KINETIC-MODEL OF THE RING CURRENT-ATMOSPHERE INTERACTIONS

Citation
Vk. Jordanova et al., KINETIC-MODEL OF THE RING CURRENT-ATMOSPHERE INTERACTIONS, J GEO R-S P, 102(A7), 1997, pp. 14279-14291
Citations number
39
Categorie Soggetti
Geosciences, Interdisciplinary","Astronomy & Astrophysics","Metereology & Atmospheric Sciences
Journal title
JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS
ISSN journal
21699380 → ACNP
Volume
102
Issue
A7
Year of publication
1997
Pages
14279 - 14291
Database
ISI
SICI code
2169-9380(1997)102:A7<14279:KOTRCI>2.0.ZU;2-7
Abstract
Our numerical model of the ring current-atmosphere coupling (RAM) is f urther developed in order to include wave-particle interaction process es. The model calculates the time evolution of the phase space distrib ution function in the region from 2 R-E to 6.5 R-E, considering losses due to charge exchange, Coulomb collisions, and plasma wave scatterin g along ion drift paths. The spatial regions of ion cyclotron wave ins tability are determined by calculating the convective growth rates for electromagnetic ion cyclotron (EMIC) waves, integrating them along wa ve paths, and selecting regions of maximum wave amplification The sour ce regions are located on the duskside in agreement with the predomina nt occurrence of EMIC waves. A spectral power density of 1 nT(2)/Hz is adopted within the unstable regions. According to quasi-linear theory , the fluctuating fields are regarded as imposed on the system, and th e losses due to wave-particle interactions are described with diffusiv e processes. The effects of the presence of heavy ion components on th e quasi-linear diffusion coefficients are also considered. Resonance w ith ion cyclotron waves reduce the anisotropy of the proton population and the unstable regions disappear with time. Global patterns of prec ipitating ion fluxes are obtained and compared with observations.