Spotting the Northern Lights

At the end of last semester, students found themselves hurrying to the beach to see the Aurora Borealis, commonly known as the Northern Lights. As the nights get longer in winter, we will have more and more opportunities to catch this electrifying display.

Solar storms from our sun send out clouds of electrically charged particles, some of which eventually reach the Earth. Luckily for us, our magnetic field protects us from this. However, the magnetic field can capture some of these charged particles and accelerate them to the Earth’s magnetic poles. These particles then interact with particles in our atmosphere, exciting certain gases and causing curtains of light. The mystical green colour we observe comes from oxygen in our atmosphere and the splashes of purple, blue, and pink are caused by nitrogen. Because the Aurora Borealis is concentrated around the poles, Scotland’s high latitude makes it a great place to view them.

The closer to the poles you go the more chance you have of seeing the Northern Lights. However, they can sometimes even be seen from the south of England. Unfortunately, location isn’t everything. Clouds are one of the greatest enemies of an Aurora hunter. Auroras form between 90 and 150 kilometres above the Earth’s surface, far above where clouds sit, so any large cluster will undoubtedly block the view. Light pollution is another issue, making it very difficult to see the Aurora Borealis. Artificial light from settlements will cause atmospheric light and decrease the visibility of stars, the moon and the Northern Lights. That is why a popular local spot is Castle Sands, where the stairs down to the beach take you to a sheltered area away from street lamps. Standing on this beach, looking out to the sea, you face north with the perfect view.

The likelihood of seeing the Aurora Borealis also changes depending on the solar cycle. Luckily for those of us here now, solar activity is rising, and we are expected to reach the solar maximum in 2025. This increased activity may result in more common and intense aurora displays, but they can still occur at any time. The phenomenon can also be seen in the southern hemisphere. Here, hunters can venture south to places like Tasmania and New Zealand in an attempt to see the less famous but just as spectacular Southern Lights; the Aurora Australis.

So how might your typical St Andrews student see the Northern Lights? One useful tool is the AuroraWatch UK app, a useful tool for monitoring geomagnetic activity. If the activity reaches a point where the Northern Lights may be visible from your location, the app will display a “red alert” and you can elect to receive notifications for when this happens. So wrap up warm, get down to Castle Sands, and take some photographs. The longer exposure time the better!

Photo by Alex Barnard