Northern Lights Make Hissing Noise Due to Corona Discharge [Listen]

(Photo: Wikimedia Commons/Dreerwin)
Northern Lights Make Hissing Noise Due To Corona Discharge [Listen]

Northern lights also make their sound. According to a researcher, they produce a hissing noise.

Northern Lights Make Noise

There were stories that aurora borealis could make music, but researchers dismissed the claim for years. However, in 1990, a young acoustic scientist who took a break during a jazz festival in the far north of Finland heard the sound of the northern lights.

Scientist Unto Laine and a pal walked outside into the chilly evening air. They were expecting near-total silence in the isolated area with no wind. However, they were startled to hear a hissing sound above them that seemed to follow the movements of an aurora.

Laine mostly forgot about the incident but decided to look into it when he returned to the festival in 1999 and heard the same noises. Laine believes he has a theory after making numerous additional observations and the initial recording of the enigmatic noises in 2012.

He claims that the noise audible from the ground results from a corona discharge. The same phenomenon occasionally produces a blue glow surrounding high-voltage electrical equipment like power lines, sometimes accompanied by a buzzing sound.

High positive and negative charges must build up near one another to provide the necessary voltages. According to Laine, this can occur over our heads on really cold evenings when the air directly above the frozen ground cools. A few hundred meters above, at the base of what is referred to as the inversion layer, the cold air becomes trapped beneath a layer of warm air.

Negative ions at the surface ascend to this layer but do not ascend higher. Positive ions, meantime, accumulate on its upper surface. According to Laine, the aurora increases this already substantial electric potential to the point where a violent discharge occurs, resulting in sounds, magnetic field pulses, and UV radiation. This happens well below the visible aurora, only a few tens or hundreds of meters over our heads.

ALSO READ: Strong Geomagnetic Storm Could Produce Atypical Northern Lights as Far South as in the US

Green, Purple Lights Steve Mistaken As Aurora Borealis

Steves are characterized by their occurrence closer to the equator than auroras, yet few scientists studying night sky phenomena like auroras or northern lights have seen one. Steve's green vertical stripes and purple-pink arch make him as brilliant as an aurora.

A citizen scientist, Neil Zeller, stated that in 2015, they had referred to it as a proton arc. The one that Zeller saw was "visually bright, narrow, and structured." Donovan, who was at the pub with MacDonald that day, assured Zeller it was different. It was reportedly "misidentified" because, according to Dr. Eric Donovan, a professor at the University of Calgary, a proton arc is "subvisual, broad, and diffuse."

On the occasion, they resolved not to refer to the phenomena as a proton arc anymore. The name "Steve" was proposed by fellow aurora chaser Chris Ratzlaff in 2016. The 2006 DreamWorks animated picture "Over the Hedge," in which many animals were scared of a tall, leafy bush and gave it the name Steve, inspired the moniker. "I'm a lot less scared of Steve," says a porcupine.