Influences of various magnetospheric and ionospheric current systems on geomagnetically induced currents around the world

de Villiers, J. S. and Kosch, Michael Jurgen and Yamazaki, Yosuke and Lotz, S. (2017) Influences of various magnetospheric and ionospheric current systems on geomagnetically induced currents around the world. Space Weather, 15 (2). pp. 403-417. ISSN 1539-4956

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Abstract

Ground-based observations of geomagnetic field (B field) are usually a superposition of signatures from different source current systems in the magnetosphere and ionosphere. Fluctuating B fields generate geoelectric fields (E fields), which drive geomagnetically induced currents (GIC) in technological conducting media at the Earth's surface. We introduce a new Fourier integral B field model of east/west directed line current systems over a one-dimensional multilayered Earth in plane geometry. Derived layered-Earth profiles, given in the literature, are needed to calculate the surface impedance, and therefore reflection coefficient in the integral. The 2003 Halloween storm measurements were Fourier transformed for B field spectrum Levenberg-Marquardt least squares inversion over latitude. The inversion modeled strengths of the equatorial electrojets, auroral electrojets, and ring currents were compared to the forward problem computed strength. It is found the optimized and direct results match each other closely and supplement previous established studies about these source currents. Using this model, a data set of current system magnitudes may be used to develop empirical models linking solar wind activity to magnetospheric current systems. In addition, the ground E fields are also calculated directly, which serves as a proxy for computing GIC in conductor-based networks.

Item Type:
Journal Article
Journal or Publication Title:
Space Weather
Additional Information:
An edited version of this paper was published by AGU. © 2017 American Geophysical Union
Uncontrolled Keywords:
/dk/atira/pure/subjectarea/asjc/1900/1902
Subjects:
ID Code:
85049
Deposited By:
Deposited On:
06 Mar 2017 13:32
Refereed?:
Yes
Published?:
Published
Last Modified:
19 Sep 2020 04:31