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Artemyev, A. V., Demekhov, A. G., Zhang, X.-J., Angelopoulos, V., Mourenas, D., Fedorenko, Y. V., et al. (2021). Role of ducting in relativistic electron loss by whistler-mode wave scattering. Journal of Geophysical Research: Space Physics, 126, e2021JA029851.

Role of ducting in relativistic electron loss by whistler-mode wave scattering

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Author: Artemyev, A. V.1,2; Demekhov, A. G.3,4; Zhang, X.-J.1;
Organizations: 1Department of Earth, Planetary, and Space Sciences, University of California, Los Angeles, USA
2Space Research Institute of Russian Academy of Sciences, Moscow, Russia
3Polar Geophysical Institute, Apatity, Russia
4Institute of Applied Physics, RAS, Nizhny Novgorod, Russia
5LPC2E, CNRS, Orleans, France
6Sodankylä Geophysical Observatory, Sodankylä, Finland
7Department of Earth and Planetary Science, School of Science, The University of Tokyo, Tokyo, Japan
8Institute for Space Earth Environmental Research, Nagoya University, Nagoya, Japan
9Graduate School of Science, Kyoto University, Kyoto, Japan
10Graduate School of Natural Science and Technology, Kanazawa University, Kakuma, Kanazawa, Japan
11Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency, Sagamihara, 252-5210, Kanagawa, Japan
12Osaka University, Osaka, Japan
Format: article
Version: published version
Access: open
Online Access: PDF Full Text (PDF, 11 MB)
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Language: English
Published: American Geophysical Union, 2021
Publish Date: 2021-10-25


Resonant interactions of energetic electrons with electromagnetic whistler-mode waves (whistlers) contribute significantly to the dynamics of electron fluxes in Earth’s outer radiation belt. At low geomagnetic latitudes these waves are very effective in pitch-angle scattering and precipitation into the ionosphere of low equatorial pitch-angle, tens of keV electrons and acceleration of high equatorial pitch-angle electrons to relativistic energies. Relativistic (hundreds of keV), electrons may also be precipitated by resonant interaction with whistlers, but this requires waves propagating quasi-parallel without significant intensity decrease to high latitudes where they can resonate with higher energy low equatorial pitch-angle electrons than at the equator. Wave propagation away from the equatorial source region in a non-uniform magnetic field leads to ray divergence from the originally field-aligned direction and efficient wave damping by Landau resonance with suprathermal electrons, reducing the wave ability to scatter electrons at high latitudes. However, wave propagation can become ducted along field-aligned density peaks (ducts), preventing ray divergence and wave damping. Such ducting may therefore result in significant relativistic electron precipitation. We present evidence that ducted whistlers efficiently precipitate relativistic electrons. We employ simultaneous near-equatorial and ground-based measurements of whistlers and low-altitude electron precipitation measurements by ELFIN CubeSat. We show that ducted waves (appearing on the ground) efficiently scatter relativistic electrons into the loss cone, contrary to non-ducted waves (absent on the ground) precipitating only < 150 keV electrons. Our results indicate that ducted whistlers may be quite significant for relativistic electron losses; they should be further studied statistically and possibly incorporated in radiation belt models.

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Series: Journal of geophysical research. Space physics
ISSN: 2169-9380
ISSN-E: 2169-9402
ISSN-L: 2169-9380
Volume: 126
Issue: 11
Article number: e2021JA029851
DOI: 10.1029/2021JA029851
Type of Publication: A1 Journal article – refereed
Field of Science: 115 Astronomy and space science
Funding: X.J.Z., A.V.A., and V.A. acknowledge support by NASA awards 80NSSC20K1270, NNX14AN68G, and NSF grants AGS-1242918, AGS-2019950, and AGS-2021749. A.G.D. and Y.V.F. acknowledge support by the Russian Ministry of Education and Science under state task AAAAA181180124901007. The work with KAN data was supported by the Academy of Finland under grants 330783 and 324025. We are grateful to NASAs CubeSat Launch Initiative for ELFIN's successful launch in the desired orbits. We acknowledge early support of ELFIN project by the AFOSR, under its University Nanosat Program, UNP-8 project, contract FA9453-12-D-0285, and by the California Space Grant program.
Academy of Finland Grant Number: 330783
Detailed Information: 330783 (Academy of Finland Funding decision)
324025 (Academy of Finland Funding decision)
Dataset Reference: ELFIN data is available at, THEMIS data is avaliable at Data access and processing was done using SPEDAS V3.1, see Angelopoulos et al. (2019). Data of ground-based VLF receivers is available at vlf/, Science data of the ERG (Arase) satellite were obtained from the ERG Science Center operated by ISAS/JAXA and ISEE/Nagoya University (, Miyoshi, Hori, et al. (2018)). The present study analyzed the HEP L2 v03 01 data (Mitani, Hori, et al., 2018), MEPe L2 v01 02 data (Y. Kasahara, Kojima, et al., 2018), MGF L2 v04 04 data (Matsuoka, Teramoto, Imajo, et al., 2018), PWE OFA L2 v02 01 data (S. Kasahara, Yokota, Hori, et al., 2018), and ORB L2 v03 data (Miyoshi, Shinohara, & Jun, 2018).
Copyright information: © AGU. This is the peer reviewed version of the following article: Artemyev, A. V., Demekhov, A. G., Zhang, X.-J., Angelopoulos, V., Mourenas, D., Fedorenko, Y. V., et al. (2021). Role of ducting in relativistic electron loss by whistler-mode wave scattering. Journal of Geophysical Research: Space Physics, 126, e2021JA029851, which has been published in final form at This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-Archiving.