A model for identifying the aerosol-only mode of SAGE II 1.02-μm extinction coefficient data at altitudes below 6.5 km

Abstract

A model is proposed for identifying the aerosol mode of the second Stratospheric Aerosol and Gas Experiment (SAGE H) 1.02-μm extinction coefficient measurements at altitudes below 6.5 km, which also contain cloud samples. This development allows one to extend the SAGE II satellite data analysis from the lower limit at 6.5 km of the SAGE II two-wavelength method into the lower troposphere. Thus the proposed model provides opportunities for fully utilizing the SAGE II tropospheric measurements important to the understanding of the global behavior of tropospheric aerosols, clouds, and ozone and related transports. The effectiveness of this model is examined by using the SAGE II two-wavelength technique at 6.5 km. Sample applications of the proposed model reveal encouraging results. To assess the quality of the aerosol 1.02-μm data, it is recommended that a comprehensive data comparison analysis be conducted by using tropospheric measurements from different instruments. Copyright 1999 by the American Geophysical Union.