Nonradial oscillations of Saturn

The periods of the natural oscillation modes of the Jovian planets are sensitive to the interior states of these planets. Since the f-mode oscillations of Saturn may be detected through their gravitational signature in the rings of that planet, this paper examines the sensitivity of these modes to variations in the assumed state of the planetary interior. Mode periods are calculated for a variety of interior models, envelope compositions, and hydrogen phase transition pressures spanning the range of the current uncertainty in these quantities. It is found that the low degree f-modes are most sensitive to the size of the planetary core while the higher degree modes are most sensitive to the rotation state of the outer layers of the planet. The physical causes of these period variations are discussed. While the predicted mode amplitudes are uncertain, displacements at the surface are unlikely to exceed ∼ 1 m.