Dispersion and Spectra of Gravity Waves in the Atmosphere

Abstract

This paper describes a method for obtaining the dispersion properties of atmospheric waves from ground-based measurements of pressure and wind fluctuations. Having found the wave dispersion, we can find the displacement spectra of the waves aloft, making only minimal assumptions about the atmospheric model and, without having very accurate sounding information. We have applied the method to a pair of events for which we had fairly complete documentation. In one case, the waves aloft were observed with a vertically-pointing, high-resolution FM-CW radar, and we have compared the observed vertical displacement spectra with those deduced from ground measurements. In another case, the waves were associated with a weather front and a nearby tropical storm. The ground measurements permitted us to deduce the history of the waves aloft, and we found that the wave system before passage of the front differed dramatically from the waves present after frontal passage.