Wednesday, May 07, 2008
Geomagnetic storms: Will the silicon die?
On September 1, 1859 there was a solar flare that fried telegraph wires all over the world.
Just before dawn the next day, skies all over planet Earth erupted in red, green, and purple auroras so brilliant that newspapers could be read as easily as in daylight. Indeed, stunning auroras pulsated even at near tropical latitudes over Cuba, the Bahamas, Jamaica, El Salvador, and Hawaii.
Even more disconcerting, telegraph systems worldwide went haywire. Spark discharges shocked telegraph operators and set the telegraph paper on fire. Even when telegraphers disconnected the batteries powering the lines, aurora-induced electric currents in the wires still allowed messages to be transmitted.
“What Carrington saw was a white-light solar flare—a magnetic explosion on the sun,” explains David Hathaway, solar physics team lead at NASA’s Marshall Space Flight Center in Huntsville, Alabama.
Now we know that solar flares happen frequently, especially during solar sunspot maximum. Most betray their existence by releasing X-rays (recorded by X-ray telescopes in space) and radio noise (recorded by radio telescopes in space and on Earth). In Carrington’s day, however, there were no X-ray satellites or radio telescopes. No one knew flares existed until that September morning when one super-flare produced enough light to rival the brightness of the sun itself.
“It’s rare that one can actually see the brightening of the solar surface,” says Hathaway. “It takes a lot of energy to heat up the surface of the sun!”...
“More than 35 years ago, I began drawing the attention of the space physics community to the 1859 flare and its impact on telecommunications,” says Louis J. Lanzerotti, retired Distinguished Member of Technical Staff at Bell Laboratories and current editor of the journal Space Weather. He became aware of the effects of solar geomagnetic storms on terrestrial communications when a huge solar flare on August 4, 1972, knocked out long-distance telephone communication across Illinois. That event, in fact, caused AT&T to redesign its power system for transatlantic cables. A similar flare on March 13, 1989, provoked geomagnetic storms that disrupted electric power transmission from the Hydro Québec generating station in Canada, blacking out most of the province and plunging 6 million people into darkness for 9 hours; aurora-induced power surges even melted power transformers in New Jersey. In December 2005, X-rays from another solar storm disrupted satellite-to-ground communications and Global Positioning System (GPS) navigation signals for about 10 minutes. That may not sound like much, but as Lanzerotti noted, “I would not have wanted to be on a commercial airplane being guided in for a landing by GPS or on a ship being docked by GPS during that 10 minutes.”
Another Carrington-class flare would dwarf these events. Fortunately, says Hathaway, they appear to be rare:
“In the 160-year record of geomagnetic storms, the Carrington event is the biggest.” It’s possible to delve back even farther in time by examining arctic ice. “Energetic particles leave a record in nitrates in ice cores,” he explains. “Here again the Carrington event sticks out as the biggest in 500 years and nearly twice as big as the runner-up.”
These statistics suggest that Carrington flares are once in a half-millennium events. The statistics are far from solid, however, and Hathaway cautions that we don’t understand flares well enough to rule out a repeat in our lifetime.
And what then?
Read the whole thing.
2 Comments:
By 
Escort81, at
Wed May 07, 04:22:00 PM:
Even Al Gore may not be able to save us!
Here's the last 30 years of history and data graphed for those who are interested.
In nature, it is hard to plan for or protect against the six sigma event, especially when it comes from beyond the Earth. As the quants at LTCM learned in the late 1990s looking at their screens in Greenwich, it's also hard to plan for a six sigma event in the world of finance. At least in the investment arena, all you lose is money.
Hopefully, fiber optic lines will help.
There's a good lesson in there for navigators, though -- don't rely exclusively on GPS. Old school dead reckoning works pretty well.
By 
, at
Wed May 07, 06:12:00 PM:
Seems a bit overblown re the electric grid.
I'm in the electric business and we studied closely the earlier damage to electric generators and transmission lines from solar flares and magnetic storms.
Lines that point towards the magnetic poles can pick up "earth currents" that can cause overloads. We've a satellite up to give us early warning. That will help a little.
Most problems can be eliminated by careful design and careful settings of protective devices.
We're never going to promise perfect reliability through all events but it will take a really big one to cause more than minor outages and trivial damages.
Or so we think.....
