Dependence of very-low- and ultra-low-frequency ocean ambient noise on wind speed

A long-held hypothesis is that ambient ocean noise at very-low (2–20 Hz) and ultra-low (0.1–2 Hz) frequencies is the result, at least in part, of wind-generated surface waves, and several researchers have addressed this matter, both in terms of measurement and theory. The present availability of high-sample-rate, long-term noise data from the United Nations Comprehensive Nuclear Test Ban Treaty Organization (CTBTO) hydrophones makes possible an in-depth examination of the wind–noise relationship. This paper presents a detailed data-based analysis of the dependence of noise level on wind speed, focused especially on how this relationship varies with location and with the time periods of the wind and noise variability. The results both support the hypothesis and indicate its limitations.