Asymptotic analysis of inertial waves in the convective envelope of the sun

Abstract

Inertial waves are propagative in convective regions of rotating stars. Half of the inertial waves have positive energy of oscillations and the other half negative energy. The inertial waves with negative energy become overstable when they are in resonance with waves having positive energy such as internal gravity waves or when they dissipate energy of oscillations through nonadiabatic effects. We calculate a frequency spectrum of inertial (oscillatory convective) modes with negative energy propagating in the surface convective zone of the sun by using an asymptotic method of nonradial oscillations of rotating stars. It is shown that the inertial modes have large amplitudes only at high latitudes. The inertial modes with negative energy have very low frequencies seen in the corotating frame and hence if they are observed in an inertial frame their frequencies are approximately equal to −mΩ⊙.