Short-term fluctuations in the ambient noise field at an Arctic chokepoint horizontal line array

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The Arctic is a region known for high variance in both ambient noise levels and local sound propagation conditions, and is currently experiencing an historic increase in shipping traffic, resulting in an acoustic environmental that is changing so rapidly that the sparse ambient noise data available from decades-old studies have been rendered obsolete. Renewed interest in Arctic acoustics have provided fresh noise data at northern sites, and in the summer of 2015 Defence R&D Canada collected a continuous two-week recording of the 48-hydrophone Northern Watch horizontal line array at Gascoyne Inlet. Over the ice-free study period, numerous ship passes, weather events, and anomalies were observed in the high-quality acoustic recordings. In this paper, spectral fluctuations, directionality, and correlation with ship tracks and weather observations in the noise data are analyzed to help improve the applicability of operational arctic noise models supporting sonar performance.The Arctic is a region known for high variance in both ambient noise levels and local sound propagation conditions, and is currently experiencing an historic increase in shipping traffic, resulting in an acoustic environmental that is changing so rapidly that the sparse ambient noise data available from decades-old studies have been rendered obsolete. Renewed interest in Arctic acoustics have provided fresh noise data at northern sites, and in the summer of 2015 Defence R&D Canada collected a continuous two-week recording of the 48-hydrophone Northern Watch horizontal line array at Gascoyne Inlet. Over the ice-free study period, numerous ship passes, weather events, and anomalies were observed in the high-quality acoustic recordings. In this paper, spectral fluctuations, directionality, and correlation with ship tracks and weather observations in the noise data are analyzed to help improve the applicability of operational arctic noise models supporting sonar performance.