The energy released during the collision of fragments of comet Shoemaker-Levy 9 with Jupiter in 1994 July may excite a spectrum of global oscillation modes. We estimate the maximum amplitudes to which the p-modes, discontinuity modes, inertial modes, and r-modes can be excited by assuming that the full kinetic energy of the fragment, which we take to be 1030 ergs, is converted into the energy of each individual mode. We have used two realistic Jovian models as the basis for our estimates: one with and one without the predicted "plasma phase transition" (PPT) of hydrogen. A density discontinuity in the planet's hydrogen-helium envelope is associated with the PPT. We find that high-frequency p-modes, with periods ≲15 minutes, may be excited to sufficiently large amplitudes to be observable as Doppler shifts (velocity amplitudes ≳ several m s-1) or temperature variations (δT ≳ 0.01 K) at the planetary surface. Inertial modes may also be observable. If the PPT exists in Jupiter, inertial modes with periods ∼ 8 hr or ∼ 2.2 days trapped in the surface region of the planet, above the PPT, may be detectable as temperature fluctuations of order δT ∼ 0.01 K. Inertial modes with periods of order 8-8.5 hr appear to be particularly strongly excited if the PPT exists. If the PPT does not exist in Jupiter, intertial modes with periods ∼8-8.5 hr have much lower amplitudes. In this case, inertial modes with periods longer than ∼18 hr may produce temperature fluctuations of order δT ∼ 0.01 K. Discontinuity modes associated with the PPT and r-modes unfortunately may not reach observable amplitudes.
- Comets: individual (Shoemaker-Levy 9)
- Planets and satellites: individual (Jupiter)
ASJC Scopus subject areas
- Astronomy and Astrophysics
- Space and Planetary Science