[OKDXA] NOAA Predicts Solar Cycle 24

[N5PA]

NOAA Predicts Solar Cycle 24

 

May 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.

Solar 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 functions.

The panel predicts the upcoming Solar Cycle 24 will peak in May 2013 with 90
sunspots per day, averaged over a month. 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.

The 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.

"As 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."

The 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 their light.

A recent 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.

The 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.

An 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."

NOAA's 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.

As 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.

"Our 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."