1985 Wehrli Standard Extraterrestrial Solar Irradiance Spectrum
The 1985 Wehrli Standard Extraterrestrial Solar Irradiance Spectrum covers the solar spectrum from 199.5 nm to 10075.0 nm in increments increasing gradually from 1 nm in the shorter wavelengths to 2290 nm at the upper end of the spectrum.
The World Meteorological Organization World Radiation Data Centre Wehrli air mass zero solar spectral irradiance curve has often been cited and used as the extraterrestrial solar spectral irradiance distribution. This spectral distribution was constructed in 1985 based on the following references:
Wehrli, C. Extraterrestrial Solar Spectrum, Publication no. 615, Physikalisch-Meteorologisches Observatorium + World Radiation Center, Davos Dorf, Switzerland, July 1985.
Neckel, H. and D. Labs. "Improved Data of Solar Spectral Irradiance from 0.33 to 1.25 µm", Solar Physics, Vol. 74, 1981.
Wehrli cites four sources for the data used to construct the World Meteorological Organization extraterrestrial spectral distribution. A preliminary version of this spectral distribution is integrated into the NREL Simple Spectral Model SPCTRAL2 and is the extraterrestrial used in generating the ASTM Reference Spectra for terrestrial applications, namely E-891 and E-892, which were combined into ASTM G-159 and later superseded by ASTM G-173.