A two-component Arctic ambient noise model ...

• Main Author: Greening, Michael Victor
• Format: Text
• Language: English
• Published: University of British Columbia 2009
• Subjects: Arctic
• Online Access: https://dx.doi.org/10.14288/1.0053203; https://doi.library.ubc.ca/10.14288/1.0053203

Short term Arctic ambient noise spectra over the frequency band 2 - 200 Hz are presented along with a two component noise model capable of reproducing these spectra. The model is based on the measured source spectrum and the spatial, temporal and source level distributions of both active pressure ridging and thermal ice cracking. Modeled ambient noise levels are determined by summing the input energy of the distributions of ice cracking and pressure ridging events and removing the propagation loss. Measurements were obtained on a 22-element vertical array along with a 7-element horizontal array deployed beneath the Arctic pack ice in 420 meters of water. Over 900 thermal ice-cracking events were detected in approximately 2 hours of data col lected over several days during April 1988. The source directivity for events beyond 40 wavelengths range was found to be accurately represented by a dipole with an approximate 3 dB increase above the dipole directivity pattern near 60° - 65° caused by the leaked ...