Abstract
The specific features of the spatial structure and time dynamics of the main geomagnetic field during the 20th century, proceeding from the present-day concepts of geomagnetic jerks have been studied. The variations, caused by global dissipation of the geomagnetic field dipole part, have been separated from the regional variations, described by nondipole spatial harmonics of the spherical harmonic expansion series. It has been indicated that the geomagnetic field westward drift manifests itself in a limited region of the Earth’s surface, forming the known Brazil anomaly. However, the drift component in the variations in the geomagnetic field morphological structures is globally found out during the considered almost 100-year period along the narrow belt around the geomagnetic axis. However, this drift is northwestward in the Northern Hemisphere, and the structures drift southeastward in the Southern Hemisphere. The detected variations of the drift nature are reflected in the variations in the integral geomagnetic characteristic, when changes in the position of the Earth’s magnetic center are considered. The direct correlation between the global geomagnetic variations of the drift nature and the trend variations in the orientation of the vector of the Earth daily rotation velocity has been detected.
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Original Russian Text © A.O. Simonyan, V.P. Golovkov, 2009, published in Geomagnetizm i Aeronomiya, 2009, Vol. 49, No. 6, pp. 843–850.
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Simonyan, A.O., Golovkov, V.P. Spatial features of the manifestation of the geomagnetic field westward drift. Geomagn. Aeron. 49, 805–812 (2009). https://doi.org/10.1134/S0016793209060140
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DOI: https://doi.org/10.1134/S0016793209060140