Lidar measurements of stratospheric ozone and aerosol

The work presented in this thesis investigates some aspects of the application of lidar (laser radar) systems to making measurements of stratospheric ozone and aerosol. In addition, this thesis also focuses on the interpretation of specific lidar-derived aerosol and ozone data sets. These data were obtained at two different locations; a midlatitude site located at York University in Toronto, Canada (44;The Toronto measurements document the arrival and subsequent decay of enhanced stratospheric aerosol levels resulting from the 1991 Mt. Pinatubo eruption. Peak aerosol optical depths of about 0.2 in the visible wavelength range were reached several months after the main eruption. The subsequent decay rates were seen to exhibit a noticeable seasonal dependence.;The Arctic data represent a full winter season's measurements of lower stratospheric aerosol and ozone. The data indicate that appreciable amounts of Arctic ozone depletion occurred during the 1994/95 winter. Correlation of the ozone data with the aerosol measurements and meteorological parameters indicates that the depletion was likely chemical in nature. The observed trends are consistent with Upper Atmospheric research Satellite (UARS) Microwave Limb Sounder (MLS) measurements made during the same time periods.;The measurements at Eureka were made with a lidar system which utilizes both the elastic (Rayleigh/Mie) scattering and the inelastic (Raman) scattering from molecular nitrogen. This enables one to make more accurate ozone measurements in the presence of aerosol and to also make some inferences about the size distribution of the aerosol. The Raman aerosol measurements were seen to be consistent with the selective removal of larger aerosol particles throughout the winter.;In addition to the presentation of the ozone and aerosol data sets, the general problem of the inversion of multiwavelength lidar data to obtain aerosol physical parameters is addressed. Principal component analysis has been used to investigate the extent to which aerosol backscatter and extinction can be used to predict height-resolved aerosol physical and optical properties from multiwavelength lidar backscatter and extinction measurements. Detailed retrieval of the size distribution is generally unfeasible. However, some aerosol bulk parameters such as volume and surface area can be usefully predicted.