Ebner Pirmin Philipp, Schneebeli Martin, Steinfeld Aldo (2016), Metamorphism during temperature gradient with undersaturated advective airflow in a snow sample, in The Cryosphere
, 10(2), 791-797.
Ebner Pirmin Philipp, Andreoli Christian, Schneebeli Martin, Steinfeld Aldo (2015), Tomography-based characterization of ice-air interface dynamics of temperature gradient snow metamorphism under advective conditions, in Journal of Geographical Research
, 120(12), 2437-2451.
Ebner Pirmin Philipp, Schneebeli Martin, Steinfeld Aldo (2015), Tomography-based monitoring of isothermal snow metamorphism under advective conditions, in The Cryosphere
, 9, 1363-1371.
Ebner Pirmin Philipp, Grimm Sascha, Schneebeli Martin, Steinfeld Aldo (2014), An instrumented sample holder for time-lapse micro-tomography measurements of snow under advective conditions, in Geoscientific Instrumentation Methods and Data Systems
, 3, 179-185.
Using in-situ micro-tomography of representative snow samples, we plan to develop an experimental system where metamorphism under airflow can be quantified. In-situ time-lapse experimental runs will be first conducted in micro computer tomography (µCT) on quasi-isothermal snow, and then extended on snow under a temperature gradient. A new sample holder will be designed for these experiments. Effective heat and mass transport properties, as well as diffusion and advection processes at the pore level, will be determined by direct pore-level numerical simulations and validated with direct measurements. Finally, phase-field modeling will simulate the observed evolution of the microstructure.The 3D geometrical representations of snow samples will be obtained by µCT and used in direct pore-level simulations (DPLS) to numerically solve the governing mass, momentum, and energy conservation equations, allowing for the determination of the snow’s effective transport properties. Of special focus is the accurate determination of the effective permeability and thermal conductivity. Vapor mass flux and recrystallization rate will be determined using an adapted version of particle image velocimetry based on time-lapse images. We will examine the coupling between recrystallization rate and permeability for experiments with an imposed temperature gradient under advective conditions.A functional understanding of snow metamorphism combined with airflow will give more in-depth understanding of the snow structure observed in polar and alpine regions. The research proposed has crucial significance to a wide range of environmental processes, as the results of our experiments and simulations can be used for improving models of firn compaction and evolution, for understanding evolution of the snowpack in arctic regions, for elucidating the flux mechanism of trace gases exchanged between the ground and atmospheric air, and for providing more accurate effective transport properties to forecasting models of late-stage alpine snowpack responsible for large scale avalanches.