THE SPECTRAL VISCOSITY METHOD APPLIED TO SIMULATION OF WAVES IN A STRATIFIED ATMOSPHERE

A spectral collocation method is used to solve an atmospheric gravity wave simulation problem, modelled by the non-linear, inviscid, two-dimensional Euler equations including gravity. The non-linear transfer of energy to higher frequencies will destroy the long-time calculations if no energy dissipation mechanism is introduced in the numerical method. The spectral viscosity method is applied for this purpose, and we discuss implementation aspects, effects on the resulting system of ordinary differential equations, tuning of parameters, and evaluation of results. An implementation is found that works well also for larger simulations, and guidelines for the application of the method are given. (C) 1994 Academic Press, Inc.