A Simple and Accurate Formula for the Absorption of Sound in Seawater

In this communication, a new empirical formula for the absorption of sound in seawater is derived. The starting point of this investigation is the formula proposed by Ainslie and McColm for attenuation due to the boron and magnesium relaxations. Constants in the expression are treated as parameters to be determined. Since this is a nonlinear inverse problem, a global search is used to find the parameter setting that yields the best fit to in situ absorption measurements. The obtained formula is simpler than and at least as accurate as the widely used absorption formula of FranÇois and Garrison (FG).