The Global and Regional Climate System

Abstract

The relationships between planetary and regional or local scales of the climate system are discussed.

The main features of the planetary scale climate may be understood as the response of the climate system to the planetary scale forcing (heating by the sun), the distribution of continents and largest mountain ranges. The regional climate, then, may be understood as the result of both the planetary scale climate and the regional features such as secondary mountains, marginal seas, land use, and the like.

The small scale features have little effect on the planetary scale in the sense that details are rather unimportant; but the statistics of the small scalefeatures modify the planetary scale state significantly. This modification may be described by parameterizations, i.e., through statistics of small scale processes, which are conditioned by the large-scale states.

The concept of randomized parameterizations is introduced.

The discourse is illustrated with various examples, ranging from energy balance models, the emergence of the general circulation of the atmosphere from a state at rest to downscaling applications.