An electrothermody namic model with distributed properties for effective perrnittivities of sea ice

This paper presents a model to calculate tile tcInperature de-pmclcncc of effective permit tivit ies for a 1 Ietero?;eneous anisotropic medium containing multiphase scatterers. With the strong pcrmit-tivity fluctuation approach, the mc)del is developed to account for the clcctrodynamic scattering effect together with the cluasi-static characteristics of multiple spccics and sulxpecics of inhomogencities with distributed orientations, sizes, and sl)apcs. DUC to a preferential direction in the orientation distribution, the medium is effectively 2 anisotropic. The size distribution is described with a probability density function in terms of normalized volumetric sizes. Scatterer shapes arc ncmunifcmn and have a genera] ellipsoidal form cllaracterizcxl by arbitrary axial ratios of correlation lengths which arc related to physical geometries of the scatterers. In tl]is formulation, sca ice consisting c)f solid ice, liquicl brine, and gaseous inclusions is moclelcd to derive a.nisotropic cffcctivc pcmnittivitics with thcrmodyrlamic phase redistribution and structural l]letal~lor])llis]l],, Theoretical results arc in goocl agrmxncnt with experimental data at 4.8 GHz for saline ice undergoing warming and cooling cycles. A competitive effect between the increase of liquid brine and the rouxidi]lg of ellipsoidal scatterers at increasing temperatures explains the trend observed in measured data. Sensitivities of cffcctivc permittivities to structural ancl physical parameters characterizing sea ice arc also studied.