Evolution of the Pinatubo Volcanic Aerosol Column Above Pasadena, California Observed With a Mid-Infrared Backscatter LidarThis paper presents an assessment of the evolutionary characteristics of the Mt. Pinatubo aerosol in the stratosphere as a result of the June 1991 eruption, which was monitored since its genesis with a ground-based backscatter lidar facility at the Jet Propulsion Laboratory.