Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Storm Killers: LSU’s Earth Scan Lab Tracks Cold Water Upwellings in Gulf

01.10.2009
Cold water cyclones may have strong impact on hurricane intensity and activity

Complex interactions between the ocean and overlying atmosphere cause hurricanes to form, and also have a tremendous amount of influence on the path, intensity and duration of a hurricane or tropical weather event.

As researchers develop new ways to better understand and predict the nature of individual storms, a largely unstudied phenomenon has caught the attention of scientists at LSU’s Earth Scan Laboratory, or ESL. Cool water upwellings occurring within ocean cyclones following alongside and behind hurricanes are sometimes strong enough to reduce the strength of hurricanes as they cross paths.

“Ocean cyclones are areas of upwelling, meaning that cold water is not far from the surface as compared to the water surrounding it,” said Nan Walker, ESL director. “The Gulf of Mexico is full of ocean cyclones, or cold water eddies, many of which move rapidly around the margin of Gulf’s Loop Current, which is the main source of water for the Gulf Stream.”

While the upwelling is important to Gulf fisheries because it delivers nutrients into the surface waters, causing algal blooms and attracting marine life to the areas, oceanographers have recently begun to realize that these cyclones intensify currents near the surface and along the bottom of the ocean in areas of gas and oil exploration.

“Now,” Walker added, “our research has shown that ocean cyclones also provide temperatures cold enough to reduce the intensity of large Gulf of Mexico hurricanes.”

Walker’s research team has been looking into the upwelling phenomena since 2004, when they were able to use satellite data received at the ESL to view ocean temperatures soon after Hurricane Ivan’s Gulf crossing.

“Clear skies gave us a rare opportunity to really analyze the oceanic conditions surrounding the wake of Ivan,” said Walker. “We saw abnormally low temperatures in two large areas along the storm’s track, where minimum temperatures were well below those required to support a hurricane, about 80 degrees Fahrenheit.” This suggested to Walker that areas of extreme cooling could be providing immediate negative feedback to Gulf hurricanes, decreasing their intensity.

“In Ivan’s case, we found that its wind field increased the counter-clockwise spinning of the ocean cyclones in its path, catapulting cold water to the surface, which in turn reduced the oceanic ‘fuel’ needed for the hurricane to maintain its strength,” said Walker. She observed that Ivan’s intensity decreased as it moved toward the Mississippi/Alabama coast, despite the presence of a large warm eddy, a feature generally known for its potential to increase hurricane strength. Thus, the impact of the cold eddies overwhelmed that of the warm eddy.

“Cool wakes are most beneficial when the storm occurs later in the season because the Gulf doesn’t warm as rapidly in fall and may not have time to warm back up,” said Walker.

The research being conducted at ESL could eventually lead to novel new weather study techniques.

“Our research, in collaboration with Robert Leben at the University of Colorado, is providing an advanced monitoring system so that likely ocean impacts can be assessed in advance of the Gulf crossing,” said Walker. “However, it is important to remember that we don’t predict; we provide valuable information that serves as tools for those in the business of predicting, such as the National Hurricane Center.”

Of course, this is only one facet of the work done at LSU’s ESL. The lab has played a major role in mapping hurricane-related flooding, tracking oil spills and determining causes for the size and location of dead zones in the Gulf of Mexico, along with many other tasks employing satellite imagery.

ESL was founded more than 20 years ago, and employs undergraduate students, many of whom stay on with the lab throughout their entire college career. The lab’s Web site, http://www.esl.lsu.edu/home/, serves as a wealth of information for researchers, students and the general public. It includes real-time imagery of atmospheric, oceanic and coastal conditions, detailed records of recent and past hurricanes, as well as various types of ocean imagery and research summaries. ESL is part of LSU’s Coastal Studies Institute and the Department of Oceanography and Coastal Sciences in the university’s School of the Coast & Environment.

Ashley Berthelot | EurekAlert!
Further information:
http://www.lsu.edu

More articles from Earth Sciences:

nachricht World’s oldest known oxygen oasis discovered
18.01.2018 | Eberhard Karls Universität Tübingen

nachricht A close-up look at an uncommon underwater eruption
11.01.2018 | Woods Hole Oceanographic Institution

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Scientists decipher key principle behind reaction of metalloenzymes

So-called pre-distorted states accelerate photochemical reactions too

What enables electrons to be transferred swiftly, for example during photosynthesis? An interdisciplinary team of researchers has worked out the details of how...

Im Focus: The first precise measurement of a single molecule's effective charge

For the first time, scientists have precisely measured the effective electrical charge of a single molecule in solution. This fundamental insight of an SNSF Professor could also pave the way for future medical diagnostics.

Electrical charge is one of the key properties that allows molecules to interact. Life itself depends on this phenomenon: many biological processes involve...

Im Focus: Paradigm shift in Paris: Encouraging an holistic view of laser machining

At the JEC World Composite Show in Paris in March 2018, the Fraunhofer Institute for Laser Technology ILT will be focusing on the latest trends and innovations in laser machining of composites. Among other things, researchers at the booth shared with the Aachen Center for Integrative Lightweight Production (AZL) will demonstrate how lasers can be used for joining, structuring, cutting and drilling composite materials.

No other industry has attracted as much public attention to composite materials as the automotive industry, which along with the aerospace industry is a driver...

Im Focus: Room-temperature multiferroic thin films and their properties

Scientists at Tokyo Institute of Technology (Tokyo Tech) and Tohoku University have developed high-quality GFO epitaxial films and systematically investigated their ferroelectric and ferromagnetic properties. They also demonstrated the room-temperature magnetocapacitance effects of these GFO thin films.

Multiferroic materials show magnetically driven ferroelectricity. They are attracting increasing attention because of their fascinating properties such as...

Im Focus: A thermometer for the oceans

Measurement of noble gases in Antarctic ice cores

The oceans are the largest global heat reservoir. As a result of man-made global warming, the temperature in the global climate system increases; around 90% of...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

10th International Symposium: “Advanced Battery Power – Kraftwerk Batterie” Münster, 10-11 April 2018

08.01.2018 | Event News

See, understand and experience the work of the future

11.12.2017 | Event News

Innovative strategies to tackle parasitic worms

08.12.2017 | Event News

 
Latest News

Polymers Based on Boron?

18.01.2018 | Life Sciences

Bioengineered soft microfibers improve T-cell production

18.01.2018 | Life Sciences

World’s oldest known oxygen oasis discovered

18.01.2018 | Earth Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>