A proposal and validation of a new space plasma observation method "Drift Echo Monitor"

2022 Fiscal Year Research-status Report

• Project/Area Number: 21K13978
• Research Institution: Nagoya University
• Principal Investigator: 中村 紗都子 名古屋大学, 高等研究院(宇宙), 特任助教 (00870247)
• Project Period (FY): 2021-04-01 – 2024-03-31
• Keywords: 磁気圏

Outline of Annual Research Achievements

あらせ衛星、Van Allen Probes衛星、THEMIS衛星、また地上磁場観測データを使用して、本研究課題で提案した「磁気圏電子ドリフトエコー」が検出されたイベントを100例以上抽出した。これらは1分スケールで放射線帯電子（500 keV - 2 MeV）が急減したのちエネルギー分散が見られるもので、特にEMIC波動による粒子散乱が疑われるものに焦点をあてている。これらのイベントを仕分けし、EMIC波動との同時性や複数衛星での同時検出の有無、EMIC発生領域からの距離や地磁気活動度との関連を調べた。多くは地磁気擾乱時に昼側外部磁気圏で発生していることが示唆され、放射線帯電子を10%程度減少させていることがわかった。またこれらのイベント検出の経験から、３次元フラックスデータからドリフトエコーを自動抽出するプログラムを開発し、ドリフトエコーの時空間スケールとその時間発展を定量評価できるようにした。ドリフトエコーの時空間スケールは電子散乱の発生領域の広さと、ドリフトエコーの長さは電子散乱が効果的に発生したエネルギー範囲を、また時間発展はドリフト周回中の第三断熱不変量の破れによる粒子拡散の効果を示している。本年度は統計解析に向けたイベントの収集を終え、その磁気圏内での位置分布や磁気擾乱度との相関関係を調べている。以上の結果は論文にまとめるとともに、国際学会での招待講演などで広く発表している。

Current Status of Research Progress

2: Research has progressed on the whole more than it was originally planned.

Reason

ドリフトエコーの結果をCOSPAR（ギリシャ）、AGU（シカゴ）などの海外学会やサイエンス会議（東京）、SGEPSS（神奈川）などの国内研究会で発表し議論を重ねた。またこれらの成果が評価され、学会奨励賞の受賞や助成金の取得につながった。現在上記の成果を２本の投稿論文として投稿中である。

Strategy for Future Research Activity

2022年度に検出した多くの観測例と、並行して開発した自動検出プログラムを用いて、ドリフトエコーモニターの定量評価を行い、統計解析を行う。これらをまとめて、放射線帯の定常モニターツールとしての性能評価を行う。

Causes of Carryover

新型コロナウイルス感染症の影響で旅費日程がずれこんだため。翌年度の国際会議参加費に充填する。

Research Products

• [Journal Article] Multi‐Event Analysis of Magnetosphere‐Ionosphere Coupling of Nighttime Medium‐Scale Traveling Ionospheric Disturbances From the Ground and the Arase Satellite (2023)
  • Author(s): Kawai K.、Shiokawa K.、Otsuka Y.、Oyama S.、Connors M. G.、Kasahara Y.、Kasaba Y.、Nakamura S.、Tsuchiya F.、Kumamoto A.、Shinbori A.、Matsuoka A.、Shinohara I.、Miyoshi Y.
  • Journal Title: Journal of Geophysical Research: Space Physics Volume: 128 Pages: -
  • DOI: 10.1029/2022JA030542
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] Phase Difference of Electron Cyclotron Harmonic (ECH) Waves Observed by Using the Interferometry Observation Mode of the Arase Satellite (2023)
  • Author(s): Nakagawa T., et al.,
  • Journal Title: URSI Radio Science Letters Volume: 4 Pages: -
  • DOI: 10.46620/22-0046
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] Latitudinal dependence of ground VLF transmitter wave power in the inner magnetosphere (2023)
  • Author(s): Xia Zhiyang、Chen Lunjin、Gu Wenyao、Horne Richard B.、Miyoshi Yoshizumi、Kasahara Yoshiya、Kumamoto Atsushi、Tsuchiya Fuminori、Nakamura Satoko、Kitahara Masahiro、Shinohara Iku
  • Journal Title: Frontiers in Astronomy and Space Sciences Volume: 10 Pages: -
  • DOI: 10.3389/fspas.2023.1135509
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] Direct Observations of Energetic Electron Scattering and Precipitation Due To Whistler‐Mode Waves in the Dayside High‐Density Regions (2023)
  • Author(s): Sugo Shin、Kasahara Satoshi、Miyoshi Yoshizumi、Katoh Yuto、Keika Kunihiro、Yokota Shoichiro、Hori Tomoaki、Kasahara Yoshiya、Matsuda Shoya、Matsuoka Ayako、Shinohara Iku、Tsuchiya Fuminori、Kumamoto Atsushi、Nakamura Satoko、Kitahara Masahiro
  • Journal Title: Journal of Geophysical Research: Space Physics Volume: 128 Pages: -
  • DOI: 10.1029/2022ja030992
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] Using Van Allen Probes and Arase Observations to Develop an Empirical Plasma Density Model in the Inner Zone (2023)
  • Author(s): Hartley D. P.、Cunningham G. S.、Ripoll J.‐F.、Malaspina D. M.、Kasahara Y.、Miyoshi Y.、Matsuda S.、Nakamura S.、Tsuchiya F.、Kitahara M.、Kumamoto A.、Shinohara I.、Matsuoka A.
  • Journal Title: Journal of Geophysical Research: Space Physics Volume: 128 Pages: -
  • DOI: 10.1029/2022ja031012
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] Off‐Equatorial Pi2 Pulsations Inside and Outside the Plasmapause Observed by the Arase Satellite (2022)
  • Author(s): Teramoto M.、Miyoshi Y.、Matsuoka A.、Kasahara Y.、Kumamoto A.、Tsuchiya F.、Nos? M.、Imajo S.、Shoji M.、Nakamura S.、Kitahara M.、Shnohara I.
  • Journal Title: Journal of Geophysical Research: Space Physics Volume: 127 Pages: -
  • DOI: 10.1029/2021JA029677
• [Journal Article] Statistical Study of Approaching Strong Diffusion of Low‐Energy Electrons by Chorus and ECH Waves Based on <i>In Situ</i> Observations (2022)
  • Author(s): Fukizawa M.、Sakanoi T.、Miyoshi Y.、Kazama Y.、Katoh Y.、Kasahara Y.、Matsuda S.、Kumamoto A.、Tsuchiya F.、Matsuoka A.、Kurita S.、Nakamura S.、Shoji M.、Teramoto M.、Imajo S.、Shinohara I.、Wang S.‐Y.、Tam S. W.‐Y.、Chang T.‐F.、Wang B.‐J.、Jun C.‐W.
  • Journal Title: Journal of Geophysical Research: Space Physics Volume: 127 Pages: -
  • DOI: 10.1029/2022JA030269
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] Relation of the Plasmapause to the Midlatitude Ionospheric Trough, the Sub‐Auroral Temperature Enhancement and the Distribution of Small‐Scale Field Aligned Currents as Observed in the Magnetosphere by THEMIS, RBSP, and Arase, and in the Topside Ionosphere by Swarm (2022)
  • Author(s): Heilig Bal?zs、Stolle Claudia、Kervalishvili Guram、Rauberg Jan、Miyoshi Yoshizumi、Tsuchiya Fuminori、Kumamoto Atsushi、Kasahara Yoshiya、Shoji Masafumi、Nakamura Satoko、Kitahara Masahiro、Shinohara Iku
  • Journal Title: Journal of Geophysical Research: Space Physics Volume: 127 Pages: -
  • DOI: 10.1029/2021JA029646
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] Simultaneous Observations of EMIC‐Induced Drifting Electron Holes (EDEHs) in the Earth's Radiation Belt by the Arase Satellite, Van Allen Probes, and THEMIS (2022)
  • Author(s): Nakamura S.、Miyoshi Y.、Shiokawa K.、Omura Y.、Mitani T.、Takashima T.、Higashio N.、Shinohara I.、Hori T.、Imajo S.、Matsuoka A.、Tsuchiya F.、Kumamoto A.、Kasahara Y.、Shoji M.、Spence H.、Angelopoulos V.
  • Journal Title: Geophysical Research Letters Volume: 49 Pages: -
  • DOI: 10.1029/2021GL095194
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] Statistical Survey of Arase Satellite Data Sets in Conjunction With the Finnish Riometer Network (2022)
  • Author(s): Thomas Neethal et al
  • Journal Title: Journal of Geophysical Research: Space Physics Volume: 127 Pages: -
  • DOI: 10.1029/2022ja030271
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] Modulation of the energetic electron distribution caused by toroidal mode ULF waves in association with periodic enhancement of whistler-mode chorus emissions (2022)
  • Author(s): Ono Atsuhiro、Katoh Yuto、Teramoto Mariko、Hori Tomoaki、Kumamoto Atsushi、Tsuchiya Fuminori、Kasaba Yasumasa、Isono Ko、Miyoshi Yoshizumi、Kasahara Satoshi、Kasahara Yoshiya、Matsuda Shoya、Nakamura Satoko、Matsuoka Ayako、Yokota Shoichiro、Keika Kunihiro、Mitani Takefumi、Shinohara Iku
  • Journal Title: - Volume: - Pages: -
  • DOI: 10.1002/essoar.10511461.1
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] Signatures of Auroral Potential Structure Extending Through the Near‐Equatorial Inner Magnetosphere (2022)
  • Author(s): Imajo S.、Miyoshi Y.、Asamura K.、Shinohara I.、Nos? M.、Shiokawa K.、Kasahara Y.、Kasaba Y.、Matsuoka A.、Kasahara S.、Yokota S.、Keika K.、Hori T.、Shoji M.、Nakamura S.、Teramoto M.
  • Journal Title: Geophysical Research Letters Volume: 49 Pages: -
  • DOI: 10.1029/2022GL098105
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] Asymmetric Distributions of Auroral Kilometric Radiation in Earth's Northern and Southern Hemispheres Observed by the Arase Satellite (2022)
  • Author(s): Xiao Fuliang、Tang Jiawen、Zhang Sai、Zhou Qinghua、Liu Si、He Yihua、Yang Qiwu、Kasahara Yoshiya、Miyoshi Yoshizumi、Kumamoto Atsushi、Nakamura Yosuke、Tsuchiya Fuminori、Shinohara Iku、Nakamura Satoko
  • Journal Title: Geophysical Research Letters Volume: 49 Pages: -
  • DOI: 10.1029/2022GL099571
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] Analysis of Electron Precipitation and Ionospheric Density Enhancements Due To Hiss Using Incoherent Scatter Radar and Arase Observations (2022)
  • Author(s): Ma Q.、Xu W.、Sanchez E. R.、Marshall R. A.、Bortnik J.、Reyes P. M.、Varney R. H.、Kaeppler S. R.、Miyoshi Y.、Matsuoka A.、Kasahara Y.、Matsuda S.、Tsuchiya F.、Kumamoto A.、Kasahara S.、Yokota S.、Keika K.、Hori T.、Mitani T.、Nakamura S.、Kazama Y.、Wang S.‐Y.、Jun C.‐W.、Shinohara I.、Tam S. W.‐Y.
  • Journal Title: Journal of Geophysical Research: Space Physics Volume: 127 Pages: -
  • DOI: 10.1029/2022ja030545
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] Quantifying the Size and Duration of a Microburst‐Producing Chorus Region on 5 December 2017 (2022)
  • Author(s): Elliott S. S.、Breneman A. W.、Colpitts C.、Pettit J. M.、Cattell C. A.、Halford A. J.、Shumko M.、Sample J.、Johnson A. T.、Miyoshi Y.、Kasahara Y.、Cully C. M.、Nakamura S.、Mitani T.、Hori T.、Shinohara I.、Shiokawa K.、Matsuda S.、Connors M.、Ozaki M.、Manninen J.
  • Journal Title: Geophysical Research Letters Volume: 49 Pages: -
  • DOI: 10.1029/2022gl099655
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] A Calibration Method of Short‐Time Waveform Signals Passed Through Linear Time‐Invariant Systems: 1. Methodology and Simple Examples (2022)
  • Author(s): Kitahara M.、Matsuda S.、Katoh Y.、Kojima H.、Kasahara Y.、Miyoshi Y.、Nakamura S.、Hikishima M.
  • Journal Title: Radio Science Volume: 57 Pages: -
  • DOI: 10.1029/2022rs007454
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] Observation of Source Plasma and Field Variations of a Substorm Brightening Aurora at <i>L</i> ???6 by a Ground‐Based Camera and the Arase Satellite on 12 October 2017 (2022)
  • Author(s): Chen L.et al.
  • Journal Title: Journal of Geophysical Research: Space Physics Volume: 127 Pages: -
  • DOI: 10.1029/2021ja030072
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] Direct observations of energy transfer from resonant electrons to whistler-mode waves in magnetosheath of Earth (2022)
  • Author(s): Kitamura N et al
  • Journal Title: Nature Communications Volume: 13 Pages: -
  • DOI: 10.1038/s41467-022-33604-2
  • Peer Reviewed / Int'l Joint Research
• [Presentation] Progress of Japan's action against extreme space weather (2022)
  • Author(s): 中村 紗都子
  • Organizer: AGU Fall Meeting 2022
  • Int'l Joint Research / Invited
• [Presentation] Roles of ion hole and hill in a triggering process of EMIC rising-tone emissions (2022)
  • Author(s): Satoko Nakamura,Yoshizumi Miyoshi,Masafumi Shoji,Masahiro Kitahara
  • Organizer: 地球電磁気・地球惑星圏学会 第152回総会及び講演会
• [Presentation] Drastic time variations of transfer function of geomagnetically induced current (GIC) in Japan (2022)
  • Author(s): Satoko Nakamura,Yusuke Ebihara,Shinichi Watari,Tadanori Goto
  • Organizer: 地球電磁気・地球惑星圏学会 第152回総会及び講演会
• [Presentation] SIMULTANEOUS OBSERVATIONS OF EMIC-INDUCED DRIFTING ELEC- TRON HOLES (EDEHS) IN THE EARTH’S RADIATION BELT BY THE ARASE SATELLITE, VAN ALLEN PROBES, AND THEMIS (2022)
  • Author(s): S. Nakamura,Y. Miyoshi,K. Shiokawa,Y. Omura,T. Mitani,T. Takashima,N. Higashio,I. Shinohara,T. Hori,S. Imajo,A. Matsuoka,F. Tsuchiya,A. Kumamoto,Y. Kasahara,M. Shoji,H. Spence,V. Angelopoulos
  • Organizer: 44th COSPAR Scientific Assembly 2022
  • Int'l Joint Research