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Global Simulation of Electromagnetic Ion Cyclotron WavesIt is well known that the effects of electromagnetic ion cyclotron (EMIC) waves on ring current (RC) ion and radiation belt (RB) electron dynamics strongly depend on such particle/wave characteristics as the phase-space distribution function, frequency, wave-normal angle, wave energy, and the form of wave spectral energy density. The consequence is that accurate modeling of EMIC waves and RC particles requires robust inclusion of the interdependent dynamics of wave growth/damping, wave propagation, and particles. Such a self-consistent model is being progressively developed by Khazanov et al. [2002 - 2007]. This model is based on a system of coupled kinetic equations for the RC and EMIC wave power spectral density along with the ray tracing equations. We will discuss the recent progress in understanding EMIC waves formation mechanisms in the inner magnetosphere. This problem remains unsettled in spite of many years of experimental and theoretical studies. Modern satellite observations by CRRES, Polar and Cluster still do not reveal the whole picture experimentally since they do not stay long enough in the generation region to give a full account of all the spatio-temporal structure of EMIC waves. The complete self-consistent theory taking into account all factors significant for EMIC waves generation remains to be developed. Several mechanisms are discussed with respect to formation of EMIC waves, among them are nonlinear modification of the ionospheric reflection by precipitating energetic protons, modulation of ion-cyclotron instability by long-period (Pc3/4) pulsations, reflection of waves from layers of heavy-ion gyroresonances, and nonlinearities of wave generation process. We show that each of these mechanisms have their attractive features and explains certain part experimental data but any of them, if taken alone, meets some difficulties when compared to observations. We conclude that development of a refined nonlinear theory and further correlated analysis of modern satellite and ground-based data is needed to solve this very intriguing problem.
Document ID
20080013289
Acquisition Source
Marshall Space Flight Center
Document Type
Conference Paper
Authors
Khazanov, G. V.
(NASA Marshall Space Flight Center Huntsville, AL, United States)
Gamayunov, K.
(NASA Marshall Space Flight Center Huntsville, AL, United States)
Gallagher, D. L.
(NASA Marshall Space Flight Center Huntsville, AL, United States)
Kozyra, J. U.
(NASA Marshall Space Flight Center Huntsville, AL, United States)
Date Acquired
August 24, 2013
Publication Date
December 10, 2007
Subject Category
Physics (General)
Meeting Information
Meeting: 2007 Fall Meeting of the American Geophysical Union
Location: San Francisco, CA
Country: United States
Start Date: December 10, 2007
End Date: December 14, 2007
Distribution Limits
Public
Copyright
Work of the US Gov. Public Use Permitted.

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