CEAREX ambient noise data measured northeast of Svalbard
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Authors
Cousins, John David
Subjects
CEAREX
Ambient Noise
Arctic Ambient Noise
Svalbard
Ambient Noise
Arctic Ambient Noise
Svalbard
Advisors
Bourke, Robert H.
Pritchard, Robert S.
Date of Issue
1991-03
Date
Publisher
Monterey, California. Naval Postgraduate School
Language
en_US
Abstract
Ambient noise measurements made northeast of Svalbard from two omni-directional
hydrophones, deployed at 60 and 90 m beneath the ice, were acquired as the research
vessel Polarbjoern drifted southward from 11 October to 18 November 1988. The ambient
noise data as well as the accompanying meteorological and ice motion data were collected
as part of the Coordinated Eastern Arctic Experiment, CEAREX. The ambient noise
measurements were composed of one and a half minute samples that were averaged
hourly to provide a 38-day time series at 10, 31.5, and 100 Hz. Higher frequencies were
considered valid only above the median level due to high system electronic noise.
Measurements were obtained in deep and shallow water (<100 m) as the ship drifted
generally southwestward with the ice pack towards the Svalbard Archipelago. The
ambient noise time series were correlated with hourly-averaged wind, air temperature, and
ice motion data in order to determine its association with the major noise generating mechanisms. Both visual and numerical comparisons between the ambient noise and the
environmental parameters revealed significant correlations. The two primary forces
operating on the ice pack were the wind stress and 12-hour tidal /inertial oscillations.
When either of these forces opposed the mean direction of ice motion, there was increased
convergence and higher levels of ambient noise were experienced. The mean ambient
noise levels northeast of Svalbard were 20-30 dB higher than typical central Arctic basin
values due to the active ridging encountered immediately north of the Svalbard
Archipelago. These noise levels compare favorably with other active ridging regions or
dynamically active regions such as the marginal ice zone.
Type
Thesis
Description
Series/Report No
Department
Meteorology
Physical Oceanography
Organization
Naval Postgraduate School
Identifiers
NPS Report Number
Sponsors
Funding
Format
119 p.;28 cm.
Citation
Distribution Statement
Approved for public release; distribution is unlimited.