Featured Research

from universities, journals, and other organizations

Are Changes In Earth's Main Magnetic Field Induced By Oceans' Circulation?

Date:
June 15, 2009
Source:
Institute of Physics
Summary:
A researcher has defied the long-standing convention by applying equations from magnetohydrodynamics to our oceans' salt water (which conducts electricity) and found that the long-term changes in the Earth's main magnetic field are possibly induced by our oceans' circulation.

A controversial new theory suggests that long-term changes (the secular variation) in Earth's main magnetic field are possibly induced by the oceans' circulation.
Credit: iStockphoto/Renι Mansi

Some 400 years of discussion and we’re still not sure what creates the Earth’s magnetic field, and thus the magnetosphere, despite the importance of the latter as the only buffer between us and deadly solar wind of charged particles (made up of electrons and protons). New research raises question marks about the forces behind the magnetic field and the structure of Earth itself.

Related Articles


The controversial new paper, published in New Journal of Physics, will deflect geophysicists’ attention from postulated motion of conducting fluids in the Earth’s core, the twentieth century’s answer to the mysteries of geomagnetism and magnetosphere.

Professor Gregory Ryskin from the School of Engineering and Applied Science at Northwestern University in Illinois, US, has defied the long-standing convention by applying equations from magnetohydrodynamics to our oceans’ salt water (which conducts electricity) and found that the long-term changes (the secular variation) in the Earth’s main magnetic field are possibly induced by our oceans’ circulation.

With calculations thus confirming Ryskin’s suspicions, there were also time and space correlations - specific indications of the integral relationship between the oceans and our magnetospheric buffer. For example, researchers had recorded changes in the intensity of current circulation in the North Atlantic; Ryskin shows that these appear strongly correlated with sharp changes in the rate of geomagnetic secular variation (“geomagnetic jerks”).

Tim Smith, senior publisher of the New Journal of Physics, said, "This article is controversial and will no doubt cause vigorous debate, and possibly strong opposition, from some parts of the geomagnetism community. As the author acknowledges, the results by no means constitute a proof but they do suggest the need for further research into the possibility of a direct connection between ocean flow and the secular variation of the geomagnetic field."

In the early 1920s, Einstein highlighted the large challenge that understanding our Magnetosphere poses. It was later suggested that the Earth’s magnetic field could be a result of the flow of electrically-conducting fluid deep inside the Earth acting as a dynamo.

In the second half of the twentieth century, the dynamo theory, describing the process through which a rotating, convecting, and electrically conducting fluid acts to maintain a magnetic field, was used to explain how hot iron in the outer core of the Earth creates a magnetosphere.

The journal paper also raises questions about the structure of our Earth’s core.

Familiar text book images that illustrate a flow of hot and highly electrically-conducting fluid at the core of the Earth are based on conjecture and could now be rendered invalid. As the flow of fluids at the Earth’s core cannot be measured or observed, theories about changes in the magnetosphere have been used, inversely, to infer the existence of such flow at the core of the Earth.

While Ryskin’s research looks only at long-term changes in the Earth’s magnetic field, he points out that, “If secular variation is caused by the ocean flow, the entire concept of the dynamo operating in the Earth’s core is called into question: there exists no other evidence of hydrodynamic flow in the core.”

On a practical level, it means the next time you use a compass you might need to thank the seas and oceans for influencing the force necessary to guide the way.

Dr Raymond Shaw, professor of atmospheric physics at Michigan Technological University, said, “It should be kept in mind that the idea Professor Ryskin is proposing in his paper, if valid, has the potential to deem irrelevant the ruling paradigm of geomagnetism, so it will be no surprise to find individuals who are strongly opposed or critical."


Story Source:

The above story is based on materials provided by Institute of Physics. Note: Materials may be edited for content and length.


Journal Reference:

  1. Gregory Ryskin. Secular variation of the Earth's magnetic field: induced by the ocean flow? New Journal of Physics, 2009; 11 (6): 063015 DOI: 10.1088/1367-2630/11/6/063015

Cite This Page:

Institute of Physics. "Are Changes In Earth's Main Magnetic Field Induced By Oceans' Circulation?." ScienceDaily. ScienceDaily, 15 June 2009. <www.sciencedaily.com/releases/2009/06/090615094038.htm>.
Institute of Physics. (2009, June 15). Are Changes In Earth's Main Magnetic Field Induced By Oceans' Circulation?. ScienceDaily. Retrieved October 25, 2014 from www.sciencedaily.com/releases/2009/06/090615094038.htm
Institute of Physics. "Are Changes In Earth's Main Magnetic Field Induced By Oceans' Circulation?." ScienceDaily. www.sciencedaily.com/releases/2009/06/090615094038.htm (accessed October 25, 2014).

Share This



More Earth & Climate News

Saturday, October 25, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

EU Gets Climate Deal, UK PM Gets Knock

EU Gets Climate Deal, UK PM Gets Knock

Reuters - Business Video Online (Oct. 24, 2014) — EU leaders achieve a show of unity by striking a compromise deal on carbon emissions. But David Cameron's bid to push back EU budget contributions gets a slap in the face as the European Commission demands an extra 2bn euros. David Pollard reports. Video provided by Reuters
Powered by NewsLook.com
Deep Sea 'mushroom' Could Be Early Branch on Tree of Life

Deep Sea 'mushroom' Could Be Early Branch on Tree of Life

Reuters - Innovations Video Online (Oct. 24, 2014) — Miniature deep sea animals discovered off the Australian coast almost three decades ago are puzzling scientists, who say the organisms have proved impossible to categorise. Academics at the Natural History of Denmark have appealed to the world scientific community for help, saying that further information on Dendrogramma enigmatica and Dendrogramma discoides could answer key evolutionary questions. Jim Drury has more. Video provided by Reuters
Powered by NewsLook.com
Raw: Tornado Rips Roofs in Washington State

Raw: Tornado Rips Roofs in Washington State

AP (Oct. 24, 2014) — A rare tornado ripped roofs off buildings, uprooted trees and shattered windows Thursday afternoon in the southwest Washington city of Longview, but there were no reports of injuries. (Oct. 24) Video provided by AP
Powered by NewsLook.com
Fast-Moving Lava Headed For Town On Hawaii's Big Island

Fast-Moving Lava Headed For Town On Hawaii's Big Island

Newsy (Oct. 24, 2014) — Lava from the Kilauea volcano on Hawaii's Big Island has accelerated as it travels toward a town called Pahoa. Video provided by Newsy
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