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GCN : June 2014
IT'S ONE OF THOSE in- stances where the interests of science, business and the public all meet. Researchers at NASA s Goddard Space Flight Center have been given access to Dominion Virginia Power transmission power lines in order to mea- sure fluctuations in geomag- netically induced currents, or GICs. "In a worst-case scenario, when we have these coronal mass ejections where billions of tons of charged particles are hurled right at us, when these things blow through our magnetosphere it induces currents in our ionosphere," said NASA s Todd Bonalsky, an engineer working on the project. "As a result, we get sheets of very large currents, thousands of amps that run through our upper atmo- sphere. That, in turn, will induce currents in anything conductive on the ground, like high-tension wires and pipes." Why is the power company interested? Because GICs can cause circuit overloads and, if the surge is enough, power outages. "That is pretty much the interest that the power-grid people have and obviously the public in general; we don t like to have our power go out," said Bonalsky. And what s in it for NASA? "For space weather scien- tists here, the power grid can o er us a very large antenna so we can indirectly measure space weather events in the upper atmosphere," Bonalsky said. And for the economy and the general public, the stakes are not small. After a huge magnetic storm struck in Canada in March 1989, the U.S. Geological Survey estimated that if the storm had hit the northeastern United States, the economic cost would have been more than $10 billion, not count- ing the impact on emergency services and public safety. Since GICs reach the Earth one to three days after a coronal mass ejection on the sun, there is, in principle, time for power companies to take measures to protect against the coming power surges. The problem, howev- er, is predicting the location on Earth of strongest impact of an approaching GIC. "It s a very complicated process where charged par- ticles get trapped in our mag- netosphere and are funneled around," Bonalsky said. "Magnetic field lines can stretch around either side of the planet and reconnect on the other side, and when they do they give o an extreme amount of energy as the lines reconnect and snap back to the poles of the earth. Depending on the angle that they come in at, there are so many di erent variations of what can happen," he said. The goal of the Goddard GIC project is to better understand how those processes work. The project, headed by heliophysicist Antti Pulkkinen, is funded by NASA s Center Innovation Fund and Goddard s Internal Research and Development (IRAD) program. Pulkkinen s team is creat- ing three monitoring stations equipped with commercially available magnetometers. Two of the magnetometers are buried four feet directly beneath power lines to mea- sure the e ect of GICs on the current. The third magne- tometer is being placed away from power lines and other conductors to serve as a reference control. According to Bonalsky, the data from the magnetometer is relayed to an iPad station, equipped with a solar panel for power, about 25 feet away. "We do that for magnetic cleanliness reasons," he ex- plained. "We re looking at fields down to a few parts per million." Since there isn t re- liable wireless connectivity in the remote locations, data is transmitted via text messages over the cellular network. "It s a bit of an engineer- ing challenge, because these are unmanned stations," said Bonalsky. "We re just ready now to start installing them in the field." The initial funding of the project is only for one year, and the impromptu antenna it is creating only covers a few kilometers. But the team has hopes of expanding after the results from measure- ments made this summer prove their worth. According to Bonalsky, a larger network of monitors will deliver better data. "The better the coverage, the more area we can see, the higher the resolution that we can get about what s going on in the upper atmosphere," he said. "The idea is to put as many of the stations all over as we can so that we can utilize es- sentially the entire grid." • Can NASA help keep the lights on? BY PATRICK MARSHALL EMERGING TECH 34 GCN JUNE 2014 • GCN.COM Geomagnetically induced currents--- generated when solar events send waves of charged particles toward Earth---can cause circuit overloads and, if the surge is enough, power outages.