Carriers of Sargassum and mechanism for coastal inundation in the Caribbean Sea

We identify effective carriers of Sargassum in the Caribbean Sea and describe a mechanism for coastal choking. Revealed from satellite altimetry, the carriers of Sargassum are mesoscale eddies (vortices of 50-km radius or larger) with coherent material (i.e., fluid) boundaries. These are observer-independent-unlike eddy boundaries identified with instantaneously closed streamlines of the altimetric sea-surface height field-and furthermore harbor finite-time attractors for networks of elastically connected finite-size buoyant or inertial particles dragged by ocean currents and winds, a mathematical abstraction of Sargassum rafts. The mechanism of coastal inundation, identified using a minimal model of surface-intensified Caribbean Sea eddies, is thermal instability in the presence of bottom topography.

Automated summary

The effective carriers of Sargassum in the Caribbean Sea are identified as mesoscale eddies with coherent boundaries, which can harbor finite-time attractors for networks of buoyant or inertial particles. The mechanism of coastal choking is attributed to thermal instability in the presence of bottom topography, as identified in a minimal model of surface-intensified Caribbean Sea eddies.