Electrical properties of saline ice at 1 kHz down to −150 °C

Abstract

The temperature dependence of the dielectric properties of artificial sea ice are reported at 1 kHz, over a temperature range from −25 to −150 °C. Evidence is seen of predicted eutectic processes near −37, −42, and −54 °C, plus an additional one at −47 °C. The solidus point appears to lie between −70 and −75 °C. Brief reviews are given of relevant recent work involving pure and impure ices. The variation with temperature of the relaxation time and strength of the protonic relaxation process, the only one active below −80 °C, is analyzed and the results compared with this work. Their behavior is reasonably well understood in terms of the fluoride content of the original brine. There seems to be no direct evidence of doping which may be attributed to substitutionally included chloride.