DOI: 10.1002/2017JA024931
Scopus记录号: 2-s2.0-85045896171
论文题名: Neoclassical Diffusion of Radiation-Belt Electrons Across Very Low L-Shells
作者: Cunningham G.S. ; Loridan V. ; Ripoll J.-F. ; Schulz M.
刊名: Journal of Geophysical Research: Space Physics
ISSN: 21699380
出版年: 2018
卷: 123, 期: 4 起始页码: 2884
结束页码: 2901
语种: 英语
英文关键词: Coulomb collisions
; Fokker-Planck equation
; IGRF
; neoclassical transport across low L-shells
; radial diffusion
英文摘要: In the presence of drift-shell splitting intrinsic to the International Geomagnetic Reference Field magnetic field model, pitch angle scattering from Coulomb collisions experienced by radiation-belt electrons in the upper atmosphere and ionosphere produces extra radial diffusion, a form of neoclassical diffusion. The strength of the neoclassical radial diffusion at L < 1.2 exceeds that expected there from radial-diffusion mechanisms traditionally considered and decreases with increasing L-shell. In this work we construct a numerical model for this coupled (radial and pitch angle) collisional diffusion process and apply it to simulate raw count-rate data observed aboard the Gemini spacecraft for several years after the 1962 Starfish nuclear detonation. The data show apparent lifetimes 10–100 times as long as would have been expected from collisional pitch angle diffusion and Coulomb drag alone. Our model reproduces apparent lifetimes for >0.5-MeV electrons in the region 1.14 < L < 1.26 to within a factor of 2 (comparable to the uncertainty quoted for the observations). We conclude that neoclassical radial diffusion (resulting from drift-shell splitting intrinsic to International Geomagnetic Reference Field's azimuthal asymmetries) mitigates the decay expected from collisional pitch angle diffusion and inelastic energy loss alone and thus contributes importantly to the long apparent lifetimes observed at these low L-shells. ©2018. American Geophysical Union. All Rights Reserved.
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资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/114152
Appears in Collections: 气候减缓与适应
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作者单位: Space Science and Applications, Los Alamos National Laboratory, Los Alamos, NM, United States; CEA, DAM, DIF, Arpajon, France; Lockheed Martin Retiree, Redondo Beach, CA, United States
Recommended Citation:
Cunningham G.S.,Loridan V.,Ripoll J.-F.,et al. Neoclassical Diffusion of Radiation-Belt Electrons Across Very Low L-Shells[J]. Journal of Geophysical Research: Space Physics,2018-01-01,123(4)