Acoustic propagation in an Arctic shallow-water environment

A short-range, shallow-water transmission loss experiment was conducted in the South Lincoln Sea, under an irregular rough ice canopy. A barrel-stave source was used to transmit 800-Hz tonal signals at depths of 10 and 30 in. The signals were received on a four-element vertical line array distributed over the 65-m water depth. To support the transmission loss measurements, a bottom loss experiment was carried out using broadband signals generated by imploding light bulbs at three depths and with data received on the same hydrophone array. Previous drilling experiments in the vicinity of this site have provided seabed information and revealed the presence of a subbottom permafrost layer. Preliminary modeling of the acoustic propagation in this highly irregular channel was carried out using a wave-based model. This paper reviews the measurements, and discusses the challenges associated with the modeling, in view of the experimental uncertainties associated with this complicated environment.