Next solar storm cycle will start late (Forwarded)

National Oceanic & Atmospheric Administration
U.S. Department of Commerce
Washington, D.C.

Media Contact:
Anatta, NOAA Research
(303) 497-6288

FOR IMMEDIATE RELEASE: April 25, 2007

NEXT SOLAR STORM CYCLE WILL START LATE

Experts Split Over Intensity

The next 11-year cycle of solar storms will most likely start next March
and peak in late 2011 or mid-2012 -- up to a year later than expected --
according to a forecast issued by the NOAA Space Environment Center in
coordination with an international panel of solar experts. The NOAA Space
Environment Center led the prediction panel and issued the forecast at its
annual Space Weather Workshop in Boulder, Colo. NASA sponsored the panel.

Expected to start last fall, the delayed onset of Solar Cycle 24 stymied
the panel and left them evenly split on whether a weak or strong period of
solar storms lies ahead, but neither group predicts a record-breaker.

During an active solar period, violent eruptions occur more often on the
sun. Solar flares and vast explosions, known as coronal mass ejections,
shoot energetic photons and highly charged matter toward Earth, jolting
the planet's ionosphere and geomagnetic field, potentially affecting power
grids, critical military and airline communications, satellites, Global
Positioning System (GPS) signals, and even threatening astronauts with
harmful radiation. These same storms illuminate night skies with brilliant
sheets of red and green known as auroras, or the northern or southern
lights.

Solar cycle intensity is measured in maximum number of sunspots -- dark
blotches on the sun that mark areas of heightened magnetic activity. The
more sunspots there are, the more likely it is that major solar storms
will occur.

In the cycle forecast issued Wednesday, half of the panel predicts a
moderately strong cycle of 140 sunspots, plus or minus 20, expected to
peak in October 2011. The other half predicts a moderately weak cycle of
90 sunspots, plus or minus 10, peaking in August 2012. An average solar
cycle ranges from 75 to 155 sunspots. The late decline of Cycle 23 has
helped shift the panel away from its earlier leaning toward a strong Cycle
24. Now the group is evenly split between strong and weak.

The first year after solar minimum, marking the end of Cycle 23, will
provide the information scientists need to arrive at a consensus. NOAA and
the panel decided to issue their best estimate now and update the forecast
as the cycle progresses, since NOAA Space Environment Center customers
have been requesting a forecast for more than a year.

"By giving a long-term outlook, we're advancing a new field -- space
climate -- that's still in its infancy," said retired Air Force Brig. Gen.
David L. Johnson, director of the NOAA National Weather Service. "Issuing
a cycle prediction of the onset this far in advance lies on the very edge
of what we know about the sun."

Scientists have issued cycle predictions only twice before. In 1989, a
panel met to predict Cycle 22, which peaked that same year. Scientists met
again in September of 1996 to predict Cycle 23 -- six months after the
cycle had begun. Both groups did better at predicting timing than
intensity, according to NOAA Space Environment Center scientist Douglas
Biesecker, who chairs the current panel. He describes the group's
confidence level as "high" for its estimate of a March 2008 onset and
"moderate" overall for the two estimates of peak sunspot number and when
those peaks would occur.

One disagreement among the current panel members centers on the importance
of magnetic fields around the sun's poles as the previous cycle decays.
End-cycle polar fields are the bedrock of the approach predicting a weak
Cycle 24. The strong-cycle forecasters place more importance on other
precursors extending over a several-cycle history. Another clue will be
whether Cycle 24 sunspots appear by mid 2008. If not, the strong-cycle
group might change its forecast.

"The panelists in each camp have clear views on why they believe in their
prediction, why they might be wrong, and what it would take to change
their minds," said Biesecker. "We're on the verge of understanding and
agreeing on which precursors are most important in predicting future solar
activity."

The NOAA Space Environment Center is the nation's first alert of solar
activity and its affects on Earth. Just as NOAA's hurricane experts
predict the upcoming season of Atlantic storms and forecast individual
hurricanes, the agency's space weather experts issue outlooks for the next
11-year solar cycle and warn of storms occurring on the sun that could
impact Earth. Both the NOAA National Hurricane Center and NOAA Space
Environment Center are among nine NOAA National Centers for Environmental
Prediction, part of the NOAA National Weather Service. The NOAA Space
Environment Center also is the world warning agency of the International
Space Environment Service, a consortium of 11 member nations.

NOAA, an agency of the U.S. Commerce Department, is celebrating 200 years
of science and service to the nation. From the establishment of the Survey
of the Coast in 1807 by Thomas Jefferson to the formation of the Weather
Bureau and the Commission of Fish and Fisheries in the 1870s, much of
America's scientific heritage is rooted in NOAA. NOAA is dedicated to
enhancing economic security and national safety through the prediction and
research of weather and climate-related events and information service
delivery for transportation, and by providing environmental stewardship of
the nation's coastal and marine resources. Through the emerging Global
Earth Observation System of Systems (GEOSS), NOAA is working with its
federal partners, more than 60 countries and the European Commission to
develop a global monitoring network that is as integrated as the planet it
observes, predicts and protects.

Relevant Web Sites:

* NOAA Solar Cycle
http://www.sec.noaa.gov/SolarCycle/
* NOAA Space Environment Center
http://www.spaceweather.noaa.gov/

IMAGE CAPTION:
[http://www.noaanews.noaa.gov/stories...olar-cycle.jpg (166KB)]
The solar cycle. Please credit "NOAA".