ONR-Acoustics: Under-ice Acoustic propagation
The impact of sea ice on acoustic propagation is one of the least understood in Arctic propagation, because it is a combined effect of reflection (ice thickness and material properties) and scattering from a highly variable and rough surface.
The overall objective of the project is to better understand the capabilities and limitations of acoustic signal propagation in the marginal ice zones and ice covered regions in order to ultimately improve and optimize the technologies for underwater communication, navigation and the observation of ocean and sea ice processes. This is a PhD program for Mr. Gaute Hope.
The specific scientific questions to be addressed by this project are:
- How does the spatial and temporal ocean variability in the marginal ice zones, such as strong vertical stratification of the water masses, internal waves, frontal zones, and eddies influence the acoustic signal propagation (stability in travel time, phase and intensity)?
- How does sea ice properties (e.g. thickness, roughness, elastic properties, and surface waves propagation) influence the propagation of underwater and cryogenic acoustic signals (travel time, phase and intensity)?
The work in this project includes analysis of acoustic and oceanographic data collected in several field experiments as part of the WIFAR, ACOBAR, and UNDER-ICE projects (funded by EU and the Norwegian Research Council). Acoustic observations are analyzed and we use acoustic models (OASES and RAM) to understand the results.