Towards a better understanding of tidal dissipation at corotation layers in differentially rotating stars and planets

TL;DR

This paper develops a local analytic model to understand how differential rotation in stars and planets affects the propagation and dissipation of tidal inertial waves at critical layers, impacting tidal dissipation.

Contribution

It introduces a new local analytic model that captures the effects of latitudinal differential rotation on inertial wave dissipation at critical layers in stellar and planetary interiors.

Findings

Differential rotation significantly alters inertial wave propagation.

Critical layers can greatly enhance tidal dissipation.

The model provides insights into tidal evolution in star-planet systems.

Abstract

Star-planet tidal interactions play a significant role in the dynamical evolution of close-in planetary systems. We investigate the propagation and dissipation of tidal inertial waves in a stellar/planetary convective region. We take into account a latitudinal differential rotation for the background flow, similar to what is observed in the envelope of low-mass stars like the Sun. Previous works have shown that differential rotation significantly alters the propagation and dissipation properties of inertial waves. In particular, when the Doppler-shifted tidal frequency vanishes in the fluid, a critical layer forms where tidal dissipation can be greatly enhanced. Our present work develops a local analytic model to better understand the propagation and dissipation properties of tidally forced inertial waves at critical layers.