic Oscillation response to greenhouse gases. Geophys. Res. Lett.,29, 1500, doi:10.1029/2001GL014444.

    • Search Google Scholar
    • Export Citation
  • Green, J. S. A., 1977: The weather during July 1976: Some dynamical considerations of the drought. Weather, 32 , 120128.

  • Haines, K., , and J. Marshall, 1987: Eddy-forced coherent structures as a prototype of atmospheric blocking. Quart. J. Roy. Meteor. Soc, 113 , 681704.

    • Search Google Scholar
    • Export Citation
  • Hall, N. M. J., , B. J. Hoskins, , P. J. Valdes, , and C. A. Senior, 1994: Storm tracks in a high resolution GCM with doubled carbon dioxide. Quart. J. Roy. Meteor. Soc, 120 , 12091230.

    • Search Google Scholar
    • Export Citation
  • Hamming, R. W., 1989: Digital filters. Prentice Hall International, 284 pp.

  • Hoppel, K., , R. Bevilacqua, , D. Allen, , G. Neboluha, , and C. Randall, 2003: POAM III observations of the anomalous 2002 Antarctic ozone hole. Geophys. Res. Lett.,30, 1394, doi:10.1029/2003GL016899.

    • Search Google Scholar
    • Export Citation
  • Hoskins, B. J., , and P. D. Sardeshmukh, 1987: A diagnostic study of the dynamics of the Northern Hemisphere winter of 1985–1986. Quart. J. Roy. Meteor. Soc, 113 , 759778.

    • Search Google Scholar
    • Export Citation
  • Hoskins, B. J., , and T. Ambrizzi, 1993: Rossby wave propagation on a realistic longitudinally varying flow. J. Atmos. Sci, 50 , 16611671.

    • Search Google Scholar
    • Export Citation
  • Houghton, J. T., , B. A. Callendar, , and S. K. Varney, Eds.,. 1992: Climate Change 1992: The Supplementary Report to the IPCC Scientific Assessment. Cambridge University Press, 198 pp.

    • Search Google Scholar
    • Export Citation
  • Hu, Z. Z., , L. Bengtsson, , E. Roeckner, , M. Christoph, , A. Bacher, , and J. M. Oberhuber, 2001: Impact of global warming on the interannual and interdecadal climate modes in a coupled GCM. Climate Dyn, 17 , 361374.

    • Search Google Scholar
    • Export Citation
  • Illari, L., 1984: A diagnostic study of the potential vorticity in a warm blocking anticyclone. J. Atmos. Sci, 41 , 35183526.

  • Itoh, H., , and K. I. Harada, 2004: Coupling between tropospheric and stratospheric leading modes. J. Climate, 17 , 320336.

  • Källén, E., 1981: The nonlinear effects of orographic and momentum forcing in a low-order, barotropic model. J. Atmos. Sci, 38 , 21502163.

    • Search Google Scholar
    • Export Citation
  • Källén, E., 1982: Bifurcation properties of quasi-geostrophic, barotropic models and their relations to atmospheric blocking. Tellus, 34 , 255265.

    • Search Google Scholar
    • Export Citation
  • Kalnay, E., and Coauthors, 1996: The NCEP/NCAR 40-Year Reanalysis Project. Bull. Amer. Meteor. Soc, 77 , 437471.

  • Knippertz, P., , U. Ulbrich, , and P. Speth, 2000: Changing cyclones and surface wind speeds over the North Atlantic and Europe in a transient GHG experiment. Climate Res, 15 , 109122.

    • Search Google Scholar
    • Export Citation
  • König, W. R., , R. Sausen, , and F. Sielman, 1993: Objective identification of cyclones in GCM simulations. J. Climate, 6 , 22172231.

  • Kushner, P. J., , I. M. Held, , and T. L. Delworth, 2001: Southern Hemisphere atmospheric circulation response to global warming. J. Climate, 14 , 22382249.

    • Search Google Scholar
    • Export Citation
  • Labitzke, K., 1982: On the interannual variability of the middle stratosphere during northern winters. J. Meteor. Soc. Japan, 60 , 124139.

    • Search Google Scholar
    • Export Citation
  • Lambert, S. J., 1995: The effects of enhanced greenhouse warming on winter cyclone frequencies and strengths. J. Climate, 8 , 14471452.

    • Search Google Scholar
    • Export Citation
  • Lau, K. M., , P. J. Sheu, , and I. S. Kang, 1994: Multiscale low-frequency circulation modes in the global atmosphere. J. Atmos. Sci, 51 , 11691193.

    • Search Google Scholar
    • Export Citation
  • Limpasuvan, V., , and D. L. Hartmann, 1999: Eddies and the annular modes of climate variability. Geophys. Res. Lett, 26 , 31333136.

  • Maeda, S., , C. Kobayashi, , K. Takano, , and T. Tsuyuki, 2000: Relationship between singular modes of blocking and high-frequency eddies. J. Meteor. Soc. Japan, 78 , 631645.

    • Search Google Scholar
    • Export Citation
  • Marshall, G. J., 2003: Trends in the southern annular mode from observations and reanalyses. J. Climate, 16 , 41344143.

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

  • Mo, K. C., , and M. Ghil, 1987: Statistics and dynamics of persistent anomalies. J. Atmos. Sci, 44 , 877901.

  • Mo, K. C., , and J. N. Paegle, 2001: The Pacific–South American modes and their downstream effects. Int. J. Climatol, 21 , 12111229.

  • North, G. R., , T. L. Bell, , R. F. Cahalan, , and F. J. Moeng, 1982: Sampling errors in the estimation of empirical orthogonal functions. Mon. Wea. Rev, 110 , 699706.

    • Search Google Scholar
    • Export Citation
  • Ostermeier, G. M., , and J. M. Wallace, 2003: Trends in the North Atlantic Oscillation–Northern Hemisphere annular mode during the twentieth century. J. Climate, 16 , 336341.

    • Search Google Scholar
    • Export Citation
  • Palmer, T. N., 1999: A nonlinear dynamical perspective on climate prediction. J. Climate, 12 , 575591.

  • Räisänen, J., 2001: CO2-induced climate change in CMIP2 experiments: Quantification of agreement and role of internal variability. J. Climate, 14 , 20882104.

    • Search Google Scholar
    • Export Citation
  • Roeckner, E., , L. Bengtsson, , J. Feichter, , J. Lilieveld, , and H. Rodhe, 1999: Transient climate change simulations with a coupled atmosphere–ocean GCM including the sulfur cycle. J. Climate, 12 , 30043032.

    • Search Google Scholar
    • Export Citation
  • Rogers, J. C., , and H. van Loon, 1982: Spatial variability of sea level pressure and 500-mb height anomalies over the Southern Hemisphere. Mon. Wea. Rev, 110 , 13751392.

    • Search Google Scholar
    • Export Citation
  • Schubert, M. J., , J. Perlwitz, , R. Blender, , K. Fraedrich, , and F. Lunkeit, 1998: North Atlantic cyclones in CO2-induced warm climate simulations: Frequency, intensity, and tracks. Climate Dyn, 14 , 827837.

    • Search Google Scholar
    • Export Citation
  • Shindell, D. T., , R. L. Miller, , G. A. Schmidt, , and L. Pandolfo, 1999: Simulation of recent northern winter climate trends by greenhouse-gas forcing. Nature, 399 , 452455.

    • Search Google Scholar
    • Export Citation
  • Shutts, G. J., 1983: The propagation of eddies in diffluent jetstreams: Eddy vorticity forcing of ‘blocking’ flow fields. Quart. J. Roy. Meteor. Soc, 109 , 737761.

    • Search Google Scholar
    • Export Citation
  • Sinclair, M. R., , and I. G. Watterson, 1999: Objective assessment of extratropical weather systems in simulated climates. J. Climate, 12 , 34673485.

    • Search Google Scholar
    • Export Citation
  • Sinnhüber, M., , M. Weber, , A. Amankwah, , and J. P. Burrows, 2003: Total ozone during the unusual Antarctic winter of 2002. Geophys. Res. Lett.,30, 1580, doi:10.1029/2002GL016798.

    • Search Google Scholar
    • Export Citation
  • Stone, D. A., , A. J. Weaver, , and R. J. Stouffer, 2001: Projection of climate change onto modes of atmospheric variability. J. Climate, 14 , 35513565.

    • 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., , 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
  • Ulbrich, U., , and M. Christoph, 1999: A shift in the NAO and increasing storm track activity over Europe due to anthropogenic greenhouse gas forcing. Climate Dyn, 15 , 551559.

    • Search Google Scholar
    • Export Citation
  • Vautard, R., , and B. Legras, 1988: On the source of midlatitude low-frequency variability. Part II: Nonlinear equilibration of weather regimes. J. Atmos. Sci, 45 , 28452867.

    • Search Google Scholar
    • Export Citation
  • Vautard, R., , B. Legras, , and M. Déqué, 1988: On the source of midlatitude low-frequency variability. Part I: A statistical approach to persistence. J. Atmos. Sci, 45 , 28112844.

    • Search Google Scholar
    • Export Citation
  • Yang, S., , B. Reinhold, , and E. Källén, 1997: Multiple weather regimes and baroclinically forced spherical resonance. J. Atmos. Sci, 54 , 13971409.

    • Search Google Scholar
    • Export Citation
  • Zhang, Y., , and W-C. Wang, 1997: Model-simulated northern winter cyclone and anticyclone activity under a greenhouse warming scenario. J. Climate, 10 , 16161634.

    • Search Google Scholar
    • Export Citation
  • Zorita, E., , and F. González-Rouco, 2000: Disagreement between predictions of the future behavior of the Arctic Oscillation as simulated in two different climate models: Implications for global warming. Geophys. Res. Lett, 27 , 17551758.

    • Search Google Scholar
    • Export Citation
All Time Past Year Past 30 Days
Abstract Views 0 0 0
Full Text Views 15 15 5
PDF Downloads 9 9 6

The Response of the Southern Hemisphere Atmospheric Circulation to an Enhanced Greenhouse Gas Forcing

View More View Less
  • 1 Department of Meteorology, Stockholm University, Stockholm, Sweden
© Get Permissions
Restricted access

Abstract

The response of the atmospheric circulation to an enhanced radiative greenhouse gas forcing is investigated. It has been proposed that the response of the climate system to an enhanced forcing projects directly onto the preexisting natural modes of variability. An evaluation of this possibility and in particular of the implications of unchanged flow regimes is performed with a focus on the Southern Hemisphere extratropical atmospheric circulation. Low-pass-filtered mean sea level pressure and geopotential height at 500 and 200 hPa from a transient integration with a coupled global climate model is used.

The response to an enhanced forcing projects strongly onto the leading modes of present-day variability, in agreement with other studies. However, the spatial patterns of the leading modes are changed in response to enhanced forcing. The first and second modes of interweekly variability are the Pacific–South American modes, zonal wavenumber-3 wave trains from the central Pacific to the southern Atlantic. In response to the enhanced forcing, the spatial patterns of these modes change, and the wave train extends along a circumpolar path with amplitude also in the Eastern Hemisphere. This change in the spatial patterns is associated with a strengthening of the waveguide for barotropic Rossby waves.

Corresponding author address: Dr. Jenny Brandefelt, Department of Meteorology, Stockholm University, S-10691 Stockholm, Sweden. Email: jenny@misu.su.se

Abstract

The response of the atmospheric circulation to an enhanced radiative greenhouse gas forcing is investigated. It has been proposed that the response of the climate system to an enhanced forcing projects directly onto the preexisting natural modes of variability. An evaluation of this possibility and in particular of the implications of unchanged flow regimes is performed with a focus on the Southern Hemisphere extratropical atmospheric circulation. Low-pass-filtered mean sea level pressure and geopotential height at 500 and 200 hPa from a transient integration with a coupled global climate model is used.

The response to an enhanced forcing projects strongly onto the leading modes of present-day variability, in agreement with other studies. However, the spatial patterns of the leading modes are changed in response to enhanced forcing. The first and second modes of interweekly variability are the Pacific–South American modes, zonal wavenumber-3 wave trains from the central Pacific to the southern Atlantic. In response to the enhanced forcing, the spatial patterns of these modes change, and the wave train extends along a circumpolar path with amplitude also in the Eastern Hemisphere. This change in the spatial patterns is associated with a strengthening of the waveguide for barotropic Rossby waves.

Corresponding author address: Dr. Jenny Brandefelt, Department of Meteorology, Stockholm University, S-10691 Stockholm, Sweden. Email: jenny@misu.su.se

Save