Short wavelength cut-offs and maximum spectral irradiance wavelengths comparisons of the spectra for erythema and pre-vitamin D3 synthesis

Abstract

This paper has compared the short wavelength cut-offs and the wavelengths of the maximum irradiances for the biologically effective spectral UV for erythema (UVEry) and pre-vitamin D3 synthesis (UVD3) over a six month period for the range of solar zenith angles from 4.7o to 80o. When averaged over the six month period, the short wavelength cut-off for the UVD3 is higher by 0.9 nm than that for UVEry. The wavelength of the maximum spectral irradiance is higher for the UVD3 compared to the UVEry for SZA less than approximately 60o. For higher SZA, there is a change with the wavelength of the maximum spectral irradiance for UVD3 being reduced compared to that for the UVEry.