Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Surprises from the Sun’s South Pole

20.02.2007
Although very close to the minimum of its 11-year sunspot cycle, the Sun showed that it is still capable of producing a series of remarkably energetic outbursts - ESA-NASA Ulysses mission revealed.

In keeping with the first and second south polar passes (in 1994 and 2000), the latest high-latitude excursion of the joint ESA-NASA Ulysses mission has already produced some surprises. In mid-December 2006, although very close to the minimum of its 11-year sunspot cycle, the Sun showed that it is still capable of producing a series of remarkably energetic outbursts.

The solar storms, which were confined to the equatorial regions, produced quite intense bursts of particle radiation that were clearly observed by near-Earth satellites. Surprisingly, similar increases in radiation were detected by the instruments on board Ulysses, even though it was three times as far away and almost over the south solar pole. "Particle events of this kind were seen during the second polar passes in 2000 and 2001, at solar maximum," said Richard Marsden, ESA's Ulysses Project Scientist and Mission Manager. "We certainly didn't expect to see them at high latitudes at solar minimum!"

Scientists are busy trying to understand how the charged particles made it all the way to the poles. "Charged particles have to follow magnetic field lines, and the magnetic field pattern of the Sun near solar minimum ought to make it much more difficult for the particles to move in latitude," said Marsden.

One of the puzzles remaining from the first high-latitude passes in 1994 and 1995 has to do with the temperature of the Sun's poles. When Ulysses first passed over the south and then the north solar pole near solar minimum, it measured the temperatures of the large polar coronal holes.

"Surprisingly, the temperature in the north polar coronal hole was about 7 to 8 percent lower compared with the south polar coronal hole," said Professor George Gloeckler, Principal Investigator for the Solar Wind Ion Composition Spectrometer (SWICS) on board Ulysses.

"We couldn't tell then whether this was simply due to progressive cooling of both polar coronal holes as the Sun was approaching its minimum level of activity in 1996, or whether this was an indication of a permanently cooler north pole."

Now, as Ulysses again passes over the large polar coronal holes of the Sun at solar minimum we will finally have the answer. Recent SWICS observations show that the average temperature of the southern polar coronal hole at the current solar minimum is as low as it was 10 years ago in the northern polar coronal hole. "This implies that the asymmetry between north and south has switched with the change of the magnetic polarity of the Sun," said Gloeckler. The definitive proof will come when Ulysses measures the temperature of the north polar coronal during the next 15 months.

Richard Marsden | alfa
Further information:
http://www.esa.int/esaSC/SEMB3KBE8YE_index_0.html

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 >>>