A Statistical Test of the Relationship Between Chorus Wave Activation and Anisotropy of Electron Phase Space Density
Whistler mode chorus wave is considered to play a critical role in accelerating and precipitating the electrons in the outer radiation belt. In this paper we test a conventional scenario of triggering chorus using THEMIS satellite observations of waves and particles. Specifically, we test if the c...
| Main Authors: | , , , , |
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| Format: | Article |
| Language: | English |
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The Korean Space Science Society
2014-12-01
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| Series: | Journal of Astronomy and Space Sciences |
| Subjects: | |
| Online Access: | http://ocean.kisti.re.kr/downfile/volume/kosss/OJOOBS/2014/v31n4/OJOOBS_2014_v31n4_295.pdf |
| _version_ | 1797370287490072576 |
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| author | Dong-Hee Lee Dae-Young Lee Dae-Kyu Shin Jin-Hee Kim Jung-Hee Cho |
| author_facet | Dong-Hee Lee Dae-Young Lee Dae-Kyu Shin Jin-Hee Kim Jung-Hee Cho |
| author_sort | Dong-Hee Lee |
| collection | DOAJ |
| description | Whistler mode chorus wave is considered to play a critical role in accelerating and precipitating the electrons in the outer
radiation belt. In this paper we test a conventional scenario of triggering chorus using THEMIS satellite observations of
waves and particles. Specifically, we test if the chorus onset is consistent with development of anisotropy in the electron
phase space density (PSD). After analyzing electron PSD for 73 chorus events, we find that, for ~80 % of them, their
onsets are indeed associated with development of the positive anisotropy in PSD where the pitch angle distribution of
electron velocity peaks at 90 degrees. This PSD anisotropy is prominent mainly at the electron energy range of ≤ ~20 keV.
Interestingly, we further find that there is sometimes a time delay among energies in the increases of the anisotropy: A
development of the positive anisotropy occurs earlier by several minutes for lower energy than for an adjacent higher
energy. |
| first_indexed | 2024-03-08T17:59:12Z |
| format | Article |
| id | doaj.art-5f7562e1527d4b5abfa0aadcd15eaa1d |
| institution | Directory Open Access Journal |
| issn | 2093-5587 2093-1409 |
| language | English |
| last_indexed | 2024-03-08T17:59:12Z |
| publishDate | 2014-12-01 |
| publisher | The Korean Space Science Society |
| record_format | Article |
| series | Journal of Astronomy and Space Sciences |
| spelling | doaj.art-5f7562e1527d4b5abfa0aadcd15eaa1d2024-01-02T02:31:02ZengThe Korean Space Science SocietyJournal of Astronomy and Space Sciences2093-55872093-14092014-12-0131429530110.5140/JASS.2014.31.4.295A Statistical Test of the Relationship Between Chorus Wave Activation and Anisotropy of Electron Phase Space DensityDong-Hee Lee0Dae-Young Lee1Dae-Kyu Shin2Jin-Hee Kim3Jung-Hee Cho4Department of Astronomy and Space Science, Chungbuk National University, Cheongju 361-763, KoreaDepartment of Astronomy and Space Science, Chungbuk National University, Cheongju 361-763, KoreaDepartment of Astronomy and Space Science, Chungbuk National University, Cheongju 361-763, KoreaDepartment of Astronomy and Space Science, Chungbuk National University, Cheongju 361-763, KoreaDepartment of Astronomy and Space Science, Chungbuk National University, Cheongju 361-763, KoreaWhistler mode chorus wave is considered to play a critical role in accelerating and precipitating the electrons in the outer radiation belt. In this paper we test a conventional scenario of triggering chorus using THEMIS satellite observations of waves and particles. Specifically, we test if the chorus onset is consistent with development of anisotropy in the electron phase space density (PSD). After analyzing electron PSD for 73 chorus events, we find that, for ~80 % of them, their onsets are indeed associated with development of the positive anisotropy in PSD where the pitch angle distribution of electron velocity peaks at 90 degrees. This PSD anisotropy is prominent mainly at the electron energy range of ≤ ~20 keV. Interestingly, we further find that there is sometimes a time delay among energies in the increases of the anisotropy: A development of the positive anisotropy occurs earlier by several minutes for lower energy than for an adjacent higher energy.http://ocean.kisti.re.kr/downfile/volume/kosss/OJOOBS/2014/v31n4/OJOOBS_2014_v31n4_295.pdfwhistler chorusradiation belt electronswave-particle interaction |
| spellingShingle | Dong-Hee Lee Dae-Young Lee Dae-Kyu Shin Jin-Hee Kim Jung-Hee Cho A Statistical Test of the Relationship Between Chorus Wave Activation and Anisotropy of Electron Phase Space Density Journal of Astronomy and Space Sciences whistler chorus radiation belt electrons wave-particle interaction |
| title | A Statistical Test of the Relationship Between Chorus Wave Activation and Anisotropy of Electron Phase Space Density |
| title_full | A Statistical Test of the Relationship Between Chorus Wave Activation and Anisotropy of Electron Phase Space Density |
| title_fullStr | A Statistical Test of the Relationship Between Chorus Wave Activation and Anisotropy of Electron Phase Space Density |
| title_full_unstemmed | A Statistical Test of the Relationship Between Chorus Wave Activation and Anisotropy of Electron Phase Space Density |
| title_short | A Statistical Test of the Relationship Between Chorus Wave Activation and Anisotropy of Electron Phase Space Density |
| title_sort | statistical test of the relationship between chorus wave activation and anisotropy of electron phase space density |
| topic | whistler chorus radiation belt electrons wave-particle interaction |
| url | http://ocean.kisti.re.kr/downfile/volume/kosss/OJOOBS/2014/v31n4/OJOOBS_2014_v31n4_295.pdf |
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