Observations of traveling ionospheric disturbances and 3-m scale irregularities in the nighttime F-region ionosphere with the MU radar and a GPS network

• Saito A.

  304 Rhodes Hall, School of Electrical and Computer Engineering, Cornell University On leave from Department of Geophysics, Graduate School of Science, Kyoto University

• Nishimura M.

  Radio Science Center for Space and Atmosphere, Kyoto University

• Yamamoto M.

  Radio Science Center for Space and Atmosphere, Kyoto University

• Fukao S.

  Radio Science Center for Space and Atmosphere, Kyoto University

• Tsugawa T.

  Department of Geophysics, Graduate School of Science, Kyoto University

• Otsuka Y.

  Solar-Terrestrial Environment Laboratory, Nagoya University

• Miyazaki S.

  Geographical Survey Institute

• Kelley M. C.

  304 Rhodes Hall, School of Electrical and Computer Engineering, Cornell University

書誌事項

タイトル別名

• Observations of traveling ionospheric disturbances and 3-m scale irregularities in the nighttime <I>F</I>-region ionosphere with the MU radar and a GPS network

抄録

The nighttime traveling ionospheric disturbances (TIDs) and the F-region 3-m scale field-aligned irregularities were simultaneously observed with the MU radar and GEONET, a GPS network, during the FRONT (F-region Radio and Optical measurement of the Nighttime TID) campaign periods in May 1998 and August 1999. The vertical profile of electron density detected by the incoherent scatter observation of the MU radar clarified that ionized atmosphere on the bottomside of the ionospheric F-region was deeply modulated by TIDs, which would cause the variations of the 630 nm band airglow luminosity. The coherent echoes from the 3-m scale fieldaligned irregularities were detected also on the bottomside of the F-region in the nights when TIDs were intense in amplitude and the ionosphere was uplifted. Two-dimensional structures of the field-aligned irregularities detected by the multi-beam observation of the MU radar revealed that the 3-m scale irregularities formed band-like structures and traveled to the southwest in several nights. Their wave vector and traveling velocity were coincident with those of the nighttime TIDs that were simultaneously detected by the TEC observation of GEONET. The intense Doppler velocities of the coherent echoes indicate that the polarization electric field is generated inside the TIDs. We consider that the horizontal gradient of the electric conductivity associated by TIDs and the vertical gradient of the conductivity on the bottomside of the F-region ionosphere generates the 3-m scale irregularities through the gradient-drift instability process. The anti-correlation of the occurrence rate of the F-region field-aligned irregularities to the solar activity would be caused by the anti-correlation of the amplitude of TIDs and of the vertical gradient of the Pedersen conductivity.

収録刊行物

• Ｅａｒｔｈ，　Ｐｌａｎｅｔｓ　ａｎｄ　Ｓｐａｃｅ

  Ｅａｒｔｈ，　Ｐｌａｎｅｔｓ　ａｎｄ　Ｓｐａｃｅ 54 (1), 31-44, 2002

  地球電磁気・地球惑星圏学会 、公益社団法人 日本地震学会、特定非営利活動法人 日本火山学会、日本測地学会、日本惑星科学会

詳細情報

• CRID: 1390282681488669184
• NII論文ID: 10008634117
• NII論文ID: 130003780823
• NII書誌ID: AA11211921
• DOI: 10.1186/bf03352419
• ISSN: 18805981
• ISSN: 13438832
• NDL書誌ID: 6062392
• Web Site: http://id.ndl.go.jp/bib/6062392
• Web Site: https://ndlsearch.ndl.go.jp/books/R000000004-I6062392
• Web Site: https://link.springer.com/content/pdf/10.1186/BF03352419.pdf
• Web Site: https://link.springer.com/article/10.1186/BF03352419/fulltext.html
• Web Site: http://link.springer.com/content/pdf/10.1186/BF03352419
• 本文言語コード: en
• データソース種別:
  • JaLC
  • NDL
  • Crossref
  • CiNii Articles
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