LAUSR

The Arctic Ocean is undergoing dramatic changes, with the most apparent being the rapidly reducing extent and thickness of the summer ice cover. Furthermore, a persistent inflow of a shallow tongue of warm Pacific water has recently been discovered in the Beaufort Sea region of the Arctic, often called the Beaufort Lens, which creates a strong acoustic duct between approximately 100 and 200 m depth. These changes have had a significant effect on underwater acoustic propagation and noise properties. In spring 1994, acoustic data was collected in the Beaufort Sea region of the Arctic using a suspended vertical array; in spring 2016, similar data was collected in the same region. The 1994 data features meandering narrow-band features due to ice ridge friction, while the 2016 data in the new Arctic is largely dominated by ice mechanical events at discrete ranges and bearings. Supported by acoustic noise modeling, we illustrate these and other noise properties measured more than two decades apart in a region o...