The Role of Cold Plasma and its Composition on the Growth of EMIC Waves in the Inner Magnetosphere

Jesse M. Snelling, Andrews University


While it is currently well accepted that the free energy for growth of electromagnetic ion cyclotron (EMIC) waves in Earth's magnetosphere comes from unstable configurations of hot anisotropic ions injected into the ring current, in some cases the measured anisotrophy is not adequate to explain local instability. Additionally, the relative importance of the density and composition of a cold plasma population is uncertain. In this study, several intervals of observed EMIC wave activity are analyzed using WHAMP stability code with fitted plasma distributions to determine the role of a cold population in driving instability on each of the wave branches.