Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Engineers work on their SUNTANS as they track waves and beaches

10.12.2002


Nearly a month has passed since the wounded tanker Prestige spilled thousands of tons of heavy oil into the Atlantic and fouled dozens of Spanish beaches. But anxious residents of coastal Spain and Portugal remain on high alert - wondering where and when the noxious crude will wash ashore next.



In recent years, tanker accidents have ruined fisheries and tourist beaches from Alaska to France. But do oil spills always have to end in catastrophe? Perhaps the most vulnerable beaches and coastal habitats could be identified and protected well in advance, if scientists had some way to predict where a glob of spilled crude was likely to end up.

A team of engineers from Stanford University is trying to accomplish that challenging task by developing a computer code capable of tracking massive internal waves that begin on the ocean floor and gather strength as they rise to the surface.


Internal waves can reach heights of 300 feet and often contain enough energy to move pollutants, debris and even boats long distances. Despite their size, internal waves are difficult to detect because they move invisibly below the surface.

"Tracking internal waves is important to the fishing industry and for understanding ocean pollution," said Margot Gerritsen, an assistant professor of petroleum engineering. "If you accidentally drop some pollutants into a coastal region, you’ll want to be able to predict how quickly they mix."

Gerritsen and Stanford colleagues Robert Street and Oliver Fringer are spearheading SUNTANS - a federally funded research project to develop a computer code that can identify internal waves and forecast when they will reach the shore.

"What we’re trying to do is simulate a coastal region precisely enough to find internal waves with our computer code and predict where they will break. Currently, there is no code that can do this accurately," Gerritsen said. She and her colleagues were scheduled to discuss the SUNTANS project at the annual fall meeting of the American Geophysical Union in San Francisco on Dec. 9.

"SUNTANS certainly will have an impact on the fishing industry, because with this code, we can predict where there will be a lot of vertical mixing, which tells us a lot about the availability of nutrients in the water," Gerritsen noted. "We’ll also be able to use it to track the transport of red tides and other toxic blooms."

SUNTANS also could be used to create better forecasting models of global climate change. "Internal waves are generated by the tides, and 75 percent of all tidal energy gets dissipated in coastal regions," Gerritsen said. "If we have a better sense of why this is and how this works, then we can apply that to a global model. Right now, global climate models don’t even take the tides into account most of the time."

Navier-Stokes

SUNTANS is the acronym for the Stanford Unstructured Non-hydrostatic Terrain-following Adaptive Navier-Stokes Simulator - a long name that reflects the enormous complexity of trying to simulate and forecast oceanic wave movement. "Navier-Stokes" refers to a set of 19th-century equations that have become standard tools in the field of fluid dynamics.

"The Navier-Stokes equations provide the means of finding the accelerations of fluid masses caused by the forces acting in the ocean," explained Street, the William Alden and Martha Campbell Professor in the School of Engineering. "They’re very hard to solve, in part because things like wind on the surface or varying densities in the fluid itself can produce a complex variety of forces that, together, make the fluid accelerate."

The SUNTANS team is using Navier-Stokes equations and cutting-edge computer algorithms to create a universal code that can be applied to any of the world’s oceans. So far, the research effort is focused on two sites in the Pacific: Hawaii’s Mamala Bay, which includes Pearl Harbor and Waikiki; and California’s Monterey Bay, located about 50 miles southwest of the Stanford campus.

Monterey Bay provides an ideal setting because it includes a near-shore canyon that is deeper than the Grand Canyon.

"When water comes up against the slope of Monterey Canyon, it excites internal waves that propagate throughout the canyon," Street said. "Some of these waves get pretty big, but they’re very subtle, sometimes appearing as little ripples on the surface."

When internal waves are funneled up the canyon, they intensify and often turn into breaking waves that pick up sand and other material from the ocean floor.

"Internal waves have even been known to move a ship from its anchorage," Street noted, citing a 1991 Coast Guard report that described how a breaking internal wave in Monterey Canyon may have contributed to a mishap in which the propeller of a tanker became entangled with a buoy chain.

"People in Hawaii are interested in SUNTANS from a tourism point of view," Gerritsen added, "especially in Mamala Bay, where tankers and ships pass very close by the coast."

Better mousetrap

Street predicted that the SUNTANS team "could have a code we’re happy with a year from now. With Margot and Oliver’s numerical expertise, we can build a better mousetrap - a better numerical code that would be very accurate, very fast and would allow people to predict internal waves and circulation accurately to solve coastal environment problems."

SUNTANS requires thousands of parallel computers operating in tandem - the kind of enormous computing power available at only a handful of national centers.

"If we put this on the fastest parallel computer currently available, it would be fast enough to do realistic cases," Gerritsen said. "Of course, the average researcher does not have this kind of computer technology now, but it should be widely available in a few years when the SUNTANS code is up and running."


###
The SUNTANS project is supported by the National Science Foundation and the Office of Naval Research.

By Mark Shwartz

CONTACT: Mark Shwartz, News Service: (650) 723-9296, mshwartz@stanford.edu

Mark Shwartz | EurekAlert!
Further information:
http://fluid.stanford.edu/suntans/
http://ekofisk.stanford.edu/faculty/gerritsen/
http://www-ce.stanford.edu/faculty/street/

More articles from Earth Sciences:

nachricht Upwards with the “bubble shuttle”: How sea floor microbes get involved with methane reduction in the water column
27.05.2020 | Leibniz-Institut für Ostseeforschung Warnemünde

nachricht An international team including scientists from MARUM discovered ongoing and future tropical diversity decline
26.05.2020 | MARUM - Zentrum für Marine Umweltwissenschaften an der Universität Bremen

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Biotechnology: Triggered by light, a novel way to switch on an enzyme

In living cells, enzymes drive biochemical metabolic processes enabling reactions to take place efficiently. It is this very ability which allows them to be used as catalysts in biotechnology, for example to create chemical products such as pharmaceutics. Researchers now identified an enzyme that, when illuminated with blue light, becomes catalytically active and initiates a reaction that was previously unknown in enzymatics. The study was published in "Nature Communications".

Enzymes: they are the central drivers for biochemical metabolic processes in every living cell, enabling reactions to take place efficiently. It is this very...

Im Focus: New double-contrast technique picks up small tumors on MRI

Early detection of tumors is extremely important in treating cancer. A new technique developed by researchers at the University of California, Davis offers a significant advance in using magnetic resonance imaging to pick out even very small tumors from normal tissue. The work is published May 25 in the journal Nature Nanotechnology.

researchers at the University of California, Davis offers a significant advance in using magnetic resonance imaging to pick out even very small tumors from...

Im Focus: I-call - When microimplants communicate with each other / Innovation driver digitization - "Smart Health“

Microelectronics as a key technology enables numerous innovations in the field of intelligent medical technology. The Fraunhofer Institute for Biomedical Engineering IBMT coordinates the BMBF cooperative project "I-call" realizing the first electronic system for ultrasound-based, safe and interference-resistant data transmission between implants in the human body.

When microelectronic systems are used for medical applications, they have to meet high requirements in terms of biocompatibility, reliability, energy...

Im Focus: When predictions of theoretical chemists become reality

Thomas Heine, Professor of Theoretical Chemistry at TU Dresden, together with his team, first predicted a topological 2D polymer in 2019. Only one year later, an international team led by Italian researchers was able to synthesize these materials and experimentally prove their topological properties. For the renowned journal Nature Materials, this was the occasion to invite Thomas Heine to a News and Views article, which was published this week. Under the title "Making 2D Topological Polymers a reality" Prof. Heine describes how his theory became a reality.

Ultrathin materials are extremely interesting as building blocks for next generation nano electronic devices, as it is much easier to make circuits and other...

Im Focus: Rolling into the deep

Scientists took a leukocyte as the blueprint and developed a microrobot that has the size, shape and moving capabilities of a white blood cell. Simulating a blood vessel in a laboratory setting, they succeeded in magnetically navigating the ball-shaped microroller through this dynamic and dense environment. The drug-delivery vehicle withstood the simulated blood flow, pushing the developments in targeted drug delivery a step further: inside the body, there is no better access route to all tissues and organs than the circulatory system. A robot that could actually travel through this finely woven web would revolutionize the minimally-invasive treatment of illnesses.

A team of scientists from the Max Planck Institute for Intelligent Systems (MPI-IS) in Stuttgart invented a tiny microrobot that resembles a white blood cell...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Dresden Nexus Conference 2020: Same Time, Virtual Format, Registration Opened

19.05.2020 | Event News

Aachen Machine Tool Colloquium AWK'21 will take place on June 10 and 11, 2021

07.04.2020 | Event News

International Coral Reef Symposium in Bremen Postponed by a Year

06.04.2020 | Event News

 
Latest News

Black nitrogen: Bayreuth researchers discover new high-pressure material and solve a puzzle of the periodic table

29.05.2020 | Materials Sciences

Argonne researchers create active material out of microscopic spinning particles

29.05.2020 | Materials Sciences

Smart windows that self-illuminate on rainy days

29.05.2020 | Power and Electrical Engineering

VideoLinks
Science & Research
Overview of more VideoLinks >>>