The Northern Lights are recognized as one of the world’s most spectacular natural occurrences. Created by the Earth’s interaction with the sun, the Northern Lights see the night sky light up in a panoply of brilliant colors. With aurora tourism becoming increasingly popular and visitors from around the world heading to the Arctic Circle every year to witness the Northern Lights, some may be wondering what role, if any, the North Pole has in creating auroras.
Auroras typically only occur around the North and South Poles due to the nature of Earth’s magnetic field. Read on to learn about the connection between the North Pole and the Northern Lights.
The North Pole and the Northern Lights
As mentioned above, the Northern Lights are created by interactions between the Earth and the sun. Most people know that the sun’s light is what makes life on Earth possible, but few know that the sun also gives off harmful radiation in the form of solar wind. Earth is protected from solar wind by the magnetosphere, an invisible barrier that surrounds the planet and is created by Earth’s magnetic field. The magnetosphere deflects or neutralizes solar wind before it can reach the Earth’s surface, keeping the planet safe.
The vast majority of the magnetosphere is located in outer space, far away from the planet itself. However, because the North and South Poles are the source of the magnetic field, the magnetosphere intersects with the atmosphere at these locations. When the charged particles that comprise solar wind impact the atmosphere in these places, it creates the Northern Lights.
All matter is made up of atoms, and atoms themselves are made up of three types of particles: protons, neutrons, and electrons. At the core of an atom is the nucleus, which contains protons (which have a positive electrical charge) and neutrons (which have no charge). Electrons (which have a negative charge) orbit the nucleus in a fashion similar to how the moon orbits the Earth or the Earth orbits the sun.
When charged particles from solar wind impact atoms in the atmosphere, those atoms become excited, meaning that their electrons migrate to higher-energy orbits that are further away from the nucleus. When the atoms cease to be excited, their electrons return to their original orbits, giving off a photon (a unit of light) in the process. When many countless atoms are excited all at once, their photons are visible to humans in the form of an aurora. Neon lights work in a similar way, using electricity to excite atoms of neon gas, causing them to produce light.
The reason why auroras are generally only visible at or near the North and South Poles is because these are the only locations on the planet where the magnetosphere intersects with the atmosphere. Charged particles can only travel along magnetic field lines, which are invisible lines that form the boundaries of the magnetosphere. Earth’s magnetic field lines connect the North and South Poles together, but outside of the poles, the lines extend far into space. Because of this, not enough solar wind can impact the atmosphere in other places to cause auroras.
Auroras are generally only visible outside of the North and South Poles during periods of intense solar activity. The most recent example of this was the Carrington event of 1859, a solar storm that caused auroras across much of North America, Europe, and Asia, and which also damaged telegraph lines, causing them to spark, explode, or burst into flame.
However, auroras are not tied to the geographic poles, but to the magnetic poles. The magnetic North Pole is distinct from the geographic North Pole, in that the former denotes the source of Earth’s magnetic field while the latter denotes the northernmost point on the planet. The locations of the magnetic poles are not fixed and have changed over time.
Indeed, every so often, the Earth undergoes what is called a “magnetic reversal,” in which the magnetic North and South Poles switch places. This occurs over a period of time and results in the poles gradually drifting towards each others’ positions on the globe. During this period, it will become possible to see auroras at the equator and other points on Earth where they don’t usually occur. Magnetic reversals occur every 450,000 years, with the most recent on record having occurred 750,000 years ago, suggesting that the planet might undergo one soon.
The North Pole, specifically the magnetic North Pole, is intimately tied to the Northern Lights. Without the protective magnetic barrier generated by the North and South Poles, the Earth would be vulnerable to deadly solar radiation. The complex interplay between the magnetosphere and the Sun is responsible for creating the Northern Lights, a visual feast for the eyes that all people who visit the Arctic Circle can enjoy.