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Time Variations of the Frequencies of Low-Degree Solar P-Modes

  • Martin F. Woodard
  • Robert W. Noyes
Conference paper
Part of the International Astronomical Union / Union Astronomique Internationale book series (IAUS, volume 123)

Abstract

A comparison of three separate years (1980, 1984, 1985) of SMM/ACRIM solar total irradiance data reveals small but significant changes in the frequencies of low-degree solar p-modes. Specifically, a decrease in the mean frequency of the nine strongest ℓ = 0 and 1 oscillation peaks was observed between 1980 and 1984 such that \({\left\langle {\Delta v} \right\rangle _{1984 - 1980}} = - 0.41\pm 0.13\mu Hz.\)

A further comparison, between 1980 and 1985, gives \({\left\langle {\Delta v} \right\rangle _{1985 - 1980}} = - 0.45\pm 0.23\mu Hz.\)

Thus, the mean frequency of these modes is approximately 1.5 parts in 104 higher at the time of solar maximum than near solar minimum, a result which may shed light on the mechanism of the solar activity cycle.

Keywords

Solar Minimum Solar Maximum Solar Radius Solar Activity Cycle Radius Variation 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

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References

  1. 1.
    Woodard, M.F., and Noyes, R.W., Nature 318, 449–450 (1985).ADSCrossRefGoogle Scholar
  2. 2.
    Grec, G., Fossat, E. and Pomerantz, M., Sol. Phys. 82, 55–66 (1983).ADSCrossRefGoogle Scholar

Copyright information

© International Astronomical Union 1988

Authors and Affiliations

  • Martin F. Woodard
    • 1
  • Robert W. Noyes
    • 2
  1. 1.Jet Propulsion LaboratoryCalifornia Institute of TechnologyPasadenaUSA
  2. 2.Harvard-Smithsonian Center for AstrophysicsCambridgeUSA

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