Jovian dual-sinusoidal HOM lane features observed by Galileo

A well defined sinusoidal-shaped "band" of reduced emission intensity exist s within Jovian HOM from 500 kHz to 3 MHz at all Jovian longitudes as obser ved by the Galileo spacecraft. A less prominent sinusoidal-shaped band feat ure exists in the same frequency range but is 180 degrees out of phase with the more prominent feature. We used a multiple Jovian rotation spectrogram technique to fully display both bands and found that these sinusoidal-shap ed features are the source of the "lanes" previously studied in Voyager and Ulysses data. Our extension of the simple straight-line ray model by Gurne tt et al. [1998] provides a qualitative explanation for the observed featur es. We found that the two sinusoidal bands show an asymmetry about the long itude of the northern tip of the magnetic dipole (202 degrees CML). Enhance ments of emission can be seen along the edges of the bands which may be int erpreted as caustic surfaces.