Featured Research

from universities, journals, and other organizations

Gulf stream: Charting the chaotic current that warms Norway

Date:
December 2, 2011
Source:
The Research Council of Norway
Summary:
The North Atlantic Current – popularly known as the Gulf Stream – warms Norway and Northern Europe. But if its waters flowed smoothly north along the Norwegian coastline, the current would deliver far less warmth to Norway. It is the chaos of the seas that warms the country, researchers have discovered.

Chaotic: A spaghetti plot shows the trajectories of the drifting buoys.
Credit: Illustration: POLEWARD

The North Atlantic Current -- popularly known as the Gulf Stream -- warms Norway and Northern Europe. It is the chaos of the seas that warms the country, researchers have discovered. If its waters flowed smoothly north along the Norwegian coastline, the current would deliver far less warmth.

Related Articles


Norway is situated at the same high northern latitude as Greenland, Northern Canada and Northern Siberia, but thanks to the Gulf Stream, its climate is significantly more temperate.

If the Norwegian branch of the North Atlantic Current flowed evenly, it would surge past Norway at a speed approaching one metre per second, roughly as fast as many rivers run. At that rate, the waters would need only 60 days or so to travel the length of Norway's mainland and reach Svalbard. This would mean that less of the current's heat would be transferred to the atmosphere, resulting in a substantially colder climate for Norway.

In the research project POLEWARD: A drifter experiment to quantify the poleward transport, transformation and spreading of oceanic properties, scientists have discovered that the current takes more than 500 days to flow past Norway, giving the waters more time to release their heat and warm up the country. The project received funding from the research programme on Climate Change and Impacts in Norway (NORKLIMA) at the Research Council of Norway.

Using buoys to chart the current

By deploying 150 marine buoys tracked by satellite, the POLEWARD project researchers were able to chart in detail how the current flows northward along the Norwegian coast.

The buoys revealed that the current often travels quickly, but because it is so irregular and thus highly variable -- indeed, chaotic may be the best description -- the Gulf Stream's journey takes perhaps as much as ten times longer than it would if it flowed smoothly. In this way there is time for the warm ocean current to convey a vastly greater proportion of its heat into the atmosphere, from which the warm air is carried on the predominantly westerly winds towards mainland Norway.

"The large number of 'drifters' (marine buoys) deployed means the statistical significance of our findings was high," explains POLEWARD project manager Cecilie Mauritzen. "We were able to deploy two or three buoys at a time and thus collect more information and carry out more sophisticated statistical calculations than with just one buoy." Dr Mauritzen is director of the Climate Division at the Norwegian Meteorological Institute in Oslo.

Chaos models

The researchers studied how simultaneously deployed buoys drifted away from one another, observing that their trajectories were in line with different chaos theories at different stages of their journey.

"In much the same way as biologists track migratory birds, we were able to chart the movements of the current's water particles through the Norwegian Sea. We now have a very clear picture of how the northeastern extension of the North Atlantic Current -- what we researchers like to call the Norwegian Atlantic Current -- flows north along the coastline."

Chaos explains climate

When watching the tiny particles of water, oil or ash in motion, it may appear they are moving along smoothly. But in reality their movements are always more or less chaotic.

The disorderly movement of the ocean current off the Norwegian coast is an example of turbulent advection -- streams that do not move in a uniform line of flow. Other examples include the dispersion of ash from Iceland's Eyjafjallajökull eruptions and the dispersion of oil from BP's Deepwater Horizon leakage in the Gulf of Mexico.

Greater insight into this apparent chaos can help scientists to develop better climate models. Not least they will better understand how heat is transferred from the ocean to the air, helping to define the role of oceans in global climate.

From 10°C to less than 5°C

As the Norwegian Atlantic Current flows northward between Scotland and Iceland, it forms a layer that is a couple of hundred metres deep and 8-10°C. Along the western coast of Norway, much of the current's water mass follows the continental slope before dividing into two branches when it reaches Troms County. The smaller branch continues on to the Barents Sea, the larger one to the Fram Strait between Svalbard and Greenland. At this point the ocean temperature has dropped to well below 5°C.

After releasing a tremendous amount of its heat, the current dives beneath the cold Arctic waters. Eventually the current flows back to the Atlantic at a depth of 4 000 to 5 000 metres and can remain submerged at that depth for hundreds of years as it circulates in the world's oceans.

Keeping Lofoten relatively warm

The POLEWARD project researchers found that the buoys took an average of 515 days to drift from their deployment site off Møre (on Norway's west coast) to the Fram Strait (the body of water between Greenland and Spitsbergen). The vast majority of buoys had drifted chaotically in and out of the Norwegian Atlantic Current, swiftly but in all directions. Nevertheless they slowly but surely made their way generally northward, just as the Gulf Stream is thought to travel.

In the Lofoten Basin, the paths of the POLEWARD drifters were particularly variable. The researchers found that extreme amounts of heat were radiated up into the atmosphere at precisely this point.


Story Source:

The above story is based on materials provided by The Research Council of Norway. The original article was written by Bård Amundsen/Else Lie. Translation: Darren McKellep/Carol B. Eckmann. Note: Materials may be edited for content and length.


Cite This Page:

The Research Council of Norway. "Gulf stream: Charting the chaotic current that warms Norway." ScienceDaily. ScienceDaily, 2 December 2011. <www.sciencedaily.com/releases/2011/12/111202091148.htm>.
The Research Council of Norway. (2011, December 2). Gulf stream: Charting the chaotic current that warms Norway. ScienceDaily. Retrieved November 25, 2014 from www.sciencedaily.com/releases/2011/12/111202091148.htm
The Research Council of Norway. "Gulf stream: Charting the chaotic current that warms Norway." ScienceDaily. www.sciencedaily.com/releases/2011/12/111202091148.htm (accessed November 25, 2014).

Share This


More From ScienceDaily



More Earth & Climate News

Tuesday, November 25, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Antarctic Sea Ice Mystery Thickens... Literally

Antarctic Sea Ice Mystery Thickens... Literally

Newsy (Nov. 25, 2014) — Antarctic sea ice isn't only expanding, it's thicker than previously thought, and scientists aren't sure exactly why. Video provided by Newsy
Powered by NewsLook.com
3D Map of Antarctic Sea Ice to Shed Light on Climate Change

3D Map of Antarctic Sea Ice to Shed Light on Climate Change

Reuters - Innovations Video Online (Nov. 24, 2014) — A multinational group of scientists have released the first ever detailed, high-resolution 3-D maps of Antarctic sea ice. Using an underwater robot equipped with sonar, the researchers mapped the underside of a massive area of sea ice to gauge the impact of climate change. Ben Gruber reports. Video provided by Reuters
Powered by NewsLook.com
Car Park Solution for Flexible Green Energy

Car Park Solution for Flexible Green Energy

Reuters - Innovations Video Online (Nov. 24, 2014) — A British solar power start-up says that by covering millions of existing car park spaces around the UK with flexible solar panels, the country's power problems could be solved. Suzannah Butcher reports. Video provided by Reuters
Powered by NewsLook.com
Yellow-Spotted Turtles Rescued from Trafficking

Yellow-Spotted Turtles Rescued from Trafficking

Reuters - Light News Video Online (Nov. 24, 2014) — Hundreds of Amazon River turtles released into the wild in Peru. Sharon Reich reports. Video provided by Reuters
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