Approaches to a Quantitative Analytical Description of Low Frequency Sound Absorption in Sea Water

摘要

The absorption of sound in sea water at low frequency (1-100 kHz) and intermediate frequency (50-500 kHz) ranges can be defined by a series of relaxation phenomena, each of which can be described mathematically by a Debye relationship. Below 5 kHz, the principal absorption mechanism is attributed to borate and magnesium/carbonate interactions, while in the range 5 to 50 kHz the absorption arises from magnesium sulphate ion pair formation in sea water. The dependence of the various relaxation modes on oceanographic variables is outlined in quantitative terms based on results from deep ocean sound channel experiments and laboratory experiments.