Analysis of mountain wave 3D wind fields in the Andes derived from high-altitude sailplane flights

Abstract

Mountain lee waves are of importance in meteorology since they produce drag that affects the general circulation, and can influence windstorms, clear-air turbulence and ozone abundance. Since mountain waves are used routinely by sailplane pilots, data collected during wave flights are potentially useful for studying the structure of mountain waves. We have previously described methods for determining 3D wind velocities in mountain waves from limited sailplane flight data. These methods are applied to data from a high-altitude sailplane flight in the lee of the Andes that reached an altitude of over 15,000 m, well into the stratosphere, allowing a unique kind of in-situ observation of stratospheric mountain waves. The derived wind fields show parts of the wave structure in the troposphere and the stratosphere, and are compared with other observational data. Thus, a minimally instrumented sailplane can provide useful data for mountain wave research.