A NASA scientist is launching a one-to-two-year pilot project this summer that takes advantage of US high-voltage power transmission lines to measure a phenomenon that has caused widespread power outages in the past.
Heliophysicist Antti Pulkkinen of NASA’s Goddard Space Flight Center in Greenbelt, Md. and his team are installing scientific substations beneath high-voltage power transmission lines operated by Virginia’s Dominion Virginia Power this summer to measure in real-time a phenomenon known as geomagnetically induced currents (GICs). "This is the first time we have used the U.S. high-voltage power transmission system as a science tool to map large-scale GICs," Pulkkinen said. "This application will allow unprecedented, game-changing data gathering over a wide range of spatial and temporal scales."
In addition to gathering data important to the power industry — especially if it’s expanded nationwide as currently planned — the project will allow heliophysicists to "reverse engineer" the data to learn more about the conditions in Earth’s upper atmosphere that lead to the generation of GICs during severe space weather events, Pulkkinen said, adding he is now developing computer algorithms to extract that data for scientific research. "Not only will this benefit the utility industry, it also benefits science," he said.
Solar Storms the Culprit
GICs typically occur one-to-three days after the sun unleashes a coronal mass ejection, or CME, a gigantic bubble of charged particles that can carry up to 10 billion tons of matter. CMEs can accelerate to several million miles per hour as they race across space. If a CME slams into Earth’s magnetosphere, the impact causes electromagnetic fluctuations, which result in geomagnetic storms at Earth. These storms increase electric currents that in turn, drive the fluctuations in Earth’s magnetic field near the ground. These surface currents can flow through any large-scale conductive structure, including power lines, oil and gas pipelines, undersea communications cables, telephone and telegraph networks, and railways.
An extreme example of a GIC occurrence was the great magnetic storm of March 1989 — one of the largest disturbances of the 20th century. Rapid variations in the geomagnetic field led to intensely induced electric fields at the Earth’s surface. This electric field caused electrical currents to flow through conducting structures — in this case, the Canadian Hydro-Quebec power grid. The excess current collapsed the transmission system, causing the loss of electric power to more than six million people.
According to the U.S. Geological Survey, had the blackout occurred in the Northeastern U.S., the economic impact could have exceeded $10 billion, to say nothing of the deleterious impact on emergency services and reduction in public safety.
Space weather events can have a range of effects including disrupting communications and navigation systems, damaging satellite instrumentation, and even potentially corroding pipeline steel. The impact on the nation’s electric grid is perhaps the highest concern at the moment, Pulkkinen said. "It’s the hottest topic out there right now," he said, adding that the Federal Energy Regulatory Commission is now developing standards to mitigate the GIC threat. "We need to better understand how these events affect the U.S. power grid," he added.
His pilot program is designed to help find out, Pulkkinen said.