A radiation belt‐ring current forecasting model

Abstract

A radiation belt‐ring current (RB‐RC) forecasting model is presented. This model solves the convection‐diffusion equation of plasma distribution in the 10 keV to a few MeV range. There are four major auxiliary components to the RB‐RC model: a global magnetic field model, an electric field model, a plasma sheet model (plasma source), and a radial diffusion model. All four components are driven by solar wind and interplanetary magnetic field conditions. In this paper, a brief description of the model and input parameters is given. This model has been used to simulate several geomagnetic storms. In particular, the effects of the inductive electric field on the evolution of the radiation belt electron fluxes are investigated in detail via a case study of the 12 August 2000 storm. It is found that, in general, the inductive electric field arising from the time‐varying magnetic field can enhance the flux level around geosynchronous orbit during the recovery phase of the storms. The model is validated through comparing the simulation results with the Los Alamos National Laboratory satellite measurements. Further refinement and improvement of the model is also discussed.

Recent developments in the radiation belt environment model

“…A convection-diffusion model, namely the Radiation Belt Environment (RBE) model, has been developed to understand the radiation belt dynamics in order to predict the flux variation during active times (Fok et al, 2001(Fok et al, , 2005(Fok et al, , 2008Zheng et al, 2003). The RBE model employs time-varying, realistic magnetic field so that radial diffusion effects due to slow magnetic fluctuations and inductive radial transport owing to fast magnetic reconfiguration can be modeled.…”

“…They found both chorus wave acceleration and radial diffusion were required to account for the observed increase in relativistic electron flux during the recovery phase. For models that cover a wide range of energy, drift motion must be considered since convection is an important transport mechanism for lower-energy ( o50 keV) particles (Bourdarie et al, 1997;Zheng et al, 2003;Miyoshi et al, 2006;Fok et al, 2008). Using the relativistic kinetic model with dipole magnetic field, Miyoshi et al (2006) simulated the dynamics of energetic electrons during the October 2001 storm.…”

Impact of Solar Wind on the Earth Magnetosphere: Recent Progress in the Modeling of Ring Current and Radiation Belts

“…In most of previous RBE calculations, we used empirical models of magnetic and electric fields (Fok et al, 2005;Fok et al, 2008;Zheng et al, 2003). Variations in magnetic and electric fields are drivers for radial diffusion in RBE.…”

“…(Lyatsky & Khazanov, 2008;Reeves et al, 2011) and references therein; (2) modeling of electron phase space density with Fokker-Plank type equation (e.g. (Albert & Young, 2005;Li et al, 2001;Shprits et al, 2009;Varotsou et al, 2005)); (3) modeling of electron phase space density with combined Fokker-Plank and drift advection equation (Bourdarie et al, 1997;Fok et al, 2008;Miyoshi et al, 2006;Zheng et al, 2003). A necessity including advection terms (for gradient B drift and ExB drift) is dictated by the extension of a model to wider energy and L-shell ranges.…”

Preliminary Global Radiation Belt Formation and Prediction Model

“…A convection-diffusion model [Fok et al, 2001;Zheng et al, 2003;Fok et al, 2008] has been developed to simulate electron radiation belt dynamics. The model was used to simulate a substorm injection during a dipolarization of the magnetic field during a substorm.…”