A Temperature-Dependent Multi-Relaxation Spectroscopic Dielectric Model for Thawed and Frozen Organic Soil at 0.05-15 GHz

Publication date: Available online 14 March 2015 Source:Physics and Chemistry of the Earth, Parts A/B/C Author(s): Valery Mironov , Igor Savin A dielectric model for thawed and frozen Arctic organic-rich soil (50% organic matter) has been developed. The model is based on soil dielectric measurements that were collected over ranges of gravimetric moisture from 0.03 to 0.55 g/g, dry soil density from 0.72 to 0.87 g/cm3, and temperature from 25 to -30°C (cooling run) in the frequency range of 0.05-15 GHz. The refractive mixing dielectric model was applied with the Debye multi-relaxation equations to fit the measurements of the soil’s complex dielectric constant as a function of soil moisture and wave frequency. The spectroscopic parameters of the dielectric relaxations for the bound, transient bound, and unbound soil water components were derived and were complimented by the thermodynamic parameters to obtain a complete set of parameters for the proposed temperature-dependent multi-relaxation spectroscopic dielectric model for moist soils. To calculate the complex dielectric constant of the soil, the following input variables must be assigned: 1) density of dry soil, 2) gravimetric moisture, 3) wave frequency, and 4) temperature. The error of the dielectric model was evaluated and yielded RMSE ε’ values of 0.348 and 0.188 for the soil dielectric constant and the loss factor, respectively. These values are on the order of the dielectric measurement error itself. The ...

Source: Physics and Chemistry of the Earth, Parts ABC - March 16, 2015 Category: Science Source Type: research