WASHINGTON – Like "flash bulbs at a rock concert," the magnetic canopy of a sunspot exhibited some 37 hours of extreme ultraviolet eruptions this past weekend.
The area of concern is sunspot AR 1654, which had been facing away from Earth but now is turning toward it, increasing what scientists of the National Oceanographic and Atmospheric Administration call the "geo-effectiveness" of those explosions.
"This could be the sunspot that breaks the recent lengthy spell of calm space weather around our plant," according to a NOAA statement.
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Scientists said the "behemoth" sunspot AR 1654 stretches some 112,000 miles, the equivalent of 14 Earth diameters from end to end.
The flares could create M-class flares and a "risk" of X-class flares, the scientists said.
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NOAA rates the flares as A-class, followed by C, M and X, which is the most severe. A-class is the smallest and, like a Richter scale for earthquakes, each letter represents a 10-fold increase in energy output. X-class is 10 times an M-class and 100 times a C-class.
These solar flares are giant explosions on the sun's surface that send electromagnetic energy in high-speed particles into space.
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A C-class storm and smaller flares are too weak to noticeably affect Earth. M-class flares can cause brief radio blackouts at the poles and minor radiation storms that could endanger astronauts.
Read the documentation behind the worry over EMP from solar flares.
Within the X-class flares are flares more than 10 times the power of an Xi, meaning that X-class flares can go higher than 9.
According to NOAA, the most powerful flare measured with modern methods was in 2003 during the last solar maximum. It was so powerful that it overloaded the sensors measuring it. The sensors cut out at X28.
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NASA has issued repeated warnings that the sun will reach the most intense period of its 11-year cycle this year and into 2014, with the prospect of continued solar flares into 2020.
If the Earth gets a direct hit from one of these solar flares – some of which can be up to four times the size of Earth – NASA says the damage could cost the United States alone up to $2 trillion in the first year for repairs.
It also could take four to 10 years to recover and could affect the lives of more than 160 million people.
By "affect," scientists say they mean put in the position of being threatened with death.
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They say they would expect many casualties because of America's dependence on electric power, electronics and digital telecommunications and information networks.
Further, there are thousands of so-called SCADAs – Supervisory Control and Data Acquisition Data systems, or automated control systems – which control large sections of industry and commerce.
All of these systems are vulnerable to an electromagnetic pulse, or EMP, a high-intensity burst of electromagnetic energy of which solar flares is but one source. Another source would be from a high-altitude nuclear explosion.
Other forms of electromagnetic energy include gamma rays, X-rays, ultraviolet radiation, visible light, infrared radiation, microwaves and radio waves.
SCADAs are referred to as the "ubiquitous robots of the modern age" and are vital to the interdependence of the critical infrastructures that comprise modern society.
According to the congressionally mandated 2008 EMP commission, these automated control systems and their mutual interdependence are two of the most important aspects of America's modern infrastructures. They pose the greatest vulnerability in all of the country’s infrastructures.
The SCADA systems are especially used in such critical infrastructure applications as electrical transmission and distribution, water management, and oil and gas pipelines.
America is crisscrossed with thousands of miles of pipelines, and if a SCADA were to fail, it could cause explosions in natural gas pipelines and serious leakage.
In November 1999, for example, the San Diego County Water Authority and San Diego Gas and Electric companies experienced a severe electromagnetic interference to their SCADA wireless networks.
Both companies were unable to operate critical valve openings and closings under remote control.
The episode prompted technicians to go to remote locations to manually open and close the water and natural gas values. If that had not been done, there could have been a "catastrophic failure" of the water system, according to a letter of complaint at the time by the San Diego County Water Authority to the Federal Communications Commission.
Not only are SCADA systems important to natural gas companies to monitor and control the flow volume in a gas pipeline, but they also are critical in measuring the temperature in nuclear power plants, sending an alarm when it exceeds normal operating conditions.
In the San Diego water case, the danger was that some 825 million gallons of water flowing daily would have been released by a ruptured line, causing severe flooding and serious damage and destruction to property.
After an extensive investigation, it was determined that the SCADA failure was caused by the radar of a ship some 25 miles off the coast of San Diego.
Read the documentation behind the worry over EMP attacks, both natural and man-made.