The Narrow Band of Energy That Reaches Earth due to Ozone Depletion

A 50% decrease in total column ozone increases the amount of ultraviolet radiation reaching Earth’s surface by ~2 W m^-2 between 290 and 340 nm (red shaded area) when Sun is directly overhead (Madronich, 1993). O₃ and SO₂, absorb solar energy strongly at wavelengths <400 nm. Absorption by O₃ typically leads to photodissociation for wavelengths <411 nm. Actinic flux is photons cm^-2 s^-1, absorption cross section is cm² per molecule, and increase in UV radiation is mW m^-2 nm^-1. Absorption data for O₃ from (Rothman et al., 2013) and for SO₂ from Hermans et al. (2009) and Vandaele et al. (2009).