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  - 
TY  - JOUR
A1  - Drozdov, Alexander
A1  - Shprits, Yuri Y.
A1  - Usanova, Maria E.
A1  - Aseev, Nikita
A1  - Kellerman, Adam C.
A1  - Zhu, H.
T1  - EMIC wave parameterization in the long-term VERB code simulation
JF  - Journal of geophysical research : Space physics
N2  - Electromagnetic ion cyclotron (EMIC) waves play an important role in the dynamics of ultrarelativistic electron population in the radiation belts. However, as EMIC waves are very sporadic, developing a parameterization of such wave properties is a challenging task. Currently, there are no dynamic, activity-dependent models of EMIC waves that can be used in the long-term (several months) simulations, which makes the quantitative modeling of the radiation belt dynamics incomplete. In this study, we investigate Kp, Dst, and AE indices, solar wind speed, and dynamic pressure as possible parameters of EMIC wave presence. The EMIC waves are included in the long-term simulations (1year, including different geomagnetic activity) performed with the Versatile Electron Radiation Belt code, and we compare results of the simulation with the Van Allen Probes observations. The comparison shows that modeling with EMIC waves, parameterized by solar wind dynamic pressure, provides a better agreement with the observations among considered parameterizations. The simulation with EMIC waves improves the dynamics of ultrarelativistic fluxes and reproduces the formation of the local minimum in the phase space density profiles.
KW  - radiation belts
KW  - VERB code
KW  - EMIC
Y1  - 2017
U6  - https://doi.org/10.1002/2017JA024389
SN  - 2169-9380
SN  - 2169-9402
VL  - 122
SP  - 8488
EP  - 8501
PB  - American Geophysical Union
CY  - Washington
ER  -