Relativistic Electron Increase During Chorus Wave Activities on the 6–8 March 2016 Geomagnetic Storm

Abstract

There was a geomagnetic storm on 6–8 March 2016, in which Van Allen Probes A and B separated by ∼2.5 h measured increase of relativistic electrons with energies approximately several hundred keV to 1 MeV. Simultaneously, chorus waves were measured by both Van Allen Probes and Magnetospheric Multiscale (MMS) mission. Some of the chorus elements were rising tones, possibly due to nonlinear effects. These measurements are compared with a nonlinear theory of chorus waves incorporating the inhomogeneity ratio and the field equation. From this theory, a chorus wave profile in time and one‐dimensional space is simulated. Test particle calculations are then performed in order to examine the energization rate of electrons. Some electrons are accelerated, although more electrons are decelerated. The measured time scale of the electron increase is inferred to be consistent with this nonlinear theory.

The Electric and Magnetic Fields Instrument Suite and Integrated Science (EMFISIS): Science, Data, and Usage Best Practices

“…Numerous follow-up studies have confirmed the critical role played by chorus waves in accelerating electrons to relativistic (MeV) and ultra-relativistic (several MeV) energies, elucidating the controlling roles of boundary conditions, storm type (CME compared to CIR storms), injections, and other wave types such as ULF and hiss (Tu et al 2014;Xiao et al 2014;Li et al 2014b;Su et al 2014a;Liu et al 2015;Katsavrias et al 2015;Matsui et al 2017;Yang et al 2018;Hua et al 2018;Bingham et al 2018;Zhang et al 2020).…”

Quantitative Assessment of Radiation Belt Modeling

“…There are four main types of RB models: (1) Fokker-Planck diffusion models, which are based on the Fokker-Planck diffusion equation operating in the adiabatic invariant space (e.g., Subbotin et al, 2011;Tu et al, 2013); (2) convection-diffusion models which, besides diffusion, also include the drift phase of RB electrons (e.g., Fok et al, 2008;Jordanova et al, 2016); (3) test particle codes which trace a large number of test particles in given global electric and magnetic fields or some analytical wave models (e.g., Kress et al, 2007;Matsui et al, 2017); and (4) particle-in-cell codes and hybrid codes, which include the 10.1029/2018JA026414…”

“…There are four main types of RB models: (1) Fokker‐Planck diffusion models, which are based on the Fokker‐Planck diffusion equation operating in the adiabatic invariant space (e.g., Albert et al, ; Subbotin et al, ; Tu et al, ); (2) convection‐diffusion models which, besides diffusion, also include the drift phase of RB electrons (e.g., Fok et al, ; Jordanova et al, ); (3) test particle codes which trace a large number of test particles in given global electric and magnetic fields or some analytical wave models (e.g., Kress et al, ; Matsui et al, ); and (4) particle‐in‐cell codes and hybrid codes, which include the feedback from plasma to fields (e.g., Camporeale, ). Models of Types 1–3 can provide global evolution of RB electrons with Types 1 and 2 being more efficient, though relying on the assumptions of diffusion and quasilinear theory, and Type 3 being more computationally expensive.…”