Contribution of Ultraviolet Irradiance Variations to Changes in the Sun's Total Irradiance

  title={Contribution of Ultraviolet Irradiance Variations to Changes in the Sun's Total Irradiance},
  author={Judith Lean},
  pages={197 - 200}
  • J. Lean
  • Published 14 April 1989
  • Environmental Science, Medicine
  • Science
The sun's total irradiance decreased from 1980 to mid-1985, remained approximately constant until mid-1987, and has recently begun to increase. This time interval covered the decrease in solar activity from the maximum of solar cycle 21 to solar minimum and the onset of cycle 22. The sun's ultraviolet irradiance also decreased during the descending phase of cycle 21 and, like the total irradiance, is now increasing concurrently with the increase in cycle 22 activity. Although only 1 percent of… Expand

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