Coupling of dynamical tide and orbital motion

TL;DR

This paper investigates how the interaction between dynamical tides and orbital motion affects tidal dissipation and orbital evolution, using a simplified 2D model and Earth-Moon system as a case study.

Contribution

It introduces a simple 2D shallow water model to analyze the coupling of dynamical tide and orbital motion, highlighting its significance in orbital evolution.

Findings

Tidal dissipation can increase with orbital separation due to coupling.

The coupling significantly influences secular orbital evolution.

The model applies to rocky planets with thin oceans or atmospheres.

Abstract

Dynamical tide consists of various waves that can resonate with orbital motion. We test this coupling of dynamical tide and orbital motion using a simple two-dimensional shallow water model, which can be applied to a rocky planet covered with thin ocean or atmosphere. Then we take the earth-moon system as a fiducial model to calculate the tidal resonances and orbital evolution. We find that tidal dissipation can even increase with increasing orbital separation because of the coupling of dynamical tide and orbital motion. We draw the conclusion that the coupling is not negligible to study the orbital evolution on secular timescale.