Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

1 of deep ocean's most turbulent areas has big impact on climate

14.08.2007
FSU study in Nature says newfound turbulence in undersea mountains affects ocean circulation

More than a mile beneath the Atlantic’s surface, roughly halfway between New York and Portugal, seawater rushing through the narrow gullies of an underwater mountain range much as winds gust between a city’s tall buildings is generating one of the most turbulent areas ever observed in the deep ocean.

In fact, the turbulence packs an energy wallop equal to about five million watts -- comparable to output from a small nuclear reactor, according to a landmark study led by Florida State University researcher Louis St. Laurent and described in the August 9 edition of the journal Nature.

The study -- an international collaboration of scientists from the United States and France -- documents for the first time the turbulent conditions in an undersea mountain range known as the Mid-Atlantic Ridge. It provides never-before-seen evidence that deep water turbulence swirling in the small passageways of such mountains is generating much of the mixing of warm and cold waters in the Atlantic Ocean.

Better understanding of the mechanisms of mixing is crucial, says St. Laurent, an assistant professor of physical oceanography at FSU and the study’s co-principal investigator, because mixing produces the overall balance of water temperatures that helps control the strength of the Gulf Stream -- the strong, warm ocean current that starts in the Gulf of Mexico, flows along the U.S. east coast to Canada and on to Europe, and plays a crucial climate role.

“Oceanographers are working hard to understand how processes in the ocean help to keep the Earth’s climate stable,” St. Laurent said. “We are aware that the climate is warming, but we don’t yet fully understand how the changes will affect society. Our work will result in better models for predicting how the ocean will affect the climate in the future and a better understanding of sea-level rise, weather patterns such as El Nino, and the impact of these events on fisheries.”

St. Laurent compared the flow of seawater through underwater gullies in the Mid-Atlantic Ridge to the wind, so familiar to hikers, that blows through mountain passages on land.

“That wind creates a condition known as turbulence, which can blow the hat from your head,” St. Laurent said. “In the ocean, turbulence is produced when water flows quickly though oceanic passages. The turbulence stirs the almost freezing-water near the bottom with warmer water that is closer to the surface much as you would mix cream into coffee by stirring it with a spoon.

“We know that the mixing of warm surface water with very cold deep water is one of several factors that influence the Earth's climate,” he said. “The mixing we observed and measured for our study allows the warmth at the surface of the ocean to ‘diffuse’ deep into the sea. The overall balance between warm and cold water in the Atlantic helps control the strength of the Gulf Stream, which moves heat away from the Earth’s equator toward regions that receive much less heating from the sun’s rays.”

St. Laurent’s co-principal investigator and co-author was Andreas M. Thurnherr, a former postdoctoral researcher in the FSU oceanography department and now a scientist at Columbia University. The field study took place in August 2006 during a three-week expedition aboard a French research vessel to a location close to the Azores, volcanic islands 2,000 miles east of the U.S. and west of Europe that comprise an above-sea portion of the mostly submerged Mid-Atlantic Ridge.

To measure the energy generated by the extraordinarily intense turbulence more than a mile below the ocean’s surface, St. Laurent and crew used a custom-made instrument called the "turbulence profiler," outfitted with special sensors.

“The turbulence profiler measured the output using ‘watts,’ the same unit of measurement as printed on light bulbs,” St. Laurent said. “In the undersea mountain passage where we intentionally looked, we found turbulence levels as large as one-10th watt per cubic meter of seawater. This is a huge amount of energy when you add all the seawater in the passage, equal to around five million watts, which is comparable to output from a nuclear reactor.”

Louis St. Laurent | EurekAlert!
Further information:
http://ocean.fsu.edu
http://press.nature.com

More articles from Earth Sciences:

nachricht Ice cave in Transylvania yields window into region's past
28.04.2017 | National Science Foundation

nachricht Citizen science campaign to aid disaster response
28.04.2017 | International Institute for Applied Systems Analysis (IIASA)

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Making lightweight construction suitable for series production

More and more automobile companies are focusing on body parts made of carbon fiber reinforced plastics (CFRP). However, manufacturing and repair costs must be further reduced in order to make CFRP more economical in use. Together with the Volkswagen AG and five other partners in the project HolQueSt 3D, the Laser Zentrum Hannover e.V. (LZH) has developed laser processes for the automatic trimming, drilling and repair of three-dimensional components.

Automated manufacturing processes are the basis for ultimately establishing the series production of CFRP components. In the project HolQueSt 3D, the LZH has...

Im Focus: Wonder material? Novel nanotube structure strengthens thin films for flexible electronics

Reflecting the structure of composites found in nature and the ancient world, researchers at the University of Illinois at Urbana-Champaign have synthesized thin carbon nanotube (CNT) textiles that exhibit both high electrical conductivity and a level of toughness that is about fifty times higher than copper films, currently used in electronics.

"The structural robustness of thin metal films has significant importance for the reliable operation of smart skin and flexible electronics including...

Im Focus: Deep inside Galaxy M87

The nearby, giant radio galaxy M87 hosts a supermassive black hole (BH) and is well-known for its bright jet dominating the spectrum over ten orders of magnitude in frequency. Due to its proximity, jet prominence, and the large black hole mass, M87 is the best laboratory for investigating the formation, acceleration, and collimation of relativistic jets. A research team led by Silke Britzen from the Max Planck Institute for Radio Astronomy in Bonn, Germany, has found strong indication for turbulent processes connecting the accretion disk and the jet of that galaxy providing insights into the longstanding problem of the origin of astrophysical jets.

Supermassive black holes form some of the most enigmatic phenomena in astrophysics. Their enormous energy output is supposed to be generated by the...

Im Focus: A Quantum Low Pass for Photons

Physicists in Garching observe novel quantum effect that limits the number of emitted photons.

The probability to find a certain number of photons inside a laser pulse usually corresponds to a classical distribution of independent events, the so-called...

Im Focus: Microprocessors based on a layer of just three atoms

Microprocessors based on atomically thin materials hold the promise of the evolution of traditional processors as well as new applications in the field of flexible electronics. Now, a TU Wien research team led by Thomas Müller has made a breakthrough in this field as part of an ongoing research project.

Two-dimensional materials, or 2D materials for short, are extremely versatile, although – or often more precisely because – they are made up of just one or a...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Fighting drug resistant tuberculosis – InfectoGnostics meets MYCO-NET² partners in Peru

28.04.2017 | Event News

Expert meeting “Health Business Connect” will connect international medical technology companies

20.04.2017 | Event News

Wenn der Computer das Gehirn austrickst

18.04.2017 | Event News

 
Latest News

Wireless power can drive tiny electronic devices in the GI tract

28.04.2017 | Medical Engineering

Ice cave in Transylvania yields window into region's past

28.04.2017 | Earth Sciences

Nose2Brain – Better Therapy for Multiple Sclerosis

28.04.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>