BOULDER, Colo., Oct. 28 (UPI) -- A little before 12 o'clock noon EST on Wednesday, Earth will be buffeted by a major geomagnetic storm, one that has the potential to disrupt satellites, communications and power.
"It looks to me like it is going to be a a significant geomagnetic storm," John Kohl, a solar astrophysicist at the Harvard-Smithsonian Center for Astrophysics and principal investigator for the Ultraviolet Coronagraph Spectrometer on board NASA's Solar and Heliospheric Observatory spacecraft, told United Press International.
"The flare as measured by X-ray flux is the largest we've ever seen," he said.
Just before 6:00 a.m. EST on Tuesday, a large solar flare erupted from a sunspot, sending a coronal mass ejection directly toward Earth. "This is the strongest flare we've seen in the past 30 years," said Leon Golub, also a Harvard-Smithsonian CfA astrophysicist. The solar flare was classified as an X18-category explosion, meaning it can trigger planet-wide radio blackouts and long-lasting radiation storms.
"Shortly after this occurred, the high-energy protons starting hitting our (SOHO) instrument," Kohl said. The bombardment was so powerful, he added, "We had to turn our detectors off."
Because the event occurred in the center of the sun as it was facing toward Earth, "the Earth is essentially right on the axis of this material," Kohl said.
"Certainly this is a significant event," David Hathaway, solar physics group leader at the NASA Marshall Space Flight Center in Huntsville, Ala., told UPI. It has already produced enhanced radiation 100,000 times the background levels at the geostationary satellite orbits."
These solar storms do not threaten the health or welfare of humans on Earth, but they have in the past disrupted communications and power. Hathaway said weather and communications satellites -- such as those that handle television traffic -- are vulnerable, as are radio communications. Astronauts in the space station will be safe, he said, as long as they stay inside the station and do not undertake space walks.
In 1989, a solar storm knocked out power in Canada to hundreds of thousands of customers of Hydro-Quebec.
"Everyone points to the 1989 storm at Hydro-Quebec," Dave Fugate, president of Electric Research and Management in Pittsburgh, which operates the Sunburst Network for the Electric Power Research Institute, told UPI. "The real danger is that you lose one main thing and then it cascades," much like what happened during the recent blackout in the Northeast.
To deal with potential problems, Fugate said, utility operators "don't run things as close to the limit ... and they bring other peaking generators on line so that they have some reserves. The storm has the potential to stress the system. If they have that reserve, they can meet the stress without something tripping."
In the wake of the storms, it took Hydo-Quebec several steps to prevent a recurrence, the utility said in a statement. It recalibrated some equipment that increased the level, at which its safety system tripped.
"This measure has proved effective," the statement said. "Magnetic storms of about the same intensity as the 1989 storm have occurred since then without causing any problems."
Hydro-Quebec also suspended major switching operations during the previous magnetic storms and installed compensators on transmission lines to increase stability.
Solar "weather" impacts Earth's magnetic field, Fugate said. It induces an electrical current that flows toward Earth's surface. "Absent any man-made stuff," he continued, "these currents would still be induced to flow."
Although the solar-induced currents are DC or direct currents, they can interact with earthbound alternating or AC currents in electric grid systems that are grounded in the Earth at many points.
"The power line is a parallel path," Fugate said. "The currents will also flow on a pipeline or anything else that goes a long way."
The currents pass through electrical transformers, creating an unusual flow within the power system. "They saturate the transformers ... causing heating and harmonics and general problems because the transformer is not operating the way it is supposed to," Fugate explained.
Generally, the sun erupts into a major burst of activity every 11 years or so. The most recent "solar maximum" occurred in an unusual double peak of sunspot activity during the summer of 2001. "It's ironic," Hathaway comment. "Here we are halfway toward the solar minimum and the sun decides to act up."
He said these slightly anomalous surges of activity have attracted solar research recently. "In addition to the 11-year cycles, there appear to be shorter periods of activity with one- or two-year variations," he added.
"This activity doesn't occur typically right at the solar maximum," Kohl noted. "They occur in the declining phase right after the maximum."
The National Oceanic and Atmospheric Administration classifies geomagnetic storms on a scale from 1 to 5. Initial indications show this storm has the potential to be a category 5 storm -- the top of the scale. The most benign effect of such a storm would be bright auroras visible from more southern latitudes than usual.