This study concentrates on the modelling of interactions of sea ice with atmospheric and oceanic boundary layers. Here, the main interest focuses on frazil ice which is the first stage of the ice cycle (sea ice formation). Frazil forms in the ocean mixed layer (OML) during severe turbulent conditions (strong winds, large waves) and episodes of supercooling events related to heat loss due to atmospheric cooling. In this study, a numerical model is used to simulate frazil ice production in the open areas within sea ice sheets to imitate (such as) a polynya or a lead. The simulations are based on the CROCO model with implemented frazil-related processes. The mentioned phenomenon is investigated in terms of frazil influence on the OML properties (with and without ice crystals) and changes in frazil concentration. The results are presented as a reference case which includes OML properties and circulation without frazil under various wind velocity and air temperatures, and cases with frazil ice. Besides, changes of frazil ice concentration in time and surface fluxes (heat and moist) are studied either. In general, the simulations are used to investigate the dependence of frazil ice production on the ambient environment (the ocean and the atmosphere) which is confirmed by this study.