Special AM0 Spectra


The New Synthetic Gueymard Spectrum, Down to 0.5 nm

Dr. C. Gueymard recently produced an excellent survey article, submmitted to the journal Solar Energy, covering the history and development of most of these extraterrestrial spectra. He has assembled a new ETR spectrum from recent sources. The spectrum covers the spectral region from 0.5 nm to 280 nm in 1 nm steps, 280 to 400 nm in 0.5 nm steps, from 400 nm to 1705 nm in 1 nm steps, 5 nm steps from 1705 nm to 4000 nm, and variable steps beyond 4000 nm.

See C. Gueymard, "The Sun's total and spectral irradiance for solar energy applications and solar radiation models." Solar Energy, Vol 76 #4 (April 2004) Pages 423-453.

The New Synthetic Gueymard Spectrum, down to 0.5 nm are available in a text file, and in the following compressed formats:

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ISO Process Oriented Spectral Reference

The International Standards Organization (ISO) is developing a solar irradiance standard to specify representations of solar irradiances. The standard addresses various methods of arriving at AM 0 spectra (measurements, models) rather than a particular reference spectrum. The standard is based on the principle that continued improvements in engineering measurements and theoretical calculations will result in ever changing estimates of extraterrestrial spectral solar irradiances. For a description, see the article by W.K. Tobiska and A.A. Nusinov, (2000) "Status of the draft ISO Solar Irradiance Standard" in Phys. Chem. Earth (C) Vol 25 No. 4 pp 387-388.

See also http://www.sel.noaa.gov/spacewx/Solar_Spectrum.html#TSI.

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The Thekaekara Spectrum

Dr. M.P. Thekaekara was instrumental in publishing some of the earliest AM0 spectra. The 1973 spectrum was the basis for ASTM E490 from 1974 to 2000, when it was replaced by the most recent AM0 upgrade, in ASTM E490-00. For comparative purposes, we provide the Thekaekara spectrum as published in table 4.5, page 114 of "The Extraterrestrial Solar Spectrum" A.J Drummond and M.P. Thekaekara, Eds. Institute of Environmental Sciences, Mount Prospect Illinois, 1973.

The historical 1973 Thekaekara Spectrum is available here in a text file, and in the following compressed formats:

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