Photolysis rate coefficient ($J=\int F_{\lambda }{\sigma }_{\lambda }{\Phi }_{\lambda }d\lambda$)

The first-order rate coefficient for a specified photodissociation channel. It integrates spectral actinic flux, absorption cross section and channel quantum yield. Absorption without dissociation does not contribute to that channel's rate. Its units are inverse time.

In a direct-beam model with an effective ozone cross section $\sigma$, removal of an overlying column $\Delta N$ multiplies the transmitted photodissociation flux by $e^{\sigma \Delta N}$. A real photodissociation coefficient integrates wavelength-dependent cross section, quantum yield and actinic flux, including scattering and the local radiation field.