2026/02/12 by Jim Fuller, Marzia Parisi, Steve Markham +2
Physics and Astronomy · Earth and Planetary Sciences · Biochemistry, Genetics and Molecular Biology · #Astro and Planetary Science #High-pressure geophysics and materials #Geomagnetism and Paleomagnetism Studies
paper · pdf · doi:10.3847/psj/ae7bf4
Abstract The excitation and damping mechanisms for oscillation modes of gas giant planets are undetermined. We show that differential rotation may greatly enhance the convective viscosity in giant planets, resulting in damping times of t damp ∼ 10 5 –10 6 yr for f -modes and low-order p -modes. Radiative diffusion damps p -modes on timescales of t damp ∼ 10 3 –10 7 yr. While the lethargic convective motions cannot effectively excite f- mode or p- modes, storms driven by condensation of water and/or silicates may play a role. High-order p- modes are most effectively excited by cometary/asteroid impacts. Applying these calculations to solar system planets, water storms, rock storms, and impacts may all contribute to exciting the observed f- mode amplitudes of Saturn via ring seismology. Similar f- mode amplitudes with fractional gravitational perturbations of δ Φ/Φ ∼ 10 −10 –10 −9 are expected for Jupiter and Uranus, apart from their lowest- ℓ f- modes, which could have larger gravitational perturbations of δ Φ/Φ ∼ 10 −7 . Rock storms may contribute to mode driving in Jupiter, while water storms are more important for Uranus. The highest-amplitude p- modes are predicted to have periods of ∼10–30 minutes, with surface velocities of ∼10 cm s −1 for Jupiter and Saturn and ∼1 cm s −1 for Uranus. These oscillation modes may be detectable with radial velocity measurements, ring seismology, or spacecraft Doppler tracking. However, both the damping and excitation physics are uncertain by orders of magnitude, so more careful examination of the relevant physics is required for robust estimates.