Abstract
THE Active Cavity Radiometer Irradiance Monitor (ACRIM I), an instrument carried on NASA's Solar Maximum Mission satellite, measured the Sun's luminosity (total power outflow) from early 1980 to late 19891â5. Here we present the first account of the complete ACRIM I data set, and give evidence confirming our previous suggestion that solar luminosity varies with the 11-year solar cycle6. As previously reported, this slow variation closely follows statistical measures of the distribution of magnetic and photospheric features on the Sun's surface4â8. But there was an exception to this correlation in the form of a remarkable irradiance excess during 1980, at about the time of the sunspot maximum of solar cycle 21. The linkage, over a whole cycle, of luminosity variation to photospheric activity suggests the existence of an unknown physical mechanism other than the thermal diffusion model that explains luminosity deficits due to sunspots. Luminosity models connecting total irradiance to global indicators of solar activity, such as the equivalent width of the 1,083-nm helium line, are consistent with the gross features of the variability, but fail to account for the 1980 irradiance excess.
This is a preview of subscription content, access via your institution
Access options
Subscribe to this journal
Receive 51 print issues and online access
$199.00 per year
only $3.90 per issue
Buy this article
- Purchase on SpringerLink
- Instant access to full article PDF
Prices may be subject to local taxes which are calculated during checkout
Similar content being viewed by others
References
Willson, R. C., Gulkis, S., Janssen, M., Hudson, H. S. & Chapman, G. A. Science, 211, 700â702 (1981).
Willson, R. C. J. geophys. Res. 86, 4319â4326 (1982).
Hudson, H. S., Silva, S., Woodard, M. & Willson, R. C. Solar Physics, 76, 211 (1982).
Willson, R. C., Hudson, H. S., Frohlich, C. & Brusa, R. W. Science 234, 1114â1117 (1986).
Foukal, P. & Lean, J. Astrophys. J. 302, 826â835 (1986).
Willson, R. C. & Hudson, H. S. Nature 332, 810â812 (1988).
Foukal, P. A. & Lean, J. L. Astrophys. J. 328, 347 (1988).
Foukal, P. & Lean, J. Science 246, 556â558 (1990).
Woodard, M. & Hudson, H. Nature 305, 589 (1983).
Woodard, M. & Noyes, R. Nature 318, 449 (1985).
Livingston, W. C., Wallace, L. & White, O. R. Science 240, 1765â1767 (1988).
Hickey, J. R., Alton, B. M., Kyle, H. L. & Hoyt, D. V. Space Sci. Rev. 48, 321â342 (1989).
Hoyt, D. V. & Kyle, H. L. An Alternative Derivation of the Nimbus 7 Total Solar Irradiance Variations in Climate Impact of Solar Variability NASA Conf. Publ. 3086 (eds Schatten, K. & Anting, A.) 293â300 (NASA Goddard Space Flight Center. Greenbelt, 1990).
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Willson, R., Hudson, H. The Sun's luminosity over a complete solar cycle. Nature 351, 42â44 (1991). https://doi.org/10.1038/351042a0
Received:
Accepted:
Issue Date:
DOI: https://doi.org/10.1038/351042a0