The purpose of this project is to install and operate a sodium lidar at the South Pole Station to study the dynamical behavior of the upper atmosphere. The lidar can detect the sodium layer at about 90 kilometers altitude, and by measuring the height and density of the layer determine the vertical motion of the upper atmosphere. There has been a recent increase in interest in this subject due to the discovery, by this investigator, that there was a dramatic decrease, by a factor of 50, in sodium above Svalbard in the arctic during July of 1987. The reason for this loss is unknown, and it is important to determine whether a similar phenomenon occurs over the antarctic. The results, particularly the study of atmospheric gravity waves, may shed some light on the dynamical characteristics of the antarctic ozone hole. This research is jointly supported by the Division of Polar Programs and the Division of Atmospheric Sciences