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MAGNETOSPHERIC VLF LINE RADIATION OBSERVED AT HALLEY, ANTARCTICA
https://nipr.repo.nii.ac.jp/records/1077
https://nipr.repo.nii.ac.jp/records/1077c513f5eb-0436-4054-9ef6-57f92b9ee041
名前 / ファイル | ライセンス | アクション |
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Item type | 紀要論文(ELS) / Departmental Bulletin Paper(1) | |||||||||
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公開日 | 1980-09-01 | |||||||||
タイトル | ||||||||||
言語 | en | |||||||||
タイトル | MAGNETOSPHERIC VLF LINE RADIATION OBSERVED AT HALLEY, ANTARCTICA | |||||||||
言語 | ||||||||||
言語 | eng | |||||||||
資源タイプ | ||||||||||
資源タイプ識別子 | http://purl.org/coar/resource_type/c_6501 | |||||||||
資源タイプ | departmental bulletin paper | |||||||||
ページ属性 | ||||||||||
内容記述タイプ | Other | |||||||||
内容記述 | P(論文) | |||||||||
論文名よみ | ||||||||||
その他のタイトル | MAGNETOSPHERIC VLF LINE RADIATION OBSERVED AT HALLEY, ANTARCTICA | |||||||||
著者名(英) |
MATTHEWS, J. P.
× MATTHEWS, J. P.
× YEARBY, K.
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著者所属(英) | ||||||||||
en | ||||||||||
Department of Physics, University of Sheffield | ||||||||||
著者所属(英) | ||||||||||
en | ||||||||||
Department of Physics, University of Sheffield | ||||||||||
抄録(英) | ||||||||||
内容記述タイプ | Other | |||||||||
内容記述 | Spectrograms of broad-band ELF/VLF goniometer data obtained from ground based measurements made at Halley, Antarctica (L=4.3,conjugate near St. Anthony, Newfoundland) have shown the presence of discrete line radiation of magnetospheric origin, in the frequency range 1-4 kHz. The properties of this radiation are broadly similar to Power Line Harmonic Radiation (PLHR), studied from ground based observations made at Siple, Antarctica (L=4.1,conjugate-Roberval, Quebec), although there are some interesting differences. Line radiation observed at Halley, is never regularly spaced in frequency by 120Hz, as one may expect if signals from the Newfoundland power distribution system (60Hz fundamental) are entering the magnetosphere, and being amplified. Instead, frequency spacings are widely distributed about mean values between 50 to 90Hz. The lines are observed to trigger emissions and often exhibit 2 hop amplitude modulation, which demonstrates that they are of magnetospheric origin. Events occur mostly in quiet to moderate geomagnetic conditions, and during the late afternoon period of local time. Arrays of lines are often observed to drift upwards together in frequency. Line bandwidths are 20-30Hz-much larger than the bandwidths of locally generated induction lines. We show that the line spacing of ∿80 z is too large to correspond to sideband separation for waves of equatorial field strength ∿10 pT, and we investigate the conditions required for effective particle trapping by the wave array, of the type described by NUNN (J. Plasma Phys., 11,189,1974). It is proposed that the line radiation either originates in the signals which enter the magnetosphere from Newfoundland, or is 'naturally' generated, possibly by a linear instability which takes place if the electron distribution is unstable in restricted ranges of wave frequency and wave number. | |||||||||
雑誌書誌ID | ||||||||||
収録物識別子タイプ | NCID | |||||||||
収録物識別子 | AA00733561 | |||||||||
書誌情報 |
Memoirs of National Institute of Polar Research. Special issue 巻 16, p. 95-112, 発行日 1980-09 |