Energy Balance Climate Models

Chapter 9Perturbation by Noise

In this chapter, we take up the problem of the climate system's energy balance disturbed by noise. The noise term is taken to imitate weather and other small space–time scale perturbations of the energy balance. First, we consider the basic case of the model with constant coefficients on the sphere. This starting point is in line with our approach throughout the book of step-by-step understanding of the convergence toward a more comprehensive and realistic climate model. The new element in our process is an attempt to capture the fluctuations of the system about the ensemble mean. The idea was introduced in Chapter 2 for the global average model. In Section 6.5, we introduced the idea of fluctuations in the system ...