To find what makes the auroral breakup occur – a phenomenon in which the auroras fragment into separate glowing features that fill the entire sky – scientists used a computer model.
In a paper – published December 21 in the Journal of Geophysical Research – scientists wrote that the bright spectacle occurs due to an electrical interaction between Earth’s magnetic field and charged particles coming from the Sun.
According to Yusuke Ebihara of Kyoto University and author of the study, the auroral breakup is a fascinating and beautiful phenomenon.
Dr. Ebihara says that the aurora, also known as Northern or Southern Lights (depending on where it occurs), does not usually move. However that changes when the auroral breakup takes place. All of a sudden it starts to expend (could cover the whole sky) and becomes a lot brighter. It normally lasts from thirty minutes to an hour.
When plasma – which comes from the Sun and is also referred to as solar wind – reaches the Earth, it produces electrical currents. These then flow along our planet’s magnetic field, according to Dr. Ebihara.
The electrons follow the magnetosphere toward Earth’s two poles. They collide with atoms and molecules in the upper atmosphere, and the energy from these collisions is released in the form of light. The light comes in various colours due to the different energy levels of the atoms.
Scientists teamed up and developed a computer model to help them determine exactly how auroral breakups occur. As the plasma reaches the Earth from the sun, it stretches much like an elastic band. When stretched too far it snaps, releasing the tension and hurtling toward Earth. Earth’s magnetic field forces it toward the poles, leading to a surge of energy that produces the auroral breakup.
Jeffrey Hughes, an astronomer at Boston University who was not involved in the study, said that the new research – although not revolutionary – is very reasonable as it confirms how the auroral breakups work with the help of a computer model.
According to Hughes, the question about auroral breakups has been bugging scientists for thirty to forty years. Although knowing the mechanisms behind it is not going to solve any important problems of mankind, it is still a good thing to understand how nature works, he added.
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