Editorial Type:
Article
Article Type:
Research Article

Observed Patterns of Month-to-Month Storm-Track Variability and Their Relationship to the Background Flow

Justin J. Wettstein Bjerknes Centre for Climate Research, Bergen, Norway, and Department of Atmospheric Sciences, University of Washington, Seattle, Washington

Search for other papers by Justin J. Wettstein in
Current site
Google Scholar
PubMed Close
and
John M. Wallace Department of Atmospheric Sciences, University of Washington, Seattle, Washington

Search for other papers by John M. Wallace in
Current site
Google Scholar
PubMed Close
Print Publication:
01 May 2010
DOI:
https://doi.org/10.1175/2009JAS3194.1
Page(s):
1420–1437
Restricted access

Abstract

Month-to-month storm-track variability is investigated via EOF analyses performed on ERA-40 monthly-averaged high-pass filtered daily 850-hPa meridional heat flux and the variances of 300-hPa meridional wind and 500-hPa height. The analysis is performed both in hemispheric and sectoral domains of the Northern and Southern Hemispheres. Patterns characterized as “pulsing” and “latitudinal shifting” of the climatological-mean storm tracks emerge as the leading sectoral patterns of variability. Based on the analysis presented, storm-track variability on the spatial scale of the two Northern Hemisphere sectors appears to be largely, but perhaps not completely, independent.

Pulsing and latitudinally shifting storm tracks are accompanied by zonal wind anomalies consistent with eddy-forced accelerations and geopotential height anomalies that project strongly on the dominant patterns of geopotential height variability. The North Atlantic Oscillation (NAO)–Northern Hemisphere annular mode (NAM) is associated with a pulsing of the Atlantic storm track and a meridional displacement of the upper-tropospheric jet exit region, whereas the eastern Atlantic (EA) pattern is associated with a latitudinally shifting storm track and an extension or retraction of the upper-tropospheric jet. Analogous patterns of storm-track and upper-tropospheric jet variability are associated with the western Pacific (WP) and Pacific–North America (PNA) patterns. Wave–mean flow relationships shown here are more clearly defined than in previous studies and are shown to extend through the depth of the troposphere. The Southern Hemisphere annular mode (SAM) is associated with a latitudinally shifting storm track over the South Atlantic and Indian Oceans and a pulsing South Pacific storm track. The patterns of storm-track variability are shown to be related to simple distortions of the climatological-mean upper-tropospheric jet.

Corresponding author address: Justin J. Wettstein, Bjerknes Centre for Climate Research, Allégaten 55, NO-5007 Bergen, Norway. Email: justin.wettstein@bjerknes.uib.no

Abstract

Month-to-month storm-track variability is investigated via EOF analyses performed on ERA-40 monthly-averaged high-pass filtered daily 850-hPa meridional heat flux and the variances of 300-hPa meridional wind and 500-hPa height. The analysis is performed both in hemispheric and sectoral domains of the Northern and Southern Hemispheres. Patterns characterized as “pulsing” and “latitudinal shifting” of the climatological-mean storm tracks emerge as the leading sectoral patterns of variability. Based on the analysis presented, storm-track variability on the spatial scale of the two Northern Hemisphere sectors appears to be largely, but perhaps not completely, independent.

Pulsing and latitudinally shifting storm tracks are accompanied by zonal wind anomalies consistent with eddy-forced accelerations and geopotential height anomalies that project strongly on the dominant patterns of geopotential height variability. The North Atlantic Oscillation (NAO)–Northern Hemisphere annular mode (NAM) is associated with a pulsing of the Atlantic storm track and a meridional displacement of the upper-tropospheric jet exit region, whereas the eastern Atlantic (EA) pattern is associated with a latitudinally shifting storm track and an extension or retraction of the upper-tropospheric jet. Analogous patterns of storm-track and upper-tropospheric jet variability are associated with the western Pacific (WP) and Pacific–North America (PNA) patterns. Wave–mean flow relationships shown here are more clearly defined than in previous studies and are shown to extend through the depth of the troposphere. The Southern Hemisphere annular mode (SAM) is associated with a latitudinally shifting storm track over the South Atlantic and Indian Oceans and a pulsing South Pacific storm track. The patterns of storm-track variability are shown to be related to simple distortions of the climatological-mean upper-tropospheric jet.

Corresponding author address: Justin J. Wettstein, Bjerknes Centre for Climate Research, Allégaten 55, NO-5007 Bergen, Norway. Email: justin.wettstein@bjerknes.uib.no

Save
Cover Journal of the Atmospheric Sciences
Journal of the Atmospheric Sciences

  • Burkhardt, U., and I. N. James, 2006: The effect of Doppler correction on measures of storm track intensity. Climate Dyn., 27 , 515–530.

    • Search Google Scholar
    • Export Citation

  • Chang, E. K. M., 1993: Downstream development of baroclinic waves as inferred from regression analysis. J. Atmos. Sci., 50 , 2038–2053.

    • Search Google Scholar
    • Export Citation

  • Chang, E. K. M., 2004: Are the Northern Hemisphere winter storm tracks significantly correlated? J. Climate, 17 , 4230–4244.

  • Chang, E. K. M., 2007: Assessing the increasing trend in Northern Hemisphere winter storm track activity using surface ship observations and a statistical storm track model. J. Climate, 20 , 5607–5628.

    • Search Google Scholar
    • Export Citation

  • Chang, E. K. M., 2009: Are band-pass variance statistics useful measures of storm track activity? Re-examining storm track variability associated with the NAO using multiple storm track measures. Climate Dyn., 33 , 277–296.

    • Search Google Scholar
    • Export Citation

  • Chang, E. K. M., and Y. Fu, 2002: Interdecadal variations in Northern Hemisphere winter storm track intensity. J. Climate, 15 , 642–658.

    • Search Google Scholar
    • Export Citation

  • Codron, F., 2005: Relation between annular modes and the mean state: Southern Hemisphere summer. J. Climate, 18 , 320–330.

  • Codron, F., 2007: Relations between annular modes and the mean state: Southern Hemisphere winter. J. Atmos. Sci., 64 , 3328–3339.

  • Gong, D., and S. Wang, 1999: Definition of Antarctic Oscillation index. Geophys. Res. Lett., 26 , 459–462.

  • Harnik, N., and E. K. M. Chang, 2003: Storm track variations as seen in radiosonde observations and reanalysis data. J. Climate, 16 , 480–495.

    • Search Google Scholar
    • Export Citation

  • Hoskins, B. J., 1983: Modelling of the transient eddies and their feedback on the mean flow. Large-Scale Dynamical Processes in the Atmosphere, B. J. Hoskins and R. P. Pearce, Eds., Academic Press, 169–199.

    • Search Google Scholar
    • Export Citation

  • Hoskins, B. J., and K. I. Hodges, 2002: New perspectives on the Northern Hemisphere winter storm tracks. J. Atmos. Sci., 59 , 1041–1061.

    • Search Google Scholar
    • Export Citation

  • Hurrell, J. W., 1995: Decadal trends in the North Atlantic Oscillation: Regional temperatures and precipitation. Science, 269 , 676–679.

    • Search Google Scholar
    • Export Citation

  • Hurrell, J. W., Y. Kushnir, G. Otterson, and M. Visbeck, 2003: An overview of the North Atlantic Oscillation. The North Atlantic Oscillation: Climate Significance and Environmental Impact, Geophys. Monogr., Vol. 134, Amer. Geophys. Union, 1–35.

    • Search Google Scholar
    • Export Citation

  • Lau, N-C., 1988: Variability of the observed midlatitude storm tracks in relation to low-frequency changes in the circulation pattern. J. Atmos. Sci., 45 , 2718–2743.

    • Search Google Scholar
    • Export Citation

  • Lorenz, D. J., and D. L. Hartmann, 2003: Eddy–zonal flow feedback in the Northern Hemisphere winter. J. Climate, 16 , 1212–1227.

  • Lorenz, E. N., 1951: Seasonal and irregular variations of the Northern Hemisphere sea-level pressure profile. J. Meteor., 8 , 52–59.

  • Lorenz, E. N., 1955: Available potential energy and the maintenance of the general circulation. Tellus, 7 , 157–167.

  • Nakamura, H., 1992: Midwinter suppression of baroclinic wave activity in the Pacific. J. Atmos. Sci., 49 , 1629–1642.

  • Quadrelli, R., and J. M. Wallace, 2004: A simplified linear framework for interpreting patterns of Northern Hemisphere wintertime climate variability. J. Climate, 17 , 3728–3744.

    • Search Google Scholar
    • Export Citation

  • Robinson, W. A., 2000: A baroclinic mechanism for the eddy feedback on the zonal index. J. Atmos. Sci., 57 , 415–422.

  • Simmons, A. J., and B. J. Hoskins, 1978: The life cycles of some nonlinear baroclinic waves. J. Atmos. Sci., 35 , 414–432.

  • Simmons, A. J., J. M. Wallace, and G. W. Branstator, 1983: Barotropic wave propagation and instability, and atmospheric teleconnection patterns. J. Atmos. Sci., 40 , 1363–1392.

    • 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 , 1297–1300.

    • 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 , 1000–1016.

    • Search Google Scholar
    • Export Citation

  • Trenberth, K. E., 1981: Observed Southern Hemisphere eddy statistics at 500 mb: Frequency and spatial dependence. J. Atmos. Sci., 38 , 2585–2605.

    • Search Google Scholar
    • Export Citation

  • Walker, G. T., and E. W. Bliss, 1932: World weather V. Mem. Roy. Meteor. Soc., 4 , 53–84.

  • Wallace, J. M., and D. S. Gutzler, 1981: Teleconnections in the geopotential height field during the Northern Hemisphere winter. Mon. Wea. Rev., 109 , 784–812.

    • Search Google Scholar
    • Export Citation

  • Wettstein, J. J., 2007: Storm track variability and interaction with the background flow on daily, interannual and climate change time scales. Ph.D. thesis, University of Washington, 130 pp. [Available online at http://folk.uib.no/jwe061/].

  • Zhang, Y., J. M. Wallace, and D. S. Battisti, 1997: ENSO-like interdecadal variability: 1900–93. J. Climate, 10 , 1004–1020.

All Time Past Year Past 30 Days
Abstract Views 0 0 0
Full Text Views 553 170 9
PDF Downloads 485 129 11