Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

University of Miami-led Team to Study Climatically Important Agulhas Current Using $3.4 Million NSF Grant

01.07.2009
Three-years of in situ measurements, combined with along-track satellite data to create long-term index of Agulhas Current transport; study possible impact current may have had on end of last Ice Age

The U.S. National Science Foundation (NSF) announced that it is funding a study with the goal of building a multi-decadal time series of Agulhas Current volume transport, which will contribute to the Global Ocean Observing System.

Led by Principal Investigator, Lisa Beal, Ph.D. of the University of Miami’s Rosenstiel School of Marine and Atmospheric Science, the international team will include scientists from the National Oceanography Centre (Southampton, United Kingdom) and the University of Cape Town (Cape Town, South Africa).

The Agulhas Current is the “Gulf Stream” of the southern Indian Ocean, carrying warm and salty tropical waters southward along the east coast of Africa as a narrow, fast jet. At the tip of Africa the Agulhas retroflects, looping around to eventually flow eastward toward Australia. This retroflection is unstable and regularly sheds large Agulhas Rings, which carry Indian Ocean waters into the South Atlantic.

“We anticipate this study will shed light on the seasonal to decadal variability of the Agulhas,“ said Beal. “Locally, the warm waters of the Agulhas effect African rainfall rates, and globally, there is paleo-oceanographic evidence suggesting that changes in the amount of Agulhas water reaching the Atlantic may have triggered the end of the last ice age.” In addition, Beal believes there may be other, so far unstudied climatic impacts such as heat transport into the Southern Ocean via the unstable retroflection.

The Agulhas Current Time-series (ACT) project will be conducted in two phases. The first requires the deployment of an array of instruments across the Agulhas Current and along an altimeter ground track, to obtain a three-year series of transport data. Using the in situ measurements gathered, the team will embark on the second phase, to correlate the along-track satellite altimeter data with measured transports to produce a proxy for Agulhas Current transport, which can be extended forwards and backwards in time.

The ACT mooring array will be positioned offshore and to the southwest of East London, South Africa, in up to 4700 m of water. The array will consist of seven full-depth current meter moorings, spanning the mean width of the Agulhas Current, one tide gauge, plus four pressure gauge-equipped inverted echo-sounders (C-PIES) to cover the Current’s offshore meandering events cost-effectively.

On each full-depth mooring upward-looking profiling current meters will measure the top 350 m of the water column, where velocities are strongest. Below these, up to six single-point current meters will measure the rest of the water column. All current meters are acoustic, with no moving parts, measuring velocity using the principle of Doppler shift, whereby the frequency of a sound wave changes as it reflects off a moving particle in the ocean.

Offshore recirculations and meandering events will be captured using the C-PIES, which can give information about the transport over the upper 2000 m, when combined with local hydrographic data collected during each mooring cruise. The shallow-water tide gauge will be placed on the continental shelf, allowing for an hourly record of sea surface height shoreward of the Agulhas Current.

The initial deployment cruise is scheduled to leave Cape Town, South Africa, in March 2010, aboard a U.S. University-National Oceanographic Laboratory System (UNOLS) research vessel. The ACT array will be in the water until approximately March 2013.

“Ultimately, a twenty year proxy of Agulhas Current transport will provide an important climate index for the Indian Ocean, which can be linked to other climate indices, such as the Atlantic Meridional Overturning, and hopefully improve our predictive capabilities for the future,” Beal added.

The University of Miami is the largest private research institution in the southeastern United States. The University’s mission is to provide quality education, attract and retain outstanding students, support the faculty and their research, and build an endowment for University initiatives.

Founded in the 1940’s, the Rosenstiel School of Marine & Atmospheric Science has grown into one of the world's premier marine and atmospheric research institutions. Offering dynamic interdisciplinary academics, the Rosenstiel School is dedicated to helping communities to better understand the planet, participating in the establishment of environmental policies, and aiding in the improvement of society and quality of life.

Barbra Gonzalez
Communications Director
University of Miami
Rosenstiel School of Marine & Atmospheric Science 4600 Rickenbacker Causeway Virginia Key, FL 33149
Tel: 305-421-4704
Fax: 305-421-4711

Barbra Gonzalez | Research asia research news
Further information:
http://www.rsmas.miami.edu
http://www.researchsea.com

More articles from Earth Sciences:

nachricht Scientists shed light on carbon's descent into the deep Earth
19.07.2017 | European Synchrotron Radiation Facility

nachricht Thawing permafrost releases old greenhouse gas
19.07.2017 | GFZ GeoForschungsZentrum Potsdam, Helmholtz Centre

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Manipulating Electron Spins Without Loss of Information

Physicists have developed a new technique that uses electrical voltages to control the electron spin on a chip. The newly-developed method provides protection from spin decay, meaning that the contained information can be maintained and transmitted over comparatively large distances, as has been demonstrated by a team from the University of Basel’s Department of Physics and the Swiss Nanoscience Institute. The results have been published in Physical Review X.

For several years, researchers have been trying to use the spin of an electron to store and transmit information. The spin of each electron is always coupled...

Im Focus: The proton precisely weighted

What is the mass of a proton? Scientists from Germany and Japan successfully did an important step towards the most exact knowledge of this fundamental constant. By means of precision measurements on a single proton, they could improve the precision by a factor of three and also correct the existing value.

To determine the mass of a single proton still more accurate – a group of physicists led by Klaus Blaum and Sven Sturm of the Max Planck Institute for Nuclear...

Im Focus: On the way to a biological alternative

A bacterial enzyme enables reactions that open up alternatives to key industrial chemical processes

The research team of Prof. Dr. Oliver Einsle at the University of Freiburg's Institute of Biochemistry has long been exploring the functioning of nitrogenase....

Im Focus: The 1 trillion tonne iceberg

Larsen C Ice Shelf rift finally breaks through

A one trillion tonne iceberg - one of the biggest ever recorded -- has calved away from the Larsen C Ice Shelf in Antarctica, after a rift in the ice,...

Im Focus: Laser-cooled ions contribute to better understanding of friction

Physics supports biology: Researchers from PTB have developed a model system to investigate friction phenomena with atomic precision

Friction: what you want from car brakes, otherwise rather a nuisance. In any case, it is useful to know as precisely as possible how friction phenomena arise –...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

»We are bringing Additive Manufacturing to SMEs«

19.07.2017 | Event News

The technology with a feel for feelings

12.07.2017 | Event News

Leipzig HTP-Forum discusses "hydrothermal processes" as a key technology for a biobased economy

12.07.2017 | Event News

 
Latest News

Researchers create new technique for manipulating polarization of terahertz radiation

20.07.2017 | Information Technology

High-tech sensing illuminates concrete stress testing

20.07.2017 | Materials Sciences

First direct observation and measurement of ultra-fast moving vortices in superconductors

20.07.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>