Radial and Latitudinal Distributions of the Exohiss Under the Effect of Landau Damping

Abstract

Exohiss serves as a typical imprint of the outward energy release from plasmaspheric hiss. The distribution of exohiss under the effect of Landau damping has not been thoroughly evaluate. On the basis of observations from the Van Allen Probes on 17 February 2014, we performed two-dimensional ray tracing simulations to model the evolution of hiss waves propagating from the geomagnetic equator in plasmasphere. The results show that the hiss wave power decreases rapidly as the waves enter the plasmatrough under the enhanced Landau damping effect of hot electrons. Furthermore, we perform a statistical analysis of the simulation results from multiple rays and obtain the radial, latitudinal, and frequency distributions of the exohiss wave power. The modeled distribution characteristics of exohiss align well with observations, suggesting that Landau damping is crucial in shaping the morphology of exohiss in the inner magnetosphere.