Mario Lavorato

Intercomparison of ozone profiles measurements by a differential absorption lidar system and satellites at Buenos Aires, Argentina

A ground-based differential Absorption Lidar (DIAL) system has been implemented at CEILAP laboratory, located in the Buenos Aires industrial suburbs, The goal was to perform measurements of the stratospheric ozone layer. Since early 199 systematic measurements of zone concentration profiles from approximately 18 to 35 km altitude are performed. Our measurements are carried out in 5 hours in average during the night and in cloudless conditions. The DIAL system allows us to calculate directly the ozone profile from the lidar backscattering radiation since it is a self- calibrating technique. The signals processing takes into account the influence of the temperature profile on the ozone cross section. The temperature data is obtained from the radiosondes measurements performed at Ezeira International Airport. The evolution of the stratospheric ozone profile is studied for different months. Results are compared with the data obtained by different satellites like SAGE II and HALOE. The spatial and temporal range of the satellites must be taken into account.

Lidar studies of atmospheric boundary layer dynamics, aerosols, and cirrus cloud properties at Buenos Aires (34.6 S/58.5 W)

Since 1996 a lidar station is operated routinely at CEILAP (CITEFA-CONTCET), located in Buenos Aires suburb. The scientific objectives are related to environmental and atmospheric radiative budget studies. Two backscatter lidars operating at 532 nm and 308 nm are used to document the atmospheric boundary layer dynamics, and cirrus clouds and tropospheric aerosols radiative properties. The lidar measurements are made in conjuction with visible radiometer measurements on the same site and radiosoundings made twice daily at the nearby meteorological station. Atmospheric boundary layer measurements during daytime are conducted since 1996 on a regular basis using the backscatter lida.r operating at 532 nm, and more recently using a second lidar on the same site operating at 308 nm. Similarly, cirrus clouds and tropospheric aerosols measurements are conducted during clear days (e.g. without low clouds) since 1996 using the backscatter lidars. Since the late 1997 more interest is given to urban ABL dynamics in connection with pollution events, and biomass burning taking place in the tropical South America. It happened that such plumes can be frequently transported over the Buenos Aires area by large scale circulation