We are especially thankful to Isaac Held for his comments and suggestions. We are also grateful for valuable discussions with Alan Plumb, Lorenzo Polvani, Walter Robinson, Edwin Gerber, and Michael Ring. We thank three anomalous reviewers for helpful comments, and Bruce Wyman and S. J. Lin for integrating the GCM experiments. The lead author is supported by a NOAA Climate and Global Change Postdoctoral Fellowship, administered by the University Corporation for Atmospheric Research, and most of the work was done when he was a graduate student at Princeton University, supported by Award NA17RJ2612 from the National Oceanic and Atmospheric Administration, U.S. Department of Commerce. PZG is supported by the Ramon y Cajal program of the Ministerio de Educación y Ciencia of Spain and by a Universidad Complutense-Flores Valles fellowship.
Baldwin, M. P., , and T. J. Dunkerton, 1999: Propagation of the Arctic Oscillation from the stratosphere to the troposphere. J. Geophys. Res., 104 , 30937–30946.
Baldwin, M. P., , and T. J. Dunkerton, 2001: Stratospheric harbingers of anomalous weather regimes. Science, 294 , 581–584. doi:10.1126/science. 1063315.
Chang, E. K. M., 1995: The influence of Hadley circulation intensity changes on extratropical climate in an idealized model. J. Atmos. Sci., 52 , 2006–2024.
Chang, E. K. M., 1998: Poleward-propagating angular momentum perturbations induced by zonally symmetric heat sources in the tropics. J. Atmos. Sci., 55 , 2229–2248.
Chen, G., , and I. M. Held, 2007: Phase speed spectra and the recent poleward shift of Southern Hemisphere surface westerlies. Geophys. Res. Lett., 34 .L21805, doi:10.1029/2007GL031200.
Chen, G., , I. M. Held, , and W. A. Robinson, 2007: Sensitivity of the latitude of the surface westerlies to surface friction. J. Atmos. Sci., 64 , 2899–2915.
Chen, P., , and W. A. Robinson, 1992: Propagation of planetary waves between the troposphere and stratosphere. J. Atmos. Sci., 49 , 2533–2545.
Gerber, E. P., , S. Voronin, , and L. M. Polvani, 2008: Testing the annular mode autocorrelation time scale in simple atmospheric general circulation models. Mon. Wea. Rev., 136 , 1523–1536.
GFDL Global Atmospheric Model Development Team, 2004: The new GFDL global atmosphere and land model AM2/LM2: Evaluation with prescribed SST simulations. J. Climate, 17 , 4641–4673.
Haigh, J. D., , M. Blackburn, , and R. Day, 2005: The response of tropospheric circulation to perturbations in lower-stratospheric temperature. J. Climate, 18 , 3672–3685.
Haynes, P. H., , C. J. Marks, , M. E. McIntyre, , T. G. Shepherd, , and K. P. Shine, 1991: On the “downward control” of extratropical diabatic circulations by eddy-induced mean zonal forces. J. Atmos. Sci., 48 , 651–678.
Held, I. M., , and M. J. Suarez, 1994: A proposal for the intercomparison of the dynamical cores of atmospheric general circulation models. Bull. Amer. Meteor. Soc., 75 , 1825–1830.
Kushner, P. J., , and L. M. Polvani, 2004: Stratosphere–troposphere coupling in a relatively simple AGCM: The role of eddies. J. Climate, 17 , 629–639.
Limpasuvan, V., , D. W. J. Thompson, , and D. L. Hartmann, 2004: The life cycle of the Northern Hemisphere sudden stratospheric warmings. J. Climate, 17 , 2584–2596.
Norton, W. A., 2003: Sensitivity of Northern Hemisphere surface climate to simulation of the stratospheric polar vortex. Geophys. Res. Lett., 30 .1627, doi:10.1029/2003GL016958.
Perlwitz, J., , and N. Harnik, 2003: Observational evidence of a stratospheric influence on the troposphere by planetary wave reflection. J. Climate, 16 , 3011–3026.
Polvani, L. M., , and P. J. Kushner, 2002: Tropospheric response to stratospheric perturbations in a relatively simple general circulation model. Geophys. Res. Lett., 29 .1114, doi:10.1029/2001GL014284.
Randel, W. J., , and I. M. Held, 1991: Phase speed spectra of transient eddy fluxes and critical layer absorption. J. Atmos. Sci., 48 , 688–697.
Ring, M. J., , and R. A. Plumb, 2007: Forced annular mode patterns in a simple atmospheric general circulation model. J. Atmos. Sci., 64 , 3611–3626.
Scaife, A. A., , J. R. Knight, , G. K. Vallis, , and C. K. Folland, 2005: A stratospheric influence on the winter NAO and North Atlantic surface climate. Geophys. Res. Lett., 32 .L18715, doi:10.1029/2005GL023226.
Scott, R. K., , and L. Polvani, 2006: Internal variability of the winter stratosphere. Part I: Time-independent forcing. J. Atmos. Sci., 63 , 2758–2776.
Seager, R., , N. Harnik, , Y. Kushnir, , W. Robinson, , and J. Miller, 2003: Mechanisms of hemispherically symmetric climate variability. J. Climate, 16 , 2960–2978.
Simmons, A. J., , and B. J. Hoskins, 1980: Barotropic influences on the growth and decay of nonlinear baroclinic waves. J. Atmos. Sci., 37 , 1679–1684.
Simmons, A. J., , and D. M. Burridge, 1981: An energy and angular-momentum conserving vertical finite-difference scheme and hybrid vertical coordinates. Mon. Wea. Rev., 109 , 758–766.
Son, S. W., , and S. Lee, 2005: The response of westerly jets to thermal driving in a primitive equation model. J. Atmos. Sci., 62 , 3741–3757.
Song, Y., , and W. A. Robinson, 2004: Dynamical mechanisms for stratospheric influences on the troposphere. J. Atmos. Sci., 61 , 1711–1725.
Stephenson, D. B., 1994: The Northern Hemisphere tropospheric response to changes in the gravity-wave drag scheme in a perpetual January GCM. Quart. J. Roy. Meteor. Soc., 120 , 699–712.
Stern, W. F., , and R. T. Pierrehumbert, 1988: The impact of an orographic gravity wave drag parameterization on extended range predictions with a GCM. Preprints, Eighth Conf. on Numerical Weather Prediction, Baltimore, MD, Amer. Meteor. Soc., 745–750.
Taguchi, M., 2003: Tropospheric response to stratospheric degradation in a simple global circulation model. J. Atmos. Sci., 60 , 1835–1846.
Thompson, D. W. J., , M. P. Baldwin, , and S. Solomon, 2005: Stratosphere–troposphere coupling in the Southern Hemisphere. J. Atmos. Sci., 62 , 708–715.
Thompson, D. W. J., , J. C. Furtado, , and T. G. Shepherd, 2006: On the tropospheric response to anomalous stratospheric wave drag and radiative heating. J. Atmos. Sci., 63 , 2616–2629.
Thorncroft, C. D., , B. J. Hoskins, , and M. E. McIntyre, 1993: Two paradigms of baroclinic wave life-cycle behaviour. Quart. J. Roy. Meteor. Soc., 119 , 17–55.
Wittman, M., , L. M. Polvani, , and A. J. Charlton, 2007: The effect of lower-stratospheric shear on baroclinic instability. J. Atmos. Sci., 64 , 479–496.