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Solar Physics

, Volume 76, Issue 2, pp 211–219 | Cite as

The effects of sunspots on solar irradiance

  • H. S. Hudson
  • S. Silva
  • M. Woodard
  • R. C. Willson
Article

Abstract

Sunspots have an obvious direct effect upon the visible radiant energy falling upon the Earth. We show how to estimate this effect and compare it quantitatively with recent observations of the solar total irradiance (Willson et al., 1981). The sunspots explain about half of the total observed variance of one-day averages. Since the sunspot effect on irradiance produces an asymmetry of the solar radiation, rather than (necessarily) a variation of the total luminosity, we have also estimated the sunspot population on the invisible hemisphere. This extrapolation allows us to estimate the true luminosity deficit produced by sunspots, in a manner that tends toward the correct long-term average value. We find no evidence for instantaneous global re-emission to compensate for the sunspot flux deficit.

Keywords

Radiation Direct Effect Solar Radiation Radiant Energy Recent Observation 
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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Copyright information

© D. Reidel Publishing Co. 1982

Authors and Affiliations

  • H. S. Hudson
    • 1
  • S. Silva
    • 1
  • M. Woodard
    • 1
  • R. C. Willson
    • 2
  1. 1.Center for Astrophysics and Space Sciences, University of CaliforniaSan DiegoUSA
  2. 2.Jet Propulsion LaboratoryUSA

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