Abstract
An atmosphere-ocean climate box model is used to examine the influence of the atmospheric component of the hydrological cycle on the steady-state and time-dependent behaviour of the climate system. The model consists of three nonlinear ordinary differential equations that are simplified forms of the first law of thermodynamics for the atmosphere and ocean and the continuity equation for the atmospheric component of the hydrological cycle. In this model, energy is exchanged between the ocean, atmosphere and space by short and long-wave radiation and by sensible and latent heat. The mass continuity equation expresses the cloud liquid water content as a function of the evaporation rate from the ocean surface and the precipitation rate. The model also simulates snow-ice albedo feedback and water vapor feedback. Cloud feedback can lead to the occurrence of multiple climate equilibria. Some are warmer with increased precipitation and others colder with reduced precipitation. The present equilibrium may be accompanied by other equilibria that are either stable or unstable. Oscillations of the climate can occur around the present equilibrium as a result of cloud feedback.
