Magnetotelluric source effect due to 3D ionospheric current systems using the complex image method for 1D conductivity structures

• Viljanen Ari

  Finnish Meteorological Institute, Geophysical Research Division

• Pirjola Risto

  Finnish Meteorological Institute, Geophysical Research Division

• Amm Olaf

  Finnish Meteorological Institute, Geophysical Research Division

抄録

The complex image method (CIM) is an efficient tool to calculate the electromagnetic field at the earth's surface produced by 3D ionospheric current systems when the earth has a layered conductivity structure. The calculations are applicable to the estimation of source effects on magnetotelluric data. In this paper CIM is used in connection with some typical high-latitude ionospheric events: a westward travelling surge, a Harang discontinuity, an omega band, and a giant pulsation. The complicated ionospheric current systems are constructed of short horizontal current filaments with vertical currents at both ends. The currents are given numerically on a 50 km×50 km grid covering a region of even 1000 km × 2000 km. The investigations indicate that the source distortion very much depends on the event, and may be significant in a wide period range, especially for a resistive earth structure. The source effect seems quite unpredictable. Sometimes the apparent resistivity is larger and sometimes smaller than the plane wave value. At times the source effect is very small even if the ionospheric current is strongly inhomogeneous.

収録刊行物

• Ｅａｒｔｈ，　Ｐｌａｎｅｔｓ　ａｎｄ　Ｓｐａｃｅ

  Ｅａｒｔｈ，　Ｐｌａｎｅｔｓ　ａｎｄ　Ｓｐａｃｅ 51 (9), 933-945, 1999

  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

キーワード

• Space and Planetary Science
• Geology

詳細情報

• CRID: 1390001206510223232
• NII論文ID: 10002698408
• NII論文ID: 130003780754
• NII書誌ID: AA11211921
• DOI: 10.1186/bf03351564
• ISSN: 18805981
• ISSN: 13438832
• NDL書誌ID: 4891116
• Web Site: https://ndlsearch.ndl.go.jp/books/R000000004-I4891116
• Web Site: https://link.springer.com/content/pdf/10.1186/BF03351564.pdf
• Web Site: https://link.springer.com/article/10.1186/BF03351564/fulltext.html
• Web Site: http://link.springer.com/content/pdf/10.1186/BF03351564
• 本文言語コード: en
• データソース種別:
  • JaLC
  • NDL
  • Crossref
  • CiNii Articles
• 抄録ライセンスフラグ: 使用不可