Prepare a Case Study on Aurora Borealis ( Artic Phenomena )
Answers
Explanation:
Definition: An aurora is a natural phenomenon which is characterised by a display of a natural-coloured (green, red, yellow or white) light in the sky. It is a light show which is caused when electrically-charged particles from the sun collide with particles from gases such as oxygen and nitrogen present in the Earth’s atmosphere.
Description: Aurora is sometimes referred to as ‘polar light’. It is predominantly seen in the regions of high altitudes like the Arctic and Antarctic. An aurora is caused by the streams of electrified particles (which are emitted by the sun) trapped in the magnetic field of the earth. It is produced when this magnetosphere is disturbed by the solar wind carrying the charged particles. Auroras are seen in latitudes of around 70 degrees. They generally occur in a band known as ‘auroral zone’. The auroral zone is 3 to 6 degrees wide in latitude. It lies between 10 and 20 degrees from the geomagnetic poles. This is visible quite clearly during the night. Auroras can sometimes be seen at latitudes below the actual auroral zone. Auroras can appear in various forms like streamers, patches, arcs, scattered light, diffused light etc. The brightest and the most distinctive of all forms of auroras are the ones which are curtain-like in the shape of an arc, extending in the east-west direction. This natural light effect is known as ‘aurora borealis’ in northern altitudes, while the effect in the southern latitudes is known as ‘aurora australis’. (Auroras that occur in Northern hemisphere are known as aurora borealis and auroras that take place in Southern hemisphere are known as aurora australis.) Aurora borealis is also known as ‘Northern lights’. Similarly, aurora australis is also known as ‘Southern lights’
Answer:
Auroras are the result of disturbances in the magnetosphere caused by solar wind. These disturbances alter the trajectories of charged particles in the magnetospheric plasma. These particles, mainly electrons and protons, precipitate into the upper atmosphere (thermosphere/exosphere). The resulting ionization and excitation of atmospheric constituents emit light of varying colour and complexity. The form of the aurora, occurring within bands around both polar regions, is also dependent on the amount of acceleration imparted to the precipitating particles.
Most of the planets in the Solar System, some natural satellites, brown dwarfs, and even comets also host auroras.
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