The poles are a very cold area, so there are no plants that live and grow there. Thick snow stretched as far as the eye could see. But behind it there is a charm of beauty that is offered there, and may have never met in other areas on earth. What beauty is there? Aurora with all the beauty proved able to hypnotize many people to be interested in going to the polar regions.
Aurora beauty is not without reason, the colorful lights that circulate on the horizon make the dark polar regions become dawn. Green lights from Aurora grow more beautiful when combined with the black sky at night.
So, what is Aurora? Aurora is a colored light that lies above the horizon, an area that is at high latitude and occurs due to the wind deflection of the Sun by the earth's magnetic field to the polar region, and reaction with molecular particles in the atmosphere. There are two types of Aurora located in the north polar region called **"Aurora Borealis"** and at the south pole under the name **"Aurora Australis"**.
Because Borealis is in the north polar region, it will only appear between September and October, while for Aurora Austalis appears in March and April every year in the southern hemisphere. So the essence of Aurora is only seen in autumn and winter, because that's when the polar regions have got little sun exposure, in other words the day is shorter than at night.
Aurora Genesis Process:
The presence of areas with high magnetic fields on a planet, in this case located around the north and south poles of the earth. When asked why did not happen at the equator? Because the magnetic axis of the earth is only in the polar regions.
There is a solar wind which is a charged stream that emanates from Corona or the outer parts of the sun. This solar wind is filled with protons that can be removed because of the very hot part of the Sun known as the Sun Spot. Sun Spot is another name formed by the convection flow from the center of the Sun, where thermonuclear reactions occur and flows into the corona surface.
High intensity of convection flow leads to the appearance of darker parts and colder temperatures, so that in the area around the dark area the temperature increases. Continuous pressures make Sunspot explode to form flares or fire and release heavy particles known as solar winds or, if they are large they can become solar storms.
The sun has a cycle, where the number of spots on the surface more and occur on average every eleven years. In this condition the number of charged particles that are released is larger, so it can trigger the occurrence of solar storms that will affect human activity on earth, such as disruption of satellite and telecommunications signals and power grids.
The speed of the blowing solar winds ranges from 20 km/second to 2000 km/sec, but the average speed of 350 km/sec. It takes 1 to 3 days to reach the earth. The energy released from the bursts of Corona is huge, ie 6 x 10 ^ 24 Joule for single tosses.
Once the energy filled from the Sun reaches the Earth, it directly interacts with the Earth's atmospheric particles, then as it approaches the center of the magnet located in the polar region so that electrons occur and cause the formation of beautiful colors. pedal known as Aurora.
Aurora can be an indicator that measures the intensity of the solar wind, if the Aurora appears longer and lighter than usual, it will be more powerful energy interference from the Sun and this often happens when the sun is active at its peak that occurs every 11 years. In addition there are also further disturbances in the earth's polar field, which is often called the Magnetic Storm, so it can trigger a sudden change of the magnetic field.
The suddenly changed magnetic field causes the number of particles in the geosphere element such as the ionosphere layer to increase dramatically, in addition Aurora can also be oval and symmetrical in case of further phenomena in the earth's magnetosphere, the event is often referred to as Magnetic Substromes. In fact, many scientists have suspected the phenomenon for a long time, but can only prove the truth of this theory in 2001 through a series of NASA research.
The phenomenon of the occurrence of the Aurora because it is formed from the reaction of solar particles to atmospheric particles that are affected by the magnetic field attraction, so that causes Aurora visible and formed in areas that are still within the polar circle and very rarely appear, in the area near the equator. Aurora Borealis is more common when compared with Australis. Aurora Borealis often appears in Alaska, Canada, Northern Europe such as Iceland, North Scandinavia and other areas close to the north pole. As for Aurora Australis is reported rarely seen because it only appears in areas that are sparsely populated. Because there is no State close to the south pole or Antarctica. Aurora Australis can be seen in New Zealand and Tasmania.
Aurora sightings are not the same from one place to another, because there are factors that affect, such as location, weather and pollution levels of a place. Closer to the pole would be the more clearly visible Aurora, as well as Weather which is the best month to observe in the fall, where the temperature is not too extreme. For areas with severe pollution levels, will not be able to see clearly the beauty of Aurora, for those who want to watch it go to the area with clean air quality. In addition to the most interesting is the Aurora has a different shape in every place, though at the same time. Aurora form while in Alaska will be different when viewed in Greenland or elsewhere.
The fading process of the auroral light will be more clearly visible at midnight and begin to fade before dawn, this formation often resembling green, yellow, blue and crimson bands. The color difference depends on the height of the location, where relaxation occurs between the particles, otherwise the type of atmospheric molecule at that time will also cause the resulting color difference.
In general, there are two main types of gases that form the Earth's atmosphere layer that most influence the formation of Aurora lamps such as Oxygen and Nitrogen. The oxygen gas will produce the most prominent green and yellow Aurora colors most often present with a wavelength of 557 nanometers, and red with a wavelength of 630 namometers, but the frequency of occurrence is very rare. For Nitrogen Gas will produce a light blue color and at normal concentration will cause the Aurora color to be red red.
Thank you, this is my writing for this time, if there are words that are not good, not polite, not clear. I can only apologize. Perfection belongs only to God, I am only human who can not escape from mistakes. So, greetings from me @youngky. For my friends in steemit and for all my faithful followers.
Note: All letters and numbers are mine, but the picture I got from google, I just use it to connect from my writing.
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