DERIVATION OF MOUNT-PINATUBO STRATOSPHERIC AEROSOL MEAN SIZE DISTRIBUTION BY MEANS OF A MULTIWAVELENGTH LIDAR

A multiwavelength lidar operated in Sodankyla, Finland, during the Eur opean Arctic Stratospheric Ozone Experiment (December 1991-March 1992) . It produced vertical profiles of stratospheric aerosols at four wave lengths. The determination of aerosol mean size distribution has been performed by use of extinction/backscattering ratios as obtained from lidar data processing at 355, 352, and 750 nm. Log-normal distribution s of sulfuric particles with mode radius of r(m) = 0.12-0.25 mum and c orresponding widths of s = 2-1.6 have been retrieved as best fits of e xperimental data, in good agreement with in situ measurements. A succe ssful attempt to derive bimodal log-normal distributions is also descr ibed, together with the experimental and theoretical problems involved .