EGU23-798, updated on 22 Feb 2023
https://doi.org/10.5194/egusphere-egu23-798
EGU General Assembly 2023
© Author(s) 2023. This work is distributed under
the Creative Commons Attribution 4.0 License.

Investigating the acceleration efficiency of VLF and ULF waves on different electron populations in the outer radiation belt through multi-point observations and modeling 

Afroditi Nasi1, Christos Katsavrias1, Sigiava Aminalragia-Giamini1,2, Nour Dahmen3, Antoine Brunet3, Constantinos Papadimitriou1,2, Ingmar Sandberg2,4, Sébastien Bourdarie3, Viviane Pierrard5, Edith Botek5, Fabien Darrouzet5, Ondrej Santolik6, Benjamin Grison6, Ivana Kolmasova6, David Pisa6, Yoshizumi Miyoshi7, Wen Li8, Hugh Evans9, Ioannis A. Daglis1,10, and the Arase Team*
Afroditi Nasi et al.
  • 1Department of Physics, National and Kapodistrian University of Athens (NKUA), Athens, Greece
  • 2Space Applications & Research Consultancy (SPARC), Greece
  • 3Department of Physics, Instrumentation, Environment, Space (DPHY), Office National d'Etudes et de Recherches Aérospatiales (ONERA), University of Toulouse, Toulouse, France
  • 4Department of Aerospace Science and Technology, National and Kapodistrian University of Athens (NKUA), Athens, Greece
  • 5Royal Belgian Institute for Space Aeronomy (BIRA-IASB), Brussels, Belgium
  • 6Institute of Atmospheric Physics (IAP) of the Czech Academy of Sciences, Prague, Czechia
  • 7Institute for Space-Earth Environmental Research (ISEE), Nagoya University, Nagoya, Japan
  • 8Center for Space Physics, Boston University, Boston, MA, USA
  • 9European Space Research and Technology Centre (ESTEC), European Space Agency (ESA), Noordwijk, The Netherlands
  • 10Hellenic Space Center (HSC), Athens, Greece
  • *A full list of authors appears at the end of the abstract

During the second half of 2019, the Earth’s magnetosphere was impacted by a sequence of Corotating Interaction Regions (CIRs) during four consecutive solar rotations. Based on the solar wind properties, the CIRs can be divided in four groups, with the 3rd group, which arrived on August-September 2019, resulting in significant multi-MeV electron enhancements, up to ultra-relativistic energies of 9.9 MeV.

Each CIR group has a different effect on the outer radiation belt electron populations; we investigate them by exploiting combined measurements from the Van Allen Probes, THEMIS, and Arase satellites. We produce Phase Space Density (PSD) radial profiles and inspect their dependence on the values of the first and second adiabatic invariants (μ,K), ranging from seed to ultra-relativistic electrons and from near-equatorial to off equatorial mirroring populations, respectively.

Focusing on the 3rd CIR group, and in order to assess the relative contribution of radial diffusion and gyro-resonant acceleration, we perform numerical simulations of the radiation belt environment, combining several relevant models: EMERALD (NKUA), GEO model (NKUA), Salammbô (ONERA), VLF model (IAP), Plasmaspheric model (BIRA-IASB), FARWEST (ONERA). We further compare the temporal evolution of the simulated electron PSD with the above observations.

This work has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No 870437 for the SafeSpace project.

Arase Team:

Takefumi Mitani (11), Ayako Matsuoka (12), Iku Shinohara (11), Takeshi Takashima (11), Tomoaki Hori (7)

How to cite: Nasi, A., Katsavrias, C., Aminalragia-Giamini, S., Dahmen, N., Brunet, A., Papadimitriou, C., Sandberg, I., Bourdarie, S., Pierrard, V., Botek, E., Darrouzet, F., Santolik, O., Grison, B., Kolmasova, I., Pisa, D., Miyoshi, Y., Li, W., Evans, H., and Daglis, I. A. and the Arase Team: Investigating the acceleration efficiency of VLF and ULF waves on different electron populations in the outer radiation belt through multi-point observations and modeling , EGU General Assembly 2023, Vienna, Austria, 24–28 Apr 2023, EGU23-798, https://doi.org/10.5194/egusphere-egu23-798, 2023.

Supplementary materials

Supplementary material file