What are the Northern Lights?
Looking up into the black, cloudless, Icelandic night sky the glittering stars are not the only thing that charm and amaze. The bright and colorful illumination that make the Northern Lights such a beautiful spectacle to behold quietly beg the question, What are the Northern Lights?
The Northern Lights or the Aurora Borealis and its sister phenomena in the south the Aurora Australis have been the subject of wonder and speculation for generations.
For decades scientist have studied their source and origin and have come to understand the phenomena. Explaining it however can be a challenge, but simply put, the Northern Lights are collisions between electrically charged particles from the sun that enter the earth’s atmosphere.
These bright lights can best be seen above the magnetic poles of the northern and southern hemispheres.
What makes the Northern Lights?
Scientists have suspected a connection between the Northern Lights and sunspot activity since about 1880. The suspicion was confirmed with research done in the 1950’s which confirmed that the Aurora Borealis is the result of electrons and protons from the sun which are blown towards the earth on what has been called the ‘solar wind’.
These solar winds continuously pushes on the Earth’s magnetic field (the magnetosphere), effecting it’s shape by stretching it into a long leeward tail commonly referred to as the magnetotail.
The Aurora Borealis makes its majestic appearance when energetic particles (protons and electrons) from the Sun enter the Earth’s magnetosphere and are captured in the magnetotail.
The particles are drawn towards the magnetic poles and become more dense there.
As the protons and electrons hit the ionosphere they collide violently with the gas atoms that layer the ionosphere. This adds energy to the gas atoms which in turn will release light and more electrons and the ionosphere starts to glow. The glowing ionosphere is what we call the Northern lights.
Colors of the Northern Lights
Auroral displays, especially those seen in Iceland, appear in many colours and the spectrum of colour depends on the distribution of different gases at different altitudes.
Pale green and yellow are the most common colors of the Northern Lights in Iceland but different shades of green and yellow fly by and create a wonderful display of light.
The ghostly green and yellow is produced by oxygen molecules located about 60 miles above the earth.
Shades of red, yellow, green, blue, and violet in the Aurora Borealis are rarer, they appear irregularly but can add depth and mystique to the show. Rare, all-red auroras are produced by high-altitude oxygen, at heights of up to 200 miles while nitrogen produces blue or purplish-red aurora.
Appearance Of the Northern Lights
The Northern Lights appear in many forms and can be described as anything from small patches or scattered clouds of light to rippling streams, bulging arcs, or curtains flowing in an invisible wind. They can also flash along the dark velvet sky as shooting rays that light up the sky with an eerie glow. These shows of light can last for anything between a few minutes and up to hours depending on visibility and solar activity.