The period 17 - 20 November 2003 saw a large amount of Aurora Borealis activity over Shetland. Having lived here since 1991, the display on 20 November 2003 over the Maywick valley was undoubtedly one of the best I have ever witnessed. The main highlight of this particular aurora was its redness combined with some spectacular green 'columns'.
Using a Canon D1 with a 17 - 35 mm lens and bulb exposure varying from 45 seconds to 110 seconds I was able to capture the display over a period of two hours.
The Aurora Borealis or 'Northern Lights' are mesmerizing, dynamic displays of light that appear in the night-time sky. They are, in effect, nature's light show and as those who have witnessed an aurora can attest, few sights can equal the magic and mystery of these luminous sheets of colour undulating in the frigid air of a cold Shetland night.
Northern
Lights occur when charged particles blowing away from the
sun, called solar winds, interact and collide with the Earth's
magnetic field. These collisions produce electrical discharges
which energise atoms of oxygen and nitrogen, causing the
release of various colours of light. During periods of high
activity, a single auroral storm can produce one trillion
watts of electricity with a current of one million amps!
The colour of the aurora depends upon what type of molecule is struck by the particles and at what atmospheric level. Oxygen at about sixty miles up produces a green colour, which is the most common colour. Higher-level oxygen produces the rare all-red auroras, while ionised nitrogen produces blue light and neutral nitrogen glows purplish-red at the edges of the aurora. Variations in sunspot activity or the occurrence of so-called 'coronal holes' can often considerably enhance the auroral discharge adding to the intensity and duration of the displays.
Indigenous peoples have many different myths to explain the Aurora Borealis. The Inuit, for example, attach spiritual significance to the lights, believing them to represent the souls of their unborn children or the torches of long-departed ancestors. In Middle-Age Europe, the Northern Lights were thought to be reflections of slain warriors battling valiantly in the heavenly skies for eternity. For me, the Aurora Borealis represents the most beautiful sight Earth can offer.
