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Simulations of the inner magnetospheric energetic electrons using the IMPTAM-VERB coupled model

Castillo A. M., Y. Y. Shprits, N. Ganushkina, A. Drozdov, N. Aseev, D. Wang, S. Dubyagin, (2019), Simulations of the inner magnetospheric energetic electrons using the IMPTAM-VERB coupled model, Journal Of Atmospheric And Solar-terrestrial Physics, 191, 105050, doi:10.1016/j.jastp.2019.05.014

Abstract

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 ∼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.

Authors (sorted by name)

Aseev Castillo Drozdov Dubyagin Ganushkina Shprits Wang

Journal / Conference

Journal Of Atmospheric And Solar-terrestrial Physics

Acknowledgments

The project leading to these results has received funding from the European Union’s Horizon 2020 research and innovation program under grant agreement No. 637302 PROGRESS, Germany and No. 776287 SWAMI. The work of A. Castillo has been funded by the Deutsche Forschungsgemeinschaft (DFG), Germany under grant agreement CRC 1294, Project B06. The work of N. Ganushkina at the University of Michigan was partly supported by the National Aeronautics and Space Administration, United States under grant agreement NNX17AI48G and by the National Science Foundation, United States under grant agreement NSF 1663770. The work of S. Dubyagin and, partly, of N. Ganushkina leading to these results has been carried out in the Finnish Centre of Excellence in Research and Sustainable Space (Academy of Finland grant numbers 312351 and 312390), which we gratefully acknowledge. The authors used geomagnetic indices provided by OMNIWeb ( http://omniweb.gsfc.nasa.gov/form/dx1.html) and are grateful to the RBSP-ECT team for the provision of Van Allen Probes observations (http://www.rbsp-ect.lanl.gov/). We sincerely acknowledge Adam Kellerman for the preparation of the used satellite data. In addition, the authors are appreciative of the valuable comments from the reviewers.

Grants

1663770 312351 312390 637302 776287 NNX17AI48G

Bibtex

@article{CASTILLO2019105050,
title = "Simulations of the inner magnetospheric energetic electrons using the IMPTAM-VERB coupled model",
journal = "Journal of Atmospheric and Solar-Terrestrial Physics",
volume = "191",
pages = "105050",
year = "2019",
issn = "1364-6826",
doi = "10.1016/j.jastp.2019.05.014",
url = "http://www.sciencedirect.com/science/article/pii/S1364682618305728",
author = "Angelica M. Castillo and Yuri Y. Shprits and Natalia Ganushkina and Alexander Drozdov and Nikita Aseev and Dedong Wang and Stepan Dubyagin",
keywords = "Electron populations, Radiation belts, IMPTAM, VERB",
abstract = "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 ∼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."
}