取得学位 【 表示 ／ 非表示 】

取得学位 【 表示 ／ 非表示 】

学内職務経歴 【 表示 ／ 非表示 】

学内職務経歴 【 表示 ／ 非表示 】

学外略歴 【 表示 ／ 非表示 】

学外略歴 【 表示 ／ 非表示 】

専門分野（科研費分類） 【 表示 ／ 非表示 】

専門分野（科研費分類） 【 表示 ／ 非表示 】

論文 【 表示 ／ 非表示 】

論文 【 表示 ／ 非表示 】

• Magnetic Field and Energetic Particle Flux Oscillations and High-Frequency Waves Deep in the Inner Magnetosphere During Substorm Dipolarization: ERG Observations

  Miyashita Y., Chang T.F., Miyoshi Y., Hori T., Kadokura A., Kasahara S., Wang S.Y., Keika K., Matsuoka A., Tanaka Y., Kasahara Y., Teramoto M., Jun C.W., Asamura K., Kazama Y., Tam S.W.Y., Wang B.J., Yokota S., Kumamoto A., Tsuchiya F., Shoji M., Kurita S., Imajo S., Shinohara I.

  Journal of Geophysical Research: Space Physics    126 ( 9 )   2021年09月  [査読有り]

   概要を見る

  Using Exploration of energization and Radiation in Geospace (ERG or Arase) spacecraft data, we studied low-frequency magnetic field and energetic particle flux oscillations and high-frequency waves deep in the inner magnetosphere at a radial distance of ~4–5 (Formula presented.) during substorm dipolarization. The magnetic field oscillated alternately between dipole-like and taillike configuration at a period of (Formula presented.) 1 min during dipolarization. When the magnetic field was dipole-like, the parallel magnetic component of the Pi2 waves was at trough. Both energetic ion and electron fluxes with a few to tens of kiloelectronvolts enhanced out of phase, indicating that magnetosonic waves were in slow mode. Field-aligned currents also oscillated. These observations are consistent with signatures of ballooning instability. In addition, we found that broadband waves from the Pi1 range to above the electron cyclotron frequency tended to appear intermittently in the central plasma sheet near dipole-like configuration.

  DOI Scopus

• Field-Aligned Low-Energy O⁺ Flux Enhancements in the Inner Magnetosphere Observed by Arase

  Nosé M., Matsuoka A., Miyoshi Y., Asamura K., Hori T., Teramoto M., Shinohara I., Hirahara M.

  Journal of Geophysical Research: Space Physics    126 ( 8 )   2021年08月  [査読有り]

   概要を見る

  The present study examines the low-energy ion flux variations observed by the Arase satellite in the inner magnetosphere. From the magnetic field and ion flux data obtained by the fluxgate magnetometer and the low-energy particle experiments–ion mass analyzer onboard Arase, we find 55 events of the low-energy O+ flux enhancement accompanied with magnetic field dipolarization in the periods of April 1–October 31, 2017 and July 1, 2018–January 31, 2019. The low-energy O+ flux enhancements (a) start a few minutes after the dipolarization onset, (b) have energy-dispersed signatures with decreasing energy from a few keV down to ∼10 eV, (c) are observed in both storm and non-storm periods, (d) have a field-aligned distribution (α ∼ 0° in the southern hemisphere and α ∼ 180° in the northern hemisphere), (e) are accompanied by the low-energy H+ flux enhancements that have lower energies than O+ by a factor of 3–10, and (f) increase the O+ density and the O+/H+ density ratio by ∼10 times and 4–5 times, respectively. We perform a numerical simulation to trace ion trajectories forward in time from the Arase positions. It is revealed that both H+ and O+ ions drift eastward and reach the dawn-to-morning sector without being lost in the ionosphere, if the pitch angle scattering effect is considered near the equatorial plane. This result suggests that these low-energy field-aligned ions can contribute to formation of the warm plasma cloak.

  DOI Scopus

• Arase Observation of Simultaneous Electron Scatterings by Upper-Band and Lower-Band Chorus Emissions

  Kazama Y., Miyoshi Y., Kojima H., Kasahara Y., Kasahara S., Usui H., Wang B.J., Wang S.Y., Tam S.W.Y., Chang T.F., Asamura K., Matsuda S., Kumamoto A., Tsuchiya F., Kasaba Y., Shoji M., Matsuoka A., Teramoto M., Takashima T., Shinohara I.

  Geophysical Research Letters    48 ( 14 )   2021年07月  [査読有り]

   概要を見る

  This study reports a relation between electron flux modulations and chorus emissions by using correlation analysis. On April 18, 2017, Arase observed an enhancement of electron fluxes and intensification of banded chorus emissions at the same time. A result of the analysis shows that both the upper-band and lower-band chorus emissions have good correlations with field-aligned electron fluxes that satisfy their resonance conditions. This indicates simultaneous interactions with both the emission bands and electrons, resulting in electron pitch-angle scattering toward the magnetic field direction. In addition, low-energy electron fluxes in the perpendicular direction also show positive correlations with the chorus intensities, probably because the chorus emissions are modulated by a fluctuation of perpendicular low-energy electron fluxes.

  DOI Scopus

• Penetration of MeV electrons into the mesosphere accompanying pulsating aurorae

  Miyoshi Y., Hosokawa K., Kurita S., Oyama S.I., Ogawa Y., Saito S., Shinohara I., Kero A., Turunen E., Verronen P.T., Kasahara S., Yokota S., Mitani T., Takashima T., Higashio N., Kasahara Y., Matsuda S., Tsuchiya F., Kumamoto A., Matsuoka A., Hori T., Keika K., Shoji M., Teramoto M., Imajo S., Jun C., Nakamura S.

  Scientific Reports    11 ( 1 )   2021年07月  [査読有り]

   概要を見る

  Pulsating aurorae (PsA) are caused by the intermittent precipitations of magnetospheric electrons (energies of a few keV to a few tens of keV) through wave-particle interactions, thereby depositing most of their energy at altitudes ~ 100 km. However, the maximum energy of precipitated electrons and its impacts on the atmosphere are unknown. Herein, we report unique observations by the European Incoherent Scatter (EISCAT) radar showing electron precipitations ranging from a few hundred keV to a few MeV during a PsA associated with a weak geomagnetic storm. Simultaneously, the Arase spacecraft has observed intense whistler-mode chorus waves at the conjugate location along magnetic field lines. A computer simulation based on the EISCAT observations shows immediate catalytic ozone depletion at the mesospheric altitudes. Since PsA occurs frequently, often in daily basis, and extends its impact over large MLT areas, we anticipate that the PsA possesses a significant forcing to the mesospheric ozone chemistry in high latitudes through high energy electron precipitations. Therefore, the generation of PsA results in the depletion of mesospheric ozone through high-energy electron precipitations caused by whistler-mode chorus waves, which are similar to the well-known effect due to solar energetic protons triggered by solar flares.

  DOI Scopus

• Energy Transfer Between Hot Protons and Electromagnetic Ion Cyclotron Waves in Compressional Pc5 Ultra-low Frequency Waves

  Kitamura N., Shoji M., Nakamura S., Kitahara M., Amano T., Omura Y., Hasegawa H., Boardsen S.A., Miyoshi Y., Katoh Y., Teramoto M., Saito Y., Yokota S., Hirahara M., Gershman D.J., Giles B.L., Russell C.T., Strangeway R.J., Ahmadi N., Lindqvist P.A., Ergun R.E., Fuselier S.A., Burch J.L.

  Journal of Geophysical Research: Space Physics    126 ( 5 )   2021年05月  [査読有り]

   概要を見る

  The Magnetospheric Multiscale (MMS) spacecraft observed many enhancements of electromagnetic ion cyclotron (EMIC) waves in an event in the late afternoon outer magnetosphere. These enhancements occurred mainly in the troughs of magnetic field intensity associated with a compressional ultralow frequency (ULF) wave. The ULF wave had a period of ∼2–5 min (Pc5 frequency range) and was almost static in the plasma rest frame. The magnetic and ion pressures were in antiphase. They are consistent with mirror-mode type structures. We apply the Wave-Particle Interaction Analyzer method, which can quantitatively investigate the energy transfer between hot anisotropic protons and EMIC waves, to burst-mode data obtained by the four MMS spacecraft. The energy transfer near the cyclotron resonance velocity was identified in the vicinity of the center of troughs of magnetic field intensity, which corresponds to the maxima of ion pressure in the compressional ULF wave. This result is consistent with the idea that the EMIC wave generation is modulated by ULF waves, and preferential locations for the cyclotron resonant energy transfer are the troughs of magnetic field intensity. In these troughs, relatively low resonance velocity due to the lower magnetic field intensity and the enhanced hot proton flux likely contribute to the enhanced energy transfer from hot protons to the EMIC waves by cyclotron resonance. Due to the compressional ULF wave, regions of the cyclotron resonant energy transfer can be narrow (only a few times of the gyroradii of hot resonant protons) in magnetic local time.

  DOI Scopus

全件表示 >>

口頭発表・ポスター発表等 【 表示 ／ 非表示 】

口頭発表・ポスター発表等 【 表示 ／ 非表示 】

• Educational and research activities of nanosatellite technologies at the Kyusyu Institute of Technology

  Mariko Teramoto, Mengu Chom Hirokazu Masui, Sangkyun Kim, Takashi Yamauchi, Necmi Chihan Orger, George Maeda  [招待有り]

  43rd COSPAR Scientific Assembly  2021年01月  -  2021年02月   

• Observations of radiation belt by Arase during declining phase of cycle 24

  Yoshizumi Miyoshi, Satoshi Kurita, Tomoaki Hori, Syun Imajo, Mariko Teramoto, Takafumi Mitani, Takeshi Takashima, Iku Shinohara, Nana Higashio, Satoshi Kasahara, Shoichiro Yokota, Kunihiro Keika, Fuminori Tsuchiya, Atsushi Kumamoto, Yoshiya Kasahara, Masafumi Shoji, Satoko Nakamura, Ayako Matsuoka

  43rd COSPAR Scientific Assembly  2021年01月  -  2021年02月   

• Data assimilation of electron radiation belts : estimation of radial diffusion coefficients and life times

  Yoshizumi Miyoshi, Genta Ueno, Takefumi Mitani, Takeshi Takashima, Iku Shinohara, Nana Higashio, Tomoaki Hori, Satoshi Kurita, Mariko Teramoto

  43rd COSPAR Scientific Assembly  2021年01月  -  2021年02月   

• An event study of the M-I-T coupling at a pseudo breakup during geomagnetically quiet conditions

  Shin-ichiro Oyama, Atsuki Shinbori, Yasunobu Ogawa, Mirjam Kellinsalmi, Tero Raita, Michael T Rietveld, Anita Taina Aikio, Heikki Vanhamaki, Kazuo Shiokawa, Ilkka I Virtanen, Lei Cai, Abiyot Workayehu, Marcus Pedersen, Kirsti Kauristie, Takuo T Tsuda, Boris V Kozelov, Andrei G Demekhov, Alexander G Yahnin, Fuminori Tsuchiya, Atsushi Kumamoto, Yoshiya Kasahara, Ayako Matsuoka, Masafumi Shoji and Mariko Teramoto

  AGU Fall meeting 2020  2020年12月  -  2020年12月   

• Modulation of energy transfer between hot protons and electromagnetic ion cyclotron waves by compressional Pc5 ULF waves

  Naritoshi Kitamura, Masafumi Shoji, Masahiro Kitahara, Satoko Nakamura, Takanobu Amano, Yoshiharu Omura, Yoshizumi Miyoshi, Hiroshi Hasegawa, Yuto Katoh, Yoshifumi Saito, Mariko Teramoto, Reiko Nomura, Shoichiro Yokota, Daniel J Gershman, Scott A Boardsen, Adolfo F. Vinas, Barbara L Giles, William R Paterson, Craig J Pollock, Christopher T Russell, Robert J Strangeway, Narges Ahmadi, Per-Arne Lindqvist, Robert Ergun, Stephen A Fuselier, James L Burch

  AGU Fall meeting 2020  2020年12月  -  2020年12月   

全件表示 >>

学術関係受賞 【 表示 ／ 非表示 】

学術関係受賞 【 表示 ／ 非表示 】

• 井上研究奨励賞

  2013年02月   井上科学振興財団   日本国

  受賞者：  寺本万里子

• 学生発表賞

  2007年03月   地球電磁気・地球惑星圏学会   日本国

  受賞者：  寺本万里子

寄附金・講座 【 表示 ／ 非表示 】

寄附金・講座 【 表示 ／ 非表示 】

• 村田学術振興財団

    2021年08月

担当授業科目 【 表示 ／ 非表示 】

担当授業科目 【 表示 ／ 非表示 】

全件表示 >>

学会・委員会等活動 【 表示 ／ 非表示 】

学会・委員会等活動 【 表示 ／ 非表示 】