Earth's ionosphere: Theory and phenomenology of cowling channels

Akimasa Yoshikawa, Ryoichi Fujii

研究成果: 書籍/レポート タイプへの寄稿

3 被引用数 (Scopus)


The Cowling channel is a generic name of a current system forming inside a high conductivity band in which a secondary polarization electric field modifies the current flow. The polarization field is excited when a divergent part of Hall current driven by the primary electric field is prevented from flowing out to the magnetosphere as the field-aligned current. The purpose of this chapter is to review the recent development of the Cowling channel model. Recent work provides an extension of the theoretical description of the classical Cowling channel with respect to the following aspects: (1) taking into account the 3D nature of the ionosphere by introducing two current layers at different altitudes, and (2) considering finite length of the Cowling channel by introducing a conductance boundary not only at the meridional borders of the Cowling channel, but also at its zonal boundaries. Using this improved model, we discuss current closure and the energy principle for evolution of the Cowling channel. Energy flow inside the Cowling channel and impact of the polarization effect on Joule dissipation in the more general M-I coupling scheme are also provided. We also clarify how shear Alfvén waves interact to the Cowling channel and their application to the global magnetosphere- ionosphere coupling simulations.

ホスト出版物のタイトルElectric Currents in Geospace and Beyond
出版ステータス出版済み - 4月 17 2018

!!!All Science Journal Classification (ASJC) codes

  • 農業および生物科学一般
  • 生化学、遺伝学、分子生物学一般
  • 医学一般


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