Unstable interaction of gravity-inertial waves with Rossby waves with application to solar system atmospheres

J. F. McKenzie, T. B. Doyle
2010 Astronomy and Astrophysics  
This letter reports on the important features of an analysis of the combined theory of gravity -inertial -Rossby waves on a β-plane in the Boussinesq approximation. In particular, it is shown that the coupling between higher frequency gravity -inertial waves and lower frequency Rossby waves, arising from the accumulated influences of the β effect, stratification characterized by the Väisäla -Brunt frequency N, the Coriolis frequency f , and the component of vertical propagation wave number k z
more » ... may lead to an unstable coupling between buoyancy -inertial modes with westward propagating Rossby waves. "Supersonic" fast rotators (such as Jupiter) are predicted to be unstable in a fairly narrow band of latitudes around their equators. The Earth is moderately supersonic and exhibits instability within about 34 • of its equator. Slow "subsonic" rotators (e.g. Mercury, Venus, and the Sun's corona) are unstable at all latitudes except those very close to the poles where the β effect vanishes.
doi:10.1051/0004-6361/200913453 fatcat:snv753zw5ndn5m3zmhb5s2ja3m