Numerical study of tides in Ontario Lacus, a hydrocarbon lake on the surface of the Saturnian moon Titan
David Vincent (Université Catholique de Louvain)
Özgur Karatekin (Royal Observatory of Belgium)
Valentin Vallaeys (Université Catholique de Louvain)
Alexander G Hayes (Cornell University)
Marco Mastrogiuseppe (Cornell University)
Claudia Notarnicola (EURAC - Institute for Applied Remote Sensing)
Véronique Dehant (Université Catholique de Louvain, Royal Observatory of Belgium)
E.L.C. Deleersnijder (TU Delft - Mathematical Physics, Université Catholique de Louvain)
More Info
expand_more
Other than for strictly personal use, it is not permitted to download, forward or distribute the text or part of it, without the consent of the author(s) and/or copyright holder(s), unless the work is under an open content license such as Creative Commons.
Abstract
In the context of the emergence of extraterrestrial oceanography, we adapted an existing oceanographic model, SLIM (www.climate.be/slim), to the conditions of Titan, a moon of Saturn. The tidal response of the largest southern lake at Titan’s surface, namely Ontario Lacus, is simulated. SLIM solves the 2D, depth-averaged shallow water equations on an unstructured mesh using the discontinuous Galerkin finite element method, which allows for high spatial resolution wherever needed. The impact of the wind forcing, the bathymetry, and the bottom friction is also discussed. The predicted maximum tidal range is about 0.56 m in the southern part of the lake, which is more than twice as large as the previous estimates (see Tokano, Ocean Dyn 60:(4) 803–817
doi:10.1007/s10236-010-0285-3 2010). The patterns and magnitude of the current are also markedly different from those of previous studies: the tidal motion is not aligned with the major axis of the lake and the speed is larger
nearshore. Indeed, the main tidal component rotates clockwise in an exact period of one Titan day and the tidal currents can reach 0.046 ms−1 close to the shores depending on the geometry and the bathymetry. Except for these
specific nearshore regions, the current speed is less than 0.02 ms−1. Circular patterns can be observed offshore, their rotational direction and size varying along the day.