Global simulation of EMIC wave excitation during the 21 April 2001 storm from coupled RCM‐RAM‐HOTRAY modeling

Abstract

The global distribution and spectral properties of electromagnetic ion cyclotron (EMIC) waves in the He + band are simulated for the 21 April 2001 storm using a combination of three different codes: the Rice Convection Model, the Ring current‐Atmospheric interactions Model, and the HOTRAY ray tracing code (incorporated with growth rate solver). During the storm main phase, injected ions exhibit a non‐Maxwellian distribution with pronounced phase space density minima at energies around a few keV. Ring current H + injected from the plasma sheet provides the source of free energy for EMIC excitation during the storm. Significant wave gain is confined to a limited spatial region inside the storm time plume and maximizes at the eastward edge of the plume in the dusk and premidnight sector. The excited waves are also able to resonate and scatter relativistic electrons, but the minimum electron resonant energy is generally above 3 MeV.