Ocean Ultrasonic Shear and Compression Viscosities

Abstract

A comprehensive description of ocean molecular flow and deformation is provided with the help of\nhydrodynamic and ultrasonic principles. Hydrodynamic computation of true or natural viscosities shows that ocean shear\nviscosity (?G), compression viscosity (?K), and extensional viscosity (?E) are interrelated. There are no experimental\nmethods available for the in situ measurement of these viscosities. Sound absorption coefficients (? obs) allow to know the\nultrasonic shear (?UG), compression (?UK), and longitudinal (?L) viscosities, which decrease with increasing frequency and\nincrease with increasing temperature, the flow activation energies having nearly equivalent values; pressure (depth)\nincrease/decrease them at low/high frequencies. The viscosities ?*\nUG, ?*\nUK, ?*\nL are approached at about 1000 KHz. They\ndecrease with temperature and pressure, and increase with salinity. The ?*UG becomes equal to the true shear viscosity ? G\nat the viscosity ratio ? = ?UK / ?UG = 0.