photo #6082689

Phytoplankton are microscopic organisms that live in water. They’re usually single-celled plants, and, like most plant life, they capture sunlight via photosynthesis. In the right conditions, a population of phytoplankton at sea can grow into a bloom so immense that it is visible from space. This image photographed with equipment aboard NASA’s Landsat 9 satellite shows a bloom off the coast of South Australia and covers an area 20 miles (35 km) from side to side. Just like clouds of microscopic water particles blown about in the sky, these clouds of phytoplankton are subject to the fluid dynamics of ocean currents. And in both cases when differing flows interact, the clouds can sometimes form into curling wave shapes like the ones show here. Such vortices are the result of Kelvin-Helmholtz instability, or the interaction between neighbouring flows of different densities moving at different velocities. Such a flow of winds up in the sky can produce curls of cloud known as fluctus. But underwater, they can stir a bloom of the tiny plankton into huge spirals that resemble the tentacles of some gigantic sea monster.