DC Resistivity Measurements of Model Saline Ice Sheets

The dc resistivity structure of an artificially grown saline ice sheet at various stages of growth, thermal modification, and desalination has been determined by finding layered models to best fit Schlumberger array sounding data. Values between 2 and 90 ¿ · were obtained for model layers varying from 2-to 200-%o brine volume. After a strong warming and cooling cycle following 32-cm growth, the average resistivity had decreased by a factor of about 2 despite the brine volume having also decreased by nearly a factor of 2. This change with age plus the variability in the resistivity values implies that no simple correlation exists between brine volume and resistivity because permeability, which is related to age and temperature, is also a strong factor. The low resistivity values measured show that resistivity will strongly affect microwave radiometric emissions from young or warm sea ice.