Early phase analysis of OCTS radiance data for aerosol remote sensing

An analysis of ocean color temperature scanner [(OCTS) on board the advance d earth observation satellite (ADEQS)] spectral radiance data was performed for retrieving global distributions of Angstrom factor and exponent, which represent the aerosol optical thickness at a reference wavelength (500 nm in our study) and a spectral dependence of the optical thicknesses, respect ively, over ocean. Determination of calibration constants for OCTS-received radiances and development of an efficient look-up table method for synthes izing the radiances are key issues for development of the present two-chann el algorithm with use of channel 6 and 8 radiances of OCTS. This algorithm has been applied to Level-1B OCTS GAC data sets for producing three month ( April, May, and June 1997) global distributions of Angstrom parameters. Geo graphical and seasonal distribution patterns of Angstrom parameters suggest that anthropogenic sulfate aerosols in mid-latitudes and biomass burning a erosols in the subtropical region are characterized by small particles havi ng large Angstrom exponents, whereas mineral dust particles from subtropica l arid regions are characterized by large particles having small Angstrom e xponents. There was a fairly good agreement between satellite-retrieved val ues of Angstrom parameters and values obtained by sky radiometers located o n coasts.