Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

New Location of Deep Convection May Exist in North Atlantic, Altering Views of Atmosphere-Ocean Interaction

18.07.2003


Deep convection, or mixing, of ocean waters in the North Atlantic, widely thought to occur in only the Labrador Sea and the Mediterranean, may occur in a third location first proposed nearly 100 years ago by the explorer and oceanographer Fridtjof Nansen. The findings, reported this week in the journal Nature, may alter thinking about the ocean’s overturning circulation that affects earth’s climate.



An international team of scientists reports in Nature that convection, a process that forms deep waters of the world’s oceans and plays a major role in the climate system, may also be occurring in the Irminger Sea east of Greenland because of a sporadic and localized atmospheric phenomenon known as the Greenland tip jet.

Lead author Robert Pickart of the Woods Hole Oceanographic Institution (WHOI) says the study places an additional complexity to the climate puzzle that must now be taken into account in observations and models, and that the implications of an additional source of Labrador Sea Water are far-reaching.


"I believe we found the smoking gun in the debate about deep water formation east of Greenland," Pickart says. "This study essentially ends a 100-year controversy, and I am convinced we will acquire the data from the ocean profiling system now in place in the Irminger Sea to prove it conclusively in the future."

The Labrador Sea and the Mediterranean have been thought to be the only locations where open-ocean convection leads to formation of deep water in the North Atlantic to depths of 1500-2000 meters. Polar air blows across Canada during the winter, removing heat over much of the Labrador Sea and causing the surface layers to sink and mix into deep waters. New evidence rekindled interest in Nansen’s idea that a large amount of Labrador Sea Water may actually be formed outside the Labrador Sea in the Irminger Sea.

A recent study by atmospheric scientists focused attention on a phenomenon known as the Greenland tip jet, a narrow, sporadic atmospheric jet that develops off of Cape Farewell when high-level northwesterly winds descend on the eastern or leeward side of Greenland and accelerate as they drop down over the ocean, drawing cold air over the southern Irminger Sea in a relatively small area. Pickart’s team, consisting of WHOI colleague Mike Spall and researchers at the Danish Meteorological Institute, University of Toronto, and Colorado Research Associates Division recognized that this was likely the cause of deep convection in the Irminger Sea. They pulled together corroborating evidence from atmospheric models, meteorological data, remote sensing fields, and oceanic modeling in order to make their case.

Nansen first proposed the idea nearly 100 years ago but much debate and controversy followed in the scientific literature and the notion was never embraced by the oceanographic community. Pickart knew nothing of Nansen’s forgotten theory until a few years ago when he gave a lecture about the "new" idea, and was told by a Norwegian scientist that it had been proposed but discounted decades ago. Intrigued as to why the idea died out, he hired a German translator and reviewed many journal articles for evidence. He is currently working on a popular science book on the demise of Nansen’s hypothesis.

Pickart and colleagues may be able to finally prove the idea with a new ocean profiling system deployed in the Irminger Sea three years ago. Pickart will head to sea in late July to recover and redeploy the instrument for another year, and a five-year deployment is planned by Institution colleagues starting in 2005.

About WHOI

WHOI is a private, independent marine research and engineering, and higher education organization located in Falmouth, MA. Its primary mission is to understand the oceans and their interaction with the Earth as a whole, and to communicate a basic understanding of the ocean’s role in the changing global environment. Established in 1930 on a recommendation from the National Academy of Sciences, the Institution is organized into five departments, interdisciplinary institutes and a marine policy center, and conducts a joint graduate education program with the Massachusetts Institute of Technology.

Shelley Dawicki | WHOI
Further information:
http://www.whoi.edu

More articles from Earth Sciences:

nachricht Geomagnetic jerks finally reproduced and explained
23.04.2019 | CNRS

nachricht "Flight recorder" of rocks within the Earth’s crust
16.04.2019 | Universität Bern

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Quantum gas turns supersolid

Researchers led by Francesca Ferlaino from the University of Innsbruck and the Austrian Academy of Sciences report in Physical Review X on the observation of supersolid behavior in dipolar quantum gases of erbium and dysprosium. In the dysprosium gas these properties are unprecedentedly long-lived. This sets the stage for future investigations into the nature of this exotic phase of matter.

Supersolidity is a paradoxical state where the matter is both crystallized and superfluid. Predicted 50 years ago, such a counter-intuitive phase, featuring...

Im Focus: Explosion on Jupiter-sized star 10 times more powerful than ever seen on our sun

A stellar flare 10 times more powerful than anything seen on our sun has burst from an ultracool star almost the same size as Jupiter

  • Coolest and smallest star to produce a superflare found
  • Star is a tenth of the radius of our Sun
  • Researchers led by University of Warwick could only see...

Im Focus: Quantum simulation more stable than expected

A localization phenomenon boosts the accuracy of solving quantum many-body problems with quantum computers which are otherwise challenging for conventional computers. This brings such digital quantum simulation within reach on quantum devices available today.

Quantum computers promise to solve certain computational problems exponentially faster than any classical machine. “A particularly promising application is the...

Im Focus: Largest, fastest array of microscopic 'traffic cops' for optical communications

The technology could revolutionize how information travels through data centers and artificial intelligence networks

Engineers at the University of California, Berkeley have built a new photonic switch that can control the direction of light passing through optical fibers...

Im Focus: A long-distance relationship in femtoseconds

Physicists observe how electron-hole pairs drift apart at ultrafast speed, but still remain strongly bound.

Modern electronics relies on ultrafast charge motion on ever shorter length scales. Physicists from Regensburg and Gothenburg have now succeeded in resolving a...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Revered mathematicians and computer scientists converge with 200 young researchers in Heidelberg!

17.04.2019 | Event News

First dust conference in the Central Asian part of the earth’s dust belt

15.04.2019 | Event News

Fraunhofer FHR at the IEEE Radar Conference 2019 in Boston, USA

09.04.2019 | Event News

 
Latest News

Marine Skin dives deeper for better monitoring

23.04.2019 | Information Technology

Geomagnetic jerks finally reproduced and explained

23.04.2019 | Earth Sciences

Overlooked molecular machine in cell nucleus may hold key to treating aggressive leukemia

23.04.2019 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>