CEAREX Ambient Noise Data Measured Northeast of Svalbard
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.
Document Details
- Document Type
- Technical Report
- Publication Date
- Mar 01, 1991
- Accession Number
- ADA247483
Entities
People
- John D. Cousins
Organizations
- Naval Postgraduate School