Categories: Earth ObservationNASA

A Swirling Oasis of Life

[/caption]

A serpentine eddy swirls in the southern Indian Ocean several hundred kilometers off the coast of South Africa in this natural-color image, acquired by NASA’s Terra satellite on December 26, 2011.

The blue color is created by blooms of phytoplankton, fertilized by the nutrient-rich deep water drawn up by the 150-km-wide eddy.

The counter-clockwise anticyclonic structure of the eddy may resemble a hurricane or typhoon, but unlike those violent storms eddies bring nourishment rather than destruction.

“Eddies are the internal weather of the sea,” said Dennis McGillicuddy, an oceanographer at the Woods Hole Oceanographic Institution in Massachusetts.

And also unlike atmospheric storms, ocean eddies can last for months, even up to a year. The largest ones can contain up to 1,200 cubic miles (5,000 cubic kilometers) of water.

The nutrient-drawing power of eddies can supply the relatively barren waters of the open ocean with nutrients, creating “oases in the oceanic desert,” according to McGillicuddy.

Read more about the WHOI study of eddies here.

The eddy imaged here likely peeled off from the Agulhas Current, which flows along the southeastern coast of Africa and around the tip of South Africa. Agulhas eddies tend to be among the largest in the world.

The image below shows the eddy in context with the surrounding area:

Eddy off the coast of South Africa. December 26, 2011. (NASA/Terra-MODIS)

MODIS (or Moderate Resolution Imaging Spectroradiometer) is a key instrument aboard NASA’s Terra (EOS AM) satellite. Terra MODIS views the entire Earth’s surface every 1 to 2 days, acquiring data in 36 spectral bands. These data improve our understanding of global dynamics and processes occurring on the land, in the ocean, and in the lower atmosphere.

Read more on NASA’s Earth Observatory site here.

NASA Earth Observatory image created by Jesse Allen, using data obtained from the Land Atmosphere Near real-time Capability for EOS (LANCE).

Jason Major

A graphic designer in Rhode Island, Jason writes about space exploration on his blog Lights In The Dark, Discovery News, and, of course, here on Universe Today. Ad astra!

Recent Posts

If Launched by 2028, a Spacecraft Could Catch up With Oumuamua in 26 Years

A new study by the Institute of Interstellar Studies (i4is) shows that with the right…

9 hours ago

The Moon’s Crust was Formed From a Frozen Slushy Magma

Scientists' detailed study of the Moon dates back to the Apollo missions when astronauts brought…

15 hours ago

Tom Cruise Movie’s Producers Aim to Add Film Studio to the Space Station in 2024

The production company that's playing a key role in a space movie project involving Tom…

16 hours ago

Even Tiny Mimas Seems to Have an Internal Ocean of Liquid Water

Data from the Cassini mission keeps fuelling discoveries. The latest discovery is that Saturn's tiny…

17 hours ago

Ice Peeks out of a Cliffside on Mars

The HiRISE (High-Resolution Imaging Science Experiment) camera on the Mars Reconnaissance Orbiter has captured another…

1 day ago

A new Kind of Supernova has Been Discovered

A new supernova discovery shows that Wolf-Rayet stars explode after all.

2 days ago