Basic concepts of climate modelling

ABSTRACT

climate system consists of the atmosphere, the hydrosphere, the cryosphere, the lithosphere and the biosphere. The difficulty of modelling this system and its variations is related not only to the complexity of each of these physical entities, but also to their interactions. Moreover the large difference between their characteristic time prevents the climate to ever reach an equilibrium. For simulating the climate variations at a specific time scale, the slow parts of that system are thus considered as prescribed boundary conditions to the more "mobile" ones (for example, the dynamics of the ice sheets are not taken into account for the interannual climate variability). (AU)