Three‐dimensional lee waves

Linear wave theory is used to find the stationary, trapped lee waves behind an isolated mountain. The lower atmosphere is approximated by a three-layer model with Brunt-Vaisala frequency and wind velocity constant in each layer. The Fourier-integrals are solved by a uniformly valid asymptotic expansion and also by numerical methods. The wave pattern is found to be strongly dependent on the atmospheric stratification. The way the waves change when the parameters describing the atmosphere and the shape of the mountain vary, is studied. Further, the results predicted by the theory are compared with waves observed on satellite photographs. It is found that the observed wave patterns are described well by the linear theory, and there is good agreement between observed and computed wavelengths.