Subscribe to our free daily newsletters
. 24/7 Space News .

Subscribe to our free daily newsletters

What Earth's climate system and topological insulators have in common
by Staff Writers
Providence RI (SPX) Oct 09, 2017

New research shows that equatorial waves - pulses of warm ocean water that play a role in regulating Earth's climate - are driven by the same dynamics as the exotic materials known as topological insulators. Equatorial Kelvin waves, which are responsible for the El Nino-Southern Oscillation, travel from West to East. Another type of equatorial wave--Rossby waves--move in the opposite direction.

Topological insulators, materials that insulate on the inside but conduct electricity along their outer edges, have created quite a buzz in condensed matter physics. Now a new study in the journal Science shows that the same topological behavior that governs these exotic materials also drives equatorial waves - pulses of warm ocean water that play a major role in regulating the Earth's climate, including the El Nino-Southern Oscillation.

"These waves were discovered by geophysicists in the 1960s, but they lacked a deep understanding of why they existed," said Brad Marston, a physics professor at Brown University and coauthor of the new study. "What we've shown is that they have the same origin as the waves that are important in solid state physics - the waves of electrons that travel around the edges of topological insulators."

The research was inspired by a special type of topological insulator that exhibits what's known as the quantum Hall effect, which was discovered in 1980. The topology plays an essential role in the quantum Hall effect was recognized by the 2016 Nobel Prize in physics that was awarded to trio of physicists, including Brown University's Michael Kosterlitz.

In the quantum Hall effect, a magnetic field causes electrons inside a semiconducting material to travel in circles called cyclotron orbits. That circular movement prevents a flow of electrons - a current - from moving across the material, except at the material's outer edges.

There, electrons can only complete a half-circle before running out of real estate and banging against the edge. Because all of the electrons on a given edge execute their movement in the same direction, all those half-circles can link up and form an edge current. Thus, topological insulators conduct on the outside and insulate on the inside.

Marston and his collaborators, Pierre Delplace and Antoine Venaille from the University of Lyon in France, showed that analogous dynamics are at play with Earth's equatorial waves. In the case of the Earth, the role of the magnetic field is played by the Coriolis effect - an apparent force caused by the planet's rotation.

It's what causes hurricanes to spin in opposite directions in the Northern and Southern hemispheres. The role of the edge is played by the equator, where the Coriolis force breaks down.

"In each of the two hemispheres, you have the Coriolis force pushing in opposite directions," Marston said. "That traps the waves at the equator in a way that's very similar to how the current in a topological insulator is trapped at its edges. While the Earth doesn't have an 'edge' per se, the equator is essentially the edges of the two hemispheres stuck together."

The mathematics behind the two phenomena, Marston and his colleagues showed, is essentially identical.

"If you look in recent solid state physics papers at diagrams that describe the dispersion of electrons in a topological insulator, the plots looks exactly like the diagram in a geophysics textbook that depicts the dispersion of equatorial waves," Marston said. "When topological insulators were discovered a decade ago it was new physics, but to our surprise the Earth has been doing it all along."

The research helps to explain the existence of several types of equatorial waves. One of them, known as the equatorial Kelvin wave, delivers periodic pulses of warm water to the coast of South America, which is the El Nino oscillation.

The findings also explain how these waves persist despite being battered by storms and shifting wind, and how they pass straight by islands that might be expected to cause the waves to scatter.

"In topological insulators, the current is able to move right through impurities in the material as if they weren't there," Marston said. "That's because of their topological nature, and it helps us understand why equatorial waves and the El Nino oscillation persist despite being jostled around by weather and other obstacles."

In addition to helping explain the persistence of El Nino cycles, Marston says these same dynamics are likely happening elsewhere in the climate system - in the upper atmosphere, for example. Recognizing the topological nature of these phenomena could help deepen scientists' understanding of how they work, Marston says.

"As a practical matter, this will give us new ways to identify these kinds of climate dynamics by looking at the topology," he said. "We might be able to find and understand topological structures that may have been missed before."

JILA's 3-D quantum gas atomic clock offers new dimensions in measurement
Washington DC (SPX) Oct 09, 2017
JILA physicists have created an entirely new design for an atomic clock, in which strontium atoms are packed into a tiny three-dimensional (3-D) cube at 1,000 times the density of previous one-dimensional (1-D) clocks. In doing so, they are the first to harness the ultra-controlled behavior of a so-called "quantum gas" to make a practical measurement device. With so many atoms completely i ... read more

Related Links
Brown University
Understanding Time and Space

Thanks for being here;
We need your help. The SpaceDaily news network continues to grow but revenues have never been harder to maintain.

With the rise of Ad Blockers, and Facebook - our traditional revenue sources via quality network advertising continues to decline. And unlike so many other news sites, we don't have a paywall - with those annoying usernames and passwords.

Our news coverage takes time and effort to publish 365 days a year.

If you find our news sites informative and useful then please consider becoming a regular supporter or for now make a one off contribution.

SpaceDaily Contributor
$5 Billed Once

credit card or paypal
SpaceDaily Monthly Supporter
$5 Billed Monthly

paypal only

Comment using your Disqus, Facebook, Google or Twitter login.

Share this article via these popular social media networks DiggDigg RedditReddit GoogleGoogle

OECD calls for tourism to be more sustainable

Fast-moving space industries create new ethical challenges

Space Cooperation Between China, Russia Needs Long-Term Mechanism

NASA's New Hubble E-Book Series Dives into the Solar System and Beyond

Arianespace to launch COSMO-SkyMed satellites manufactured by Thales

New Zealand opens first rocket launch site

Arianespace signs contract for 10 Vega and Vega C launchers

Launch Vehicle and Missile Ascent Trajectories

Lockheed Martin Reveals New Details to its Mars Base Camp Vision

Lockheed Martin unveils reusable water-powered Mars lander

SpaceX's Musk unveils plan to reach Mars by 2022

Research sheds new light on how Earth and Mars were created

Mars probe to carry 13 types of payload on 2020 mission

China's cargo spacecraft separates from Tiangong-2 space lab

Work on China's mission to Mars 'well underway'

Chinese company eyes development of reusable launch vehicle

GomSpace and Luxembourg to develop space activities in the Grand Duchy

Spacepath Communications Acquires Tango Wave

Brodeur Partners Launches Entrepreneurial Space Group

SSL-Built Satellite for AsiaSat Begins Post-Launch Maneuvers According to Plan

Microlasers get a performance boost from a bit of gold

Atomistic simulations go the distance on metal strength

Surfactants have surprising effect on nanobubble stability

Teleoperating robots with virtual reality

MATISSE to Shed Light on the Formation of Earth and Planets

Glenn Tests Thruster Bound for Metal World

Searching for Distant Worlds With a Flying Telescope

Scientists propose new concept of terrestrial planet formation

Helicopter test for Jupiter icy moons radar

Solving the Mystery of Pluto's Giant Blades of Ice

Global Aerospace Corporation to present Pluto lander concept to NASA

Pluto features given first official names

Memory Foam Mattress Review
Newsletters :: SpaceDaily :: SpaceWar :: TerraDaily :: Energy Daily
XML Feeds :: Space News :: Earth News :: War News :: Solar Energy News

The content herein, unless otherwise known to be public domain, are Copyright 1995-2017 - Space Media Network. All websites are published in Australia and are solely subject to Australian law and governed by Fair Use principals for news reporting and research purposes. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA news reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. All articles labeled "by Staff Writers" include reports supplied to Space Media Network by industry news wires, PR agencies, corporate press officers and the like. Such articles are individually curated and edited by Space Media Network staff on the basis of the report's information value to our industry and professional readership. Advertising does not imply endorsement, agreement or approval of any opinions, statements or information provided by Space Media Network on any Web page published or hosted by Space Media Network. Privacy Statement