Numerical Problems Connected with Weather Prediction

Large scale atmospheric motions can propagate on vastly different time scales. The time scale of the so called Rossby waves which describe the “weather”is of the order of a day while inertia-gravity waves can have time scales of order] 0 sec. Meteorologically the main interest is in the first type of motion. There are two ways to suppress the fast waves. One can prepare the initial data such that the fast waves are not excited or can change the equations such that the fast waves are not present or have been slowed down. In this paper we shall discuss some of the mathematical and numerical difficulties of these procedures.