TY  - JOUR
A1  - Shprits, Yuri Y.
A1  - Drozdov, Alexander Y.
A1  - Spasojevic, Maria
A1  - Kellerman, Adam C.
A1  - Usanova, Maria E.
A1  - Engebretson, Mark J.
A1  - Agapitov, Oleksiy V.
A1  - Zhelavskaya, Irina S.
A1  - Raita, Tero J.
A1  - Spence, Harlan E.
A1  - Baker, Daniel N.
A1  - Zhu, Hui
A1  - Aseev, Nikita A.
T1  - Wave-induced loss of ultra-relativistic electrons in the Van Allen radiation belts
JF  - Nature Communications
Y1  - 2016
U6  - https://doi.org/10.1038/ncomms12883
SN  - 2041-1723
VL  - 7
PB  - Nature Publ. Group
CY  - London
ER  - 
TY  - JOUR
A1  - Kronberg, Elena A.
A1  - Rashev, M. V.
A1  - Daly, P. W.
A1  - Shprits, Yuri Y.
A1  - Turner, D. L.
A1  - Drozdov, Alexander Y.
A1  - Dobynde, M.
A1  - Kellerman, Adam C.
A1  - Fritz, T. A.
A1  - Pierrard, V.
A1  - Borremans, K.
A1  - Klecker, B.
A1  - Friedel, R.
T1  - Contamination in electron observations of the silicon detector on board
JF  - Space Weather: The International Journal of Research and Applications
N2  - Since more than 15 years, the Cluster mission passes through Earth's radiation belts at least once every 2 days for several hours, measuring the electron intensity at energies from 30 to 400 keV. These data have previously been considered not usable due to contamination caused by penetrating energetic particles (protons at >100 keV and electrons at >400 keV). In this study, we assess the level of distortion of energetic electron spectra from the Research with Adaptive Particle Imaging Detector (RAPID)/Imaging Electron Spectrometer (IES) detector, determining the efficiency of its shielding. We base our assessment on the analysis of experimental data and a radiation transport code (Geant4). In simulations, we use the incident particle energy distribution of the AE9/AP9 radiation belt models. We identify the Roederer L values, L⋆, and energy channels that should be used with caution: at 3≤L⋆≤4, all energy channels (40–400 keV) are contaminated by protons (≃230 to 630 keV and >600 MeV); at L⋆≃1 and 4–6, the energy channels at 95–400 keV are contaminated by high-energy electrons (>400 keV). Comparison of the data with electron and proton observations from RBSP/MagEIS indicates that the subtraction of proton fluxes at energies ≃ 230–630 keV from the IES electron data adequately removes the proton contamination. We demonstrate the usefulness of the corrected data for scientific applications.
Y1  - 2016
U6  - https://doi.org/10.1002/2016SW001369
SN  - 1542-7390
VL  - 14
SP  - 449
EP  - 462
PB  - American Geophysical Union
CY  - Washington
ER  - 
TY  - JOUR
A1  - Aseev, Nikita A.
A1  - Shprits, Yuri Y.
A1  - Drozdov, Alexander Y.
A1  - Kellerman, Adam C.
T1  - Numerical applications of the advective-diffusive codes for the inner magnetosphere
JF  - Space Weather: The International Journal of Research and Applications
N2  - In this study we present analytical solutions for convection and diffusion equations. We gather here the analytical solutions for the one-dimensional convection equation, the two-dimensional convection problem, and the one- and two-dimensional diffusion equations. Using obtained analytical solutions, we test the four-dimensional Versatile Electron Radiation Belt code (the VERB-4D code), which solves the modified Fokker-Planck equation with additional convection terms. The ninth-order upwind numerical scheme for the one-dimensional convection equation shows much more accurate results than the results obtained with the third-order scheme. The universal limiter eliminates unphysical oscillations generated by high-order linear upwind schemes. Decrease in the space step leads to convergence of a numerical solution of the two-dimensional diffusion equation with mixed terms to the analytical solution. We compare the results of the third- and ninth-order schemes applied to magnetospheric convection modeling. The results show significant differences in electron fluxes near geostationary orbit when different numerical schemes are used.
KW  - advective-diffusive codes
KW  - inner magnetosphere
KW  - numerical schemes
Y1  - 2016
U6  - https://doi.org/10.1002/2016SW001484
SN  - 1542-7390
VL  - 14
SP  - 993
EP  - 1010
PB  - American Geophysical Union
CY  - Washington
ER  -