High Frequency Broadband Acoustic Spatiotemporal Characterization of Arctic Thermohaline Structure: Postdoctoral Scholar Support
Abstract
The proposed work focuses on high frequency acoustic characterization of ocean structure inArctic coastal environments. This work is motivated by the need for consistent Very HighFrequency (VHF) underwater acoustic communications (UWCOMMS), defined here between100 kHz and 1 MHz. The wide bandwidths of VHF UWCOMMS can achieve both high datarates and low signal to noise ratio performance and the short acoustic wavelengths enable theconstruction of compact arrays for deployment on a wide range of platforms. However, VHFenergy in seawater is naturally limited by high rate of absorption which limits the range ofdetectability by hostile assets. The performance of VHF UWCOMMS systems depend onunderstanding the acoustics and physics of the channels the signals propagate through, which inturn rely on an understanding of the thermohaline structure of the water column and VHF noisesources in the soundscape. In Arctic coastal environments, little has been done to characterizeunderwater acoustic propagation around marine-terminating glaciers, where sound speed profilesare complicated by the mixing meltwater with tidally driven seawater flows. Meltwater drivesthe formation of seasonally-variable, freshwater lenses, which create transient and variablewaveguides near the sea surface. The proposed work aims to: I. Develop new methods forbroadband acoustic study of oceanic stratification, associated mixing phenomena, and the ice-water interface of tidewater glaciers, II. Inform on how sound propagation at high latitudes isimpacted by localized variability in water column structure through multi-scale processes, andIII. Assist in the characterization the high-frequency (>100 kHz) soundscape of high-latitudesystems and identify those processes that will impact the soundscape as climate warms.This abstract is publicly releasable.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Jun 29, 2023
- Source ID
- N000142312620
Entities
People
- Grant B Deane
Organizations
- Office of Naval Research
- United States Navy
- University of California, San Diego