Plasma Wave Observations at Earth, Jupiter, and Saturn

Plasma wave emissions have been detected at all of the planets that have been visited by spacecraft equipped with plasma wave instruments. (Mercury will be explored by the plasma wave instrument on BepiColombo Mercury Magnetospheric Orbiter in 2022.) Many of these emissions are believed to play a role in the acceleration of energetic particles, especially those observed in association with the radiation belts of Earth, Jupiter, and Saturn. Wave-particle interactions involving whistler mode chorus, hiss, equatorial noise, and electron cyclotron harmonics participate in both the acceleration and loss of these radiation belt particles and play a major role in radiation belt dynamics throughout the solar system. The effects of these wave modes, their occurrence probabilities, their amplitudes, and their relationships to solar wind properties and geomagnetic storm conditions have been investigated using a variety of spacecraft observations. This paper summarizes these studies and discusses the similarities and differences of the plasma waves detected at Earth, Jupiter, and Saturn.