Induction effects on ionospheric electric and magnetic fields

Heikki Vanhamäki, A. Viljanen, O. Amm

    研究成果: Contribution to journalArticle査読

    8 被引用数 (Scopus)


    Rapid changes in the ionospheric current system give rise to induction currents in the conducting ground that can significantly contribute to magnetic and especially electric fields at the Earth's surface. Previous studies have concentrated on the surface fields, as they are important in, for example, interpreting magnetometer measurements or in the studies of the Earth's conductivity structure. In this paper we investigate the effects of induction fields at the ionospheric altitudes for several realistic ionospheric current models (Westward Travelling Surge, Ω-band, Giant Pulsation). Our main conclusions are: 1) The secondary electric field caused by the Earth's induction is relatively small at the ionospheric altitude, at most 0.4 mV/m or a few percent of the total electric field; 2) The primary induced field due to ionospheric self-induction is locally important, ∼ a few mV/m, in some "hot spots", where the ionospheric conductivity is high and the total electric field is low. However, our approximate calculation only gives an upper estimate for the primary induced electric field; 3) The secondary magnetic field caused by the Earth's induction may significantly affect the magnetic measurements of low orbiting satellites. The secondary contribution from the Earth's currents is largest in the vertical component of the magnetic field, where it may be around 50% of the field caused by ionospheric currents.

    ジャーナルAnnales Geophysicae
    出版ステータス出版済み - 2005

    All Science Journal Classification (ASJC) codes

    • 天文学と天体物理学
    • 地質学
    • 大気科学
    • 地球惑星科学(その他)
    • 宇宙惑星科学


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