Three‐dimensional ray tracing of the Jovian magnetosphere in the low‐frequency range

Abstract

Three‐dimensional ray tracing of the Jovian DAM emission has been performed utilizing the O‐4 magnetic field model (Acuna and Ness, 1979) and a realistic plasma model. Minimal assumptions about the emission mechanism have been made that include radiation in the right‐hand extraordinary mode, propagating nearly perpendicular to the field line at source points located just above the RX cutoff frequency along Io flux tubes. We have performed ray tracing in the frequency range from 2–35 MHz from successive Io flux tubes separated by ten degrees of central meridian longitude for a full circumference of northern hemisphere sources. Our results show unusual complexity in model arc spectra that is displayed in a constant Io phase format with many similarities to the Voyager PRA data. The results suggest much of the variation in observed DAM spectral features is a result of propagation effects rather than emission process differences. We feel our work represents a comprehensive ray tracing investigation of DAM arc emission and presentation of the results in a unique format.