8, 2009: A new active period of Earth-threatening solar
storms will be the weakest since 1928 and its peak is still four
years away, after a slow start last December, predicts an international
panel of experts led by NOAA's Space Weather Prediction Center.
Even so, Earth could get hit by a devastating solar storm at any
time, with potential damages from the most severe level of storm
exceeding $1 trillion. NASA funds the prediction panel.
storms are eruptions of energy and matter that escape from the sun
and may head toward Earth, where even a weak storm can damage satellites
and power grids, disrupting communications, the electric power supply
and GPS. A single strong blast of solar wind can threaten national
security, transportation, financial services and other essential
panel predicts the upcoming Solar Cycle 24 will peak in
May 2013 with a daily sunspot number of 90. If the prediction
proves true, Solar Cycle 24 will be the weakest cycle since number
16, which peaked at 78 daily sunspots in 1928, and ninth weakest
since the 1750s, when numbered cycles began.
most common measure of a solar cycle’s intensity is the number of
sunspots—Earth-sized blotches on the sun marking areas of heightened
magnetic activity. The more sunspots there are, the more likely
it is that solar storms will occur, but a major storm can occur
at any time.
with hurricanes, whether a cycle is active or weak refers to the
number of storms, but everyone needs to remember it only takes one
powerful storm to cause expensive problems," said NOAA scientist
Doug Biesecker, who chairs the panel. "The strongest solar
storm on record occurred in 1859 during another below-average cycle
similar to the one we are predicting."
1859 storm shorted out telegraph wires, causing fires in North America
and Europe, sent readings of Earth's magnetic field soaring, and
produced northern lights so bright that people read newspapers by
report by the National Academy of Sciences found that if a storm
that severe occurred today, it could cause $1-2 trillion in damages
the first year and require four to ten years for recovery, compared
to $80-125 billion that resulted from Hurricane Katrina.
panel also predicted that the lowest sunspot number between
cycles—or solar minimum—occurred in December 2008, marking the end
of Cycle 23 and the start of Cycle 24. If the December prediction
holds up, at 12 years and seven months Solar Cycle 23 will be the
longest since 1823 and the third longest since 1755. Solar cycles
span 11 years on average, from minimum to minimum.
unusually long, deep lull in sunspots led the panel to revise its
2007 prediction that the next cycle of solar storms would start
in March 2008 and peak in late 2011 or mid-2012. The persistence
of a quiet sun since the last prediction has led the panel to a
consensus that the next cycle will be "moderately weak."
Space Weather Prediction Center (SWPC) is the nation's first alert
of solar activity and its effects on Earth. The Center'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. SWPC is
also the world warning agency for the International Space Environment
Service, a consortium of 12 member nations.
the world economy becomes more reliant on satellite-based communications
and interlinked power grids, interest in solar activity has grown
dramatically. In 2008 alone, SWPC acquired 1,700 new subscription
customers for warnings, alerts, reports, and other products. Among
the new customers are emergency managers, airlines, state transportation
departments, oil companies, and nuclear power stations. SWPC's customers
reside in 150 countries.
customer growth reflects today’s reality that all sectors of society
are highly dependent on advanced, space-based technologies,"
said SWPC director Tom Bogdan. "Today every hiccup from the
sun aimed at Earth has potential consequences."
-- daily predictions of space weather issued in language lay
people can understand