TY  - JOUR
A1  - Castillo, Angelica M.
A1  - Shprits, Yuri Y.
A1  - Ganushkina, Natalia
A1  - Drozdov, Alexander
A1  - Aseev, Nikita
A1  - Wang, Dedong
A1  - Dubyagin, Stepan
T1  - Simulations of the inner magnetospheric energetic electrons using the IMPTAM-VERB coupled model
JF  - Journal of Atmospheric and Solar-Terrestrial Physics
N2  - In this study, we present initial results of the coupling between the Inner Magnetospheric Particle Transport and Acceleration Model (IMPTAM) and the Versatile Electron Radiation Belt (VERB-3D) code. IMPTAM traces electrons of 10-100 keV energies from the plasma sheet (L = 9 Re) to inner L-shell regions. The flux evolution modeled by IMPTAM is used at the low energy and outer L* computational boundaries of the VERB code (assuming a dipole approximation) to perform radiation belt simulations of energetic electrons. The model was tested on the March 17th, 2013 storm, for a six-day period. Four different simulations were performed and their results compared to satellites observations from Van Allen probes and GOES. The coupled IMPTAM-VERB model reproduces evolution and storm-time features of electron fluxes throughout the studied storm in agreement with the satellite data (within similar to 0.5 orders of magnitude). Including dynamics of the low energy population at L* = 6.6 increases fluxes closer to the heart of the belt and has a strong impact in the VERB simulations at all energies. However, inclusion of magnetopause losses leads to drastic flux decreases even below L* = 3. The dynamics of low energy electrons (max. 10s of keV) do not affect electron fluxes at energies >= 900 keV. Since the IMPTAM-VERB coupled model is only driven by solar wind parameters and the Dst and Kp indexes, it is suitable as a forecasting tool. In this study, we demonstrate that the estimation of electron dynamics with satellite-data-independent models is possible and very accurate.
KW  - Electron populations
KW  - Radiation belts
KW  - IMPTAM
KW  - VERB
Y1  - 2019
U6  - https://doi.org/10.1016/j.jastp.2019.05.014
SN  - 1364-6826
SN  - 1879-1824
VL  - 191
PB  - Elsevier
CY  - Oxford
ER  - 
TY  - JOUR
A1  - Zhu, Hui
A1  - Shprits, Yuri Y.
A1  - Spasojevic, M.
A1  - Drozdov, Alexander
T1  - New hiss and chorus waves diffusion coefficient parameterizations from the Van Allen Probes and their effect on long-term relativistic electron radiation-belt VERB simulations
JF  - Journal of Atmospheric and Solar-Terrestrial Physics
N2  - New wave frequency and amplitude models for the nightside and dayside chorus waves are built based on measurements from the Electric and Magnetic Field Instrument Suite and Integrated Science (EMFISIS) instrument onboard the Van Allen Probes. The corresponding 3D diffusion coefficients are systematically obtained. Compared with previous commonly-used (typical) parameterizations, the new parameterizations result in differences in diffusion rates that depend on the energy and pitch angle. Furthermore, one-year 3D diffusive simulations are performed using the Versatile Electron Radiation Belt (VERB) code. Both typical and new wave parameterizations simulation results are in a good agreement with observations at 0.9 MeV. However, the new parameterizations for nightside chorus better reproduce the observed electron fluxes. These parameterizations will be incorporated into future modeling efforts.
KW  - Inner magnetosphere
KW  - Radiation belts
KW  - Chorus waves
KW  - Diffusion coefficients
KW  - VERB code
Y1  - 2019
U6  - https://doi.org/10.1016/j.jastp.2019.105090
SN  - 1364-6826
SN  - 1879-1824
VL  - 193
PB  - Elsevier
CY  - Oxford
ER  -