Concern has risen over the last decade concerning the release of gases into the atmosphere which when photolyzed in the stratosphere can catalyze the destruction of ozone. Although the expected change is only on the order of 5%, significant changes in the vertical profile are anticipated. Predictions at 40 km run as high as a 60% change in the next 50 to 100 years. Because of the importance of ozone in the thermal budget of the atmosphere, such a change will have a direct impact on the earth's climate. Long term monitoring of stratospheric ozone is required to validate the predictions and Differential Absorption Lidar is particularly well suited to this measurement. GSFC is currently constructing a mobile lidar system based on a high powered XeCl excimer laser. The system is expected to be operating by fall 1986 and a campaign to compare the lidar results with a series of ROCOZ flights is planned
