Another Solar Storm Reaches Earth; Largest Flare On Record

NOAA

Media Contact:
Barbara McGehan, NOAA Space Environment Center
(303) 497-6288,

Nov. 6, 2003

ANOTHER SOLAR STORM REACHES EARTH; LARGEST FLARE ON RECORD

Forecasters at the NOAA Space Environment Center in Boulder, Colo., say that the
coronal mass ejection, CME, associated with the huge X-28 flare that occurred on
Tuesday, reached the Earth's magnetic field Thursday afternoon at 3:37 p.m. EST.
It's the largest flare recorded by NOAA since records began in 1976. This latest
flare kicked off a geomagnetic storm at the G-1 or minor level, based on the
NOAA space weather scales that run 1 to 5.

Because the flare was nearing the western side of the sun when it erupted, the
most significant result of the flare was a total HF (high frequency) radio
blackout over the western U.S. and Pacific, which happened almost immediately on
Tuesday when the flare exploded. An associated radiation storm, S-2, or moderate
storm, seriously degraded HF communications at higher latitudes.

A minor or S-1 radiation storm was declining Thursday afternoon. NOAA space
weather forecaster Bill Murtagh said, "We were very fortunate that this storm
was directed away from the Earth. The effects could have been even stronger than
the X-17 flare that erupted on Oct. 28, which caused considerable disruption to
various technological systems around the planet."

NOAA 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. NOAA is
part of the U.S. Department of Commerce.

Relevant Web Sites

* NOAA Space Environment Center
http://sec.noaa.gov/
* NOAA Space Weather Scales
http://sec.noaa.gov/NOAAscales/
* NOAA Solar X-ray Imager -- Latest Views of the Sun
http://www.sec.noaa.gov/sxi/latest.html
* Latest SOHO images
http://sohowww.nascom.nasa.gov/data/...me-images.html

IMAGE CAPTION:
[http://www.noaanews.noaa.gov/stories...0503-1202z.jpg (33KB)]
NOAA satellite image of sun taken on Nov. 5, 2003, at 7:02 a.m. EST. Credits: NOAA

*****

ESA News
http://www.esa.int

6 November 2003

It's official: the biggest solar X-ray flare ever is classified as X28

It has just been announced that the massive solar X-ray flare which occurred on
4 November was, at best estimate, an X28. There is still a small chance this
will be revised by a small amount, but it is now official: We have a new number
1 X-ray flare for the record books, the most powerful in recorded observational
history.

On Tuesday, 4 November 2003, this flare saturated the X-ray detectors on several
monitoring satellites. The associated coronal mass ejection (CME) came out of
the Sun's surface at about 2300 kilometres per second (8.2 million km/h). Only
part of the CME is directed towards Earth, so we expect the Earth will receive
only a glancing blow, since the source region is pointing away from us on the
right on the limb of the Sun as seen from Earth.

How we classify solar flares

Scientists classify solar flares according to their brightness in the x-ray
wavelengths. There are three categories:

X-class flares are big; they are major events that can trigger radio blackouts
around the whole world and long-lasting radiation storms in the upper atmosphere.

M-class flares are medium-sized; they generally cause brief radio blackouts that
affect Earth's polar regions. Minor radiation storms sometimes follow an M-class
flare.

Compared to X- and M-class events, C-class flares are small with few noticeable
consequences here on Earth.

More about ...

* SOHO overview
http://www.esa.int/esaSC/120373_index_0_m.html

Related articles

* Safety tips for observing the Sun
http://www.esa.int/esaSC/SEMB6P7O0MD_index_0.html
* How the Sun affects us on Earth
http://www.esa.int/esaSC/SEML7BS1VED_foryou_0.html
* Space weather
http://www.esa.int/esaSC/SEMLC2T1VED_index_0.html
* What are solar flares?
http://www.esa.int/esaSC/SEMHKP7O0MD_index_0.html

Related links

* ESA's SOHO home page
http://sohowww.estec.esa.nl/
* The Sun now
http://www.esa.int/export/esaCP/ASE0...tecting_0.html

MOVIE CAPTION:
[http://www.esa.int/export/esaCP/SEM5..._index_1.html]
Just as solar scientists were ready to start breathing normally again after the
solar activity of October 2003, active region 10486 blasted off yet another
mega-flare. This one saturated the X-ray detectors on the NOAA's GOES satellites
on 4 November 2003.