Space Weather and Earth: Equator Power-Grid Effects

In a kind of replaying of the theme song, "Space ghost, coast to coast," now it's: "Space weather, pole to pole, but also in the middle." While extreme space weather has long been considered a threat to electrical grids in Earth's two hemispheres, it now seems that space weather events on even a small, ghostly scale sometimes affect conditions near the equator too. This means power grids in those regions may not be as safe as previously thought.

Researchers from Boston College and elsewhere recently wrote about those findings in the journal Geophysical Research Letters. The scientists say that smaller electrical events -- caused by geomagnetically induced currents -- could be behind the scenes at the Earth's mid-section.

In the study, scientists analyzed 14 years of space and Earth data, learning that the geomagnetically induced currents are increased by the equatorial electrojet. This is a current that flows about 62 miles above the Earth's surface. The electrojet swoops along above much of Africa, South America, Southeast Asia and India's southern tip, according to a release.

They also examined interplanetary shocks of the solar wind-charged particles that flow from the Sun. The Sun's surface and its explosions can cause these shocks, although some are generated in a less violent way. When the shocks arrive on Earth, this sometimes provokes spikes in current at the Earth's surface, said a release.

In particular, when the spikes and the equatorial electrojet interact, ground-level currents near the equator increase, the release noted.

The end result? Such changes can damage power infrastructure if it's unprotected, and can cause fluctuations in wholesale electricity pricing.
"I think this is cause for a new way of looking at the impact of adverse space weather in a largely unstudied region, where health and economic well-being are increasingly reliant on dependable power infrastructure," added Brett Carter, lead author of the report, from Boston College, in the release.