The Sargasso Sea in the middle of the North Atlantic is the only sea in the world without a coastline. Its borders are currents: the Gulf Stream and the North Atlantic Current in the west and north, the Canary Current in the east and the North Equatorial Current in the south. Together they turn clockwise around it. We spread 20,000 floating particles over the North Atlantic and let the surface currents of a global ocean model carry them for five years. Within a few years most of them gather in the middle of the loop, because the wind pushes surface water towards the centre of the gyre. That is why the golden-brown Sargassum seaweed, which floats its whole life and never attaches to the seabed, collects in this sea and gave it its name. Sailors in the age of sail feared becalming in it. The same calm centre is where European and American eels hatch, and where floating plastic now collects too. This is a simple model: passive particles moved by the monthly average surface currents, with some random spreading. It does not include the large Sargassum blooms that since 2011 have formed further south, in the tropical Atlantic.
Source: Currents: E.U. Copernicus Marine Service, global ocean reanalysis (GLOBAL_MULTIYEAR_PHY_001_030), monthly climatology of surface currents, used at 0.5°. Drift model: The Moving Sea. Visualisation by The Moving Sea
Free for personal and educational use with credit to The Moving Sea. For commercial use, contact [email protected].