2012: Could solar “Katrina” take down the grid?

File this one under low probability high impact events. But if it happens, it could be the solar equivalent of the perfect storm.

Scientists at NASA and elsewhere are increasingly concerned about the potential for a massive solar "mega-storm" that could disrupt power grids in the U.S. and elsewhere.

Solar cycle 24 is headed for a peak sometime in 2011 or 2012, and some forecasters believe there is historical precedent for gigantic coronal mass (CME) ejections that could take down power grids here on earth.

NASA is getting ready.

"Every hundred years or so, a solar storm comes along so potent it fills the skies of Earth with blood-red auroras, makes compass needles point in the wrong direction, and sends electric currents coursing through the planet's topsoil. The most famous such storm, the Carrington Event of 1859, actually shocked telegraph operators and set some of their offices on fire. A 2008 report by the National Academy of Sciences warns that if such a storm occurred today, we could experience widespread power blackouts with permanent damage to many key transformers."

Another massive solar flare in 1989 provoked geomagnetic storms that disrupted electric power transmission from the Hydro Quebec generating station in Canada, blacking out most of the province and plunging 6 million people into darkness for 9 hours.

If it happened in the past we know it can happen again in the future. The question this time is, what will happen if such an extreme event strikes today's aging North American power grid?

A modern solar flare recorded Dec. 5, 2006, by the X-ray Imager onboard NOAA's GOES-13 satellite. The flare was so intense, it actually damaged the instrument that took the picture. Researchers believe Carrington's flare was much more energetic than this one.

Not taking any chances.

The so called "Solar Shield" project is designed to issue warnings to electric utilities when massive solar storms are racing earthward.

"Solar Shield springs into action when we see a coronal mass ejection (CME) billowing away from the sun. Images from SOHO and NASA's twin STEREO spacecraft show us the cloud from as many as three points of view, allowing us to make a 3D model of the CME, and predict when it will arrive."

While the CME is crossing the sun-Earth divide, a trip that typically takes 24 to 48 hours, the Solar Shield team prepares to calculate ground currents. "We work at Goddard's Community Coordinated Modeling Center (CCMC)," says Pulkkinen. The CCMC is a place where leading researchers from around the world have gathered their best physics-based computer programs for modeling space weather events. The crucial moment comes about 30 minutes before impact when the cloud sweeps past ACE, a spacecraft stationed 1.5 million km upstream from Earth. Sensors onboard ACE make in situ measurements of the CME's speed, density, and magnetic field. These data are transmitted to Earth and the waiting Solar Shield team.

No one knows for sure if the dreaded "kill shot" could be unleashed in 2012. But the sun will be watched closely for the potential of a rare but devastating solar storm that could drastically change life here on earth for a period of days, weeks or longer.

PH