Abstract
An update is provided on the Jet Propulsion Laboratory aerosol backscatter climatology database, with emphasis on the impact of the June 1991 eruption of Mt. Pinatubo. The data set is acquired at thermal infrared wavelengths with a range-gated coherent CO2 lidar system, which has been in regular operation since 1984. A number of analyses have been carried out to assess long-term trends in the tropospheric and lower stratospheric aerosol backscatter, as observed from the lidar site at Pasadena, California.