Does the poleward propagation of zonal-mean zonal wind anomalies depend upon the slope of the tropopause?

Observations have shown that the leading mode of variability is associated with the meridional oscillation of the eddy-driven jet. Through empirical orthogonal function analysis, this leading mode captures significantly more variability than rest of the modes and have given rise to the annular mode literature. However, there are occasions when this single mode is insufficient in representing the variability. Evidence through observations and numerical modeling indicate this arises when the wind anomalies no longer indicate a “wobbling” of the jet, but instead a systematic poleward propagation. The GFDL GCM will be used to investigate this behavior and determine whether the latitudinal structure of the static stability (and more specifically the slope of the tropopause) plays a role.