As Earth’s Magnetic Field Weakens, the Northern Lights will Push Farther South

The Aurora Borealis, also commonly known as the Northern Lights, are an atmospheric phenomenon caused by the interaction of charged particles emitted from the sun that interact with various gasses in Earth’s atmosphere, creating beautiful and mesmerizing displays. Typically, these aurora are confined to regions close to the poles, due to the charged particle’s interaction with Earth’s magnetic field, but a new study says that the display may push farther south in the near future.

The study, conducted at Columbia University’s Lamont-Doherty Earth Observatory, says that as Earth’s magnetic field weakens, the stream of the sun’s particles will be confined less and less to northern latitudes, and in time the aurora may be witnessed as far south as the southern United States.

“The Earth’s magnetic field more or less keeps the solar wind at bay, and it’s the solar wind interacting with the field that contributes to the auroras,” says Dennis Kent, a paleomagnetism expert at Columbia. “With a strong field, that interaction is pushed to high latitudes. With a weaker field more of the Earth is bathed in these charged particles. So a consequence would be that the aurora would be visible at lower latitudes.”

Kent is co-author of a recently published paper that studies how Earth’s magnetic field is in the process of weakening, having dropped by roughly ten percent over the past two centuries. The study suggests that the field has been abnormally strong, and is currently declining to it’s historically average levels. The study also looks at the phenomenon of the poles periodically reversing themselves, where the north and south poles swap polarities, as evidenced in the orientation of the magnetic fields found in subsurface rocks.