Equatorial electron density measurements in Saturn's inner magnetosphere

Abstract

Upper hybrid resonance emissions detected by the Radio and Plasma Wave Science (RPWS) instrument on the Cassini spacecraft are used to obtain electron densities on five equatorial orbits of Saturn at radial distances ranging from 3 to 9 saturnian radii (R S ). The electron density profiles for these orbits show a highly repeatable radial dependence beyond 5 R S , decreasing with increasing radial distance approximately as (1/R) 3.63 . Inside 5 R S , the electron density profiles are highly variable. We show that these radial variations are consistent with a centrifugally‐driven outward transport of plasma from a source inside 5 R S .