Living here in Singapore, one seldom get to witness such amazing spectacular phenomena (also known as aurora) captured here wonderfully in video by some generous youtubers.
We are so blessed with the beauties nature has bestowed upon us. But the sad fact is that lots of us failed to take the time in our busyness to bring the bacon home to appreciate what nature has given us. I'd like to take some time to dedicate some bit of my blog on nature appreciation since I for one love to admire the wonders found in nature.
The Northern Lights are one of nature's most spectacular visual phenomena, and in this time lapse video they provide a breathtaking display of light, shape, and color over the course of a single night in Norway.
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Virginia Autumn Sunset sea |
When to see the northern lights
The lights are at their most frequent in late autumn and winter/early spring.
In the time span between autumn equinox and spring equinox (21 September - 21 March), it is dark the whole time between 6 pm and 1 am, and you have maximum chances of spotting the lights. However, the weather is also of importance, and September, October and November tend to be wet and snowless in the north.
From December the weather dries up, and there is normally plenty of snow. If you come in December or January, you experience the polar nights with atmospheric evenings and very short days.
In February and March the days are longer and you see more of the snow-clad landscapes during daytime, and the evenings still offer maximum northern lights chances.
Note: The above excerpt is taken from the website below. I'm not paid a cent for the referral since am a nature-lover.
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Northern lights over Tromsø in Northern Norway |
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Northern Lights dancing above an igloo on a cold winter day in northern Alaska |
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Northern Lights curls into the sky over the Arctic region. |
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Yukon Canada |
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Aurora Borealis on an Alaskan night. |
Below are some additional interesting facts on Auroras taken from http://www.antarcticconnection.com
What is the Aurora Australis?
Aurora is the collective name given to the photons (light) emitted by atoms, molecules and ions that have been excited by energetic charged particles (principally electrons) travelling along magnetic field lines into the Earth's upper atmosphere. Aurora results from the interaction of the solar wind with the Earth's magnetic field.
The amazing color displays and formations are produced by the solar wind -- a stream of electrons and protons coming from the sun -- as it collides with gases in the upper atmosphere. These collisions produce electrical discharges which energize atoms of oxygen and nitrogen causing the release of various colors of light. Earth's magnetic field channels these discharges toward the poles. 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.
Where do Auroras Occur?
The global distribution of auroral activity is an oval around the magnetic poles in both hemispheres. As the level of magnetic disturbance of the Earth's magnetic field increases, the oval of auroral activity expands equatorward. Known as 'Aurora borealis' in the north, auroras occur in the upper atmosphere of both poles and are occasionally visible from middle latitudes as a dark red glow near the poleward horizon.
When is the Best Time to Observe the Aurora?
The chance of observing auroras is strongly correlated with the sunspot cycle. Auroral activity over Antarctica peaks near the peak of the sunspot cycle and for the following couple of years. Auroral displays are more common near the equinoxes, but this does not preclude the occurrence of aurora at other times. One can only observe auroral displays at the South Pole during the six months from March to Septemer; the rest of year the Pole experiences 24 hours of sunlight.
What are the Main Forms or Shapes of the Aurora?
Although auroras appear in many forms -- pillars, streaks, wisps and haloes of vibrating color -- they're most memorable when they take the form of pale curtains which seem to float on a breeze of light. Most commonly, auroral glows form a band aligned in a magnetic east-west direction. If sufficient numbers of energetic electrons are impacting the upper atmosphere, bands may have shimmering rays extending upwards from them. These rays define magnetic field lines along which the auroral electrons travel into the atmosphere. The twisting of auroral rays and bands results from the dynamic interaction of electric currents and magnetic fields in the upper atmosphere. In active displays, multiple bands may be visible. These may break into small arcs.
How Long Do Auroras Last?
The active phase of an auroral display will last on the order of 15 to 40 minutes and may recur in 2 to 3 hours. Auroral band features may persist all night. A red dominated auroral glow will be very diffuse. It will vary in location and intensity very slowly (time scales of half a minute or so).
What are the Colors of the Aurora?
Auroral displays appear in many colors with pale green and pink the most common. However, different shades of red, yellow, green, blue, and violet have all been observed. The brightest auroral color is generally a green light emitted by excited oxygen atoms. A red diffuse glow results from another oxygen atom transition. A purple color results from a transition in a Nitrogen molecular ion. The mixture of the major green, red and purple emissions may combine to give aurora a general 'whitish' appearance. The color variations are a product of the altitude of the storm, and the density and composition of the ions at that altitude. The folding effect results from the electric field induced on either side of the auroral curtain by the electrons.
How High is the Aurora?
Generally, if an auroral band has an easily discernible lower border, this will be at around 60 to 70 miles in altitude. Auroral rays may extend above the lower border for hundreds of miles. If the lower border has a pinkish edge to it (resulting from an emission of molecular Nitrogen), the altitude may be around 50 to 60 miles. A diffuse red aurora occurs above 150 miles.
Did You Know That .....
Aurora Facts | |
Where Seen | Mainly Polar latitudes |
When seen | Clear cold nights |
Average Duration | Several hours |
Avg. Height | 50 to 100 miles up |
Common colors | Pale green and pink |
Most common shape | Spiral curtains, arcs, or streamers |
The Aurora Australis is caused by plasma particles from the sun (part of the solar wind) which enter the atmosphere.
Collisions between the electrically charged particles and Earth's magnetic field ionize oxygen and nitrogen atoms, releasing light.
Blue and purplish-red light comes from ionized nitrogen molecules, green from oxygen molecules.
During periods of high activity, a single auroral storm can produce one trillion watts of electricity with a current of one million amps.
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Northern Alaska |
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