Sediment Swirls

Turbulent flows feature swirling eddies over a range of sizes — the larger the size range, the higher the Reynolds number. In this satellite image, sediment highlights these eddies in shades of turquoise, showing off the complexity of the flows created where rivers, ocean, and tides meet. The eddies we see here stretch from kilometers in width down to a handful of meters, but the flow’s turbulence persists down to millimeter-scales before viscosity damps it out. (Image credit: L. Dauphin; via NASA Earth Observatory)