Berlin 2014 – wissenschaftliches Programm
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UP: Fachverband Umweltphysik
UP 11: Postersession
UP 11.11: Poster
Mittwoch, 19. März 2014, 17:00–18:30, MAG Poster
Morphogenesis of short-time frozen microstructures in sea ice — •Bernd Kutschan1, Silke Thoms2, Klaus Morawetz1,3,4, and Sibylle Gemming5 — 1Münster University of Applied Sciences, Stegerwaldstrasse 39, 48565 Steinfurt, Germany — 2Alfred Wegener Institut, Am Handelshafen 12, D-27570 Bremerhaven, Germany — 3International Institute of Physics (IIP), Avenida Odilon Gomes de Lima 1722, 59078-400 Natal, Brazil — 4Max-Planck- Institute for the Physics of Complex Systems, 01187 Dresden, Germany — 5Institute of Ion Beam Physics and Materials Research, Helmholtz- Zentrum Dresden-Rossendorf, P.O. Box 51 01 19, 01314 Dresden, Germany
Microstructures of salty water in sea ice are a unique habitat for microorganisms with a remarkable adaptibility to extreme environmental conditions. We model the early phase of brine entrapment in sea ice without salinity conservation by a Turing model and with salinity conservation by a phase field theory. The theory includes both macroscopic salt diffusion and microscopic order parameter dynamics describing the different symmetries, hexagonal ice and liquid water. The first structures emerging during sea-ice formation are determined by the phase instability of the ice-water system in the presence of salt. Realistic parameters allow to calculate a phase diagram and two-dimensional microstructures found in agreement with the measured samples. From a methodical perspective our approach could also be used to describe the morphology of ice and snow crystals. The research is supported by DFG-Priority Program 1158.