• Ambaum, M. H. P., B. J. Hoskins, and D. B. Stephenson, 2001: Arctic Oscillation or North Atlantic Oscillation? J. Climate, 14 , 34953507.

    • Search Google Scholar
    • Export Citation
  • Barnston, A. G., and R. E. Livezey, 1987: Classification, seasonality, and persistence of the low-frequency atmospheric circulation patterns. Mon. Wea. Rev, 115 , 10831126.

    • Search Google Scholar
    • Export Citation
  • Cheng, X., and J. M. Wallace, 1993: Cluster analysis of the Northern Hemisphere wintertime 500-hPa height field: Spatial patterns. J. Atmos. Sci, 50 , 26742696.

    • Search Google Scholar
    • Export Citation
  • Cheng, X., G. Nitsche, and J. M. Wallace, 1995: Robustness of low-frequency circulation patterns derived from EOF and rotated EOF analyses. J. Climate, 8 , 17091720.

    • Search Google Scholar
    • Export Citation
  • Feldstein, S. B., and S. Lee, 1998: Is the atmospheric zonal index driven by an eddy feedback? J. Atmos. Sci, 55 , 30773086.

  • Gillett, N. P., F. W. Zwiers, A. J. Weaver, and P. A. Stott, 2003: Detection of human influence on sea level pressure. Nature, 422 , 292294.

    • Search Google Scholar
    • Export Citation
  • Gong, D., and S. Wang, 1999: Definition of Antarctic Oscillation index. Geophys. Res. Lett, 26 , 459462.

  • Honda, M., and H. Nakamura, 2001: Interannual seesaw between the Aleutian and Icelandic lows. Part II: Its significance in the interannual variability over the wintertime Northern Hemisphere. J. Climate, 14 , 45124529.

    • Search Google Scholar
    • Export Citation
  • Honda, M., H. Nakamura, J. Ukita, I. Kousaka, and K. Takeuchi, 2001: Interannual seesaw between the Aleutian and Icelandic lows. Part I: Seasonal dependence and life cycle. J. Climate, 14 , 10291042.

    • Search Google Scholar
    • Export Citation
  • Houghton, J. T., Y. Ding, D. J. Griggs, M. Noguer, P. J. van der Linden, X. Dai, K. Maskell, and C. A. Johnson, Eds.,. 2001: Climate Change 2001: The Scientific Basis. Cambridge University Press, 892 pp.

  • Hurrell, J. W., 1995: Decadal trends in the North Atlantic Oscillation: Regional temperatures and precipitation. Science, 269 , 676679.

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

  • Kidson, J. W., 1975: Eigenvector analysis of monthly mean surface data. Mon. Wea. Rev, 103 , 177186.

  • Kushnir, Y., and J. M. Wallace, 1989: Low-frequency variability in the Northern Hemisphere winter: Geographical distribution, structure and time-scale dependence. J. Atmos. Sci, 46 , 31223142.

    • Search Google Scholar
    • Export Citation
  • Kutzbach, J., 1970: Large-scale features of monthly mean Northern Hemisphere anomaly maps of sea-level pressure. Mon. Wea. Rev, 98 , 708716.

    • Search Google Scholar
    • Export Citation
  • Limpasuvan, V., and D. L. Hartmann, 2000: Wave-maintained annular modes of climate variability. J. Climate, 13 , 44144429.

  • Lorenz, D. J., and D. L. Hartmann, 2003: Eddy-zonal flow feedback in the Northern Hemisphere winter. J. Climate, 16 , 12121227.

  • Mantua, N., S. Hare, Y. Zhang, J. Wallace, and R. C. Francis, 1997: A Pacific interdecadal climate oscillation with impacts on salmon production. Bull. Amer. Meteor. Soc, 78 , 10691079.

    • Search Google Scholar
    • Export Citation
  • Molteni, F., A. Sutera, and N. Tronci, 1988: The EOFs of the geopotential eddies at 500 mb in winter and their probability density distributions. J. Atmos. Sci, 45 , 30633080.

    • Search Google Scholar
    • Export Citation
  • 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
  • Rogers, J., and M. McHugh, 2002: On the separability of the North Atlantic Oscillation and Arctic Oscillation. Climate Dyn, 19 , 599608.

    • Search Google Scholar
    • Export Citation
  • Simmons, A. J., J. M. Wallace, and G. Branstator, 1983: Barotropic wave propagation and instability, and atmospheric teleconnection patterns. J. Atmos. Sci, 40 , 13631392.

    • Search Google Scholar
    • Export Citation
  • Thompson, D. W. J., and J. M. Wallace, 1998: The Arctic Oscillation signature in the wintertime geopotential height and temperature fields. Geophys. Res. Lett, 25 , 12971300.

    • 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 , 10001016.

    • Search Google Scholar
    • Export Citation
  • Trenberth, K. E., 1984: Signal versus noise in the Southern Oscillation. Mon. Wea. Rev, 112 , 326332.

  • Trenberth, K. E., and D. Paolino Jr., 1980: The Northern Hemisphere sea-level pressure data set: Trends, errors and discontinuities. Mon. Wea. Rev, 108 , 855872.

    • Search Google Scholar
    • Export Citation
  • Trenberth, K. E., and D. Paolino Jr., 1981: Characteristic patterns of variability of sea level pressure in the Northern Hemisphere. Mon. Wea. Rev, 109 , 11691189.

    • Search Google Scholar
    • Export Citation
  • Trenberth, K. E., and D. J. Shea, 1987: On the evolution of the Southern Oscillation. Mon. Wea. Rev, 115 , 30783096.

  • Trenberth, K. E., and J. Hurrell, 1994: Decadal atmosphere–ocean variations in the Pacific. Climate Dyn, 9 , 303319.

  • Trigo, R. M., T. J. Osborn, and J. M. Corte-Real, 2002: The North Atlantic Oscillation influence on Europe: Climate impacts and associated physical mechanisms. Climate Res, 20 , 917.

    • Search Google Scholar
    • Export Citation
  • Walker, G. T., and E. W. Bliss, 1932: World weather. Mem. Roy. Meteor. Soc, 4 , 5384.

  • Wallace, J. M., and D. S. Gutzler, 1981: Teleconnections in the geopotential height field during the Northern Hemisphere winter. Mon. Wea. Rev, 109 , 784812.

    • Search Google Scholar
    • Export Citation
  • Wallace, J. M., and D. W. J. Thompson, 2002: The Pacific center of action of the Northern Hemisphere annular mode: Real or artifact? J. Climate, 15 , 19871991.

    • Search Google Scholar
    • Export Citation
  • Wallace, J. M., Y. Zhang, and J. Renwick, 1995: Dynamic contribution to hemispheric mean temperature trends. Science, 270 , 780783.

  • Walsh, J. E., W. L. Chapman, and T. L. Shy, 1996: Recent decrease of sea level pressure in the central Arctic. J. Climate, 9 , 480486.

    • Search Google Scholar
    • Export Citation
  • Wang, J., and M. Ikeda, 2000: Arctic Oscillation and Arctic Sea-Ice Oscillation. Geophys. Res. Lett, 27 , 12871290.

  • Willmott, C. J., and S. M. Robeson, 1995: Climatologically Aided Interpolation (CAI) of terrestrial air temperature. Int. J. Climatol, 15 , 221229.

    • Search Google Scholar
    • Export Citation
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A Simplified Linear Framework for Interpreting Patterns of Northern Hemisphere Wintertime Climate Variability

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  • 1 University of Washington, Seattle, Washington
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Abstract

The principal patterns of variability of the extratropical Northern Hemisphere (NH) wintertime circulation are examined, based on 42 yr of data from the NCAR–NCEP reanalyses. The two-dimensional phase space defined by the two leading PCs of the monthly mean sea level pressure (SLP) field poleward of 20°N is used as a basis for surveying the structure of the geopotential height and surface air temperature (SAT) fields. Together these two patterns account for roughly half the variance of SLP on interannual time scales and longer, and virtually all the planetary-scale SLP trends over the 42-yr period of record. The leading EOF corresponds to the NH annular mode (NAM), and the second EOF resembles the Pacific–North America (PNA) pattern.

The leading EOF of the monthly mean geopotential height field at various levels throughout the troposphere and lower stratosphere is well represented by linear combinations of these two SLP patterns, as are the intraseasonal and interannual SLP fields, the NAM, the North Atlantic Oscillation (NAO), the PNA pattern, the pattern corresponding to the North Pacific index (NP), the cold ocean–warm land (COWL) pattern, the seasaw between the depths of the Aleutian and Icelandic lows (AIS), and the leading EOFs of lower-tropospheric temperature and midtropospheric wind. The combined influence of these patterns on temperature and rainfall and other variables can be represented in terms of compact vectorial plots.

Interesting differences emerge when the EOF analysis is performed separately on the intraseasonal and interannual components of the NH SLP field. The former patterns appear to be hemispherically trapped, whereas the latter appear to be reflections of global structures, with ENSO clearly dominating the structure of interannual EOF2.

Corresponding author address: Roberta Quadrelli, JISAO, Dept. of Atmospheric Sciences, University of Washington, Box 354235, Seattle, WA 98195-4235. Email: roberta@atmos.washington.edu

Abstract

The principal patterns of variability of the extratropical Northern Hemisphere (NH) wintertime circulation are examined, based on 42 yr of data from the NCAR–NCEP reanalyses. The two-dimensional phase space defined by the two leading PCs of the monthly mean sea level pressure (SLP) field poleward of 20°N is used as a basis for surveying the structure of the geopotential height and surface air temperature (SAT) fields. Together these two patterns account for roughly half the variance of SLP on interannual time scales and longer, and virtually all the planetary-scale SLP trends over the 42-yr period of record. The leading EOF corresponds to the NH annular mode (NAM), and the second EOF resembles the Pacific–North America (PNA) pattern.

The leading EOF of the monthly mean geopotential height field at various levels throughout the troposphere and lower stratosphere is well represented by linear combinations of these two SLP patterns, as are the intraseasonal and interannual SLP fields, the NAM, the North Atlantic Oscillation (NAO), the PNA pattern, the pattern corresponding to the North Pacific index (NP), the cold ocean–warm land (COWL) pattern, the seasaw between the depths of the Aleutian and Icelandic lows (AIS), and the leading EOFs of lower-tropospheric temperature and midtropospheric wind. The combined influence of these patterns on temperature and rainfall and other variables can be represented in terms of compact vectorial plots.

Interesting differences emerge when the EOF analysis is performed separately on the intraseasonal and interannual components of the NH SLP field. The former patterns appear to be hemispherically trapped, whereas the latter appear to be reflections of global structures, with ENSO clearly dominating the structure of interannual EOF2.

Corresponding author address: Roberta Quadrelli, JISAO, Dept. of Atmospheric Sciences, University of Washington, Box 354235, Seattle, WA 98195-4235. Email: roberta@atmos.washington.edu

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