LIDAR OBSERVATIONS OF MIDDLE ATMOSPHERE TEMPERATURE VARIABILITY

We discuss 223 middle atmosphere lidar temperature observations. The r ecord was collected at Frascati (42 degrees N-13 degrees E), during th e 41-month period January 1989-May 1992, corresponding to the maximum of solar cycle 22. The choice of this interval was aimed at minimizing the temperature variability induced by the 11-year solar cycle. The a verage climatology over the 41-month period and comparison with a refe rence atmosphere (CIRA86) are presented. Monthly temperature variabili ty over the full period, during opposite quasi-biennial oscillation ph ases and on a short-term scale (0.5-4 h), is analyzed. Results indicat e the 50-55-km region as less affected by variability caused by the na tural phenomena considered in the analysis. Due to this minimum in nat ural noise characterizing the atmospheric temperature just above the s tratopause, observations of that region are well suited to the detecti on of possible temperature trends induced by industrial activities.