| The University of Alabama at Huntsville (UAHuntsville) and NASA have jointly developed a tropospheric ozone Differential Absorption Lidar (DIAL) system using two receivers and lasers at 285 and 291 nm. This lidar is making regular observations of the vertical ozone distributions in both the boundary layer and free troposphere between 0.5 and 8 km under daytime and nighttime condition.;This dissertation discusses in detail the lidar hardware components including the transmitter, receiver, and detector. A compact, LED-based lidar simulator has been designed to characterize the lidar's performance and calibrate the systematic errors associated with the ozone measurements. This dissertation describes the data processing, various retrieval algorithms, error analysis, comparisons of coincident ozonesonde measurements, and typical time-height ozone retrievals. For the tropospheric ozone lidar, it is a challenge to remove the aerosol interference in the boundary layer. An effective aerosol correction procedure for a two-wavelength DIAL has been developed to reduce the retrieval error arising from differential aerosol backscatter in lower troposphere. A three-wavelength dual-DIAl technique is also presented as a future scheme.;Lidar observations with coincident ozonesonde flights demonstrate that the retrieval accuracy ranges from better than 10% below 4 km to better than 20% below 8 km with 750-m vertical resolution and 10-min temporal integration. We give an analysis of nocturnal residual layer pollution transport and a satellite instrument validation to illustrate the scientific applications. This lidar is providing unique ozone data for studying tropospheric ozone budget/sources, air quality, trace-gas transport, photochemical modeling, and satellite validation in the southeastern United States. |
