Satellite retrieval of aerosol absorption over the oceans using sunglint

[1] Aerosol absorption of sunlight, in particular by black carbon - soot and dark organic material produced from incomplete combustion of fossil fuel and from vegetation fires, is emerging as a key component of climate forcing. However, global characterization of black carbon emissions, distribution and absorption of sunlight cannot be determined within a factor of 5. Here we propose that the oceanic sunglint can be used as a bright background against which aerosol absorption can be measured from space. The method can map global ocean glint every 4-10 days and determine the distribution of aerosol absorption optical thickness with an error of +/-25% for aerosol optical thickness of 0.2 to 0.4. 18% of the ocean observations are for this range of optical thicknesses. The monthly average aerosol absorption is estimated to have an error of +/-12% and uncertainty in the single scattering albedo of +/-0.02. We outline a satellite design to perform the measurements.