Featured Research

from universities, journals, and other organizations

Solar Structures Can Help Forecast Largest Solar Blasts

Date:
March 10, 1999
Source:
National Aeronautics And Space Administration
Summary:
"S" marks the spot for scientists trying to forecast solar eruptions that can damage satellites, disrupt communications networks and cause power outages. Using the Japanese Yohkoh spacecraft, NASA-sponsored scientists have discovered that an S-shaped structure often appears on the Sun in advance of a violent eruption, called a coronal mass ejection, that is as powerful as billions of nuclear explosions.

"S" marks the spot for scientists trying to forecast solar eruptions that can damage satellites, disrupt communications networks and cause power outages.

Using the Japanese Yohkoh spacecraft, NASA-sponsored scientists have discovered that an S-shaped structure often appears on the Sun in advance of a violent eruption, called a coronal mass ejection, that is as powerful as billions of nuclear explosions.

"Early warnings of approaching solar storms could prove useful to power companies, the communications industry and organizations that operate spacecraft, including NASA," said Dr. George Withbroe, science director for Sun-Earth Connection research at NASA Headquarters. "This is a major step forward in understanding these tremendous storms."

"S marks the spot," said Dr. Alphonse Sterling of Computational Physics, Inc., Fairfax, VA, detailed to the Institute of Space and Astronautical Science (ISAS), Japan. "We have found a strong correlation between an S-shaped pattern on the Sun, called a sigmoid, and the likelihood that an ejection will occur from that region within days. Each sigmoid is like a loaded gun that we now know has a high probability of going off."

"The S-shaped regions are the dangerous ones," said Dr. Richard Canfield, a research professor of physics at Montana State University-Bozeman, and lead author on a paper to be published in the March 15 issue of Geophysical Research Letters. "As soon as we can recognize an S-shaped region, we know that it is more likely to erupt. Other common structures look like a butterfly, quite symmetric, and these rarely erupt."

The sigmoid structures are likely the result of twisted solar magnetic fields, said Dr. Sarah Gibson of the University of Cambridge, UK. "The key to the coronal mass ejection is its magnetic field, which can structure and propel the mass outward," said Gibson.

Coronal mass ejections are violent discharges of electrically charged gas from the Sun's corona, or outer atmosphere. The largest explosions in the solar system, they hurl up to 10 billion tons of gas into space at speeds of one to two million miles an hour. The outbursts occur several times a day, but not all are hurled toward Earth.

Images from various spacecraft have provided often spectacular images and information after a coronal mass ejection had already erupted, but scientists have been trying for some time to identify a precursor for these events. Sterling and Dr. Hugh Hudson of the Solar Physics Research Corporation, Tucson, AZ, working at ISAS, first observed a relationship between a sigmoid shape before a coronal mass ejection, and an arch-shape afterwards. Later, Hudson and others found the same pattern in several other ejections.

That finding prompted Canfield, Hudson and Dr. David McKenzie, a research scientist at Montana State University, to look for a statistical correlation between the sigmoid shape and subsequent eruptions. They viewed a total of two years of daily X-ray images from the Japanese/US/UK Soft X-ray Telescope on Yohkoh. The composite pictures -- 50 images each day -- were made into movies for analysis.

"We need to get past simple classifications such as, 'Is it sigmoidal or not, is the sunspot big or small,' and get to quantitative measurements that answer, 'how twisted are the magnetic fields, how big is the spot'," Canfield said. "As well, we want to know in which direction the ejection is going to go and how many regions are likely to erupt."

Ultimately, Canfield continued, the National Oceanic and Atmospheric Administration (NOAA) may be able to include warnings of coronal mass ejections in its space weather forecasts. NOAA is building a Solar X-ray Imager similar to that on Yohkoh, scheduled for launch next year, he said.

- end -

NOTE TO EDITORS: Images and supporting material can be found on the Internet at:

http://solar.physics.montana.edu/press/ FTP://PAO.GSFC.NASA.GOV/newsmedia/CME http://www.isas.ac.jp/info/sat/yohkoh-e.html#Tag:0 http://solar.physics.montana.edu/YPOP/


Story Source:

The above story is based on materials provided by National Aeronautics And Space Administration. Note: Materials may be edited for content and length.


Cite This Page:

National Aeronautics And Space Administration. "Solar Structures Can Help Forecast Largest Solar Blasts." ScienceDaily. ScienceDaily, 10 March 1999. <www.sciencedaily.com/releases/1999/03/990310054714.htm>.
National Aeronautics And Space Administration. (1999, March 10). Solar Structures Can Help Forecast Largest Solar Blasts. ScienceDaily. Retrieved September 14, 2014 from www.sciencedaily.com/releases/1999/03/990310054714.htm
National Aeronautics And Space Administration. "Solar Structures Can Help Forecast Largest Solar Blasts." ScienceDaily. www.sciencedaily.com/releases/1999/03/990310054714.htm (accessed September 14, 2014).

Share This



More Space & Time News

Sunday, September 14, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

SpaceX's Elon Musk Really Wants To Colonize Mars

SpaceX's Elon Musk Really Wants To Colonize Mars

Newsy (Sep. 14, 2014) Elon Musk has been talking about his goal of colonizing Mars for years now, but how much of it does he actually have figured out, and is it possible? Video provided by Newsy
Powered by NewsLook.com
International Space Station Crew Returns Safely To Earth

International Space Station Crew Returns Safely To Earth

Newsy (Sep. 11, 2014) The three-man crew touched down in Kazakhstan Wednesday after more than five months of science experiments in orbit. Video provided by Newsy
Powered by NewsLook.com
Solar Storm To Hit This Weekend, Scientists Not Worried

Solar Storm To Hit This Weekend, Scientists Not Worried

Newsy (Sep. 11, 2014) Two solar flares which erupted in our direction this week will arrive this weekend. The resulting solar storm will be powerful but not dangerous. Video provided by Newsy
Powered by NewsLook.com
Solar Flare Surges Off Sun

Solar Flare Surges Off Sun

Reuters - US Online Video (Sep. 11, 2014) NASA captures video of a significant flare surging off the sun. Jillian Kitchener reports. Video provided by Reuters
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:
from the past week

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