Dielectric and mechanical alterations of snow properties near the melting temperature

Abstract

The dielectric and mechanical properties of snow were investigated in the temperature range –15 to 0°C. Dielectric measurements were carried out in the frequency range 50 Hz – 5 MHz; the low-frequency conductivity (at 100 Hz) of snow samples shows a peak in the temperature range –3 to –0.3°C and the dielectric dispersion-strength also shows a minimum in this same range. The propagation velocity of an elastic wave through snow samples was measured with a vibration response method in the frequency range 10 Hz – 1 MHz; the propagation velocity shows an increase with the bond growth as a result of progressive sintering, and a significant decrease above –0.6°C. The temperature dependence of the low-frequency conductivity and the propagation velocity for snow samples show a hysteresis near the melting temperature. A boundary between ice particles in snow samples is discussed as a means for understanding these phenomena. PACS Nos.: 61.43Gt, 77.22Gm, 46.40-f, 73.25+i