Book Description

"A diagnostic study of the mechanism responsible for producing high wavenumber oscillations (noise)in the numerical solution of the nonlinear equations governing a free surface, barotropic, atmospheric model is reported. The oscillations are identified as predominantly the result of the lattice of the difference equations and the boundary conditions employed to specified the solution. The analytic methods employed involved the use of space and time sections of the numerical solutions to provide a set of hypotheses. These are tested utilizing a one-dimensional linear analog of the model equations. The solution of the linear equations is obtained analytically, by the method of characteristics, and numerically. Several possibilities for removing the noise are suggested. Some improvement is demonstrated when the suggested methods are used in the linear one-dimensional analog.