Impact of cold O+ ions on the generation and evolution of EMIC waves

摘要: [1] We explore the effect of cool O+ ions (~11 eV) on generation and nonlinear evolution electromagnetic ion cyclotron (EMIC) waves in magnetosphere, using hybrid (kinetic ions, fluid electrons) simulations with a dipolar magnetic field. The instability is driven by temperature anisotropy hot (keV), ring current protons whose density few percent background plasma consisting cold (eV) concentrations varying between 0 30% protons. results show that for concentration 7% or less, properties EMIC are similar to those absence where generated at low latitudes propagate all way ionospheric boundary. Further increases (~15%) result being confined latitude due processes explored this paper. At densities higher, growth weak non-existent resonant damping ions. Comparing runs no 15% shows propagation change dramatically presence Specifically, they propagating parallel anti-parallel field both hemispheres reflection points move higher time. This turn aligned electrostatic large perturbations also local heating these Examination wave only present regions space larger than 1% level. In other words, controlled finding further confirmed performing test simulation which reaching 22° removed from run resulting confinement lower latitudes.