Until recently, the world's various national meteorological services routinely discarded high-resolution data from their operational balloon soundings, saving only data at the standard levels that are required to be sent over the Global Telecommunication System for use in real-time weather forecasting. In the last few years this situation has begun to change, and a few countries now archive data at quite high vertical resolution (∼100 m spacing or less). These high-resolution data provide important information on the dynamics of the upper troposphere and lower stratosphere, notably in characterizing aspects of the internal gravity wave field in this part of the atmosphere. Given the importance of parameterizing gravity wave effects in numerical climate simulation models [e.g., McFarlane, 1987; Garcia and Bouille, 1994], this is an area of considerable practical significance. In addition, data assimilation and numerical weather forecasting stand to benefit from the availability of high-resolution data.