Simultaneous event-specific estimates of transport, loss, and source rates for relativistic outer radiation belt electrons

TitleSimultaneous event-specific estimates of transport, loss, and source rates for relativistic outer radiation belt electrons
Publication TypeJournal Article
Year of Publication2017
AuthorsSchiller, Q, Tu, W, Ali, AF, Li, X, Godinez, HC, Turner, DL, Morley, SK, Henderson, MG
JournalJournal of Geophysical Research: Space Physics
Date Published03/2017
KeywordsCubeSat; data assimilation; electron; event specific; Modeling; Radiation belt; Van Allen Probes
AbstractThe most significant unknown regarding relativistic electrons in Earth's outer Van Allen radiation belt is the relative contribution of loss, transport, and acceleration processes within the inner magnetosphere. Detangling each individual process is critical to improve the understanding of radiation belt dynamics, but determining a single component is challenging due to sparse measurements in diverse spatial and temporal regimes. However, there are currently an unprecedented number of spacecraft taking measurements that sample different regions of the inner magnetosphere. With the increasing number of varied observational platforms, system dynamics can begin to be unraveled. In this work, we employ in situ measurements during the 13–14 January 2013 enhancement event to isolate transport, loss, and source dynamics in a one-dimensional radial diffusion model. We then validate the results by comparing them to Van Allen Probes and Time History of Events and Macroscale Interactions during Substorms observations, indicating that the three terms have been accurately and individually quantified for the event. Finally, a direct comparison is performed between the model containing event-specific terms and various models containing terms parameterized by geomagnetic index. Models using a simple 3/Kp loss time scale show deviation from the event-specific model of nearly 2 orders of magnitude within 72 h of the enhancement event. However, models using alternative loss time scales closely resemble the event-specific model.
Short TitleJ. Geophys. Res. Space Physics

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