@article{843c8439052e43ba968a1ebeb086aae1,
title = "Strong Diffusion of Energetic Electrons by Equatorial Chorus Waves in the Midnight-to-Dawn Sector",
abstract = "Drastic variations of radiation-belt/ring current electrons are the result of competing processes of acceleration, transport, and loss. For subrelativistic energetic electrons (10–100 keV), one of the promising loss mechanisms is precipitation into the atmosphere due to pitch angle scattering by whistler mode chorus waves. The efficiency of the scattering has yet to be quantified by direct observations, however. Using in situ measurements by the ERG (Arase) spacecraft in the midnight-to-dawn sector at and around the magnetic equator, we demonstrate that the full filling of energetic electron loss cones occurs commonly, associated with typical-amplitude (greater than 50 pT) chorus waves. The spatial distribution of the loss cone filling indicates that the efficient scattering is limited to |MLAT|< 10°.",
keywords = "loss cone, precipitation, strong diffusion, wave-particle interaction",
author = "S. Kasahara and Y. Miyoshi and S. Kurita and S. Yokota and K. Keika and T. Hori and Y. Kasahara and S. Matsuda and A. Kumamoto and A. Matsuoka and K. Seki and I. Shinohara",
note = "Funding Information: ). Part of the work of T.H. and Y.M. was done at ERG‐SC. The present study analyzed the MEPe L2‐v01_01 (3D flux), PWE/OFA L2‐v02_01, PWE/HFA L2‐v00_02, and MGF L2‐v01.01 data obtained by ERG. The ERG orbital data L2‐v02 and L3‐v02 were also used. The Arase data were analyzed using the SPEDAS (the Space Physics Environment Data Analysis Software) framework (Angelopoulos et al., ) and ERG Plug‐in tools. Note that the electric field used in this study is provisionally calibrated under the assumption of combining the theoretical antenna capacitance in a vacuum, and the typical plasma resistance. The effective antenna length is also assumed to be 15 m in the whole frequency range. The absolute value may be substantially improved in the future calibration, but the distribution shown here will not qualitatively change. This work is supported by MEXT/JSPS KAKENHI grants 15H05815 (Grant‐in‐Aid for Scientific Research on Innovative Areas), 15H05747, 17H06140 (Grant‐in‐Aid for Scientific Research (S)), 18H03727 (Grant‐in‐Aid for Scientific Research (A)), 16H06286 (Grant‐in‐Aid for Specially Promoted Research), and 17K14400 (Young Scientists (B)) and MEXT/JSPS Bilateral Open Partnership Joint Research Projects. Science data of the ERG (Arase) satellite were obtained from the ERG Science Center (ERG‐SC) operated by ISAS/JAXA and ISEE/Nagoya University ( https://ergsc.isee.nagoya‐u.ac.jp/index.shtml.en; Miyoshi, Hori, et al., Funding Information: This work is supported by MEXT/JSPS KAKENHI grants 15H05815 (Grant-in-Aid for Scientific Research on Innovative Areas), 15H05747, 17H06140 (Grant-in-Aid for Scientific Research (S)), 18H03727 (Grant-in-Aid for Scientific Research (A)), 16H06286 (Grant-in-Aid for Specially Promoted Research), and 17K14400 (Young Scientists (B)) and MEXT/JSPS Bilateral Open Partnership Joint Research Projects. Science data of the ERG (Arase) satellite were obtained from the ERG Science Center (ERG-SC) operated by ISAS/JAXA and ISEE/Nagoya University (https://ergsc.isee.nagoya-u.ac.jp/index.shtml.en; Miyoshi, Hori, et al.,). Part of the work of T.H. and Y.M. was done at ERG-SC. The present study analyzed the MEPe L2-v01_01 (3D flux), PWE/OFA L2-v02_01, PWE/HFA L2-v00_02, and MGF L2-v01.01 data obtained by ERG. The ERG orbital data L2-v02 and L3-v02 were also used. The Arase data were analyzed using the SPEDAS (the Space Physics Environment Data Analysis Software) framework (Angelopoulos et al.,) and ERG Plug-in tools. Note that the electric field used in this study is provisionally calibrated under the assumption of combining the theoretical antenna capacitance in a vacuum, and the typical plasma resistance. The effective antenna length is also assumed to be 15 m in the whole frequency range. The absolute value may be substantially improved in the future calibration, but the distribution shown here will not qualitatively change. Publisher Copyright: {\textcopyright}2019. American Geophysical Union. All Rights Reserved.",
year = "2019",
month = nov,
day = "28",
doi = "10.1029/2019GL085499",
language = "English",
volume = "46",
pages = "12685--12692",
journal = "Geophysical Research Letters",
issn = "0094-8276",
publisher = "Wiley-Blackwell",
number = "22",
}