Articles | Volume 38, issue 5
Regular paper
15 Sep 2020
Regular paper |  | 15 Sep 2020

Induced currents due to 3D ground conductivity play a major role in the interpretation of geomagnetic variations

Liisa Juusola, Heikki Vanhamäki, Ari Viljanen, and Maxim Smirnov

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Cited articles

Amm, O.: Ionospheric elementary current systems in spherical coordinates and their application, J. Geomagn. Geoelectr., 49, 947–955,, 1997. a
Amm, O. and Viljanen, A.: Ionospheric disturbance magnetic field continuation from the ground to ionosphere using spherical elementary current systems, Earth Planets Space, 51, 431–440,, 1999. a
Boteler, D. H., Pirjola, R. J., and Nevanlinna, H.: The effects of geomagnetic disturbances on electrical systems at the Earth's surface, Adv. Space Res., 22, 17–27,, 1998. a, b
Cherevatova, M., Smirnov, M. Y., Korja, T., Pedersen, L. B., Ebbing, J., Gradmann, S., and Becken, M.: Electrical conductivity structure of north-west Fennoscandia from three-dimensional inversion of magnetotelluric data, Tectonophysics, 653, 20–32,, 2015. a
Davis, T. N. and Sugiura, M.: Auroral electrojet activity index AE and its universal time variations, J. Geophys. Res., 71, 785–801, 1966. a
Short summary
Rapid variations of the magnetic field measured on the ground can be used to estimate space weather risks to power grids, but forecasting the variations remains a challenge. We show that part of this problem stems from the fact that, in addition to electric currents in space, the magnetic field variations are strongly affected by underground electric currents. We suggest that separating the measured field into its space and underground parts could improve our understanding of space weather.