Near the village of Fiskars, the team set up their recording equipment to listen for popping, crackling sounds emanating from the atmosphere.
"Using the geomagnetic data, which was measured independently, it's possible to predict when auroral sounds will happen in my recordings with 90 percent accuracy," Laine says.The work suggests that there is likely a causal link between the auroral sounds and geomagnetic activity, with different types of activity producing different sounds.The processes that produce these sounds are also different from the processes that produce auroral displays; however, since both are produced by geomagnetic activity, they can appear together.