New Solar Cycle Predictions
This plot of sunspot numbers shows the measured peak of the last solar cycle (Solar Cycle 23) in blue and the predicted peak of the next solar cycle (24) in red. Credit: NOAA/Space Weather Prediction Center.
by Tony Phillips
Boulder CO (SPX) May 28, 2009
An international panel of experts has released a new prediction for the next solar cycle, stating that Solar Cycle 24 will peak in May 2013 with a below-average number of sunspots. Led by the National Oceanic and Atmospheric Administration (NOAA) and sponsored by NASA, the panel includes a dozen members from nine different government and academic institutions.
Their forecast sets the stage for at least another year of mostly quiet conditions before solar activity resumes in earnest.
"If our prediction is correct, Solar Cycle 24 will have a peak sunspot number of 90, the lowest of any cycle since 1928 when Solar Cycle 16 peaked at 78," says panel chairman Doug Biesecker of the NOAA Space Weather Prediction Center, Boulder, Colo.
It is tempting to describe such a cycle as "weak" or "mild," but that could give the wrong impression. "Even a below-average cycle is capable of producing severe space weather," says Biesecker. "The great geomagnetic storm of 1859, for instance, occurred during a solar cycle of about the same size we're predicting for 2013."
The 1859 storm - named the "Carrington Event" after astronomer Richard Carrington who witnessed the instigating solar flare - electrified transmission cables, set fires in telegraph offices, and produced Northern Lights so bright that people could read newspapers by their red and green glow.
A recent report by the National Academy of Sciences found that if a similar storm occurred today, it could cause $1 to 2 trillion in damages to society's high-tech infrastructure and require four to ten years for complete recovery. For comparison, Hurricane Katrina caused $80 to 125 billion in damage.
The latest forecast revises a prediction issued in 2007, when a sharply divided panel believed solar minimum would come in March 2008 and would be followed by either a strong solar maximum in 2011 or a weak solar maximum in 2012. Competing models of the solar cycle produced different forecasts, and researchers were eager for the sun to reveal which was correct.
"It turns out that none of the models were really correct,"
says Dean Pesnell of the Goddard Space Flight Center, Greenbelt, Md. NASA's lead representative on the panel. "The sun is behaving in an unexpected and very interesting way."