The sun has entered a cycle of increasingly powerful flares and eruptions, catapulting to Earth high-energy particles capable of wreaking havoc on electronic and communication systems that support our high-tech civilization.
“We’re seeing so much more now, compared with the last few years,” said Ben Burress, an astronomer with the Chabot Space and Science Center in Oakland. He pointed to a satellite image that showed flares and magnetic storms roiling the sun’s surface.
“And when you have them happening five times a day, there’s a greater chance of one actually hitting us,” he said.
The powerful solar storms shift the spectacular northern lights as far south as Florida and Texas, but they also punch holes in the Earth’s protective magnetic field, which can cause health problems as well as disrupt communications. On Tuesday, radiation from a solar flare briefly interfered with shortwave radio signals, an easily affected high-frequency wave.
The disruptions are coming because the sun is entering a decadelong phase that scientists call “solar maximum.” In the midst of this phase, the sun’s magnetic field flips north to south, contributing to the solar storms that NASA says should peak in 2013 or 2014.
Solar flares typically affect radio signals on the daylight side of the planet, said Joseph Kunches, a space scientist at the Space Weather Prediction Center in Boulder, Colo.
The real danger comes when a solar storm ejects a chunk of the corona — the sun’s outermost layer — toward the Earth. It hurtles through space as a huge electrically charged cloud with its own magnetic field. Scientists call it a “coronal mass ejection.”
“That cloud of plasma is thrown off the sun like a bowling ball, and sometimes we’re at the other end of the bowling alley and it hits us,” Kunches said.
When that happens, the Earth’s magnetic field buckles and resulting magnetic storms can set off electrical surges that damage transformers and other equipment in electrical grids.
In 1989, a solar storm triggered the collapse of Canada’s Hydro-Quebec power grid, cutting power to 6 million people for as much as nine hours. That storm also knocked out a transformer at a New Jersey power plant, along with 200 other smaller disruptions in the North American power grid, according to a 2008 National Academy of Sciences report on space weather.
Other solar storm damage cited in the report:
But the “granddaddy of them all,” Kunches said, was an 1859 solar event. It blanketed the planet with stunning red, green and purple auroras so bright that people could read by them at night, according to a NASA account. The auroras, usually seen only in the upper northern latitudes, reached as far south as Hawaii and El Salvador. One early low-tech effect was disruption of telegraph systems worldwide.
A solar “superstorm” struck again in 1921 that scientists estimate was 10 times more powerful than the 1989 storm that disabled the Canadian grid.
Those storms struck the pre-electronic Earth. A repeat of it in modern times would be a “space weather Katrina,” according to the Academy of Sciences report. It estimates a severe solar storm could cause $1 trillion to $2 trillion in losses the first year, and take four to 10 years to fully recover from.
Scientists such as Kunches spend their days monitoring solar storms and other space weather through an array of satellites, and space weather forecasting is constantly advancing.
Solar flares and ejections travel the 93 million miles to the Earth in as quickly as a day, but more typically three to four days, Kunches said. Scientists can track them, though without being able to precisely detail their severity. He likened it to hurricane predictions.
Forecasting enabled electrical utilities to gird against the large 2003 solar storm, minimizing damage.
“Mother Nature’s going to do what she wants, but we’re paying attention,” Kunches said.
SEE THE SUN, CLOSE UP
Solar telescopes and other instruments for safely viewing the sun are available at the Chabot Space and Science Center in Oakland. The center also shows satellite images of solar flares, sunspots and other solar activity.
To learn more, go to www.chabotspace.org or call 510-336-7300.
