000003907 001__ 3907
000003907 005__ 20190125172501.0
000003907 0247_ $$2DOI$$a10.1016/j.icarus.2018.04.013
000003907 037__ $$aSCART-2019-0071
000003907 100__ $$aMatsuyama, Isamu
000003907 245__ $$aOcean tidal heating in icy satellites with solid shells
000003907 260__ $$c2018
000003907 520__ $$aAs 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%. Explaining Enceladus' endogenic power radiated from the south polar terrain by ocean tidal heating requires ocean and shell thicknesses that are significantly smaller than the values inferred from gravity and topography constraints. 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 <1° for eccentricity forcing, and <2.5 m and <18° for obliquity forcing. Measurement of the obliquity phase lag (e.g. by Europa Clipper) would provide a probe of ocean thickness
000003907 536__ $$aPRODEX/$$c4000120791/$$fPlanetInterior
000003907 594__ $$aNO
000003907 6531_ $$aTides, Solid body, Rotational dynamics, Satellites, Dynamics, Europa, Enceladus
000003907 700__ $$aBeuthe, Mikael
000003907 700__ $$aHay, Hamish
000003907 700__ $$aNimmo, Francis
000003907 700__ $$aKamata, Shunichi
000003907 773__ $$c208-230$$pIcarus$$v312$$y2018
000003907 8560_ $$fmikael.beuthe@observatoire.be
000003907 85642 $$ahttps://arxiv.org/abs/1804.07727
000003907 905__ $$apublished in
000003907 980__ $$aREFERD