Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Ocean life depends on single circulation pattern in Southern Hemisphere

31.12.2003


Study raises questions about potential impact of climate change

A study has shown that marine life around the world is surprisingly dependent on a single ocean circulation pattern in the Southern Hemisphere where nutrient-rich water rises from the deep and spreads across the seas.

The results suggest that ocean life may be more sensitive to climate change than previously believed because most global warming predictions indicate that major ocean circulation patterns will change. While oceanographers have identified many ocean circulation patterns, the study found that three-quarters of all biological activity in the oceans relies on this single pattern.



"When we shut off this one pathway in our models, biological productivity in the oceans drops to one-quarter of what it is today," said Jorge Sarmiento, a Princeton oceanographer who led the study published in the Jan. 1, 2004, issue of Nature. Marine organisms account for half all biological productivity on Earth.

The discovery helps oceanographers settle a longstanding question about what keeps the world’s oceans fertile. Most biological activity in the ocean is concentrated near the surface where an abundance of microorganisms perform photosynthesis and support marine food chains. These organisms and their byproducts slowly sink from the surface, decomposing along the way and carrying nutrients to the deep ocean. Until now, it has not been clear how the surface becomes replenished with the nutrients that seemed lost to the deep ocean.

Previous research has shown that ocean water does not mix well across layers of equal density, which are mostly oriented horizontally in the ocean. Once the organic matter sinks to the abyss, it takes a long time for nutrients to cross the layers and return to the surface. Without a mechanism to bring deep water back to the surface, the oceans would lose about one-fiftieth of their nutrients to this sinking process each year, Sarmiento said.

Sarmiento and colleagues identified what amounts to an enormous conveyor belt that carries nutrient-rich seawater southward in the deep ocean, brings it to the surface in the Antarctic Ocean where the density layer barrier is weak and ships it north. The water sinks again in the Northern Hemisphere and starts over. The researchers discovered a chemical signature (the presence of high nitrate and low silicate levels) that is unique to this nutrient carrier, which is called the Subantarctic Mode Water, and used it to trace the influence of this water in surface waters around the world.

"It is really quite amazing," said Sarmiento. "I had no idea of the extent of its influence."

The SAMW is responsible for feeding nearly all the world’s oceans, except for the North Pacific, which is resupplied with nutrients through another circulation pattern, the researchers found.

The finding already has attracted interest among oceanographers. "They have clearly identified the pathway that counteracts the so-called biological pump, which acts to strip the surface layer of its nutrients," said Arnold Gordon of Columbia University. "One now wonders how global change will alter the efficiency of this pathway."

Sarmiento said the research group "is now hard at work investigating the details of this nutrient circulation pattern with an eye to examining how it might respond to global warming in model simulations."


Sarmiento conducted the study in collaboration with Nicholas Gruber of the University of California-Los Angeles, Mark Brzezinski of the University of California-Santa Barbara and John Dunne of the Geophysical Fluid Dynamics Laboratory in Princeton. The research was supported by the National Science Foundation, the National Oceanic and Atmospheric Administration and the Department of Energy.

Patty Allen | EurekAlert!
Further information:
http://www.princeton.edu/

More articles from Earth Sciences:

nachricht Tracking the amount of sea ice from the Greenland ice sheet
28.09.2016 | Ca' Foscari University of Venice

nachricht A perfect sun-storm
28.09.2016 | Helmholtz-Zentrum Potsdam - Deutsches GeoForschungsZentrum GFZ

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: New welding process joins dissimilar sheets better

Friction stir welding is a still-young and thus often unfamiliar pressure welding process for joining flat components and semi-finished components made of light metals.
Scientists at the University of Stuttgart have now developed two new process variants that will considerably expand the areas of application for friction stir welding.
Technologie-Lizenz-Büro (TLB) GmbH supports the University of Stuttgart in patenting and marketing its innovations.

Friction stir welding is a still-young and thus often unfamiliar pressure welding process for joining flat components and semi-finished components made of...

Im Focus: First quantum photonic circuit with electrically driven light source

Optical quantum computers can revolutionize computer technology. A team of researchers led by scientists from Münster University and KIT now succeeded in putting a quantum optical experimental set-up onto a chip. In doing so, they have met one of the requirements for making it possible to use photonic circuits for optical quantum computers.

Optical quantum computers are what people are pinning their hopes on for tomorrow’s computer technology – whether for tap-proof data encryption, ultrafast...

Im Focus: OLED microdisplays in data glasses for improved human-machine interaction

The Fraunhofer Institute for Organic Electronics, Electron Beam and Plasma Technology FEP has been developing various applications for OLED microdisplays based on organic semiconductors. By integrating the capabilities of an image sensor directly into the microdisplay, eye movements can be recorded by the smart glasses and utilized for guidance and control functions, as one example. The new design will be debuted at Augmented World Expo Europe (AWE) in Berlin at Booth B25, October 18th – 19th.

“Augmented-reality” and “wearables” have become terms we encounter almost daily. Both can make daily life a little simpler and provide valuable assistance for...

Im Focus: Artificial Intelligence Helps in the Discovery of New Materials

With the help of artificial intelligence, chemists from the University of Basel in Switzerland have computed the characteristics of about two million crystals made up of four chemical elements. The researchers were able to identify 90 previously unknown thermodynamically stable crystals that can be regarded as new materials. They report on their findings in the scientific journal Physical Review Letters.

Elpasolite is a glassy, transparent, shiny and soft mineral with a cubic crystal structure. First discovered in El Paso County (Colorado, USA), it can also be...

Im Focus: Complex hardmetal tools out of the 3D printer

For the first time, Fraunhofer IKTS shows additively manufactured hardmetal tools at WorldPM 2016 in Hamburg. Mechanical, chemical as well as a high heat resistance and extreme hardness are required from tools that are used in mechanical and automotive engineering or in plastics and building materials industry. Researchers at the Fraunhofer Institute for Ceramic Technologies and Systems IKTS in Dresden managed the production of complex hardmetal tools via 3D printing in a quality that are in no way inferior to conventionally produced high-performance tools.

Fraunhofer IKTS counts decades of proven expertise in the development of hardmetals. To date, reliable cutting, drilling, pressing and stamping tools made of...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

European Health Forum Gastein 2016 kicks off today

28.09.2016 | Event News

Laser use for neurosurgery and biofabrication - LaserForum 2016 focuses on medical technology

27.09.2016 | Event News

Experts from industry and academia discuss the future mobile telecommunications standard 5G

23.09.2016 | Event News

 
Latest News

New imaging technique in Alzheimer’s disease - opens up possibilities for new drug development

28.09.2016 | Medical Engineering

Innovate coating extends the life of materials for industrial use

28.09.2016 | Materials Sciences

Blockchain Set to Transform the Financial Services Market

28.09.2016 | Business and Finance

VideoLinks
B2B-VideoLinks
More VideoLinks >>>