Surf music: Sonification of ocean buoy spectral data
The Coastal Data Information Program (CDIP) has been collecting data on ocean wave conditions since late 1975, first using arrays of pressure sensors, and more recently directional buoys. Fourier analysis of the data reveals the spectral and directional content of the wave-driven motions measured by the buoy. Shifting the spectrum to an audible range and synthesizing a time-domain signal creates an aurally interesting and illuminating sonification of ocean wave dynamics. The work done so far has been guided by artistic curiosity; but input from a senior oceanographer has given guidance toward interpretation and elaboration of the methodology. Examples of ocean buoy spectral data sonification are presented, each illustrating important aspects of physical oceanography. Three forms of the data are sonified, from the least detailed to the most. The obvious sonic events are the effects of energy from storms, both local and far away. From the sonification one can estimate the energy of the storm, and the distance it originated. Entire years of data have been sonified in one to thirty minute durations for buoys in different regions, which demonstrate dramatic seasonal and regional differences. Also displayed are the time-lags of South moving storm energies at three distantly separated points on the West Coast of the United States.