Retrieval of atmospheric NO2, O-3, aerosol optical depth, effective radiusand variance information from SAGE II multi-spectral extinction measurements

The direct-beam spectral extinction of solar radiation contains information on atmospheric composition in a form that is essentially free from the dat a analysis complexities that often arise from multiple scattering. Ground b ased Multi-Filter Shadowband Radiometer (MFRSR) measurements provide such i nformation for the vertical atmospheric column path, while solar occultatio n measurements from a satellite platform provide horizontal slices through the atmosphere. We describe application of a Multi-Spectral Atmospheric Col umn Extinction (MACE) analysis technique that we developed to analyze MFRSR data to occultation measurements made by Stratospheric Aerosol and Gas Exp eriment (SAGE II). For analysis, we select the 1985 Nevado del Ruiz volcani c eruption period to retrieve atmospheric profiles of ozone and NO2, and ch anges in the stratospheric aerosol size and optical depth. The time evoluti on of volcanic aerosol serves as a passive tracer to study stratospheric dy namics, and changes in particle size put constraints on the sulfur chemistr y modeling of volcanic aerosols, (C) 2000 Published by Elsevier Science Inc . All rights reserved.