As global temperatures increase, the Arctic has become a more critical area of interest for researchers across a diversity of scientific disciplines. In particular, Polar Amplification, where melting ice coverage increases radiative heat uptake accelerating further melting, presents a challenging situation for retreating ice coverage in the Arctic. Rarely does ice exists as a pure substance in nature, and knowledge about the effect of organic and inorganic matter on heat transport and melting mechanisms in ice can help to predict ice melting in natural environments as well as inform strategies to reduce ice loss in the Arctic. Thermal transport in ice is a result of convective, radiative, and conductive heat transfer processes. Convective thermal uptake results from warming of the ambient air; incident solar radiation initiates radiative absorption; and ice takes in heat by conductive means as a result of being in contact with warming aspects of the environment. This study was developed to examine the fundamentals of heat transport through ice with impurities, so that its thermal and mechanical properties may be reasonably predicted in environments with variable temperatures.  In particular, we are studying heat transfer and melting mechanisms in polycrystalline ice containing cellulose nanofibers (CNFs) and/or bentonite nanoclays (NCs). The overall goal is to investigate the hypothesis that second phase materials decrease thermal transport in ice by decreasing both interfacial and internal heat transfer. Polycrystalline ice materials with variable weight percentages (wt%) of CNFs and/or NCs were made using thermal gradients to manipulate the microstructure and location of nanomaterials within the ice microstructure. Convective, radiative, and conductive heat transfer was determined by melting, spectroradiometry, and conductivity measurements, respectively. Microstructural characterization was performed with cross-polarized, optical microscopy and microcomputed tomography. Results on ice containing CNFs disbursed throughout the ice microstructure indicate that melt rate and reflectivity of the ice samples depend on CNF and NC wt% and the resulting crystalline microstructure.

Mechanisms of heat transfer in ice containing organic and inorganic matter

2019 Fall National Meeting

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