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CSIRO Marine and Atmospheric Research
Past Seminars

Seminar Abstract

Wind, rain and underwater noise

This talk will report on measurements of underwater noise made by NOCS and the reasons for undertaking such a programme.

Measurements were made at 16 frequencies in the range 500 Hz to 50 kHz using 3 moored hydrophones located off the west coast of Ireland during Oct-Nov 2003. These data have been analysed in relation to environmental conditions, particularly wind speed and rainfall. Although there are some unexplained offsets in the overall acoustic levels compared with those obtained by other researchers, it has proved possible to develop a classification scheme enabling wind, drizzle, rain, and contamination to be separately identified. The acoustic data can be used to infer wind speed to within 2 m/s. There is also useful skill in the detection of drizzle and rain events, and some encouraging results in the quantitative estimation of rain-rate have been achieved. However, further investigation of acoustic anomalies is required.

Comparisons have also been made with deployments of the hydrophones off SW England and Canada.

Finally, suggestions are made as to how such a subsurface technique might be combined with spaceborne measurements to enable estimates of underwater sound levels globally, including the possible use of Argo floats.

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CSIRO = Marine Laboratories Auditorium, Castray Esplanade, Hobart

For further information, or to schedule a seminar, contact:
Peter Oke, (Oceanographic seminars) CSIRO Marine Research (03) 6232 5387
Piers Dunstan, (Biological seminars) CSIRO Marine Research (03) 6232 5382
Katrina Nitschke, Antarctic Climate and Ecosystems CRC (03) 6226 2265 & IASOS, University of Tasmania (03) 6226 2509