Influence of a Mean Shear on the Dynamical Instability of an Inertio–Gravity Wave

Abstract

Linear theory is used to examine the influence of a mean shear on the dynamical instability of a large-amplitude inertio-gravity wave (IGW). The strength and orientation of the mean shear and the frequency of the IGW are all found to influence the occurrence and characteristics of the dynamical instability. Neutral curves and growth rates of the instability are computed to examine this dependence. The results obtained suggest that an IGW may support dynamical instability ova a wider range of frequencies and with larger growth rates in the presence of a mean sheet.