North–South Asymmetries in Earth’s Magnetic Field

Laundal, K. M., Cnossen, I., Milan, S. E., Haaland, S. E., Coxon, John, Pedatella, N. M., Förster, M. and Reistad, J. P. (2017) North–South Asymmetries in Earth’s Magnetic Field. Space Science Reviews, 206 (1-4). pp. 225-257. ISSN 0038-6308

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The solar-wind magnetosphere interaction primarily occurs at altitudes where the dipole component of Earth’s magnetic field is dominating. The disturbances that are created in this interaction propagate along magnetic field lines and interact with the ionosphere–thermosphere system. At ionospheric altitudes, the Earth’s field deviates significantly from a dipole. North–South asymmetries in the magnetic field imply that the magnetosphere–ionosphere–thermosphere (M–I–T) coupling is different in the two hemispheres. In this paper we review the primary differences in the magnetic field at polar latitudes, and the consequences that these have for the M–I–T coupling. We focus on two interhemispheric differences which are thought to have the strongest effects: 1) A difference in the offset between magnetic and geographic poles in the Northern and Southern Hemispheres, and 2) differences in the magnetic field strength at magnetically conjugate regions. These asymmetries lead to differences in plasma convection, neutral winds, total electron content, ion outflow, ionospheric currents and auroral precipitation.

Item Type: Article
Additional Information: Funding Information: KML, SEM, SH, and JPR were supported by the Research Council of Norway/CoE under contract 223252/F50. IC was supported by a fellowship of the Natural Environment Research Council, grant number NE/J018058/1. NP was supported by the U.S. National Science Foundation AGS-1522830. JCC was funded by Natural Environment Research Council (NERC) grant NE/L007177/1.
Uncontrolled Keywords: Aurora, Ion outflow, Ionospheric currents, North–South magnetic field asymmetries, Plasma convection, Thermospheric wind, Total electron content
Subjects: F500 Astronomy
F800 Physical and Terrestrial Geographical and Environmental Sciences
Depositing User: Rachel Branson
Date Deposited: 24 Feb 2022 15:27
Last Modified: 24 Feb 2022 15:30

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