(modified 6.7.2012/ page opened 9.10.2001 / ukl)
The work around the topic of aurora related sounds and auroral acoustics started spring 2000 at HUT. At the same time a co-operation with Sodankylä Geophysical Observatory started. The initiative to start these studies come from the Laboratory of Acoustics and Audio signal Processing at HUT. Later, researchers from Finnish Meteorological Institute have also co-operated in the project.
Main steps in the project:
Fall 2011 three microphone recording tested with Zoom H4n and new VLF antenna coil
We have digitally recorded acoustic signals
together with VLF signal during more than 100 nights (July 2012). Each
night generates 8-12 Gb data! We are still
facing many methodological problems:
- how to analyze automatically the data
- how to compare and correlate the data with other simultaneous measurements
- how to select and preprocess the right features of the data
- how to finally find out those acoustical events possible produced by the geomagnetic storm
Thus we are still working with many complicated practical and methodological problems.
Dr. Robert Eather, a well known Norwegian aurora researcher mentioned in his book "Majestic Lights" ('Majestic Lights; the aurora in science, history and arts'. American Geophysical Union, Washington D.C. 1980. ISBN 0-87590-215-41980) that to proof that the aurora makes noise is not an easy scientific task. He seems to have right!
Our present status is that the collected and analyzed observations seem to speak for an objective phenomena. Our audio measurements have material which fits well the descriptions of the sounds. We have published the first, preliminary reports on the found high cross correlations between the variation of the audio range acoustic power and the geomagnetic activity (see ref  publications). The work continues with September 9 2011 event and couple of similar cases.
Go to: The MAIN PROJECT PAGE.