Energy Transfer Between Hot Protons and Electromagnetic Ion Cyclotron Waves in Compressional Pc5 Ultra-low Frequency WavesUniv Tokyo, Grad Sch Sci, Dept Earth & Planetary Sci, Tokyo, Japan..
Kyoto Univ, Res Inst Sustainable Humanosphere, Uji, Japan..
Japan Aerosp Explorat Agcy, Inst Space & Astronaut Sci, Sagamihara, Kanagawa, Japan..
NASA Goddard Space Flight Ctr, Greenbelt, MD USA.;Univ Maryland Baltimore Cty, Goddard Planetary Heliophys Inst, Baltimore, MD 21228 USA..
Nagoya Univ, Inst Space Earth Environm Res, Nagoya, Aichi, Japan..
Tohoku Univ, Grad Sch Sci, Dept Geophys, Sendai, Miyagi, Japan..
Kyushu Inst Technol, Fac Engn, Fukuoka, Japan..
Japan Aerosp Explorat Agcy, Inst Space & Astronaut Sci, Sagamihara, Kanagawa, Japan..
Osaka Univ, Grad Sch Sci, Dept Earth & Space Sci, Toyonaka, Osaka, Japan..
Nagoya Univ, Inst Space Earth Environm Res, Nagoya, Aichi, Japan..
Kyushu Inst Technol, Fac Engn, Fukuoka, Japan..
NASA Goddard Space Flight Ctr, Greenbelt, MD USA..
Univ Calif Los Angeles, Dept Earth Planetary & Space Sci, Los Angeles, CA USA..
Univ Calif Los Angeles, Dept Earth Planetary & Space Sci, Los Angeles, CA USA..
Univ Colorado, Lab Atmospher & Space Phys, Boulder, CO 80309 USA..
Univ Colorado, Lab Atmospher & Space Phys, Boulder, CO 80309 USA..
Southwest Res Inst, San Antonio, TX USA.;Univ Texas San Antonio, Dept Phys & Astron, San Antonio, TX USA..
Southwest Res Inst, San Antonio, TX USA..
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2021 (English)In: Journal of Geophysical Research - Space Physics, ISSN 2169-9380, E-ISSN 2169-9402, Vol. 126, no 5, article id e2020JA028912Article in journal (Refereed) Published
Abstract [en]
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 similar to 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.
Place, publisher, year, edition, pages
AMER GEOPHYSICAL UNION , 2021. Vol. 126, no 5, article id e2020JA028912
Keywords [en]
EMIC wave, mirror mode, MMS spacecraft, ULF wave, wave-particle interaction
National Category
Fusion, Plasma and Space Physics
Identifiers
URN: urn:nbn:se:kth:diva-297753DOI: 10.1029/2020JA028912ISI: 000657463000054Scopus ID: 2-s2.0-85107141359OAI: oai:DiVA.org:kth-297753DiVA, id: diva2:1571279
Note
QC 20210622
2021-06-222021-06-222022-06-25Bibliographically approved