Cloud radiative forcing ratio - An analytical model

The ratio of the cloud radiative forcing at the surface to the cloud radiative forcing at the top of the atmosphere has been recently deduced from a set of satellite and surface measurements, and calculated using detailed radiative transfer models. We use an adding method of radiative transfer to derive an analytical expression for the cloud radiative forcing ratio. The advantage of an analytical expression is its simplicity. The analytical expression provides insight onto how the cloud radiative forcing ratio depends on surface albedo, cloud microphysics, and atmospheric composition.