Solar Physics

, Volume 25, Issue 1, pp 5–13

Polar magnetic fields of the Sun: 1960–1971

  • Robert Howard


Observations of the magnetic fields in the polar regions of the Sun are presented for the period 1960–1971. At the start of this interval the fields at the two poles were consistently of opposite sign and averaged around 1 G. Early in 1961 the field in the south decreased suddenly and the field in the north decreased in strength slowly over the next few years. By the mid-1960's the fields at both poles were quite weak and irregular. Throughout the period of these observations the fields at both poles often showed a remarkable tendency to vary in unison. About the middle of 1971 the north polar field became significantly positive, first at lower latitudes, then above 70 °. An autocorrelation analysis of the polar fields in the north shows a weak rotation peak, indicating significant ‘features’ in these regions. A comparison of field strengths in the east and west quadrants in the north suggests that even at the extreme polar latitudes the following polarity fields are inclined slightly toward the rotation and the preceding polarity field lines are inclined slightly to trail the rotation.


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  1. Babcock, H. D.: 1959, Astrophys. J. 130, 364.Google Scholar
  2. Babcock, H. W.: 1953, Astrophys. J. 118, 387.Google Scholar
  3. Babcock, H. W.: 1961, Astrophys. J. 133, 572.Google Scholar
  4. Babcock, H. W. and Babcock, H. D.: 1955, Astrophys. J. 121, 349.Google Scholar
  5. Howard, R.: 1959, Astrophys. J. 130, 193.Google Scholar
  6. Howard, R.: 1963, in Annual Report of the Director, Mount Wilson and Palomar Observatories, in Carnegie Institution of Washington Year Book 62, p. 37.Google Scholar
  7. Howard, R.: 1965, in R. Lüst (ed.),‘Stellar and Solar Magnetic Fields’, IAU Symp. 22, 129.Google Scholar
  8. Howard, R. and Babcock, H. W.: 1960, Astrophys. J. 132, 218.Google Scholar
  9. Krause, F. and Rädler, K.-H.: 1971, in R. Howard (ed.), ‘Solar Magnetic Fields’, IAU Symp. 43, 770.Google Scholar
  10. Severny, A.: 1971, in R. Howard (ed.), ‘Solar Magnetic Fields’, IAU Symp. 43, 675.Google Scholar
  11. Waldmeier, M.: 1971, Solar Phys. 20, 332.Google Scholar
  12. Wilcox, J. M. and Howard, R.: 1970, Solar Phys. 13, 251.Google Scholar

Copyright information

© D. Reidel Publishing Company 1972

Authors and Affiliations

  • Robert Howard
    • 1
  1. 1.Hale Observatories, Carnegie Institution of Washington, California Institute of TechnologyPasadenaU.S.A.

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