Title: Observations of gravity waves in the stratosphere and their sources in the troposphere

M. Joan Alexander, NorthWest Research Associates, Colorado division alexand@cora.nwra.com

An overview of atmospheric gravity wave observations will be presented with emphasis on waves observed in the stratosphere near the jet stream. These observations date back decades, but progress in unambiguous linking of the observed waves to their source mechanisms has lagged, and continues as an active area of research. Source models for gravity waves now have sufficient resolution and domain area, and the observations now include sufficient information about the wave properties, to make positive links. The motivation for these studies has been global circulation modeling, since most global models parameterize the effects of gravity waves on the circulation, but the parameterizations have insufficient constraints on the wave sources to ensure realism. Radiosondes and satellite observations are two sources of data that have provided global perspectives. I will attempt to summarize some general principles and outstanding questions that have come from analyses of these data sets in recent years.