IN THE SPACE – SEPTEMBER 9: (EDITORIAL USE ONLY) In this photo brochure provided by the European Space … [+] Agency (ESA) On September 9, 2014, German ESA astronaut Alexander Gerst took this image of an aurora while orbiting the Earth while aboard the International Space Station (ISS). Gerst returned to Earth on November 10, 2014 after spending six months on the International Space Station completing an extensive science program, known as the ‘Blue Dot’ mission (after the description of Earth by astronomer Carl Sagan, as seen in a photograph taken by Voyager). probe from six billion miles away). (Photo by Alexander Gerst / ESA via Getty Images)
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Can the aurora “speak?”
If you stand outside under a clear sky while a geomagnetic storm rages on you, the sounds you are most likely to hear are the happy ones of other Northern Lights chasers. However, apart from the strange “wow” and the click of the camera shutters, for centuries there are myths and legends that the aurora itself makes a sound.
Suggestions that the aurora, which occurs in the Earth’s ionosphere hundreds of miles away, comes with a whistle or a whistle, a crisp or a whistle, can be found in the accounts of Greenland, the Shetland Islands, the north of Canada and Norway. “As if two tables had collided flat, not a sharp crack, but a muffled sound, loud enough for anyone to hear,” according to one account.
Discarded as psychoacoustic phenomena (science speaks for “you’re imagining it”), new recordings from Aalto University in Finland suggest that there is a strong link between geomagnetic fluctuations and “auroral sounds”.
The northern (and southern) lights are caused by the solar wind in space — charged particles from the Sun — which is accelerated by the field lines of the Earth’s magnetic field. Green lights are caused by charged particles colliding with oxygen molecules, while other colors are caused by nitrogen molecules.
It is proposed that, when the circumstances are right, a pocket of warm air about 75 feet above the ground may contain a trapped static charge that is discharged when the air is dissipated. Make an occasional burst or burst.
It is bound to geomagnetic conditions, therefore bound to the aurora, but sound can occur even when the aurora is not visible. It was a surprise because legends have always associated only the loud, animated samples of the northern lights directly on the observer with sounds.
“This dispels the argument that auroral sounds are extremely rare and that the aurora borealis should be exceptionally bright and lively,” said Unto K. Laine, professor emeritus at Aalto University and lead author of a new published article presented at the Baltic Nordic Acoustic Meeting. in Aalborg, Denmark.
Laine made four hours of recordings of auroral sounds near the village of Fiskars, Finland, some 90 miles (90 km) west of Helsinki.
There were no aurora borealis screens that night, but when the sounds of the recordings were compared to the measurements of the geomagnetic activity of the Finnish Meteorological Institute, there was a strong correlation. According to the paper, the top 60 “auroral sounds” candidates were related to changes in the geomagnetic field.
The correlation was so accurate that Laine believes she can now predict when the northern lights will sound. “Using geomagnetic data, which was measured independently, it is possible to predict when auroral sounds will occur in my recordings with 90% accuracy,” Laine said. “Sounds are much more common than anyone thought, but when people hear them without visible auroras, they think it’s just ice cracks or maybe a dog or some other animal.”
Could there now be a boom in people traveling north not only to see the aurora but also to hear it?
“It’s interesting because if we look at the myths of Greenland about the northern lights, they include a hissing or crackling sound … there was a strong feeling that the aurora could speak,” said Tom Kerss, author of Northern Lights: The definitive guide to aurores and aurores. not involved in this research. “But it’s the white whale of the aurora chasing. I’ve never heard of it.”
The northern lights are presented as an auroral oval around the North Pole at about 66-69 ° North latitude: the Arctic Circle. The best places to see them are Alaska, northern Canada, Iceland, Greenland, Norwegian Lapland, Swedish Lapland, Finnish Lapland and northern Russia.
The “season” of northern lights is from September to March, though only because it is now not getting dark above the Arctic Circle, where they occur mostly continuously. However, you may still be able to hear them …
I wish you clear skies and open eyes.