Microchannel formation in seaice

Liquid salty channels (brine) between growing ice platelets in sea ice are an important habitat for $CO_2$ - binding microalgaea with great impact on polar ecosystems. The structure formation of ice platelets is microscopically described and a phase field model is developed. The pattern formation during solidification of the two-dimensional interstitial liquid is considered by two coupled order parameters, the tetrahedricity as structure of ice and the salinity. These parameters describe the velocity of the freezing process and the velocity of structure formation, determine the phase diagram, the super-cooling and super-heating region, and the specific heat respectively. The model is used to calculate the short-time frozen micro-structures. The obtained morphological structure is compared with the vertical brine pore space obtained from Xray computed tomography. A consistent set of three parameters is achieved.