Main Page | See live article | Alphabetical index The parameters of atmospheric waves such as group velocity or vertical wavenumber depend on mean flow direction and strength. Thus, for instance westerlies might be a good waveguide for eastward-traveling waves, but might strongly dissipate westward-traveling waves because the vertical wavenumber decreases or increases, respectively. Modification of the waves' group velocity will chage their speed of meridional propagation, directing them more polewards or more equatorwards. This article is from Wikipedia. All text is available under the terms of the GNU Free Documentation License.