Climate Change and the Thermal Evolution of Fluid Permeability and Microstructure in Sea Ice

Sea ice is both an indicator and agent of climate change. It also hosts extensive microbial communities which sustain life in the polar oceans. Fluid flow through porous sea ice mediates a broad range of processes such as the growth and decay of seasonal ice, the evolution of melt ponds and ice pack reflectance, and biomass build-up. We will describe recent advances in using percolation, hierarchical, and network models to predict the fluid permeability of sea ice, and rigorous methods for bounding such transport coefficients. We'll also discuss X-ray CT imaging of the brine microstructure and connectivity analysis of random graphs derived from the tomographic images. Our work will help in predicting how global warming may affect Earth's sea ice packs and how polar ecosystems may respond. Related results on electromagnetic properties will help in monitoring ice thickness and the impact of climate change on the polar marine environment. Video from a 2007 Antarctic expedition where we measured fluid and electrical transport in sea ice will be shown.