A program of analysis of Solar Mesosphere Explorer (SME) global radiance data sets will be used to investigate the El Chichon stratospheric aerosol cloud. Global observations at wavelengths of .44, 1.27, 1.87, 6.8, and 9.6 microns were returned by SME limb sounding experiments over the 1982-1986 period, providing complete temporal coverage of the El Chichon event. The extensive latitudinal (global) and vertical (18-50 km) breadth of the SME observations leads to a comprehensive data set for definition of the evolution of the El Chichon aerosols. The project will analyze the multi-wavelength SME observations to constrain the aerosol mass and particle size distribution throughout the growth, maturity, and decay stages of the El Chichon aerosol cloud. Aerosol mass can be determined directly from the thermal-IR radiances (6.8 and 9.6 microns). Strong aerosol scattering signatures in the visible and near-IR data sets will provide the particle size distributions as a function of time. Available ground-based, aircraft, and balloon observations of El Chichon aerosols will be incorporated into the analysis for the purposes of validation. A key aspect of the proposed investigation is the involvement of a graduate student, towards the completion of a PH.D. thesis.
