Seasonal and Diel Variability of the Underwater Noise in the Baltic Sea

Journal Article

Title: Seasonal and Diel Variability of the Underwater Noise in the Baltic Sea
Publication Date:
April 04, 2016
Journal: Journal of the Acoustical Society of America
Volume: 139
Pages: 1537-1547
Publisher: Acoustical Society of America
Stressor:

Document Access

Website: External Link

Citation

Klusek, Z.; Lisimenka, A. (2016). Seasonal and Diel Variability of the Underwater Noise in the Baltic Sea. Journal of the Acoustical Society of America, 139, 1537-1547.
Abstract: 

The results of ambient seanoise measurements performed in strongly stratified shallow basins in the southern Baltic Sea are presented. The experiments were conducted with an autonomous hydroacoustic buoy that was equipped with two omnidirectional hydrophones located inside and outside the seasonal waveguide. Data were collected in two areas with contrastingly diverse sound propagation conditions—at the Bornholm Deep in winter and at the Gdansk Deep in summer. The noise spectrum levels indicate a strong dependence on the sound propagation conditions (season, location) and show significant differences with the observation depth. At frequencies f < 1 kHz, the noise at the same wind speeds is approximately 10–15 dB higher in winter than in summer. The wind-driven component of the noise frequently does not match the patterns of the Knudsen curves. Furthermore, the noise demonstrates the diel variability. The relative differences of the noise spectrum levels inside and outside of the subsurface winter waveguide reveal regular changes by as much as 15 dB, and are the most visible in the frequency range of 1–2 kHz after sunset. The changes are synchronized with the vertical migration of marine organisms and correspond to the resonant frequencies of the fishes' swim bladders.

Find Tethys on InstagramFind Tethys on FacebookFind Tethys on Twitter
 
CAPTCHA
This question is for testing whether or not you are a human visitor and to prevent automated spam submissions.