Auroral current system as estimated by a magnetic inversion method

2011 Fiscal Year Final Research Report

• Project/Area Number: 20540438
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Space and upper atmospheric physics
• Research Institution: Nagoya University
• Principal Investigator: IEDA Akimasa 名古屋大学, 太陽地球環境研究所, 助教 (70362209)
• Project Period (FY): 2008 – 2011
• Keywords: 宇宙科学 / 宇宙空間 / 磁気圏・電離圏 / 地球電磁気 / 超高層物理学

Research Abstract

The spatial distribution of field-aligned currents(FACs) is studied for an intense substorm. We first estimated the height-integrated ionospheric Hall and Pedersen conductances from ultraviolet images taken by the Polar satellite. To derive FACs, we then employed Ohm's law for the ionosphere, applying a magnetic inversion method to the input conductances and ground magnetic field data. As a result, the Hall FACs that are connected to the ionospheric Hall currents were aniti-correlated with the Pedersen FACs that are connected to the ionospheric Pedersen currents. Such anti-correlations were observed near the poleward and the equatorward edges of the auroral westward currents. This result indicates that the auroral current system included the Cowling channel that is the auroral westward currents enhanced by the polarization electric field in this particular event.

Research Products

• [Journal Article] Reformulation and energy flow of the Cowlingchannel (2011)
  • Author(s): Fujii, R., O. Amm, A. Yoshikawa, A. Ieda, and H. Vanhamaki
  • Journal Title: J. Geophys. Res. Volume: 116 Pages: A02305
  • DOI: doi:10.1029/2010JA015989
  • Peer Reviewed
• [Journal Article] A statistical investigation of the Cowling channel efficiency in the auroral zone (2011)
  • Author(s): Amm, O., R. Fujii, K. Kauristie, A. Aikio, A. Yoshikawa, A. Ieda, and H. Vanhamaki
  • Journal Title: J. Geophys. Res. Volume: 116 Pages: A02304
  • DOI: doi:10.1029/2010JA015988
  • Peer Reviewed
• [Journal Article] Pressure changes associated with substorm dipolarization in the near-Earth plasma sheet (2010)
  • Author(s): Miyashita, Y., S. Machida, A. Ieda, D. Nagata, Y. Kamide, M. Nose, K. Liou, T. Mukai, S. P. Christon, C. T. Russell, I. Shinohara, and Y. Saito
  • Journal Title: J. Geophys. Res.
  • DOI: doi:10.1029/2010JA015608
  • Peer Reviewed
• [Journal Article] Rayleigh-Taylor type instability in auroral patches (2010)
  • Author(s): Shiokawa, K., A. Nakajima, A. Ieda, K. Sakaguchi, R. Nomura, T. Aslaksen, M. Greffen, and E. Donovan
  • Journal Title: J. Geophys. Res. Volume: 115 Pages: A02211
  • DOI: doi:10.1029/2009JA014273
  • Peer Reviewed
• [Journal Article] Geotail observations of plasma sheet ion composition over 16 years : On variations of average plasma ion mass and O+triggering substorm model (2009)
  • Author(s): Nose, M., A. Ieda, and S. P. Christon
  • Journal Title: J. Geophys. Res. Volume: 114 Pages: A07223
  • DOI: doi:10.1029/2009JA014203
  • Peer Reviewed
• [Journal Article] Longitudinal association between magnetotail reconnection and auroral breakup based on Geotail and Polar observations (2008)
  • Author(s): Ieda, A., D. H. Fairfield, J. A. Slavin, K. Liou, C.-I. Meng, S. Machida, Y. Miyashita, T. Mukai, Y. Saito, M. Nose, J.-H. Shue, G. K. Parks, and M. O.
  • Journal Title: J. Geophys. Res. Volume: 113 Pages: A08207
  • DOI: doi:10.1029/2008JA013127
  • Peer Reviewed
• [Journal Article] Towards understanding the electrodynamics of the 3-dimensional high-latitude ionosphere : present and future (2008)
  • Author(s): Amm, O., A. Aruliah, S. C. Buchert, R. Fujii, J. W. Gjerloev, A. Ieda, T. Matsuo, C. Stolle, H. Vanham aki, and A. Yoshikawa
  • Journal Title: Ann. Geophys. Volume: 26 Pages: 3913-3932
  • Peer Reviewed
• [Presentation] Field-aligned currents during an intense substorm as estimated from global images and ground magnetic observations (2011)
  • Author(s): 家田章正、上出洋介、堀智明、関華奈子、三好由純、藤井良一、D. Lummerzheim、R. J. Strangeway、R. Ergun、M. O. Fillingim、K. Parks, J. P. McFadden, C. W. Carlson
  • Organizer: AGU Chapman Conference-Relationship Between Auroral Phenomenology and Magnetospheric Processes
  • Place of Presentation: Fairbanks, USA
  • Year and Date: 2011-03-01
• [Presentation] オーロラサージ極側境界の鉛磁力線電流 (2010)
  • Author(s): 家田章正
  • Organizer: 平成22年度国立極地研究所研究集会「極域における電離圏パラメータの非線形発展:モデル化と検証」
  • Place of Presentation: 国立極地研究所(東京都)
  • Year and Date: 2010-12-22
• [Presentation] FAST衛星によるオーロラサージ電流系の観測 (2010)
  • Author(s): 家田章正、藤本正樹、西野真木、堀智昭、関華奈子、西村幸敏、藤井良一、海老原祐輔、町田忍、宮下幸長、向井利典、齋藤義文
  • Organizer: 地球電磁気・地球惑星圏学会第128回総会・講演会
  • Place of Presentation: 沖縄県市町村自治会館(沖縄県)
  • Year and Date: 2010-10-31
• [Presentation] オーロラ電流系の推定と直接観測 (2010)
  • Author(s): 家田章正、上出洋介、堀智昭、藤井良一
  • Organizer: 日本地球惑星科学連合2010年大会
  • Place of Presentation: 幕張メッセ(千葉県)
  • Year and Date: 2010-05-28
• [Presentation] Field-aligned currents during an intense substorm as estimated from global images and ground magnetic observations (2010)
  • Author(s): 家田章正、上出洋介、堀智明、関華奈子、三好由純、藤井良一、D. Lummerzheim、R. J. Strangeway、R. Ergun、M. O. Fillingim、K. Parks, J. P. McFadden, C. W. Carlson
  • Organizer: 10th International conference on substorms
  • Place of Presentation: Pismo beach, CA, USA
  • Year and Date: 2010-03-22
• [Presentation] オーロラ画像と地上磁場から推定されたサブストーム時の沿磁力線電流地球電磁気 (2009)
  • Author(s): 家田章正、上出洋介
  • Organizer: 地球惑星圏学会第124回総会・講演会
  • Place of Presentation: 金沢大学(金沢)
  • Year and Date: 2009-09-27
• [Presentation] 地磁気逆計算法による電離層電流系の推定 (2009)
  • Author(s): 家田章正、上出洋介
  • Organizer: 日本地球惑星科学連合2009年大会
  • Place of Presentation: 幕張メッセ(千葉県)
  • Year and Date: 2009-05-18
• [Presentation] テミス衛星群と地上オーロラビデオとによる2008年3月のサブストーム同時観測 (2008)
  • Author(s): 家田章正、塩川和夫、堀智昭、坂口歌織、野村麗子,中島章光、宮下幸長、藤本正樹、M. Greffen、E. Donovan、E. Spanswick、I. Mann、V. A. Angelopoulos、C. T. Russell、J. P. McFadden、C. W. Carlson、D. Larson、S. Mende、H. Frey、K. H. Glassmeier、U. Auster
  • Organizer: 地球電磁気・地球惑星圏学会第124回総会・講演会
  • Place of Presentation: 仙台市戦災復興記念会館(宮城県)
  • Year and Date: 2008-10-09