I have been working for the last 3 years on noise generated by waves in the ocean. Firstly I was looking at seismic noise (measured by seismometers on land) but a recent paper by Duennebier et al. (JGR 2012) prompted me to look into acoustic noise in the water column as well.
Basically the seismic noise theory tells us that most of the noise recorded on the vertical channel of seismometers is associated to Rayleigh waves (also called pseudo-Rayleigh waves when they travel over the oceans). This theory predicts that most of the acoustic noise at depths below say 500 m is actually the water motion that comes with these pseudo-Rayleigh waves. I am right now writing a paper about it using the Duennebier et al. data and some other datasets.
However, some papers and books, and I'm particularly thinking about the 1996 book by Kibblewhite and Wu, write that the bottom only increases the noise level by 3 dB, when I have found something more like 15 to 20 dB at least for frequencies below 1 Hz. I would be curious to hear comments on these results and some other data sets.
Are you omitting earthquake and shipping noise? Depending on where you are, earthquakes induce the loudest acoustic disturbance, whereas shipping traffic induces the loudest background noise.
O.A. Godin has a done a lot of work in this area. I suggest you keyword his name on Google Scholar and see what he has to say. You might also want to give him a call and pose your questions direct. I'm sure he would not object.
As to what I have read, bottom reflections will increase noise levels by 3 dB.
Cheers
Dave Williams
Seismic noise should not be treated independent of other sources. Noise generated is a location dependent. Incorporate the suggestions of Capt. Williams.
Good luck.
Francis Akinluyi
I was thinking more about the very low frequency noise ( f < 1 Hz) which is dominated by wave-generated noise. Actually our paper has just been accepted
Article A numerical model for ocean ultra low frequency noise: wave-...
Hi Fabrice,
don't forget tit noise due to rocking of the sensor. Due to tilt the seismometer is not perfectly vertical and signal that otherwise would only affect the horizontal components is projected on the vertical. This topic is treated, for example, in the paper:
"Identifying and Removing Tilt Noise from Low-Frequency (
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