Lidar backscatter to extinction, mass and area conversions for stratospheric aerosols based on midlatitude balloonborne size distribution measurements

Abstract

Size distributions of the stratospheric sulfuric acid aerosol derived from balloonborne particle counter measurements from Laramie, Wyoming, are used to calculate ratios of particle extinction, mass, and surface area to particle backscatter, and the wavelength dependences of particle backscatter and extinction. These ratios may then be used to infer particle extinction, mass, and area from midlatitude lidar data in the spectral range 355 nm to 1064 nm for the time period 1991 to 1999. The conversions are defined in four height intervals from the tropopause to 30 km with a time resolution of four months. Results of conversions from earlier studies are included to span the time period 1979 to 1999. The eruptions of El Chichón (1982) and Pinatubo (1991) strongly influence these conversions. Extended background levels are observed prior to El Chichón and since about 1997.