Sound absorption based on ocean measurements: Part I: Pure water and magnesium sulfate contributions

Abstract

Between 10 and 1000 kHz the absorption of sound in sea water can be considered as the sum of contributions from pure water and magnesium sulfate. Near 10 kHz there is also a small contribution from boric acid. In this paper, the contribution from MgSo4 is treated extensively using the authors’ measurements of absorption in the ocean to construct a quantitative equation for absorption as a function of temperature, salinity, and depth. The frequency region below 10 kHz, where the boric acid contribution predominates, will be reviewed later in Part II which includes an equation for the total absorption in the frequency range 400 Hz to 1 MHz.

Toward ocean attenuation tomography: Determining acoustic volume attenuation coefficients in seawater using eigenray amplitudes

“…The frequency-dependent attenuation coefficients found here from experimental data agree well with those calculated using Francois and Garrison, 13 showing the attenuation coefficients in the 3.5-8.5 kHz band have not changed over the past 30 years. More important than agreeing with a model based on data more than 40 years old is the result that climate related ocean change in the same time did not result in a significant change of the equations in this frequency range.…”

Shipping noise in a dynamic sea: a case study of grey seals in the Celtic Sea

“…is defined by 10, 20 and 15 (e.g. Bailey et al, 2010;Erbe et al, 2012), representing the cylindrical spreading, spherical spreading and intermediate from Francois and Garrison (1982).…”

Differences in backscattering strength determined at 120 and 38 kHz for three species of Antarctic macroplankton

“…Spreading a n d attenuation loss corrections were applied, the latter according to absorption coefficients from Francois & Garrison (1982). The values used were interpolated to be appropriate to the water temperature and salinity in the study area.…”