Featured Research

from universities, journals, and other organizations

The Agulhas Current, In The Southern Hemisphere, May Influence Climate In Europe

Date:
March 16, 2009
Source:
Universitat Autonoma de Barcelona
Summary:
Researchers studying the Agulhas Current and the ensuing warm water transports from the tropical Indian Ocean to the southern tip of Africa can show that evidence in support of the hypothesis that the Agulhas water "leakage" into the Atlantic can affect the climate in Europe.

The PhD project presented by Gema Martínez-Méndez from the Institute of Environmental Science and Technology at the Universitat Autonoma de Barcelona focuses on the Agulhas Current and the ensuing warm water transports from the tropical Indian Ocean to the southern tip of Africa.

Related Articles


The data generated provide for the first time evidence in support of the hypothesis that the Agulhas water "leakage" into the Atlantic can affect the climate in Europe.

Her PhD thesis "Surface and Deep Circulation off South Africa: Agulhas Leakage Influence on the Meridional Overturning Circulation During the Last 345 kyr" presented data on a major ocean current in the southern hemisphere, the Agulhas Current, which transports warm waters from the tropical Indian Ocean to the southern tip of Africa. These new data profiles are not yet fully exploited and need to be implemented in global ocean models.

But they do provide for the first time robust evidence in support of the hypothesis that the Agulhas water "leakage" into the Atlantic contributes to the strength of the Atlantic Ocean circulation at large, and the Gulf Stream in particular and therefore can stabilise or destabilise climate in Europe. This knowledge will improve predictive capabilities which aim to project future climate developments in the North Atlantic region under global climate warming scenarios, such as those employed by the Intergovernmental Panel on Climate Change (IPCC).

The Agulhas Current influences rainfall patterns and weather systems in southern Africa. A part of the warm waters are transported around South Africa into the South Atlantic and influence the ocean circulation of the entire Atlantic Ocean. Climate models predict that the amount of this water "leakage" from the Indian Ocean into the Atlantic may in fact strengthen or weaken the Gulf Stream in the North Atlantic with consequences for climate in Europe, including the Iberian Peninsula. Measurements in the ocean so far have not permitted to test if a connection between the Agulhas Current around South Africa and the climate in Europe indeed exists.

For her project, Martínez-Méndez used stable isotope gas mass spectrometry and inductively coupled plasma mass spectrometry to analyse isotopic and chemical components in the sediments underneath the Agulhas Current which document variations of this current in the past. The data profiles document that systematic changes occurred in the Agulhas Current which were directly connected with global climate changes.

A combination of temperature sensitive isotopes and trace elements which are preserved in the shells of marine micro-plankton indicate that under cold climatic conditions such as the ice ages, when the rest of the world dramatically cooled, the influence of the Agulhas Current strengthened and the oceans around South Africa warmed. Ocean warming is documented also by the high abundance of tropical plankton which was preserved in the seafloor sediments. When global climate began to warm at the end of cold periods, the Agulhas Current initially became stronger and then abruptly weakened to assume a strength similar to that of today.

The implications from this research are that the flow of water coming from the tropical Indian Ocean can occasionally form a warm water pool at the southern tip of Africa. Under appropriate conditions, this water is abruptly released into the Atlantic Ocean. Because these waters also have high concentrations of salt they ultimately stimulate a density anomaly in the South Atlantic which triggers internal waves in the deep water and ultimately influence the Gulf Stream in the north.

This past December, Gema Martínez-Méndez presented the results of her PhD project at the General Assembly Fall Meeting of the AGU in San Francisco. The conference was attended by more than 12,000 researchers from the Earth Sciences worldwide representing a diverse range of expertise such as geophysics, meteorology, geochemistry, glaciology, oceanography and climatology. Out of over 16,000 research presentations, ICTA researcher Gema Martínez-Méndez's paper was chosen as one of the best student presentations and she was awarded with the 2008 AGU Fall Meeting Outstanding Student Presentation Award.

Gema Martínez-Méndez holds a degree in Marine Sciences from the University of Vigo, a European Masters from Kiel University in Germany and she received her PhD in Environmental Sciences in September 2008 from ICTA at the Universitat Autònoma de Barcelona. Her PhD project was embedded in the marine climatology projects "Transecto climático interhemisférico: comprensión de los cambios oceanográficos y climáticos rápidos en Iberia durante los dos últimos ciclos glaciales-interglaciales (TRANSCLIM)" and "Clima Ibérico y Circulación Meridional Atlántica (CIMERA)". Both are funded by the Spanish Ministry for Science and Innovation and directed by Dr Rainer Zahn, ICREA research professor at the UAB Department of Geology.


Story Source:

The above story is based on materials provided by Universitat Autonoma de Barcelona. Note: Materials may be edited for content and length.


Cite This Page:

Universitat Autonoma de Barcelona. "The Agulhas Current, In The Southern Hemisphere, May Influence Climate In Europe." ScienceDaily. ScienceDaily, 16 March 2009. <www.sciencedaily.com/releases/2009/03/090310122430.htm>.
Universitat Autonoma de Barcelona. (2009, March 16). The Agulhas Current, In The Southern Hemisphere, May Influence Climate In Europe. ScienceDaily. Retrieved December 18, 2014 from www.sciencedaily.com/releases/2009/03/090310122430.htm
Universitat Autonoma de Barcelona. "The Agulhas Current, In The Southern Hemisphere, May Influence Climate In Europe." ScienceDaily. www.sciencedaily.com/releases/2009/03/090310122430.htm (accessed December 18, 2014).

Share This


More From ScienceDaily



More Earth & Climate News

Thursday, December 18, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Navy Unveils Robot Fish

Navy Unveils Robot Fish

Reuters - Light News Video Online (Dec. 18, 2014) — The U.S. Navy unveils an underwater device that mimics the movement of a fish. Tara Cleary reports. Video provided by Reuters
Powered by NewsLook.com
Arctic Warming Twice As Fast As Rest Of Planet

Arctic Warming Twice As Fast As Rest Of Planet

Newsy (Dec. 18, 2014) — The Arctic is warming twice as fast as the rest of the planet, thanks in part to something called feedback. Video provided by Newsy
Powered by NewsLook.com
Ivory Trade Boom Swamps Law Efforts

Ivory Trade Boom Swamps Law Efforts

Reuters - Business Video Online (Dec. 17, 2014) — Demand for ivory has claimed the lives of tens of thousands of African elephants and now a conservation report says the illegal trade is overwhelming efforts to enforce the law. Amy Pollock reports. Video provided by Reuters
Powered by NewsLook.com
Indictments in West Virginia Chemical Spill Case

Indictments in West Virginia Chemical Spill Case

AP (Dec. 17, 2014) — A grand jury indicted four former executives of Freedom Industries, the company at the center of the Jan. 9, 2014 chemical spill in Charleston, West Virginia. The spill contaminated the Elk River and the water supply of 300,000 people. (Dec. 17) Video provided by AP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
 
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:  

Breaking News:

Strange & Offbeat Stories

 

Plants & Animals

Earth & Climate

Fossils & Ruins

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:  

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile iPhone Android Web
Follow Facebook Twitter Google+
Subscribe RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins