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Powerful Solar Storm Could Shut Down U.S.
for Months
A new study from the National Academy of Sciences outlines grim possibilities on Earth for a worst-case scenario solar storm.
Damage to power grids and other communications systems could be catastrophic, the scientists conclude, with effects leading to a potential loss of governmental control of the situation.
The prediction is based in part on a
major solar storm in 1859 that caused telegraph wires to short out in the United States and Europe, igniting widespread fires.
It was perhaps the worst in the past 200 years, according to the new study, and with the advent of modern power grids and satellites, much more is at risk.
"A contemporary repetition of the [1859] event would cause significantly more extensive (and possibly catastrophic) social and economic disruptions," the researchers conclude.
When the sun is in the active phase of its 11-year cycle, it can unleash
powerful magnetic storms that disable satellites, threaten astronaut safety, and even disrupt communication systems on Earth.
The worst storms can knock out power grids by inducing currents that melt transformers.
Modern power grids are so interconnected that a big space storm — the type expected to occur about once a century — could
cause a cascade of failures that would sweep across the United States, cutting power to 130 million people or more in this country alone, the new report concludes.
Such widespread power outages, though expected to be a rare possibility, would affect other vital systems.
"Impacts would be felt on interdependent infrastructures with, for example, potable water distribution affected within several hours; perishable foods and medications lost in 12-24 hours; immediate or eventual loss of heating/air conditioning, sewage disposal, phone service, transportation, fuel resupply and so on," the report states.
Outages could take months to fix, the researchers say. Banks might close, and trade with other countries might halt.
"Emergency services would be strained, and command and control might be lost," write the researchers, led by Daniel Baker, director of the Laboratory for Atmospheric and Space Physics at the University of Colorado in Boulder.
"Whether it is terrestrial catastrophes or extreme space weather incidents, the results can be devastating to modern societies that depend in a myriad of ways on advanced technological systems," Baker said in a statement released with the report.
Stormy past
Solar storms have had significant effects in modern time:
— In 1989, the sun unleashed a tempest that knocked out power to all of Quebec, Canada.
— A
remarkable 2003 rampage included 10 major solar flares over a two-week period, knocking out two Earth-orbiting satellites and crippling an instrument aboard a Mars orbiter.
"Obviously, the sun is Earth's life blood," said Richard Fisher, director of the Heliophysics division at NASA. "To mitigate possible public safety issues, it is vital that we better understand extreme space weather events caused by the sun's activity."
"Space weather can produce solar storm electromagnetic fields that induce extreme currents in wires, disrupting power lines, causing wide-spread blackouts and affecting communication cables that support the Internet," the report states. "Severe space weather also produces solar energetic particles and the dislocation of the Earth's radiation belts, which can damage satellites used for commercial communications, global positioning and weather forecasting."
Rush to prepare
The race is on for better forecasting abilities, as the next peak in solar activity is expected to come around 2012.
While the sun is in a lull now, activity can flare up at any moment, and severe space weather — how severe, nobody knows — will ramp up a year or two before the peak.
Some scientists expect the next peak to bring more severe events than other recent peaks.
"A catastrophic failure of commercial and government infrastructure in space and on the ground can be mitigated through raising public awareness, improving vulnerable infrastructure and developing advanced forecasting capabilities," the report states. "Without preventive actions or plans, the trend of increased dependency on modern space-weather sensitive assets could make society more vulnerable in the future."
The report was commissioned and funded by NASA. Experts from around the world in industry, government and academia participated. It was released this week.
Copyright © 2009 Imaginova Corp. All Rights Reserved. This material
may not be published, broadcast, rewritten or redistributed.
المصدر
روابط أخرى عن نفس الموضوع:
وقد أصدرت وكالة ناسا خبرا حول تلك العاصفة في عام 2006 هذا نصه من موقع ناسا الرئيسي:
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March 10, 2006: It's official: Solar minimum has arrived. Sunspots have all but vanished. Solar flares are nonexistent. The sun is utterly quiet.
Like the quiet before a storm.
This week researchers announced that a storm is coming--the most intense solar maximum in fifty years. The prediction comes from a team led by Mausumi Dikpati of the National Center for Atmospheric Research (NCAR). "The next sunspot cycle will be 30% to 50% stronger than the previous one," she says. If correct, the years ahead could produce a burst of solar activity second only to the historic Solar Max of 1958.
 That was a solar maximum. The Space Age was just beginning: Sputnik was launched in Oct. 1957 and Explorer 1 (the first US satellite) in Jan. 1958. In 1958 you couldn't tell that a solar storm was underway by looking at the bars on your cell phone; cell phones didn't exist. Even so, people knew something big was happening when Northern Lights were sighted three times in Mexico. A similar maximum now would be noticed by its effect on cell phones, GPS, weather satellites and many other modern technologies.
Right: Intense auroras over Fairbanks, Alaska, in 1958. [More]
Dikpati's prediction is unprecedented. In nearly-two centuries since the 11-year sunspot cycle was discovered, scientists have struggled to predict the size of future maxima—and failed. Solar maxima can be intense, as in 1958, or barely detectable, as in 1805, obeying no obvious pattern.
The key to the mystery, Dikpati realized years ago, is a conveyor belt on the sun.
We have something similar here on Earth—the Great Ocean Conveyor Belt, popularized in the sci-fi movie The Day After Tomorrow. It is a network of currents that carry water and heat from ocean to ocean--see the diagram below. In the movie, the Conveyor Belt stopped and threw the world's weather into chaos.
 Above: Earth's "Great Ocean Conveyor Belt." [More]
The sun's conveyor belt is a current, not of water, but of electrically-conducting gas. It flows in a loop from the sun's equator to the poles and back again. Just as the Great Ocean Conveyor Belt controls weather on Earth, this solar conveyor belt controls weather on the sun. Specifically, it controls the sunspot cycle.
Solar physicist David Hathaway of the National Space Science & Technology Center (NSSTC) explains: "First, remember what sunspots are--tangled knots of magnetism generated by the sun's inner dynamo. A typical sunspot exists for just a few weeks. Then it decays, leaving behind a 'corpse' of weak magnetic fields."
Enter the conveyor belt.
 "The top of the conveyor belt skims the surface of the sun, sweeping up the magnetic fields of old, dead sunspots. The 'corpses' are dragged down at the poles to a depth of 200,000 km where the sun's magnetic dynamo can amplify them. Once the corpses (magnetic knots) are reincarnated (amplified), they become buoyant and float back to the surface." Presto—new sunspots!All this happens with massive slowness. "It takes about 40 years for the belt to complete one loop," says Hathaway. The speed varies "anywhere from a 50-year pace (slow) to a 30-year pace (fast)."
When the belt is turning "fast," it means that lots of magnetic fields are being swept up, and that a future sunspot cycle is going to be intense. This is a basis for forecasting: "The belt was turning fast in 1986-1996," says Hathaway. "Old magnetic fields swept up then should re-appear as big sunspots in 2010-2011."
Like most experts in the field, Hathaway has confidence in the conveyor belt model and agrees with Dikpati that the next solar maximum should be a doozy. But he disagrees with one point. Dikpati's forecast puts Solar Max at 2012. Hathaway believes it will arrive sooner, in 2010 or 2011.
"History shows that big sunspot cycles 'ramp up' faster than small ones," he says. "I expect to see the first sunspots of the next cycle appear in late 2006 or 2007—and Solar Max to be underway by 2010 or 2011."
Who's right? Time will tell. Either way, a storm is coming.
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01-15-2009, 03:04 PM
عاصفة شمسية متوقعة عام 2012 قد تتسبب في كوارث عظيمة للكرة الأرضية
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