The theory of hydrodynamic noise of Landau and Lifshitz is extended by
the consideration of correlation times and lengths. We restrict our s
tudy to the domain of thermodynamic equilibrium. When the intensity of
the fluctuations of a phenomenological model is characterized by a ph
enomenological constant, the same procedure can be applied to nonequil
ibrium turbulent systems. Applications to one-dimensional climatic mod
els and the fluctuation-dissipation theorem in the atmosphere are disc
ussed.