Underwater noise from wind at the high north LoVe ocean observatory

Abstract

The Lofoten-Vesterålen (LoVe) Cabled Ocean Observatory is located in an oceanographic, ecological, and economical hotspot off the Northern Norwegian cost. The observatory is a national research infrastructure under development by a national consortium led by the Institute of Marine Research (IMR). The first observation node of the infrastructure was launched in September 2013 and is located at 258 m depth about 15 km offshore.

Preliminary analyses [1] using hydrophone recordings from Node 1 indicate that wind generated noise at low frequencies is significantly higher at the LoVe Observatory than in the commonly used Wenz curve. A more thorough study of wind generated noise using larger datasets from the hydrophone at Node 1 is presented here.

Hydrophone data are summarized in percentile plots to describe the variation in underwater noise. Metadata on shipping from AIS (Automatic Identification System) and metadata on wind from the Norwegian metrological institute have been used to show how much of the variation in underwater noise that may be explained by wind. Our results show that the LoVe area is a quiet area suitable to study noise from wind, and our results confirms that the wind generated noise at low frequencies is significantly higher at the LoVe Observatory than in the Wenz curve.