RECENT LIDAR DEVELOPMENTS TO MONITOR STRATOSPHERE TROPOSPHERE EXCHANGE

The simultaneous knowledge of temperature fluctuations and mean wind p rofiles allows the complete description of the gravity wave field. Suc h data have been obtained in the altitude region 30-80 km in the past few years by using the temperature from the Rayleigh lidar and the win d either from falling spheres or from the Doppler lidar. A newly devel oped rotational Raman lidar and the downward extension of the Doppler lidar method make available simultaneous temperature and wind measurem ents in the lower height range 0-30 km independently on the presence o f aerosols or thin clouds. The continuous monitoring for periods of ab out 10 h duration would give access not only to the mean values but al so to the temporal evolution of the temperature fluctuations character istic of the gravity waves, and the dependence upon the mean wind thro ugh which the waves propagate. This paper presents the first results o btained by these two newly available techniques.