Marine Physical Laboratory, Scripps Institution of Oceanography, University of California, San Diego, 9500 Gilman Drive, La Jolla, California 92093-0238, USA.
J Acoust Soc Am. 2013 May;133(5):2576-85. doi: 10.1121/1.4799341.
During the Philippine Sea experiment in May 2009, Deep Sound, a free-falling instrument platform, descended to a depth of 5.1 km and then returned to the surface. Two vertically aligned hydrophones monitored the ambient noise continuously throughout the descent and ascent. A heavy rainstorm passed over the area during the deployment, the noise from which was recorded over a frequency band from 5 Hz to 40 kHz. Eight kilometers from the deployment site, a rain gauge on board the R/V Kilo Moana provided estimates of the rainfall rate. The power spectral density of the rain noise shows two peaks around 5 and 30 kHz, elevated by as much as 20 dB above the background level, even at depths as great as 5 km. Periods of high noise intensity in the acoustic data correlate well with the rainfall rates recovered from the rain gauge. The vertical coherence function of the rain noise has well-defined zeros between 1 and 20 kHz, which are characteristic of a localized source on the sea surface. A curve-fitting procedure yields the vertical directional density function of the noise, which is sharply peaked, accurately tracking the storm as it passed over the sensor station.
在 2009 年 5 月的菲律宾海实验期间，自由落体仪器平台 Deep Sound 下降到 5.1 公里的深度，然后返回水面。两个垂直对齐的水听器在整个下降和上升过程中连续监测环境噪声。在部署过程中，一场暴雨经过该地区，记录了频率范围为 5 Hz 至 40 kHz 的噪声。在离部署地点 8 公里的地方，R/V Kilo Moana 上的一个雨量计提供了降雨量的估计值。雨滴噪声的功率谱密度显示在 5 和 30 kHz 左右有两个峰值，比背景噪声水平高出多达 20 dB，即使在深度达 5 公里的地方也是如此。声数据中的高噪声强度期与从雨量计恢复的降雨量很好地相关。雨滴噪声的垂直相干函数在 1 至 20 kHz 之间有明确的零点，这是海面局部源的特征。曲线拟合程序得出噪声的垂直方向密度函数，该函数峰值陡峭，准确地跟踪了风暴经过传感器站的过程。
