Studying Arctic ice formation stays in the focus of research groups over the past decades in the context of ice cover changes, thermal budget and climate agenda in general. Nevertheless, the phenomenon’s underlying mechanisms are still not completely understood and described. The main reason for the lack in understanding is the limited experimental access to the field data, thus there is a need to build competent analogies between the natural (ocean water – ice) and laboratory (binary alloy) conditions of the experiment as a step of data preparation for the verification of the mathematical model. In the current paper the existing qualitative models describing the process of melting and crystallization were expanded and the experimental method was developed copying the layering of the natural ocean water – ice mixture. The experimental set-up for studying the solidification within the intermediate zone was designed for Al-Cu alloys and the corresponding experimental data was used for the development of a binary phase-field model for solidification considering moving boundaries. The model includes the description of the free energy of both phases and their respective diffusion coefficients. It allows modeling of the eutectic alloys and potentially corresponding natural ocean water — ice mixture at a mesoscopic spatial level by including the concentration-driven phase transition. The novel results will help the quantitative understanding of solidification phenomena and are highly-evaluated from interdisciplinary point of view, including glaciology and geosciences, ultimately significant for the understanding the global climate change landscape.