A NEW ALGORITHM TO DETERMINE THE SPECTRAL AEROSOL OPTICAL DEPTH FROM SATELLITE RADIOMETER MEASUREMENTS

A new aerosol retrieval algorithm is presented which computes the spec tral optical depth over the ocean from spaceborne radiometers. It incl udes both multiple scattering and the bidirectional reflectance of the ocean surface. The algorithm is applied to data from the Along Track Scanning Radiometer 2 (ATSR-2). This radiometer aboard the ERS-2 satel lite has 4 bands in the visible and near-infrared. The ATSR-2 has a du al view capability: the reflectance is measured both at nadir and at a forward angle of approximately 55 degrees along track. This feature i s used to test the algorithm by comparing independent retrievals from the forward and the nadir view, applied to Southern Hemisphere data fr om 23 July 1995. The retrieved aerosol optical depths compare favorabl y. The retrieved aerosol optical depths and spectral behavior are in a greement with expected values in clean marine environments. (C) 1998 P ublished by Elsevier Science Ltd. All rights reserved.