The Dispersal of the Amazon\u27S Water

The Amazon is the largest river system in the world, contributing about 6 × 1012 m3 of fresh water to the tropical Atlantic each year1,2. This is about 16% of the annual discharge into the world\u27s oceans. Yet the fate of this water and of the dissolved and particulate material discharged with it3,4 has remained unclear. Previous observations of 300-km diameter lenses of Amazon water off South America2,5 and a plume that extends into the Atlantic6,7 indicate some offshore movement, but the relationship of these and alongshore currents has remained obscure. New information, obtained with NASA\u27s Coastal Zone Color Scanner (CZCS) and with drifting buoys, reveals that the discharge of the Amazon is carried offshore around a retroflection of the North Brazil Current and into the North Equatorial Countercurrent towards Africa between June and January each year. From about February to May the countercurrent and the retroflection weaken or vanish, and Amazon water flows northwestward towards the Caribbean Sea