Abstract
Simple and accurate parameterizations have been developed for computing the absorption of solar radiation due to O2 and CO2. The parameterizations are based on the findings that temperature has a minimal effect on the absorption and that the one-parameter scaling can be applied to take into account the effect of pressure variation along a path. Furthermore, overlapping of the absorption due to CO2 and water vapor is treated accurately in the parameterizations. Simulations with a zonally averaged multilayer energy balance model show that the absorption of solar radiation due to O2 and CO2 has a small, albeit nonnegligible, effect on climate. The global surface solar radiation is reduced by 2.2 W m−2, and the warming of the surface temperature due to a doubled CO2 concentration is reduced by 10% in the Northern Hemisphere. Because the parameterizations can be easily implemented without perturbing other parts of a radiation routine, it is suggested that the absorption of solar radiation by O2 and CO2 be included in climate studies using numerical models.
