Upper stratospheric (30–50 km) lidar observations of the ozone vertical distribution

Abstract : A maximum reduction of 20% of the ozone content in the altitude range 35-45 km is presently expected within the next 50 years. Early detection of trends is thus of particular importance to confirm such extrapolations. An active lidar system, which uses a powerful exciplex laser as the emitting source at 308 nm, has been operated at the Observatoire de Haute Provence to probe the upper stratospheric ozone distribution. A description of the lidar system and results of the measurements are given and compared with those obtained simultaneously by already proven techniques, such as Brewer-Mast sondes and Umkehr spectroscopic measurements. A general agreement within the uncertainties of the various methods is found. The data are further analyzed to determine a total error budget and to extrapolate the potentiality of lidar systems, using up-to-date laser sources to reach a precison better than 3% in the considered altitude range.