Underwater acoustic sensing applied to estimation of typhoon wind speed

Abstract

Hydrophones can capture the distant noise generated by sea surface winds caused by typhoons. These acoustic signals can be used to determine the intensity scale of typhoons. This study uses underwater noise modelling to estimate typhoon scales in terms of wind speed profiles (WSPs), which is the wind speed as a function of distance from the typhoon centre, averaged over all azimuths. The wind-driven noise intensity was considered to be the sum of the contributing noise sources in the area dominated by the typhoon. The motion paths and WSPs of typhoons were used as parameters in the modelling, and their effects on results were estimated. A typhoon eye passing over the location of acoustic measurement can cause a bias in WSP estimation. However, the simulation results demonstrated high correlation between wind speed and noise intensity for classifying typhoons and showed the potential capacity of underwater acoustics for monitoring typhoons.

Acknowledgements

We thank the Taiwan Central Weather Bureau for the detailed typhoon information and are grateful for support from the National Science Council of Taiwan (NSC99-2623-E-002-008-D).