A temperature-dependent multi-relaxation spectroscopic dielectric model for thawed and frozen organic soil at 0.05–15 GHz

The dielectric model for an arctic organic-rich soil collected on the Yamal peninsula (50% of organic matter) both thawed and frozen has been developed. The model is based on the soil dielectric measurements carried out in the ranges of gravimetric moisture 0.03 to 0.55 g/g, dry soil density 0.72 to 0.87 g/cm³, and temperature 25 to -30°C (cooling run), in the frequency range 0.05-15 GHz. To fit the results of measurements of the soil complex dielectric constant as a function of soil moisture and wave frequency, the refractive mixing dielectric model in conjunction with the Debye multi-relaxation equations were applied. As a result, the spectroscopic parameters of dielectric relaxations and electrical specific conductivities for the bound, transient bound, and unbound soil water components were derived, being further complimented with the thermodynamics parameters. Having these parameters, the complex dielectric constant of soil can be predicted as a function of 1) density of dry soil, 2) gravimetric moisture, 3) wave frequency, and 4) temperature¹.