Derivation of the specific optical properties of suspended mineral particles and their contribution to the attenuation of solar irradiance in offshore waters by ocean color remote sensing

Two independently derived algorithms which had previously been validated against in situ data were applied to 8 years of MODIS observations of the Irish Sea to obtain (i) concentrations of lithogenic mineral particles (MSSl) in surface waters and (ii) the specific backscattering and absorption coefficients for these particles in the 488 nm waveband (the values obtained were a*MSSl488=0.031 m2 g-1 and bb*MSSl488=0.010 m2 g-1). This information was used to calculate the mean attenuation coefficient for downward irradiance K-d(488) in the surface mixed layer, and the fraction of this coefficient that was attributable to suspended mineral particles. Mineral particles at relatively low concentrations (