台风中的降雨对水下环境噪声的影响

The effects of typhoon induced rainfall on underwater ambient noise

利用数值模型和实验数据分析了台风过境前后雨成噪声对水下环境噪声的影响。该数值模型是基于简正波理论和雨成噪声的统计分析方法。在没有航船噪声和生物噪声的影响下,环境噪声主要是风成噪声和雨成噪声的总和。通过对海上实验数据的分析,深海水下噪声将会在台风眼壁到达前和离开后的两小时时刻受到雨成噪声的影响。在1～3 kHz的频段处,台风中的雨成噪声要比风成噪声大5～6 dB,并且雨成噪声谱的强度随频率的变化比风成噪声谱的变化平缓。理论和实验对比结果显示,数值模型可以较好地预测实验数据。

The effects of rain generated noise on underwater ambient noise spectrum during typhoon transit are analyzed by using numerical model and experimental data.This numerical model is based on the normal mode theory and the statistical analysis of rain generated noise.The ambient noise intensity without taking account of ship and wildlife noise is mainly the sum of rain and wind generated noise.The acoustic data collected in an experiment are used to investigate the characteristics of ambient noise.It is observed that the received noise intensity in deep water would be affected by the rainfall noise at the time of two hours before the eye wall of typhoon arrival and after its departure.Besides,the spectrum levels of rain generated noise are about 5-6 dB higher than those of wind generated noise at the frequencies from 1 kHz to3 kHz,and the spectral slope of the former is flatter than the later one.By comparisons,it is shown that the simulated curves of the numerical model are in good agreement with the experimental data.