Basic Physics and Numerical Modelling of Climate

Abstract

Despite the basic significance of the environment to many needs of Mission Earth and humans, attainable climate models are likely to provide only general guidance to world simulation in the desirable time-frame, not detailed changes and statistical properties. Some aspects of climate simulation, however, illustrate difficulties that may appear in other large-scale, complicated simulations. The fundamental physics of atmospheric waves, their forcing functions and their interactions are described. As a thermodynamically open system, the atmosphere is not very close to macroscopic local detailed balance. There are interactions across many scales of physics, particularly in the budgets of latent heat and radiative flux divergence. The carbon dioxide stored in the ocean appears to be much greater than that for equilibrium with the present partial pressure in the atmosphere. Although release of stored methane appears the most likely large-scale violation of Le Châtelier's principle, it is not now known how far the atmosphere is from non-extremality of the entropy generation rate, or other major transition in thermodynamic regime, nor whether such phenomena are attainable beyond a previously suggested duality in ocean transports. One suggestion is that the climate system historically has switched between two major regimes as a result of internal and external fluctuations.