New Sun Cycle Raises Risk of Disruptive Solar Storms

The sunspot in the Sun's Northern Hemisphere appeared Thursday, NOAA scientists said. A sunspot is an area of highly organized magnetic activity on the surface of the Sun.

"This sunspot is like the first robin of spring," said solar physicist Douglas Biesecker of NOAA's Space Weather Prediction Center in Boulder. "In this case, it's an early omen of solar storms that will gradually increase over the next few years."

The new 11 year cycle, called Solar Cycle 24, is expected to build gradually, with the number of sunspots and solar storms reaching a maximum by 2011 or 2012, though devastating solar storms can occur at any time.

The new sunspot is located in the Sun's Northern Hemisphere. (Image courtesy Mauna Loa Solar Observatory.

The new sunspot, identified as #10,981, is the latest visible spot to appear since NOAA began numbering them on January 5, 1972. Its high-latitude location at 27 degrees North, and its negative polarity leading to the right in the Northern Hemisphere are clear-cut signs of a new solar cycle, according to NOAA experts.

The first active regions and sunspots of a new solar cycle can emerge at high latitudes while those from the previous cycle continue to form closer to the equator.

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. This magnetically charged material may disrupt satellites, threaten astronauts with harmful radiation, and interfere with power grids, communications, and Global Positioning System, GPS, signals, on Earth.

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.

"Our growing dependence on highly sophisticated, space-based technologies means we are far more vulnerable to space weather today than in the past," said NOAA administrator Conrad C. Lautenbacher, Jr. "NOAA's space weather monitoring and forecasts are critical for the nation's ability to function smoothly during solar disturbances."

Earth's electricity transmission lines are at risk of solar storms. (Photo by Warren Gretz courtesy NREL)

Last April, in coordination with an international panel of solar experts, NOAA issued a forecast that Solar Cycle 24 would start in March 2008, plus or minus six months.

The panel was evenly split between those predicting a strong or weak cycle. Both camps agree that the sooner the new cycle takes over the waning previous cycle, the more likely that it will be a strong season with many sunspots and major storms, said Biesecker, who chairs the current panel..

Many more sunspots with Solar Cycle 24 traits must emerge before scientists consider the new cycle dominant, with the potential for more frequent storms.

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 Biesecker.

The Space Weather Prediction Center is the nation's first alert for solar activity and its effects on Earth. The center's forecasters issue outlooks for the next 11-year solar "season" and warn of individual storms occurring on the Sun that could impact Earth.

The Space Weather Prediction Center is one of NOAA's nine National Centers for Environmental Prediction and is also the warning agency of the International Space Environment Service, a consortium of 11 member nations.

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