Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Space weather forecast step closer

12.12.2001


Loops of hot electrified gas above an active sunspot
© NASA/Standford University


American Geophysical Society Meeting, San Francisco, December 2001

The Sun’s violent outbursts have deep and twisted origins.


The Sun’s violent eruptions of material and magnetic energy have deep and twisted origins, researchers told this week’s American Geophysical Union Meeting in San Francisco, California.



These coronal mass ejections (CMEs) cause the aurora, seen at the Earth’s poles, and can knock out spacecraft. An understanding of what drives CMEs may one day make them possible to predict.

Radar aboard the NASA/European Space Agency spacecraft SOHO allowed a team from Stanford University in California to look beneath sunspots - dark patches on the Sun associated with CMEs.

Sunspots have been studied for centuries, but were thought to be exclusively a surface phenomenon. The researchers find that they in fact extend at least 100,000 kilometres below the Sun’s surface. "This is the first evidence that their roots go deep into the interior," says team member Alexander Kosovichev.

An examination of another sunspot by Junwei Zhao, also of Stanford, reveals magnetic field lines beneath the surface twisting around one another into bunches as the sunspot forms. "A huge amount of energy builds up in these bunches," says Zhao. When released, this would trigger a CME hurling solar material into space.

Sunspots had been observed rotating before, says Richard Nightingale, a solar physicist at Lockheed Martin in Palo Alto, California. "The coupling of above and below - that’s all new," he says.

Beneath the surface

"The interior of the Sun was simple before there were data," says Philip Scherer, who led the research. Models of the Sun’s interior assumed that buoyant hot material rose to the surface, where it was whipped up by the magnetic field lines that criss-cross the star’s exterior, forming sunspots and leading to CMEs.

Now it appears that material rising from deep within the Sun can twist magnetic field lines, giving them more energy. "Convection is being converted into magnetic fields," says Scherer.

This may produce the giant loops of overstretched magnetic fields that arch out of sunspots. The snapping of these loops releases energy, causing CMEs. Why the processes occur at specific locations is still a mystery.

The structure below the surface is currently too complicated to predict accurately, according to George Fisher, who models the Sun’s behaviour at the University of California at Berkeley. More data from sunspots may reveal patterns in the rising solar material and their interactions with magnetic field lines. "In about five years’ time we should be able to model some kind of real events," he says.

Fisher aims to use data from SOHO and future missions to model the Sun’s magnetic field completely. Then he hopes to be able to spot CMEs stirring within the Sun and to forecast the resulting weather in space.

TOM CLARKE | © Nature News Service

More articles from Physics and Astronomy:

nachricht Further Improvement of Qubit Lifetime for Quantum Computers
09.12.2016 | Forschungszentrum Jülich

nachricht Electron highway inside crystal
09.12.2016 | Julius-Maximilians-Universität Würzburg

All articles from Physics and Astronomy >>>

The most recent press releases about innovation >>>

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

Im Focus: Electron highway inside crystal

Physicists of the University of Würzburg have made an astonishing discovery in a specific type of topological insulators. The effect is due to the structure of the materials used. The researchers have now published their work in the journal Science.

Topological insulators are currently the hot topic in physics according to the newspaper Neue Zürcher Zeitung. Only a few weeks ago, their importance was...

Im Focus: Significantly more productivity in USP lasers

In recent years, lasers with ultrashort pulses (USP) down to the femtosecond range have become established on an industrial scale. They could advance some applications with the much-lauded “cold ablation” – if that meant they would then achieve more throughput. A new generation of process engineering that will address this issue in particular will be discussed at the “4th UKP Workshop – Ultrafast Laser Technology” in April 2017.

Even back in the 1990s, scientists were comparing materials processing with nanosecond, picosecond and femtosesecond pulses. The result was surprising:...

Im Focus: Shape matters when light meets atom

Mapping the interaction of a single atom with a single photon may inform design of quantum devices

Have you ever wondered how you see the world? Vision is about photons of light, which are packets of energy, interacting with the atoms or molecules in what...

Im Focus: Novel silicon etching technique crafts 3-D gradient refractive index micro-optics

A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.

Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...

Im Focus: Quantum Particles Form Droplets

In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.

“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ICTM Conference 2017: Production technology for turbomachine manufacturing of the future

16.11.2016 | Event News

Innovation Day Laser Technology – Laser Additive Manufacturing

01.11.2016 | Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

 
Latest News

Researchers identify potentially druggable mutant p53 proteins that promote cancer growth

09.12.2016 | Life Sciences

Scientists produce a new roadmap for guiding development & conservation in the Amazon

09.12.2016 | Ecology, The Environment and Conservation

Satellites, airport visibility readings shed light on troops' exposure to air pollution

09.12.2016 | Health and Medicine

VideoLinks
B2B-VideoLinks
More VideoLinks >>>