The Dead Sea is a hypersaline terminal lake located in the Dead Sea Rift Valley, with its surface water at -418 m below mean sea level. The Dead Sea water is dense, with 28% dissolved solids - one of the highest natural average salinities on Earth. It has a unique composition of minerals, with KCl being the major component in comparison to NaCl in the oceans. An intense exploitation of water resources as well as salt extraction by the chemical plants located in the southern Dead Sea, have severely disrupted the water balance of the lake.

Because of its hyper-salinity, the lake is lacking phytoplankton, which allows us to use the Dead Sea waters as a natural optical laboratory for study of influence of such parameters as salinity, dissolved organic matter (DOM) and total suspended matter (TSM) on optical properties of natural waters. Optical observations in the Dead Sea were carried in 1980-1986 (spectrally-averaged near-surface downwelling irradiance) and in April 2004 (spectral volume scattering function, absorption and attenuation coefficients within the water column and above-water upwelling radiance). We analyze IOPs measured within the lake for the contribution by different size and functional contributors; DOM contribute significantly to the total absorption (54.1±5.6% at 440 nm). In addition we assess their contribution to remotely sensed reflectance. Inverse models are applied to retrieve information on the particles composition and size distribution.