The Northern Lights are one of the best-known natural sights of the Arctic. Every year, countless tourists flock to Alaska, Norway, and other northern lands to watch the night sky light up in a panoply of breathtaking colors. The time and cost of traveling to the Arctic—especially during the winter—combined with the Arctic’s inhospitable climate leads many to ask the question: why can the Northern Lights only be seen near the Arctic Circle?
It’s not entirely true that the Northern Lights only occur in the Arctic: auroras are also visible in Antarctica near the South Pole (where they are known as aurora australis), and auroras have been occasionally witnessed in more temperate regions of the world, as far south as New Orleans. However, as a general rule, the Arctic is the easiest place to witness the Northern Lights. Read on to find out why.
Why Can the Northern Lights Only Be Seen Near the Arctic Circle?
The Northern Lights occur as a result of interaction between solar wind (charged particles that are regularly emitted by the sun) and the Earth’s magnetic fields. When solar wind impacts the magnetosphere (the protective barrier generated by the Earth’s magnetic field), the resulting chemical interaction creates the Northern Lights in areas where the magnetosphere intersects Earth’s atmosphere. These points of intersection are in the North and South Poles due to the fact that those locations are where the Earth’s magnetic field is generated.
When solar wind collides with the magnetosphere, the resulting charged particles can only travel along magnetic field lines, which are the lines of power that comprise the magnetosphere. Magnetic field lines begin and end at the North and South Poles, making them the areas where the bulk of solar wind particles are attracted. Additionally, these are the only points on Earth where magnetic field lines intersect with Earth’s atmosphere, with the remainder of the lines extending into space.
This is the primary reason why auroras can only be seen at the North and South Poles: they are the only areas on Earth where sufficient amounts of solar wind can collect in order to form the Northern Lights. Magnetic field lines protecting the rest of the planet extend outward into space and do not intersect the atmosphere, meaning that not enough charged particles can enter the atmosphere in order for auroras to form in those locations.
Another reason why auroras can only be seen at the North and South Poles is due to light and darkness. The Earth’s axial tilt leads to huge disparities in day and night at the poles at different times of the year. During winter in the Northern Hemisphere, there is very little daylight in the Arctic, and none at all at the North Pole itself. This extended darkness makes it far easier for auroras to be seen. Further south, where days are longer and sunlight is more prevalent, auroras cannot form due to light pollution. This is also why auroras are best viewed in rural locales, away from the lights given off by big cities and human habitation.
Auroras are generally only viewable outside of the North and South Poles during periods of unusual solar activity. For example, a major solar storm in 1859 allowed auroras to be seen as far south as Cuba and Hawaii. However, that solar storm caused massive damage to electrical systems around the world, causing telegraph lines to burst into flame and workers to suffer electric shocks. Even today, a solar storm of that magnitude would cripple the world electrical system and cause damage and downtime to computers and other equipment, meaning that seeing an aurora under such circumstances would be very bittersweet indeed.
In the future, auroras will occur with regularity in other parts of the world due to the Earth’s magnetic shifts. Scientists estimate that every 450,000 years, the Earth undergoes a magnetic reversal, a process in which the North and South Poles trade places. During this period, as each pole migrates to the other’s position, auroras will occur wherever the pole is located, making it possible to see the Northern Lights in places such as the equator.
The most recent magnetic reversal occurred 780,000 years ago, meaning that scientists predict another reversal will occur sometime in the next thousand or ten thousand years. Because of this, you shouldn’t count on a magnetic reversal occurring within your lifetime, allowing you to see the Northern Lights from the comfort of your balcony or back porch.
Finally, it is possible to witness auroras occurring in or near the South Pole. However, few Northern Lights enthusiasts travel to Antarctica for a number of reasons. Chief among them is that Antarctica is far more hostile to human life than the Arctic due to colder temperatures, thick sea ice, and a comparative lack of human habitation. The Antarctic is also far more isolated than the Arctic, meaning that only scientists and a select few individuals can afford to make the journey.
As a general rule, auroras only occur in the polar regions of the world due to physiological and scientific considerations. While auroras can sometimes be seen outside of the Arctic Circle and Antarctica, they can’t be relied upon to appear with any regularity. If you want to see the Northern Lights for yourself, book a trip to the Arctic Circle and enjoy the experience of a lifetime.