A simple formulation of the CH₂O photolysis quantum yields

Abstract

New expressions for the wavelength-dependent photolysis quantum yields of CH2O, Φj, are presented. They are based on combinations of functions of the type Ai/(1+exp[−(1/λ − 1/λ0i)/bi]). The parameters Ai, bi, and λ0i which have a physical meaning, are obtained by fits to the measured Φj data available from literature. The altitude dependence of the photolysis frequencies resulting from the new quantum yield expressions are compared to those derived from the Φj recommended by JPL and IUPAC.