Jennifer Apell has a new paper in Environmental Science: Processes & Impacts providing updated values for spectral irradiance that can be used to calculate photodegradation rates in environmental systems. These irradiance values are available for every 10° latitude in the northern and southern hemisphere, for four seasons, at solar noon and day-averaged, and for wavelengths from 280 to 800 nm in 1 nm increments.
Updated and validated solar irradiance reference spectra for estimating environmental photodegradation rates
Jennifer N. Apell and Kristopher McNeill*
Environ. Sci.: Processes Impacts. 2019 http://dx.doi.org/10.1039/C8EM00478A