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".