"The sun generates solar flare and coronal mass ejection (CME) events in an approximate 11-year cycle. The plasma clouds generated from these events have the potential to cause geomagnetic storms that can interfere with terrestrial communications and other electronic systems, posing a risk to critical infrastructure. In a recent case, Earth-orbiting satellites detected the strongest magnetic storm in more than 4 years resulting from a solar flare and CME event. Figure 1 illustrates the size of the CME shockwave edge in relation to the size of the sun at the point of the eruption. At 0156 UT [Universal Time] on February 15, Active Region 11158 unleashed an X2-class eruption. X-flares are the largest type of X-ray flares, and this is the first such eruption of new Solar Cycle 24. The explosion that produced this flare also sent a solar tsunami rippling through the sun's atmosphere and hurled a CME toward Earth. CME activity will continue to occur as this solar cycle progresses. The purpose of this Advisory is to inform the industrial control systems (ICS) community of the possible impacts of solar magnetic storms on critical infrastructure control systems. This Advisory provides a high-level overview of the potential problems and offers some general mitigation strategies for consideration by the ICS community."
ICS-CERT Advisory No. 11-084-01
United States Computer Emergency Readiness Team: http://www.us-cert.gov/