Combined convective and diffusive simulations: VERB‐4D comparison with 17 March 2013 Van Allen Probes observations. Issue 22 (19th November 2015)

• Record Type: Journal Article
• Authors: Shprits, Yuri Y.; Kellerman, Adam C.; Drozdov, Alexander Y.; Spence, Harlan E.; Reeves, Geoffrey D.; Baker, Daniel N.
• Is Part Of: Geophysical research letters. Volume 42:Issue 22(2015:Nov.)
• Page Start: 9600
• Page End: 9608
• Publication Date: 2015-11-19
• Subjects: radiation belts -- inner magnetosphere -- Van Allen Probes -- ring current -- numerical simulations -- wave‐particle interactions; Geophysics -- Periodicals; Planets -- Periodicals; Lunar geology -- Periodicals; 550
• DOI: 10.1002/2015GL065230
• Languages: English
• ISSNs: 0094-8276

Abstract

Abstract: This study is focused on understanding the coupling between different electron populations in the inner magnetosphere and the various physical processes that determine evolution of electron fluxes at different energies. Observations during the 17 March 2013 storm and simulations with a newly developed Versatile Electron Radiation Belt‐4D (VERB‐4D) are presented. Analysis of the drift trajectories of the energetic and relativistic electrons shows that electron trajectories at transitional energies with a first invariant on the scale of ~100 MeV/G may resemble ring current or relativistic electron trajectories depending on the level of geomagnetic activity. Simulations with the VERB‐4D code including convection, radial diffusion, and energy diffusion are presented. Sensitivity simulations including various physical processes show how different acceleration mechanisms contribute to the energization of energetic electrons at transitional energies. In particular, the range of energies where inward transport is strongly influenced by both convection and radial diffusion are studied. The results of the 4‐D simulations are compared to Van Allen Probes observations at a range of energies including source, seed, and core populations of the energetic and relativistic electrons in the inner magnetosphere. Key Points: Both convection and radial diffusion significantly contribute to transport at transitional energies VERB‐4D simulations qualitatively agree with observations from tens of keV to MeV Convection, radial, pitch angle, energy, and mixed diffusion all play an important role