Wave Disturbances from the Comet SL-9 Impacts into Jupiter's Atmosphere

Abstract

Wave disturbances due to the Shoemaker–Levy 9 (SL-9) cometary impacts into Jupiter's atmosphere have been simulated with a fully compressible (nonhydrostatic), time-dependent, nonlinear, axisymmetric, f-plane, finite difference computational scheme. Energy is released in a cylindrical region with a radius of 250 to 1000 km as suggested by models of the reentry of impact ejecta following the initial explosion. The model produces outward moving gravity waves at stratospheric altitudes with speeds and relative amplitudes in agreement with observations. The waves emerge from a cylindrical region of alternating inflow and outflow that extends high into the atmosphere in the main region of energy release. The disturbances originate as horizontally propagating waves at the periphery of this region, thereby providing an explanation for the observed large initial radius (∼450–700 km) of the main ring. The model results suggest that the waves are made visible by the inflow of particulate impact debris into outward moving rings of wave horizontal convergence. The inner edge of the extensive clear zone outside of the main dark ring may be the divergence phase of the leading fast wave. The results of this study remove the necessity to invoke a stable, water-rich, wave-trapping layer in Jupiter's atmosphere in order to understand the Comet SL-9 observations of dark wave-like rings expanding radially away from the impact sites.