Temporal and spatial coherence of sound at 250 Hz and 1659 km in the Pacific Ocean: Demonstrating internal waves and deterministic effects explain observations

Loading...
Thumbnail Image
Penn collection
Departmental Papers (EES)
Degree type
Discipline
Subject
Environmental Sciences
Physical Sciences and Mathematics
Funder
Grant number
License
Copyright date
Distributor
Related resources
Author
Speisberger, John L.
Contributor
Abstract

The hypothesis tested is that internal gravity waves explain temporal and spatial coherences of sound at 1659 km in the Pacific Ocean for a signal at 250 Hz and a pulse resolution of 0.02 s. From data collected with a towed array, the measured probability that coherence time is 1.8 min or longer is 0.8. Using a parabolic approximation for the acoustic wave equation with sound speeds fluctuating from internal waves, a Monte-Carlo model yields coherence time of 1.8 min or more with probability of 0.9. For spatial coherence, two subsections of the array are compared that are separated by 142 and 370 m in directions perpendicular and parallel to the geodesic, respectively. Measured coherence is 0.54. This is statistically consistent with the modeled 95% confidence interval of [0.52, 0.76]. The difference of 370 m parallel to the section causes spatial coherence to degrade deterministically by a larger amount than the effect of internal waves acting on the 142 m separation perpendicular to the section. The models are run without any tuning with data.

Advisor
Date Range for Data Collection (Start Date)
Date Range for Data Collection (End Date)
Digital Object Identifier
Series name and number
Publication date
2009-04-21
Journal title
Journal of the Acoustical Society of America
Volume number
Issue number
Publisher
Publisher DOI
Journal Issue
Comments
Suggested Citation: Spiesberger, J.L. (2009). "Temporal and spatial coherence of sound at 250 Hz and 1659 km in the Pacific Ocean: Demonstrating internal waves and deterministic effects explain observations." J. Acoust. Soc. Am. 126 (1). © 2009 Acoustical Society of America. This article may be downloaded for personal use only. Any other use requires prior permission of the author and the Acoustical Society of America. The following article appeared in J. Acoust. Soc. Am. and may be found at http://dx.doi.org/10.1121/1.3133243
Recommended citation
Collection