On Spectral Energetics of Resonantly Interacting Waves in the Two-Layer Baroclinic Model

Abstract

Spectral energetics associated with an N-wave system composed of a marginally unstable and N/1 neutral waves, interacting resonantly in triad configurations, are examined in the context of the two-layer baroclinic model. The unstable mode is found to dominate all allowable spectra at small initial energy levels. At larger initial energy levels this dominance persists only in the case of largest allowable spectra; otherwise, resonant interaction mechanism shifts the dominance to the neutral part of the spectrum. The shift occurs at lower initial energy levels and to a broader spectral range at higher values of internal rotational Froude number.