Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

UCSD physicists see solar electrons, auroras associated with recent geomagnetic storms

11.12.2003


Using an orbiting camera designed to block the light from the sun and stars, an international team of solar physicists has been able for the first time to directly image clouds of electrons surrounding Earth that travel from the sun during periods of solar flare activity.



These electron clouds, a part of the solar atmosphere that extends millions of miles from the sun, cause geomagnetic storms that can disrupt communications satellites, expose high-flying aircraft to excess radiation and even damage ground-based power-generating facilities.

The images taken by this new camera, which will be discussed at a scientific session and news conference at the fall meeting in San Francisco of the American Geophysical Union, should allow space weather forecasters to substantially improve their predictions of geomagnetic storms.


"Until now, we didn’t have a good way to view the clouds of electrons that pass Earth from coronal mass ejections," said Bernard V. Jackson, a solar physicist at the University of California, San Diego. "We are living inside the solar atmosphere, but up until now had no way to view it, so space forecasters couldn’t be certain whether an ejection from the sun would affect the Earth one to five days later or harmlessly pass us by. Now that we can see these clouds as they travel through space outward from the sun, we can map their trajectories."

The orbiting camera, known as the Solar Mass Ejection Imager, was built by scientists and engineers at UCSD, the Air Force Research Laboratory, University of Birmingham in the United Kingdom, Boston College and Boston University. The instrument was launched in January by the Air Force and has provided the team of scientists with numerous images of coronal mass ejections, which can be seen in the images because of the faint scattering of sunlight from the clouds of electrons.

To the surprise of the scientists, the images also revealed the existence of high-altitude auroras, extending more than 500 miles above the Earth’s surface. Such auroras had previously been reported by space-shuttle astronauts, but their observations were questioned because air molecules were not thought to exist in sufficient quantity at that altitude to produce such light displays.

Bright auroras seen from the surface of our planet in the high northern and southern latitudes are caused by pulses of charged particles, mostly electrons, from the sun that overload the Earth’s lower radiation belt and are discharged into the atmosphere, colliding with air molecules in the atmosphere in shimmering displays of colorful light known as the northern (or southern) lights. Auroras typically extend from 60 miles above Earth’s surface to several hundred miles. But at 500 miles above the Earth’s surface, the density of air molecules is not enough to permit auroras-or so scientists have long believed.

"It’s a mystery," said Jackson of UCSD’s Center for Astrophysics and Space Sciences. "This is far higher than anyone had ever expected. It may be that nitrogen from the ionosphere is ejected into the higher altitudes during a coronal mass ejection."

The auroras were first noted by Andrew Buffington, another UCSD solar physicist, while combing through data taken by the Solar Mass Ejection Imager. In a series of image frames taken four seconds apart during a coronal mass ejection in late May, Buffington detected a bright source of light, 100 times brighter than the scattering of sunlight from the electrons. Similar sequences were seen during subsequent mass ejections by Buffington and Boston College scientists Don Mizuno and Dave Webb.

"We’ve observed high-altitude auroras during all of the coronal mass ejection events that engulfed Earth since the instrument became operational," says Jackson. "In fact, the last big event in late October had a lot of auroras associated with it. But we still don’t understand the process that is causing them."

He said researchers at the Air Force Research Laboratory are presently studying the data to come up with some possible explanations. The project was financed by the U.S. Air Force, National Aeronautics and Space Administration, National Science Foundation and the University of Birmingham.

Kim McDonald | EurekAlert!
Further information:
http://www.ucsd.edu/

More articles from Physics and Astronomy:

nachricht Quantum optics allows us to abandon expensive lasers in spectroscopy
22.11.2017 | Lomonosov Moscow State University

nachricht Nano-watch has steady hands
22.11.2017 | University of Vienna

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: Nanoparticles help with malaria diagnosis – new rapid test in development

The WHO reports an estimated 429,000 malaria deaths each year. The disease mostly affects tropical and subtropical regions and in particular the African continent. The Fraunhofer Institute for Silicate Research ISC teamed up with the Fraunhofer Institute for Molecular Biology and Applied Ecology IME and the Institute of Tropical Medicine at the University of Tübingen for a new test method to detect malaria parasites in blood. The idea of the research project “NanoFRET” is to develop a highly sensitive and reliable rapid diagnostic test so that patient treatment can begin as early as possible.

Malaria is caused by parasites transmitted by mosquito bite. The most dangerous form of malaria is malaria tropica. Left untreated, it is fatal in most cases....

Im Focus: A “cosmic snake” reveals the structure of remote galaxies

The formation of stars in distant galaxies is still largely unexplored. For the first time, astron-omers at the University of Geneva have now been able to closely observe a star system six billion light-years away. In doing so, they are confirming earlier simulations made by the University of Zurich. One special effect is made possible by the multiple reflections of images that run through the cosmos like a snake.

Today, astronomers have a pretty accurate idea of how stars were formed in the recent cosmic past. But do these laws also apply to older galaxies? For around a...

Im Focus: Visual intelligence is not the same as IQ

Just because someone is smart and well-motivated doesn't mean he or she can learn the visual skills needed to excel at tasks like matching fingerprints, interpreting medical X-rays, keeping track of aircraft on radar displays or forensic face matching.

That is the implication of a new study which shows for the first time that there is a broad range of differences in people's visual ability and that these...

Im Focus: Novel Nano-CT device creates high-resolution 3D-X-rays of tiny velvet worm legs

Computer Tomography (CT) is a standard procedure in hospitals, but so far, the technology has not been suitable for imaging extremely small objects. In PNAS, a team from the Technical University of Munich (TUM) describes a Nano-CT device that creates three-dimensional x-ray images at resolutions up to 100 nanometers. The first test application: Together with colleagues from the University of Kassel and Helmholtz-Zentrum Geesthacht the researchers analyzed the locomotory system of a velvet worm.

During a CT analysis, the object under investigation is x-rayed and a detector measures the respective amount of radiation absorbed from various angles....

Im Focus: Researchers Develop Data Bus for Quantum Computer

The quantum world is fragile; error correction codes are needed to protect the information stored in a quantum object from the deteriorating effects of noise. Quantum physicists in Innsbruck have developed a protocol to pass quantum information between differently encoded building blocks of a future quantum computer, such as processors and memories. Scientists may use this protocol in the future to build a data bus for quantum computers. The researchers have published their work in the journal Nature Communications.

Future quantum computers will be able to solve problems where conventional computers fail today. We are still far away from any large-scale implementation,...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Ecology Across Borders: International conference brings together 1,500 ecologists

15.11.2017 | Event News

Road into laboratory: Users discuss biaxial fatigue-testing for car and truck wheel

15.11.2017 | Event News

#Berlin5GWeek: The right network for Industry 4.0

30.10.2017 | Event News

 
Latest News

Corporate coworking as a driver of innovation

22.11.2017 | Business and Finance

PPPL scientists deliver new high-resolution diagnostic to national laser facility

22.11.2017 | Physics and Astronomy

Quantum optics allows us to abandon expensive lasers in spectroscopy

22.11.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>