GLOBAL OSCILLATION AMPLITUDES EXCITED BY THE JUPITER COMET COLLISION

The energy released during the collision of fragments of comet Shoemak er-Levy 9 with Jupiter in 1994 July may excite a spectrum of global os cillation modes. We estimate the maximum amplitudes to which the p-mod es, 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 10(30) ergs, is converted into the energy of each individual mod e. We have used two realistic Jovian models as the basis for our estim ates: 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-frequen cy p-modes, with periods less than or similar to 15 minutes, may be ex cited to sufficiently large amplitudes to be observable as Doppler shi fts (velocity amplitudes greater than or similar to several m s-1) or temperature variations (deltaT greater than or similiar to 0.01 K) at the planetary surface. Inertial modes may also be observable. If the P PT exists in Jupiter, inertial modes with periods approximately 8 hr o r approximately 2.2 days trapped in the surface region of the planet, above the PPT, may be detectable as temperature fluctuations of order deltaT approximately 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 approx imately 8-8.5 hr have much lower amplitudes. In this case, inertial mo des with periods longer than approximately 18 hr may produce temperatu re fluctuations of order deltaT approximately 0.01 K. Discontinuity mo des associated with the PPT and r-modes unfortunately may not reach ob servable amplitudes.