The aurora borealis is an incredible natural phenomenon! ✨
Impressive colors and magic of the sky!
The aurora borealis, also called the northern lights, is an optical phenomenon of the glow of the upper layers of the atmosphere, which changes rapidly. It occurs under the influence of flows of charged particles directed by the Earth’s magnetic field to the poles. As a result of their interaction with protons and electrons of the solar wind.
That is, the glow is the result of solar radiation, more precisely, high-energy charged particles emitted by the Sun into space. These particles travel through space and interact with the Earth’s magnetic field. If the particles enter the Earth’s atmosphere near the polar regions, they interact with the gases in the atmosphere, which results in the emission of light of different colors – this is what we see as the aurora borealis.
Magnetic storms can cause the aurora borealis at lower latitudes than usual. They are caused by coronal mass ejections from the Sun. This is due to too large, explosive emissions of plasma and magnetic fields from the solar corona. They are able to create disturbances in the Earth’s magnetic field. These disturbances, in turn, can cause the aurora borealis.
In addition to magnetic storms caused by coronal mass ejections from the Sun, nuclear explosions in outer space can also cause auroras.
Why is the aurora of this color?
The colors of the aurora are determined by the types of gases in the Earth’s atmosphere with which charged particles interact. When the particles reach a level of 400-100 km above sea level. They excite nitrogen and oxygen atoms and the sky changes color. What it will be depends on the altitude and composition of the atmosphere. Green color is the most common, it is created by interaction with oxygen atoms at an altitude of about 100-150 kilometers. The red color, which is seen less often, occurs higher in the atmosphere, at an altitude of about 200-300 kilometers. Interaction with nitrogen atoms can create a blue or purple color.
The sun does not emit charged particles in the same way all the time. It has cyclic periods of increased activity. Known as solar maxima, which occur approximately every 11 years. During these times, there are more solar explosions and coronal mass ejections. This leads to an increase in the number of charged particles reaching the Earth. This, in turn, leads to greater aurora activity.
The aurora borealis is most often observed in the polar regions. It can also be seen further from the poles during strong geomagnetic storms caused by intense solar emissions. The best places to observe the northern lights are the northern countries. These are such as Norway, Sweden, Finland, Iceland, as well as countries of the South Pole, for example, Antarctica.
Forecast of geomagnetic storms
Scientists are trying to predict this phenomenon. They observe the sun, the weather, and forecast geomagnetic storms. But they never came up with a 100% solution.
The aurora borealis does not depend on the season, but on solar storms. It can be even in summer. To observe this phenomenon, the months from September to March are considered the best. The brightest sky burns from midnight to 3 a.m. During the day the glow blocks the sunlight.
Aurora borealis is a phenomenon that is not unique to Earth. The atmosphere and magnetic field are sufficient for this phenomenon to occur. For example, auroras have already been recorded on Jupiter and Saturn. Jupiter’s aurora is a thousand times stronger. But Mercury was not lucky. It has no atmosphere of its own and charged particles have nothing to interact with.
Aurora has a special place in the culture and folklore of many peoples living in polar regions. It was considered an ancestral spirit in the Inuit culture. It was considered a sign of war in the mythology of the Scandinavian peoples. In Maori culture, they were considered fiery swans flying in the sky. The Vikings believed that the aurora borealis was the brilliance of the heavenly palace where warriors who died in battle went to. Icelanders thought that elves danced in the sky.