SOLAR/SOLSPEC Spectral Irradiance - 0.5-3000nm

This solar spectrum is based on solar observations of the SOLAR/SOLSPEC space-based instrument. The SOLAR/SOLSPEC instrument consists of three separate double monochromators that use concave holographic gratings to cover the middle ultraviolet (UV), visible (VIS), and infrared (IR) domains. Our best ultraviolet, visible, and infrared spectra are merged into a single absolute solar spectrum covering the 165-3000nm domain.

The resulting solar spectrum has a spectral resolution varying between 0.6 and 9.5nm in the 165-3000nm wavelength range. We build a new solar reference spectrum (SOLAR-ISS) by constraining existing high-resolution spectra to SOLAR/SOLSPEC observed spectrum. For that purpose, we account for the difference of resolution between the two spectra using the SOLAR/SOLSPEC instrumental slit functions.

Using SOLAR/SOLSPEC data, a new solar spectrum covering the 165-3000nm wavelength range is built and is representative of the 2008 solar minimum. It has a resolution better than 0.1nm below 1000nm and 1nm in the 1000-3000nm wavelength range. The new solar spectrum (SOLAR-ISS) highlights significant differences with previous solar reference spectra and with solar spectra based on models.

The integral of the SOLAR-ISS solar spectrum yields a total solar irradiance of 1372.3+/-16.9W/m^2^ at 1{sigma}, that is yet 11W/m^2^ over the value recommended by the International Astronomical Union in 2015.