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Annual and semi-annual variations of the geomagnetic field components analysed by the multi-taper method
Earth, Planets and Space volume 58, pages785–791(2006)
Monthly means of three geomagnetic components (X-northern, Y-eastern and Z-vertical downward) from 154 observatories over the interval 1960-2002 have been analysed to determine the annual and semi-annual variations. The method applied is a multi-taper analysis, which gives a robust estimate of the power spectral density of the temporal variation of the field components. The main objective is to investigate the geographic dependence of the annual and semi-annual variations. Surprisingly, these variations in the vertical downward component are not homogeneously distributed all over the globe, having mainly a longitudinal dependency. The results of the analysis are briefly discussed with regard to possible mechanisms responsible for these variations and to mantle conductivity.
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Wardinski, I., Mandea, M. Annual and semi-annual variations of the geomagnetic field components analysed by the multi-taper method. Earth Planet Sp 58, 785–791 (2006). https://doi.org/10.1186/BF03351982
- Geomagnetic field variation
- multi-taper method
- time series analysis