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Auroral kilometric radiation

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The Strange Sounds of Earth's Auroral Kilometric Radiation

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Earth auroral kilometric radiation (AKR)

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Earth auroral kilometric radiation recorded in stereo by Cluster 3 and 4

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What is AURORAL KILOMETRIC RADIATION? What does AURORAL KILOMETRIC RADIATION mean?

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Earth Auroral Kilometric Radiation

Auroral kilometric radiation (AKR) is the intense radio radiation emitted in the acceleration zone of the polar lights. The radiation mainly comes from cyclotron radiation from electrons orbiting around the magnetic field lines of the Earth. The radiation has a frequency of between 50 and 500 kHz and a total power of between about 1 million and 10 million watts. The radiation is absorbed by the ionosphere and therefore can only be measured by satellites positioned at vast heights, such as the Fast Auroral Snapshot Explorer (FAST). According to the data of the Cluster mission, it is beamed out in the cosmos in a narrow plane tangent to the magnetic field at the source. The sound produced by playing AKR over an audio device has been described as "whistles", "chirps", and even "screams".
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