Northern Lights: All your questions answered
Admiring the dancing green Northern Lights in the sky is a magical experience. We’ve seen them during our Ice Diving trips at the White Sea, during expedition cruises to Greenland and on our voyages through the fjords of Northern Norway. We have gathered some frequently asked questions about this unique natural light show!
The Northern Lights are a luminous glow of the upper atmosphere which is caused by energetic particles from the sun entering our earths atmosphere around the poles. This event happens around the magnetic North Pole (Aurora Borealis) and South Pole (Aurora Australis).
The solar wind is the outermost atmosphere of our sun. The sun is so hot that it boils off its outer layers, and the result is a constant outward expanding very thin gas. This solar wind consists of protons and electrons. When these protons and electrons hit the earth’s magnetosphere they cause colourful displays in our skies.
The best places are high northern latitudes during the winter (approximately from October to March). The Northern Lights usually appear in a ring around the North Pole which is called the Auroral Oval. This circle is centered around the earth’s true north, which causes the best spots to be at various latitudes. Good locations in the Arctic are Northern Norway, Canada, Greenland, Iceland and Alaska in winter. During very large auroral events, they can be visible throughout the US and Europe, but those events are very rare.
In order to see aurora, the sky must be dark and clear. Sunlight and clouds are often the biggest obstacle to observations. Second thing you need is solar activity. The more active our sun is, the higher your chances are to see bright and powerfull Northern Lights. When the solar wind is calm, the aurora might be too faint to see. You can get an ‘Aurora notification app‘ to monitor when there are good chances to see them.
Yes, but with less certainty than weather prediction. The ultimate energy source for the Northern Lights is the sun. When the solar wind is calm, we tend to have very little activity. When the solar wind is very strong and perturbed, we have a chance of intense displays. It takes around 3 days for the sun’s particles to reach earth, for this reason Aurora forecasts usually don’t look any further than 3 days ahead.
The composition and density of the atmosphere and the altitude of the particles determine the possible light emissions. This makes various colours, ranging from red to green and even violet. They are most often seen in green, because this colour is produced when the particles collide with oxygen and green is a color our eyes can see well.
Yes, you can definitely see them in real life with you own eyes! However, the lights don’t always have the same strength. When there is a lot of solar activity, the Northern Lights will be very strong and you can see them clearly with the naked eye. When the aurora is weak, you might only see a faint green glow in the sky, like a cloud. Or you might not even see them at all untill you take a picture with slow shutter speed.
The strength of the Northern Lights is measured by a KP-index, ranging from 0 (very faint) to 9 (extreme). When the KP-index is around 3 or higher you should be able to see it clearly with the naked eye. Even if KP-index is low, you might still be able to see something. One moment they might be hardly visible and a few minutes later they can gain strength and perform a beautiful display.
Yes but it is limited to the high latitude atmosphere. Since it takes place at about 90-100 km altitude, only the atmosphere at or above that height is affected. Some ionization may occur a few tens of kilometres further down, and can have effects on radio wave propagation.
This is a difficult question to answer. There is no scientific evidence for this. The upper atmosphere is too thin to carry sound waves, and the aurora is so far away that it would take a sound wave 5 minutes to travel from an overhead display to the ground. But many people claim that they hear something at the same time when the lights are visible in the sky, this is often described as whistling, hissing, bristling, or swooshing. Maybe you should experience it yourself to answer this question.
The particles from the sun move through our earth’s athmosphere at high speeds, but the magnetic field confines the motion of auroral electrons, creating a beautiful wave motion. Think of it as pained magnetic field lines.
Sometimes you can have diffuse auroral curtains and arcs that have small gaps. These gaps are usually thinner that the arc thickness next to the gap and they look like a black aurora curtain embedded in the bright glow around them.
Northern Lights Cruise
A Northern Lights cruise is a perfect way to spot this incredible natural wonder in real life. These cruises take place in Northern Norway in winter and take you on a trip through the beautiful Norwegian fjords. In the winter months the nights are very long and in remote fjords you can enjoy total darkness, ideal circumstances!
We took the above images during our Northern Lights Cruise last January, with a Northern Lights KP-index of 3. The first two photo’s show a realistic image of what the Northern Lights looked like with the naked eye. We slightly enhanced the third image so you can see the stars and part of the ship. It was a wonderful display right above our ship, ranging all the way across the sky!
Want to experience the Northern Lights yourself? Discover our cruises in Northern Norway.