Analytical study of electromagnetic ion cyclotron wave for ring distribution with AC electric field in Saturn magnetosphere

Abstract

Characteristics of electromagnetic ion cyclotron waves in Saturn inner magnetosphere has been investigated here in close proximity of equatorial plane at approximately mid of the E ring near 5Rs by using data sets released by Voyager and Cassini spacecraft. Previous encounter of these spacecraft with Saturn exposed the strong signature of EMIC wave and harmonics believed to be originated within 7.5 Rs due to dominant O+ ions and water group ions. Maxwellian ring distribution for pickup ions contributing ring around planet is opted to find unperturbed particle density. Therefore, investigating here growth of obliquely propagating EMIC wave undergoing wave particle mechanism by opting kinetic approach to establish mathematical dispersion model in view of different parameters and extended to comparative study for parallel propagation. Parametric analysis inferred that waves propagating in the oblique direction grows more as compare to parallel propagating waves for the extended value of temperature anisotropy and the angle of propagation with respect to the ambient magnetic field B (at equator) and second harmonic of ion cyclotron waves indicating that the modified ion cyclotron wave shifts the wave spectra to higher side with increase in bandwidth. Study can be carried out to analyze other instabilities to explore magnetospheric dynamics at different radial distances.