The sound of space weather

Once the data from the solar wind hitting Earth’s magnetosphere has been collected, it's possible to create an audio file from it

Taking things a step further with an online algorithm, it’s possible to convert the output magnetic field strength data into sounds using the MIDI (Musical Instrument Digital Interface) protocol. In this process, each field strength value is converted to a MIDI value representing a particular musical note, which is then fed into music production software to prepare an audio track.

MIDI allows any digitised instrument to be assigned to play the note, although my preference is to use a synthesised wind sound to represent the solar wind. In reality, the data relate directly to local magnetism, not to the solar wind, yet to hear the sounds generated by such a method is evocative as one imagines the stream of particles pushing against our protective magnetic field, occasionally entering to create the ethereal aurora.

Once the magnetic declination data generated by my magnetometer was sonified, it could be synchronised with a timelapse video of the aurora borealis to create an audio-visual experience similar to this one: bit.ly/2n9ohFo. The correlation between the video, created by Kai-Maeius Pederson in Tromsø, Norway, and the audio is not perfect – probably because of the physical separation between it at the sound recording in the UK – but there is a satisfying degree nevertheless. More sonified geomagnetic data can be found at bit.ly/2n9rHc1.