Stormy space weather sweeping across the equator is threatening vital power grids in regions long considered safe from such events, ground-breaking new research from RMIT reveals.
The research, led by Dr Brett Carter of the RMIT SPACE Research Centre, found that these equatorial electrical disruptions threaten power grids in Southeast Asia, India, Africa and South America, where protecting electricity infrastructure from space shocks has not been a priority.
“Massive space weather events have crashed power grids across North America and Europe, but we have found that often with little warning, smaller events strike in equatorial regions more frequently than previously thought,’’ Carter said.
Together with his team from RMIT, Boston College and Dartmouth College, Carter found that areas closer to the equator experience disturbing effects on power grid infrastructure, which has largely been overlooked.
“Previous research has focused on severe geomagnetic storms, such as the 2003 Halloween storm and the March 1989 event that left millions across North America without power for up to 12 hours.
“What the historical data also shows in our study is that we don’t need huge geomagnetic storms to experience negative the effects at the equator.
“Smaller episodes can cause fluctuations in wholesale electricity prices as it can interfere with monitoring rates of supply and demand.”
The findings, published in the journal Geophysical Research Letters online, show that geomagnetic storms are amplified by the equatorial electrojet, a naturally occurring flow of current approximately 100km above the surface of the Earth.
The electrojet travels above large parts of Africa, South America, Southeast Asia and the southern tip of India.
In the report, Carter and his team examined the effects of interplanetary shocks in the solar wind, which is the stream of charged particles that flows out of the sun.
The arrival of these shocks causes a unique phenomenon in the earth’s magnetosphere and ionosphere, provoking spikes in current at the Earth’s surface.
“The Earth’s magnetic field does the job of shielding the Earth from the solar wind and when it gets hit by these shocks, you get a global magnetic signature at the ground,” Carter said.
“This magnetic signature becomes locally amplified by rapid changes in the electrojet, which increases the induced current levels in the ground near the equator.”
Carter says equatorial regions are largely unstudied and more susceptible to disruptive space weather, which should prompt scientists to examine its infrastructure and economic implications.
“It's becoming increasingly clear that we need to investigate the effects of adverse space weather in a technology-dependent society, where health and economic well-being are reliant on dependable power infrastructure.
“These countries need to consider new ways of protecting their infrastructure during geomagnetically quiet periods as well as during severe storms and scientists need to continue researching the effects these geomagnetically induce currents have on power grids, “ he said.