Arctic ambient noise in the Beaufort Sea: Seasonal relationships to sea ice kinematics

Abstract

Various modes of sea ice motion in the Beaufort Sea are correlated with under-ice noise at 10, 32, and 1000 Hz. Seasonal variations are considered, and a parameterization of ice microfracturing caused by sensible heat flux is included in the correlations. During the summer, the correlations indicate that all frequencies are primarily a response to the ice rushing through the water. During the fall, 10- and 32-Hz noise correlate best with a linear combination of the speed of the ice parcel plus the total rate of change in the shape of the ice parcel. This latter factor indicates noise generation due to the individual ice floes moving past one another as they rearrange into new shapes. The correlations indicate differential motions of other forms (primarily ice convergence) become important in generating lower frequency noise only during winter. As for 1000 Hz during fall and winter, the correlations are low and the results are ambiguous. Several factors are discussed that emphasize our lack of knowledge about higher frequency arctic ambient noise.