Editorial Type:
Article
Article Type:
Research Article

The Antarctic Circumpolar Wave: A Combination of Two Signals?

Silvia A. Venegas Danish Center for Earth System Science, Niels Bohr Institute for Astronomy, Physics and Geophysics, University of Copenhagen, Copenhagen, Denmark

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Print Publication:
01 Aug 2003
DOI:
https://doi.org/10.1175/1520-0442(2003)016<2509:TACWAC>2.0.CO;2
Page(s):
2509–2525
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Abstract

A simplified view of the possible mechanisms behind the Antarctic Circumpolar Wave (ACW) interannual variability is provided by a frequency-domain decomposition of several observed atmospheric and oceanic variables. Two significant interannual signals with different temporal and spatial characteristics are identified in the Southern Ocean, and most of the variance of the ACW in the interannual band can be accounted for by a linear combination of them. The first signal has a period of oscillation of around 3.3 yr and a zonal wavenumber-3 structure across the Southern Ocean. It involves self-sustained fluctuations inherent in the Southern Ocean and driven by coupled air–sea interactions in which the atmosphere and the ocean mutually force one another. This signal is represented by an atmospheric standing oscillation with centers at fixed locations around Antarctica and a propagating oceanic pattern, in which the surface Antarctic Circumpolar Current plays an essential role. The second signal has a periodicity of around 5 yr and a zonal wavenumber-2 structure across the Southern Ocean. It seems to be remotely forced by the tropical ENSO phenomenon and has a signature mainly in the eastern Pacific sector. This signal likely represents the southern high-latitude manifestation of a larger-scale (hemispheric or global) pattern. The constructive or destructive interference of these two superimposed signals with different periodicities and spatial characteristics gives rise to the observed irregular fluctuations of the ACW on the interannual timescale.

Corresponding author address: Dr. Silvia A. Venegas, Danish Center for Earth System Science, Niels Bohr Institute for Astronomy, Physics and Geophysics, University of Copenhagen, Juliane Maries Vej 30, Copenhagen DK-2100, Denmark. Email: silvia@dcess.ku.dk

Abstract

A simplified view of the possible mechanisms behind the Antarctic Circumpolar Wave (ACW) interannual variability is provided by a frequency-domain decomposition of several observed atmospheric and oceanic variables. Two significant interannual signals with different temporal and spatial characteristics are identified in the Southern Ocean, and most of the variance of the ACW in the interannual band can be accounted for by a linear combination of them. The first signal has a period of oscillation of around 3.3 yr and a zonal wavenumber-3 structure across the Southern Ocean. It involves self-sustained fluctuations inherent in the Southern Ocean and driven by coupled air–sea interactions in which the atmosphere and the ocean mutually force one another. This signal is represented by an atmospheric standing oscillation with centers at fixed locations around Antarctica and a propagating oceanic pattern, in which the surface Antarctic Circumpolar Current plays an essential role. The second signal has a periodicity of around 5 yr and a zonal wavenumber-2 structure across the Southern Ocean. It seems to be remotely forced by the tropical ENSO phenomenon and has a signature mainly in the eastern Pacific sector. This signal likely represents the southern high-latitude manifestation of a larger-scale (hemispheric or global) pattern. The constructive or destructive interference of these two superimposed signals with different periodicities and spatial characteristics gives rise to the observed irregular fluctuations of the ACW on the interannual timescale.

Corresponding author address: Dr. Silvia A. Venegas, Danish Center for Earth System Science, Niels Bohr Institute for Astronomy, Physics and Geophysics, University of Copenhagen, Juliane Maries Vej 30, Copenhagen DK-2100, Denmark. Email: silvia@dcess.ku.dk

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  • Baines, P. G., and W. Cai, 2000: Analysis of an interactive instability mechanism for the Antarctic Circumpolar Wave. J. Climate, 13 , 1831–1844.

    • Search Google Scholar
    • Export Citation

  • Bonekamp, H., A. Sterl, and G. J. Komen, 1999: Interannual variability in the Southern Ocean from an ocean model forced by European Centre for Medium-Range Weather Forecasts reanalysis fluxes. J. Geophys. Res., 104 , 13317–13331.

    • Search Google Scholar
    • Export Citation

  • Cai, W., and P. G. Baines, 2001: Forcing the Antarctic Circumpolar Wave by El Niño–Southern Oscillation teleconnections. J. Geophys. Res., 106 (C5) 9019–9038.

    • Search Google Scholar
    • Export Citation

  • Cai, W., P. G. Baines, and H. B. Gordon, 1999: Southern mid- to high-latitude variability, a zonal wavenumber-3 pattern, and the Antarctic Circumpolar Wave in the CSIRO coupled model. J. Climate, 12 , 3087–3104.

    • Search Google Scholar
    • Export Citation

  • Carleton, A. M., 1988: Sea ice–atmosphere signal of the Southern Oscillation in the Weddell Sea, Antarctica. J. Climate, 1 , 379–388.

    • Search Google Scholar
    • Export Citation

  • Carril, A. F., and A. Navarra, 2001: Low-frequency variability of the Antarctic Circumpolar Wave. Geophys. Res. Lett., 28 , 4623–4626.

  • Cayan, D. R., 1992a: Latent and sensible heat flux anomalies over the northern oceans: The connection to monthly atmospheric circulation. J. Climate, 5 , 354–369.

    • Search Google Scholar
    • Export Citation

  • Cayan, D. R., 1992b: Latent and sensible heat flux anomalies over the northern oceans: Driving the sea surface temperature. J. Phys. Oceanogr., 22 , 859–881.

    • Search Google Scholar
    • Export Citation

  • Christoph, M., T. P. Barnett, and E. Roeckner, 1998: The Antarctic Circumpolar Wave in a coupled ocean–atmosphere GCM. J. Climate, 11 , 1659–1672.

    • Search Google Scholar
    • Export Citation

  • Cullather, R. I., D. H. Bromwich, and M. L. van Woert, 1996: Interannual variations in Antarctic precipitation related to El Niño–Southern Oscillation. J. Geophys. Res., 101 (D14) 19109–19118.

    • Search Google Scholar
    • Export Citation

  • Deser, C., J. E. Walsh, and M. S. Timlin, 2000: Arctic sea ice variability in the context of recent atmospheric circulation trends. J. Climate, 13 , 617–633.

    • Search Google Scholar
    • Export Citation

  • Garreaud, R. D., and D. S. Battisti, 1999: Interannual (ENSO) and interdecadal (ENSO-like) variability in the Southern Hemisphere tropospheric circulation. J. Climate, 12 , 2113–2123.

    • Search Google Scholar
    • Export Citation

  • Gloersen, P., 1995: Modulation of hemispheric sea ice cover by ENSO events. Nature, 373 , 503–506.

  • Gloersen, P., and W. B. White, 2001: Reestablishing the circumpolar wave in sea ice around Antarctica from one winter to the next. J. Geophys. Res., 106 (C3) 4391–4396.

    • Search Google Scholar
    • Export Citation

  • Hines, K. M., D. H. Bromwich, and G. J. Marshall, 2000: Artificial surface pressure trends in the NCEP–NCAR reanalysis over the Southern Ocean and Antarctica. J. Climate, 13 , 3940–3952.

    • Search Google Scholar
    • Export Citation

  • Jacobs, G. A., and J. L. Mitchell, 1996: Ocean circulation variations associated with the Antarctic Circumpolar Wave. Geophys. Res. Lett., 23 , 2947–2950.

    • Search Google Scholar
    • Export Citation

  • Kalnay, E., and Coauthors. 1996: The NCEP/NCAR 40-Year Reanalysis Project. Bull. Amer. Meteor. Soc., 77 , 437–471.

  • Kalnay, E., R. Kistler, and S. Saha, 2000: The NCEP/NCAR 50-Year Reanalysis: Southern Hemisphere. Preprints, Sixth Int. Conf. on Southern Hemisphere Meteorology and Oceanography, Santiago, Chile, Amer. Meteor. Soc., 206–207.

    • Search Google Scholar
    • Export Citation

  • Karoly, D. J., 1989: Southern Hemisphere circulation features associated with El Niño–Southern Oscillation events. J. Climate, 2 , 1239–1252.

    • Search Google Scholar
    • Export Citation

  • Kistler, R., and Coauthors. 2001: The NCEP–NCAR 50-Year Reanalysis: Monthly means CD-ROM and documentation. Bull. Amer. Meteor. Soc., 82 , 247–268.

    • Search Google Scholar
    • Export Citation

  • Kushnir, Y., and N. C. Lau, 1992: The general circulation model response to a North Pacific SST anomaly: Dependence on time scale and pattern polarity. J. Climate, 5 , 271–283.

    • Search Google Scholar
    • Export Citation

  • Ledley, T. S., and Z. Huang, 1997: A possible ENSO signal in the Ross Sea. Geophys. Res. Lett., 24 , 3253–3256.

  • Mann, M. E., and J. Park, 1994: Global-scale modes of surface temperature variability on interannual to century timescales. J. Geophys. Res., 99 , 25819–25833.

    • Search Google Scholar
    • Export Citation

  • Mann, M. E., and J. Park, 1996: Joint spatiotemporal modes of surface temperature and sea level pressure variability in the Northern Hemisphere during the last century. J. Climate, 9 , 2137–2162.

    • Search Google Scholar
    • Export Citation

  • Mann, M. E., and J. Park, 1999: Oscillatory spatiotemporal signal detection in climate studies: A multiple-taper spectral domain approach. Advances in Geophysics, Vol. 41, Academic Press, 1–131.

    • Search Google Scholar
    • Export Citation

  • Parker, D. E., C. K. Folland, and M. Jackson, 1995: Marine surface temperature: Observed variations and data requirements. Climatic Change, 31 , 559–600.

    • Search Google Scholar
    • Export Citation

  • Percival, D. B., and A. T. Walden, 1993: Spectral Analysis for Physical Applications: Multitaper and Conventional Univariate Techniques. Cambridge University Press, 583 pp.

    • Search Google Scholar
    • Export Citation

  • Peterson, R. G., and W. B. White, 1998: Slow oceanic teleconnections linking the Antarctic Circumpolar Wave with the tropical El Niño–Southern Oscillation. J. Geophys. Res., 103 (C11) 24573–24583.

    • Search Google Scholar
    • Export Citation

  • Pitcher, E. J., M. L. Blackmon, G. Bates, and S. Muñoz, 1988: The effect of North Pacific sea surface temperature anomalies on the January climate of a general circulation model. J. Atmos. Sci., 45 , 173–188.

    • Search Google Scholar
    • Export Citation

  • Qiu, B., and F. F. Jin, 1997: Antarctic circumpolar waves: An indication of ocean–atmospheric coupling in the extratropics. Geophys. Res. Lett., 24 , 2585–2588.

    • Search Google Scholar
    • Export Citation

  • Simmonds, I., 2003: Modes of atmospheric variability over the Southern Ocean. J. Geophys. Res., 108 , 8078. doi:10.1029/2000JC000542.

  • Simmonds, I., and W. F. Budd, 1991: Sensitivity of the Southern Hemisphere circulation to leads in the Antarctic pack ice. Quart. J. Roy. Meteor. Soc., 117 , 1003–1024.

    • Search Google Scholar
    • Export Citation

  • Simmonds, I., and T. H. Jacka, 1995: Relationships between the interannual variability of Antarctic sea ice and the Southern Oscillation. J. Climate, 8 , 637–647.

    • Search Google Scholar
    • Export Citation

  • Simmonds, I., and K. Keay, 2000: Variability of Southern Hemisphere extratropical cyclone behavior 1958–97. J. Climate, 13 , 550–561.

    • Search Google Scholar
    • Export Citation

  • Thompson, D. W. J., and J. M. Wallace, 2000: Annular modes in the extratropical circulation. I: Month-to-month variability. J. Climate, 13 , 1000–1016.

    • Search Google Scholar
    • Export Citation

  • Thomson, D. J., 1982: Spectrum estimation and harmonic analysis. Proc. IEEE, 70 , 1055–1096.

  • Tourre, Y. M., B. Rajagopalan, and Y. Kushnir, 1999: Dominant patterns of climate variability in the Atlantic Ocean during the last 136 years. J. Climate, 12 , 2285–2299.

    • Search Google Scholar
    • Export Citation

  • Venegas, S. A., and L. A. Mysak, 2000: Is there a dominant timescale of natural climate variability in the Arctic? J. Climate, 13 , 3412–3434.

    • Search Google Scholar
    • Export Citation

  • Venegas, S. A., and M. R. Drinkwater, 2001: Sea ice, atmosphere and upper ocean variability in the Weddell Sea, Antarctica. J. Geophys. Res., 106 (C8) 16747–16766.

    • Search Google Scholar
    • Export Citation

  • Venegas, S. A., M. R. Drinkwater, and G. Shaffer, 2001: Coupled oscillations in Antarctic sea ice and atmosphere in the South Pacific sector. Geophys. Res. Lett., 28 , 3301–3304.

    • Search Google Scholar
    • Export Citation

  • Watkins, A. B., and I. Simmonds, 2000: Current trends in Antarctic sea-ice: The 1990s impact on a short climatology. J. Climate, 13 , 4441–4451.

    • Search Google Scholar
    • Export Citation

  • White, W. B., and R. G. Peterson, 1996: An Antarctic circumpolar wave in surface pressure, wind, temperature and sea-ice extent. Nature, 380 , 699–702.

    • Search Google Scholar
    • Export Citation

  • White, W. B., and S-C. Chen, 2002: Thermodynamic mechanisms responsible for the tropospheric response to SST anomalies in the Antarctic Circumpolar Wave. J. Climate, 15 , 2577–2596.

    • Search Google Scholar
    • Export Citation

  • White, W. B., C. Yi, and T. Chang-Kou, 1998: Coupling of biennial oceanic Rossby waves with the overlying atmosphere in the Pacific Basin. J. Phys. Oceanogr., 28 , 1236–1251.

    • Search Google Scholar
    • Export Citation

  • Yuan, X., and D. G. Martinson, 2000: Antarctic sea-ice variability and its global connectivity. J. Climate, 13 , 1697–1717.

  • Yuan, X., and D. G. Martinson, 2001: The Antarctic Dipole and its predictability. Geophys. Res. Lett., 28 , 3609–3612.

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