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Spherical cap modelling of Ørsted magnetic field vectors over southern Africa

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Abstract

Vector magnetic field observations by the Ørsted satellite during geomagnetic quiet conditions around January 1, 2000, have been employed to derive a spherical cap harmonic model (Haines, 1985) over the southern African region between 10° and 45° South in latitude and between 10° and 45° East in longitude. In the process a total of 9283 vector (27949 component) Ørsted observations have been used to derive a spherical cap model with minimum wavelength resolution approximately 1200 km. This model is compared with the global Ørsted magnetic field model (Olsen et al., 2000a) in terms of a fit to observatory and repeat station data over the southern African subcontinent where the Hermanus Magnetic Observatory conducts field surveys at regular 5 year intervals.

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Correspondence to P. B. Kotzé.

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Kotzé, P.B. Spherical cap modelling of Ørsted magnetic field vectors over southern Africa. Earth Planet Sp 53, 357–361 (2001) doi:10.1186/BF03352392

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Keywords

  • Earth Planet Space
  • Harmonic Model
  • Southern African Region
  • Geomagnetic Quiet Condition
  • Secular Variation Model