Unusual high frequency EMIC waves: Detailed analysis of EMIC wave excitation and energy coupling between EMIC and magnetosonic waves

A recent event study suggested a coupling process whereby suprathermal protons (10–100 eV), as result of perpendicular heating by pre-existing magnetosonic waves, can excite electromagnetic ion cyclotron (EMIC) waves with frequency near the local proton (f~0.95fcp). The present tests this process. First, one-dimensional hybrid (kinetic ions/massless fluid electrons) simulations parallel-propagating EMIC initialized plasma conditions derived from prove that high be generated anisotropic instead more energetic (10s keV) ring current protons. Calculation quasilinear pitch-angle diffusion coefficient for electrons using simulated suggests these outside plasmasphere play role in scattering ~MeV due to large wavenumber excited waves. Second, is examined theory and simple test particle calculation. It found becomes ineffective energies relevant protons, indicating low-energy (<10 eV) cannot efficiently energized observed level through multi-harmonic resonances observed. Rather, some kind non-resonant may have been at play, if were actually involved heating. This quantitative understanding energy needed.