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Modelling of spatial-temporal changes of the geomagnetic field in Japan


A geomagnetic regional model is constructed to provide a spatial-temporal variation of three orthogonal components (X, Y, Z) in Japan. In order to obtain a high temporal and spatial resolution, Natural Orthogonal Components (NOC) analysis and Spherical Cap Harmonic (SCH) analysis were employed to produce a spatial-temporal model based on the observed data from geomagnetic observatories and continuous geomagnetic stations. Using this model, we calculated the secular variation between 1999 and 2004 in Japan. The root mean square (RMS) scatter of the model is less than 3 nT, which indicates a good agreement between calculated and input data.


  1. An, Z., Spherical cap harmonic analysis of the geomagnetic field and its secular variation in China for 2000, Chinese Journal of Geophysics, 46, 68–72, 2003 (in Chinese).

  2. Burdelnaya, I. A., S. V. Filippov, V. P. Golovkov, S. Fujiwara, T. Tanabe, S. Nishi, M. Kaidzu, and S. Matsuzaka, Regional orthogonal models of the geomagnetic field changes over the Far East, Earth Planets Space, 51, 287–296, 1999.

  3. Fujiwara, S., T. Nishiki, H. Shirai, H. Hamazaki, and V. P. Golovkov, Modeling the daily mean values of regional geomagnetic total field changes in Japan, Earth Planets Space, 53, 69–73, 2001.

  4. Ji, X., H. Shirai, M. Watanabe, J. He, H. Nakagawa, and M. Utsugi, The geomagnetic model in Japan area based on the continuous observation data, Journal of the Geographical Survey Institute, 103, 89–97, 2004 (in Japanese).

  5. Haines, G. V., Spherical cap harmonic analysis, J. Geophys. Res., 90, 2583–2591, 1985.

  6. Haines, G. V., Modelling geophysical fields in source free regions by Fourier series and rectangular harmonic analysis, Geophysica, 25, 91–122, 1989.

  7. Hwang, C. and S. K. Chen, Fully normalized spherical cap harmonics: application to the analysis of sea-level data from TOPEX-POSEIDON and ERS-1, Geophys. J. Int., 129, 450–460, 1997.

  8. Kotze, P. B., The time varying geomagnetic field of southern Africa, Earth Planets Space, 55, 111–116, 2003.

  9. Langel, R. A., Main field, in Geomagnetism, edited by J. A. Jacobs, 1, pp. 249–512, Academic Press, London, 1987.

  10. Shirai, H., T. Nishiki, H. Satoh, M. Utsugi, H. Nakai, M. Morita, T. Kad-owaki, and T. Yutsudo, Magnetic charts for the epoch 2000.0, Journal of the Geographical Survey Institute, 99, 1–8, 2002 (in Japanese).

  11. Sumitomo, N. and S. Yabe, Secular change of the geomagnetic total intensity at Tottori, Japan, Disaster Prevention Research Institute Annuals Kyoto University, 21, 79–86, 1978 (in Japanese).

  12. Thebault, E., J. J. Schott, M. Mandea, and P. Hoffbeck, A new proposal for spherical cap harmonic modelling, Geophys. J. Int., 159, 83–103, 2004.

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Correspondence to Xiaoli Ji.

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Ji, X., Utsugi, M., Shirai, H. et al. Modelling of spatial-temporal changes of the geomagnetic field in Japan. Earth Planet Sp 58, 757–763 (2006).

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Key words

  • Geomagnetic regional model
  • spatial-temporal model
  • secular variation
  • Natural Orthogonal Components
  • Spherical Cap Harmonic