Suspended Particulate Matter as a Main Source and Proxy of the Sedimentation Processes

Influence of suspended particulate matter on the optical properties of seawater in the western Eurasian Arctic shelf

“…Highly turbid river waters modify chemical and biological structure of the upper layer of the White and Kara seas and limit the light penetration to the deeper layers of water column. Despite the fact that the river water's turbidity is relatively low, the spatial and temporal variations in SPM concentration in the White Sea are caused by river runoff 28 . The waters of the White Sea are characterized by high solar light absorption comparing to the Kara Sea and unlike the Barents Sea.…”

“…Mass concentration of SPM was determined by the standard technique of vacuum filtration at 400 mbar using membrane filters (diameter 47 mm, pore diameter 0.45 μm) 9,27,28 . Each sample (about 5-10 L) was simultaneously filtered through three or more membrane filters.…”

“…The size range is approximately 2-60% of the aperture diameter. For natural seawater samples, a 100 μm aperture tube is usually used 28 . The instrument was calibrated on board the vessel using a standard latex suspension with a nominal particle size of 5 μm (Coulter ® CC Size Standard L5).…”

“…The major phase composition of SPM is studied using methods of chemical and mineralogical analysis described in our papers 28,35,40,41 .…”

“…Calculation of the correct values of bio-optical characteristics in the Arctic seas based on remote sensing data is of particular difficulty: (i) low solar altitude (increased atmospheric correction errors); (ii) high cloudiness; (iii) intense river runoff (brown waters and a high share of terrigenous particulate matter) 15,25,27,28 . The shift of the wavelength of light penetrating into the water column depends on the concentration and composition of SPM, colored DOM (CDOM) or "yellow substance" (it makes the greatest contribution to the transparency of the White Sea water), and phytoplankton cell pigments 17,28,31 . River waters are enriched in different forms of СDOM including humates of iron and manganese.…”