4. Model Physics

As stated in chapter 2, the total parameterization package in CAM 3.0 consists of a sequence of components, indicated by

$$P = \{ M,R,S,T \} ,$$ (4.1)

where $M$ denotes (Moist) precipitation processes, $R$ denotes clouds and Radiation, $S$ denotes the Surface model, and $T$ denotes Turbulent mixing. Each of these in turn is subdivided into various components: $M$ includes an optional dry adiabatic adjustment normally applied only in the stratosphere, moist penetrative convection, shallow convection, and large-scale stable condensation; $R$ first calculates the cloud parameterization followed by the radiation parameterization; $S$ provides the surface fluxes obtained from land, ocean and sea ice models, or calculates them based on specified surface conditions such as sea surface temperatures and sea ice distribution. These surface fluxes provide lower flux boundary conditions for the turbulent mixing $T$ which is comprised of the planetary boundary layer parameterization, vertical diffusion, and gravity wave drag.