Ocean tidal heating in icy satellites with solid shells
| Autor: | Francis Nimmo, Hamish C. F. C. Hay, Shunichi Kamata, Isamu Matsuyama, Mikael Beuthe |
|---|---|
| Rok vydání: | 2018 |
| Předmět: |
010504 meteorology & atmospheric sciences
media_common.quotation_subject Equator Shell (structure) FOS: Physical sciences Tidal heating Forcing (mathematics) 01 natural sciences Physics::Geophysics 0103 physical sciences Eccentricity (behavior) Enceladus 010303 astronomy & astrophysics Physics::Atmospheric and Oceanic Physics 0105 earth and related environmental sciences media_common Earth and Planetary Astrophysics (astro-ph.EP) Astronomy and Astrophysics Geophysics Amplitude Space and Planetary Science Physics::Space Physics Astrophysics::Earth and Planetary Astrophysics Energy source Geology Astrophysics - Earth and Planetary Astrophysics |
| DOI: | 10.48550/arxiv.1804.07727 |
| Popis: | As a long-term energy source, tidal heating in subsurface oceans of icy satellites can influence their thermal, rotational, and orbital evolution, and the sustainability of oceans. We present a new theoretical treatment for tidal heating in thin subsurface oceans with overlying incompressible elastic shells of arbitrary thickness. The stabilizing effect of an overlying shell damps ocean tides, reducing tidal heating. This effect is more pronounced on Enceladus than on Europa because the effective rigidity on a small body like Enceladus is larger. For the range of likely shell and ocean thicknesses of Enceladus and Europa, the thin shell approximation of Beuthe (2016) is generally accurate to less than about 4%.The time-averaged surface distribution of ocean tidal heating is distinct from that due to dissipation in the solid shell, with higher dissipation near the equator and poles for eccentricity and obliquity forcing respectively. This can lead to unique horizontal shell thickness variations if the shell is conductive. The surface displacement driven by eccentricity and obliquity forcing can have a phase lag relative to the forcing tidal potential due to the delayed ocean response. For Europa and Enceladus, eccentricity forcing generally produces greater tidal amplitudes due to the large eccentricity values relative to the obliquity values. Despite the small obliquity values, obliquity forcing generally produces larger phase lags due to the generation of Rossby-Haurwitz waves. If Europa's shell and ocean are respectively 10 and 100 km thick, the tide amplitude and phase lag are 26.5 m and $ Icarus, accepted for publication |
| Databáze: | OpenAIRE |
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