Open ocean ambient noise data in the frequency band of 100 Hz-50 kHz from the Pacific Ocean

Abstract

Bubbles from wind generated breaking surface waves are the dominant ambient noise source [Dean and Stokes, Nature 418, 839-844 (2002)]. With ambient noise data collected in the open ocean between 100 Hz and 50 kHz from 1999 to 2022, the ambient noise level is observed to sharply decrease as wind speed increases beyond 15 m/s for frequencies higher than 4 kHz. Data-model comparisons show a mismatch, as existing models including the Wenz curves [Wenz, J. Acoust. Soc. Am. 34, 1936-1956 (1962)] are monotonic in nature. The decrease at high wind speeds and frequencies is likely due to attenuation when ambient sound propagates through the deeper and denser bubble layer for high sea conditions [Farmer and Lemon, J. Phys. Oceanogr. 14, 1761-1777 (1984)].