For the first time, researchers at Aalto University in Finland have located where the sounds associated with the northern lights or Aurora Borealis are created.
The auroral sounds which have been described in folktales and by wilderness wanderers are formed about 70 meters above ground level.They are similar to crackles or muffled bangs.
Researchers located the sound sources by installing three separate microphones in an observation site where the auroral sounds were recorded.
They then compared sounds captured by the microphones and identified the location of the sound source.
The aurora borealis was seen at the observation site. The simultaneous measurements of the geomagnetic disturbances, made by the Finnish Meteorological Institute, showed a typical pattern of the northern lights episodes.
— Our research proves that the source of the sounds that are associated with the aurora borealis we see is likely caused by the same energetic particles from the sun that create the northern lights far away in the sky, said Professor Unto K. Laine from Aalto University.
— These particles or the geomagnetic disturbance produced by them seem to create sound much closer to the ground.
Details about how the auroral sounds are created are still a mystery and researchers suspect that there are several mechanisms behind their formation.
Clap sound of the northern lights: