Anisotropic tidal dissipation in misaligned planetary systems

Abstract

Tides are the main driving force behind the long-term evolution of planetary systems. The associated energy dissipation and momentum exchanges are commonly described by Love numbers, which relate the exciting potential to the tidally perturbed potential. These transfer functions are generally assumed to depend solely on tidal frequency and body rheology, following the isotropic assumption, which presumes invariance of properties by rotation about the centre of mass. We examine the limitations of the isotropic assumption for fluid bodies, where Coriolis acceleration breaks spherical symmetry, resulting in rotational scattering and complex tidal responses. Using angular momentum theory, we derive a new formalism to calculate the tidal rates of energy and momentum transfers in non-isotropic cases. We apply this formalism to the Earth-Moon system to assess the effects of anisotropy in planet-satellite systems with misaligned spin and orbital angular momenta. Our findings indicate that the isotropic assumption can introduce significant errors in planetary evolution models, particularly in the dynamical tide regime. These errors stem from forced wave resonances, with inaccuracies in energy dissipation scaling in proportion to resonance amplification factors.

25 pages, 10 figures, accepted for publication in Astronomy & Astrophysics

References in corpus (32)

• Tidal dissipation in stars and giant planets
• Tidal dissipation in rotating giant planets
• Tidal dissipation in rotating solar-type stars
• Tidally Heated Terrestrial Exoplanets: Viscoelastic Response Models
• Asynchronous rotation of Earth-mass planets in the habitable zone of lower-mass stars
• Satellite dynamics on the Laplace surface
• The Physics of Bodily Tides in Terrestrial Planets, and the Appropriate Scales of Dynamical Evolution
• Tidal dissipation compared to seismic dissipation: in small bodies, in earths, and in superearths
• Tides in rotating barotropic fluid bodies: the contribution of inertial waves and the role of internal structure
• Bodily tides near spin-orbit resonances
• Tidal torques. A critical review of some techniques
• Tidal dissipation in rotating fluid bodies: a simplified model
• Ocean tidal heating in icy satellites with solid shells
• Crustal control of dissipative ocean tides in Enceladus and other icy moons
• Inertial waves in a differentially rotating spherical shell
• Tidal interaction of a rotating 1 Msun star with a binary companion
• Internal energy dissipation in Enceladus's ocean from tides and libration and the role of inertial waves
• Analysis of a Precambrian resonance-stabilized day length
• Complete spin and orbital evolution of close-in bodies using a Maxwell viscoelastic rheology
• Impact of the frequency dependence of tidal Q on the evolution of planetary systems
• The impact of rotation on turbulent tidal friction in stellar and planetary convective regions
• Scaling laws to understand tidal dissipation in fluid planetary regions and stars I - Rotation, stratification and thermal diffusivity
• Tidal inertial waves in the differentially rotating convective envelopes of low-mass stars - I. Free oscillation modes
• Solid tidal friction in multi-layer planets: Application to Earth, Venus, a Super Earth and the TRAPPIST-1 planets. Can a multi-layer planet be approximated as a homogeneous planet?
• Oceanic tides from Earth-like to ocean planets
• Final spin states of eccentric ocean planets
• The Two Rigid Body Interaction using Angular Momentum Theory Formulae
• Note on the generalized Hansen and Laplace coefficients
• The effects of nonlinearities on tidal flows in the convective envelopes of rotating stars and planets in exoplanetary systems
• Tidal excitation of the obliquity of Earth-like planets in the habitable zone of M-dwarf stars
• Tidal evolution for any rheological model using a vectorial approach expressed in Hansen coefficients
• Constraining the Earth's Dynamical Ellipticity from Ice Age Dynamics