Distribution of suspended particulate matter at the equatorial transect in the Atlantic Ocean

Abstract. A suspended particulate matter distribution against a hydrographical background was studied at the oceanographic transect across equatorial Atlantic in year 2000. An area of abnormally high volume concentrations found above Sierra Leone Rise entire water column (eastern part transect). The suggested explanation for anomaly is based on ballast hypothesis whereby solid particles are incorporated as into biogenic aggregates, leading to increased velocities sinking. This occurs within Northwest African upwelling area, where plankton exposed Saharan dust abundance form significant number which later transported equatorward via Canary Current. intermediate nepheloid layer associated with Deep Western Boundary Current recorded from South American Slope depths 3200–3700 4300 m Para Abyssal Plain. Antarctic Bottom Water enriched mostly troughs 40–41∘ W. It detached bottom, coinciding core flow due bottom rise “dam” located up-stream. grain size along has polymodal 2–4 and 8–13 µm modes. registered percentage some parts 7–21 sized suggests presence well-known coarse mode (20–60 µm) formed by aggregation transparent exopolymer (mucus).