NOAA issues space weather warning/Huge Solar Flare Spotted (Forwarded)

NOAA
Washington, D.C.

Media Contact:
Carmeyia Gillis, NOAA Space Environment Center
(301) 763-8000 ext. 7163

NOAA ISSUES SPACE WEATHER WARNING

POWERFUL SOLAR FLARE ERUPTS

KATRINA COMMUNICATIONS MAY HAVE BEEN AFFECTED

Sept. 7, 2005

Forecasters at the NOAA Space Environment Center in Boulder, Colo.,
Wednesday observed one of the largest solar flares on record at 1:40
p.m. EDT. The forecasters are predicting significant solar eruptions in
the coming days. Agencies impacted by space weather storms may
experience disruptions over the next two weeks. These include spacecraft
operations, electric power systems, high frequency communications and
low-frequency navigation systems.

The very active Region 808 produced a powerful X-17 flare (R4, severe
radio blackout, on the NOAA space weather scales), which was observed on
the NOAA GOES satellite. "This flare, the fourth largest in the last 15
years, erupted just as the Region 808 sunspot cluster was rotating onto
the visible disk of the sun," said Larry Combs, solar forecaster at the
NOAA Space Environment Center. Intense radio emissions were also
associated with this flare. A very bright and fast coronal mass ejection
was observed on coronagraph imagery. However, the material was not Earth
directed. Over the past two weeks, this active region has produced a
series of significant solar eruptions as it made its passage around the
back side of the sun with minor impacts.

"This event created a complete blackout of high frequency communications
on the daylit side of Earth, which included the entire U.S. and
basically anywhere the sun was shinning at this time," said Combs.
"Communications used by emergency services along the Gulf Coast may have
experienced problems due to this flare. Low frequency navigation systems
may also have experienced a period of significant degradation," he added.

NOAA is continuously monitoring the Earth's atmosphere -- from the sun
to the sea. Data used to provide space weather services are contributed
by NOAA, U.S. Air Force, NASA, National Science Foundation, U.S.
Geological Survey, the International Space Environment Services and
other observatories, universities and institutions.

The NOAA Space Environment Center, one of the NOAA National Centers for
Environmental Prediction, is home to the nation's early warning system
for solar activities that directly affect people and equipment on Earth
and in space. SEC's 24 hour-a-day, 7 days-a-week operations are critical
in protecting space and ground-based assets. Through the SEC, NOAA and
the U.S. Air Force jointly operate the space weather operations center
that continuously monitors, analyzes and forecasts the environment
between the sun and Earth. In addition to the data gathered from NOAA
and NASA satellites, the center receives real-time solar and geophysical
information from ground-based observatories around the world. NOAA space
weather forecasters use the data to predict solar and geomagnetic
activity and issue worldwide alerts of extreme events.

NOAA, an agency of the U.S. Department of Commerce, is dedicated to
enhancing economic security and national safety through the prediction
and research of weather and climate-related events and providing
environmental stewardship of the nation's coastal and marine resources.

Relevant Web Sites

* NOAA Space Environment Center
http://www.sec.noaa.gov/
* NOAA Space Weather Scales
http://sec.noaa.gov/NOAAscales/
* NOAA Solar X-ray Imager
http://sxi.ngdc.noaa.gov/

IMAGE CAPTION:
[http://www.noaanews.noaa.gov/stories...2005-1319z.jpg
(368KB)]
The sun from the SOHO spacecraft taken Sept. 2, 2005, at 9:19 a.m. EDT.
Credit "SOHO." To view latest images,
http://sohowww.nascom.nasa.gov/data/...me-update.html .

*****

Rachel A. Weintraub
NASA Goddard Space Flight Center September 7, 2005
Greenbelt, Md.
(Phone: 301/286-0918)

Huge Solar Flare Spotted

Scientists are currently tracking a very large flare that occurred on
the Sun around 1:40 pm EDT (17:40 UT). The current estimate of the size
of the explosion is X-17; that would place the flare as the fifth
largest ever observed.

While the blast was not aimed at Earth, the event created a complete
blackout of high frequency communications in North and South America.
According to the NOAA Space Environment Center, communications used by
emergency services along the Gulf Coast may have experienced problems
due to this flare. Low frequency navigation systems may also have
experienced a period of significant degradation. Further, they report
that agencies impacted by space weather storms may experience
disruptions over the next two weeks. These include spacecraft operators,
electric power systems, high frequency communications, and low-frequency
navigations systems.

The source of the explosion is probably the same sunspot group that
erupted in mid-August. Over the past two weeks, this active region
produced a series of significant solar eruptions as it made its way
around the back side of the Sun (facing away from Earth). More eruptions
are expected in the coming days as it rotates back into view.

Solar flares and coronal mass ejections (CMEs) -- associated giant
clouds of plasma in space -- are the largest explosions in the solar
system and can pack the force of a billion megaton nuclear bombs. They
are caused by the buildup and sudden release of magnetic stress in the
solar atmosphere above the giant magnetic poles we see as sunspots.

The NASA/ESA SOlar and Heliospheric Observatory (SOHO), missed the event
due to routine orbit maneuvers and instrument maintenance. Its
coronagraphs will be back in operation Friday morning.

More information:

* NOAA Space Weather Report
http://www.sec.noaa.gov/advisories/bulletins.html
* Understanding Space Weather Effects

http://www.nasa.gov/vision/universe/...r_feature.html

Other movies & images:

* Mauna Loa Solar Observatory
http://mlso.hao.ucar.edu/today.html
* TRACE mosaics
http://sohowww.nascom.nasa.gov/cgi-b...ynoptic+050907