The gyroresonant interaction between electromagnetic ion cyclotron (EMIC) wavesand energetic particles was studied in a multi-ion (H^+, He^+, and O^+) plasma. The minimumresonant energy E_min, resonant wave frequency ω, and pitch angle diffusion coefficient D_(αα) werecalculated at the center location of the symmetrical ring current: r 3.5R_E with R_E the Earth'sradius. E_(min) is found to decrease rapidly from 10 MeV to a few keV with the increase in ω in threebands: H^+-band, He^+-band and O^+-band. Moreover, EMIC waves have substantial potential toscatter energetic (～100 keV) ions (mainly H^+ and He^+) into the loss cone and yield precipitationloss, suggesting that wave-particle interactions contribute to ring current decay.
Primary result on the impact of the latitudinal distribution of whistler-mode chorusupon temporal evolution of the phase space density (PSD) of outer radiation belt energetic elec-trons was presented. We evaluate diffusion rates in pitch angle and momentum due to a band ofchorus frequency distributed at a standard Gaussian spectrum, and solve a 2-D bounce-averagedmomentum-pitch-angle Fokker-Planck equation at L = 4.5. It is shown that chorus is effective inaccelerating electrons and can increase PSD for energy of 1 MeV by a factor of 10 or more inabout one day, which is consistent with observation. Moreover, the latitudinal distribution of cho-rus has a great impact on the acceleration of electrons. As the latitudinal distribution increases,the efficient acceleration region extends from higher pitch angles to lower pitch angles, and evencovers the entire pitch angle region when chorus power reaches the maximum latitude λ_m = 45°.
The dynamic global core plasma model(DGCPM) is used in this paper to calculate the He+ density distribution of the Earth's plasmasphere and to investigate the configurations and 30.4 nm radiation properties of the plasmasphere.Validation comparisons between the simulation results and IMAGE mission observations show:That the equatorial structure of the plasmapause is mainly located near 5.5 RE and the typical scale of plasmasphere shrinking or expansion within 10 min is approximately 0.1 RE;that the plasmaspheric shoulders are formed and rotate noon-ward from the dawn sector under the conditions of strong southward turning of the interplanetary magnetic field(IMF);that the plasmaspheric plumes will rotate dawn-ward from the night sector and become narrow for the southward turning of the IMF.The simulated images from the lunar orbit show that the plasmasphere locating within the geocentric distance of 5.5 RE corresponds to field of view(FOV) of 10.7°×10.7° for the moon-based EUV imager,and that the 30.4 nm radiation intensity of the plasmasphere is 0.1-11.4 R.The plasmaspheric shoulders and plumes locating toward the moon-side are for the first time simulated with typical scale level of 0.1 RE from the side view of the moon.These simulated results provide an important theoretical basis for the lunar-based EUV camera design.
A new three-dimensional asymmetric magnetopause model has been developed for corrected GSM coordinates and par...
R. L. Lin1,2 X. X. Zhang3 S. Q. Liu1 Y. L. Wang4 J. C. Gong1 1Center for Space Science and Applied Research, Chinese Academy of Sciences, Beijing, China 2Graduate University of Chinese Academy of Sciences, Beijing, China 3 National Center for Space Weather, China Meteorological Administration, Beijing, China 4 NASA/Goddard Space Flight Center, Greenbelt, Maryland, USA
Interactions between very/extremely low frequency (VLF/ELF) waves and energetic electrons play a fundamental role in dynamics occurring in the inner magnetosphere. Here, we briefly discuss global properties of VLF/ELF waves, along with the variability of the electron radiation belts associated with wave-particle interactions and radial diffusion. We provide cases of electron loss and acceleration as a result of wave-particle interactions primarily due to such waves, and particularly some preliminary results of 3D evolution of phase space density from our currently developing 3D code. We comment on the existing mechanisms responsible for acceleration and loss, and identify several critical issues that need to be addressed. We review latest progress and suggest open questions for future investigation.
XIAO FuLiang1,2, ZONG QiuGang3, SU ZhenPeng4, TIAN Tian3 & ZHENG HuiNan4 1 School of Physics and Electronic Sciences, Changsha University of Science and Technology, Changsha 410004, China
