Sources and sinks of entropy in the atmosphere

Moist entropy is generally treated as a conserved variable in atmospheric models in the absence of external heat and moisture sources such as radiation and surface fluxes. However, both irreversible generation and nonadvective transport of entropy occur in the atmosphere, with many of these associated with moisture and precipitation. These entropy sources and sinks are needed to balance the global entropy budget. Existing work on calculating the irreversible generation of entropy and nonadvective transport is extended to include the major effects of ice.