Angular momentum exchange between the atmosphere/hydrosphere and interior of Saturn's moon Titan and its influence on Titan's rotation

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Saturn’s largest moon Titan possesses a dense atmosphere and a hydrological cycle with hydrocarbons. Therefore, temporal variation in the rotation rate and wobble of the rotational axis by the redistribution and motion of the atmosphere and hydrosphere can be expected by analogy with the Earth. Recent observations by the Cassini spacecraft show first evidence of a large variable rotation of Titan as theoretically predicted and open the possibility to investigate the mechnical coupling between the geophysical fluid and interior. This project aims at comprehensive and quantiative assessment of the exchange of angular momentum between the atmosphere/hydrosphere and the interior of Titan and the rotational response of Titan on seasonal timescales. Atmospheric motion and mass loading together with hydrocarbon hydrology, as implied by the precipitation and the existence of polar lakes, will be quantified. The sensitivity of the angular momentum transfer to the internal coupling in the interior will be investigated considering different interior models. Model results will be compared with ongoing geodetic measurements by Cassini to constrain the yet poorly constrained atmospheric angular momentum budget of Titan.