Daily Variation of the Geomagnetic Field and the Deformation of the Magnetosphere


IT is well known that at low latitudes the horizontal component of the geomagnetic field has a maximum Hmax around local noon and a minimum value Hmin between 1800 and 0600 h local time. The range of the daily variation ΔH is strikingly enhanced in the region ±3° geomagnetic latitude due to the electro jet current in the E-region. We have been interested in verifying whether at a low latitude station outside the influence of the electrojet, ΔH represents an increase on the day side over a base level at Hmin, or alternatively it is a decrease on the night side from a base level at Hmax. In the former case, we should have a positive correlation between ΔH and Hmax, with poor correlation between ΔH and Hmin. On the other hand, in the latter case, we should get a negative correlation between ΔH and Hmin and a poor correlation between ΔH and Hmax.

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  1. 1

    Coleman, jun., P. J., and Cummings, W. D., Conjugate Point Symp., Colorado, IV-15-1 (1967).

  2. 2

    Cummings, W. D., Barfield, J. N., and Coleman, jun., P. J., J. Geophys. Res., 73, 6687 (1968).

  3. 3

    Williams, D. J., and Mead, G. D., J. Geophys. Res., 70, 3017 (1965).

  4. 4

    Pai, G. L., Bridge, H. S., Lyon, E. F., and Egidi, A., Trans. Amer. Geophys. Un., 48, 176 (1967).

  5. 5

    Alfven, H., and Falthammer, C. G., Cosmical Electrodynamics, second ed., 56 (Oxford Univ. Press, New York, 1963).

  6. 6

    Axford, W. I., and Hines, C. O., Canad. J. Phys., 39, 1433 (1961).

  7. 7

    Dungey, J. W., Phys. Rev. Lett., 6, 47 (1961).

  8. 8

    Freeman, jun., J. W., J. Geophys. Res., 73, 4151 (1968).

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SARABHAI, V., NAIR, K. Daily Variation of the Geomagnetic Field and the Deformation of the Magnetosphere. Nature 223, 603–605 (1969). https://doi.org/10.1038/223603a0

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