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Event‐specific chorus wave and electron seed population models in DREAM3D using the Van Allen Probes
Author(s) -
Tu Weichao,
Cunningham G. S.,
Chen Y.,
Morley S. K.,
Reeves G. D.,
Blake J. B.,
Baker D. N.,
Spence H.
Publication year - 2014
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1002/2013gl058819
Subject(s) - van allen probes , chorus , van allen radiation belt , population , physics , computational physics , pitch angle , storm , diffusion , event (particle physics) , amplitude , statistical physics , magnetosphere , meteorology , geophysics , astrophysics , plasma , optics , nuclear physics , art , literature , demography , sociology , thermodynamics
The DREAM3D diffusion model is applied to Van Allen Probes observations of the fast dropout and strong enhancement of MeV electrons during the October 2012 “double‐dip” storm. We show that in order to explain the very different behavior in the two “dips,” diffusion in all three dimensions (energy, pitch angle, and L * ) coupled with data‐driven, event‐specific inputs, and boundary conditions is required. Specifically, we find that outward radial diffusion to the solar wind‐driven magnetopause, an event‐specific chorus wave model, and a dynamic lower‐energy seed population are critical for modeling the dynamics. In contrast, models that include only a subset of processes, use statistical wave amplitudes, or rely on inward radial diffusion of a seed population, perform poorly. The results illustrate the utility of the high resolution, comprehensive set of Van Allen Probes' measurements in studying the balance between source and loss in the radiation belt, a principal goal of the mission.