The Dielectric Constant of Sea Water at P-Band for Salinity From 0 to 150 pss

Measurements have been made at P-band (0.707 GHz) to construct a model for the dielectric constant of sea water and extend the model for the dielectric constant to high salinity [S > 50 practical salinity scale (pss)]. The measurements are part of research to develop a model for the dielectric constant suitable for future wide-bandwidth (BW) remote sensing of salinity and for application to water bodies, such as the Great Salt Lake with salinity significantly above that found in the open ocean. Measurements have been made at temperatures from 2 °C to 30 °C and salinity from 0 to 138 pss. The data have been fit to a Debye model for the dielectric constant with a single relaxation mode as has been employed at L-band (1.413 GHz), where remote sensing of salinity is currently done. Comparison with contemporary models developed from data at L-band indicates that the L-band model and new P-band model do well at both frequencies for salinity less than 50 pss, but at higher values of salinity, the L-band models diverge from the data. The data have also been used to test at high salinity the mathematical relationship between salinity and conductivity, which is the basis for the pss.