Measurements of the dielectric properties of seawater and NaCl solutions at 2.65 GHz

Abstract

Measurements at 2.653 GHz of the dielectric properties of seawater samples collected over the world's oceans and NaCl solutions over the concentration range 0.3 N to 0.7 N have been made over the temperature range 5.5° to 24°C to an accuracy of 0.2% in the real part of ε and 0.4% in the imaginary part of ε. The measurements demonstrate that the dielectric properties of seawater can be determined from its chlorinity alone but are substantially different from those of the 3.35 wt % NaCl solution, which has been taken in all previous work as a model for seawater. The data are presented in a form that is well fitted by a linear dependence on chlorinity. The accuracy of the measurements removes the uncertainty in the dielectric properties of seawater as a significant source of error in S band radiometric determination of ocean surface temperature.