Clouds and Climate: Sensitivity of Simple Systems

Abstract

Abstract A one-dimensional radiative convective model is used to gage the influence of clouds on simple climate systems. The radiative transfer model is developed to accommodate in a systematic and consistent manner the optical properties of a hierachy of cloud types. Cloud albedo and emissivity relationships for both ice and water clouds are introduced. The model structure is highly sensitive to cloud height for all cloud types and particularly sensitive to water path for optically thin clouds. High thin clouds at low and middle latitudes in all seasons and all clouds at high latitudes in winter tend to warm the surface relative to the clear sky; all other clouds tend to cool the surface. The summer high-latitude effects are similar to the low- and middle-latitude situation. The model sensitivity is compounded by surface albedo effects. For a given cloud a critical surface albedo may exist at which the cloud transits from cooling the surface relative to clear-sky conditions to warming the surface when th...