Articles | Volume 14, issue 1
https://doi.org/10.5194/tc-14-131-2020
© Author(s) 2020. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
https://doi.org/10.5194/tc-14-131-2020
© Author(s) 2020. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Research article
| 
17 Jan 2020
Research article |
| 17 Jan 2020
| 17 Jan 2020
Modeling snow slab avalanches caused by weak-layer failure – Part 2: Coupled mixed-mode criterion for skier-triggered anticracks
Philipp L. Rosendahl
2phi GbR, Tübingen, Germany
Department of Mechanical Engineering, Technische Universität Darmstadt, Darmstadt, Germany
2phi GbR, Tübingen, Germany
Robert Bosch GmbH, Corporate Research and Advance Engineering,
Renningen, Germany
ARENA2036 research campus, Universität Stuttgart, Stuttgart, Germany
Related authors
Philipp L. Rosendahl and Philipp Weißgraeber
The Cryosphere, 14, 115–130, https://doi.org/10.5194/tc-14-115-2020, https://doi.org/10.5194/tc-14-115-2020, 2020
Short summary
Short summary
Dry-snow slab avalanche release is preceded by a fracture process within the snowpack. Recognizing weak layer collapse as an integral part of the fracture process is crucial and explains phenomena such as whumpf sounds and remote triggering of avalanches from low-angle terrain. In this first part of the two-part work we propose a novel closed-form analytical model for a snowpack that provides a highly efficient and precise analysis of the mechanical response of a loaded snowpack.
Philipp L. Rosendahl, Johannes Schneider, Grégoire Bobillier, Florian Rheinschmidt, Bastian Bergfeld, Alec van Herwijnen, and Philipp Weißgraeber
Nat. Hazards Earth Syst. Sci. Discuss., https://doi.org/10.5194/nhess-2024-122, https://doi.org/10.5194/nhess-2024-122, 2024
Revised manuscript accepted for NHESS
Short summary
Short summary
Our research investigates the role of anticracks in snowpacks and their impact on avalanche formation, focusing on anticracks due to weak layer collapse. We discovered that slab touchdown on the snow below the weak layer decreases the energy available for crack propagation, potentially leading to a stop of crack propagation. This underscores the importance of mechanical interactions in snowpack stability. Our work offers new insights for enhancing avalanche prediction and mitigation strategies.
Philipp Weißgraeber and Philipp L. Rosendahl
The Cryosphere, 17, 1475–1496, https://doi.org/10.5194/tc-17-1475-2023, https://doi.org/10.5194/tc-17-1475-2023, 2023
Short summary
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The work presents a mathematical model that calculates the behavior of layered snow covers in response to loadings. The information is necessary to predict the formation of snow slab avalanches. While sophisticated computer simulations may achieve the same goal, they can require weeks to run. By using mathematical simplifications commonly used by structural engineers, the present model can provide hazard assessments in milliseconds, even for snowpacks with many layers of different types of snow.
Bastian Bergfeld, Alec van Herwijnen, Grégoire Bobillier, Philipp L. Rosendahl, Philipp Weißgraeber, Valentin Adam, Jürg Dual, and Jürg Schweizer
Nat. Hazards Earth Syst. Sci., 23, 293–315, https://doi.org/10.5194/nhess-23-293-2023, https://doi.org/10.5194/nhess-23-293-2023, 2023
Short summary
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For a slab avalanche to release, the snowpack must facilitate crack propagation over large distances. Field measurements on crack propagation at this scale are very scarce. We performed a series of experiments, up to 10 m long, over a period of 10 weeks. Beside the temporal evolution of the mechanical properties of the snowpack, we found that crack speeds were highest for tests resulting in full propagation. Based on these findings, an index for self-sustained crack propagation is proposed.
Philipp L. Rosendahl and Philipp Weißgraeber
The Cryosphere, 14, 115–130, https://doi.org/10.5194/tc-14-115-2020, https://doi.org/10.5194/tc-14-115-2020, 2020
Short summary
Short summary
Dry-snow slab avalanche release is preceded by a fracture process within the snowpack. Recognizing weak layer collapse as an integral part of the fracture process is crucial and explains phenomena such as whumpf sounds and remote triggering of avalanches from low-angle terrain. In this first part of the two-part work we propose a novel closed-form analytical model for a snowpack that provides a highly efficient and precise analysis of the mechanical response of a loaded snowpack.
Related subject area
Discipline: Snow | Subject: Snow Physics
Multiscale modeling of heat and mass transfer in dry snow: influence of the condensation coefficient and comparison with experiments
Separating the albedo reducing effect of different light absorbing particles on snow using deep learning
Wind tunnel experiments to quantify the effect of aeolian snow transport on the surface snow microstructure
Spatial variation in the specific surface area of surface snow measured along the traverse route from the coast to Dome Fuji, Antarctica, during austral summer
Microstructure-based simulations of the viscous densification of snow and firn
A rigorous approach to the specific surface area evolution in snow during temperature gradient metamorphism
A microstructure-based parameterization of the effective anisotropic elasticity tensor of snow, firn, and bubbly ice
Seismic attenuation in Antarctic firn
Temporospatial variability of snow's thermal conductivity on Arctic sea ice
Heterogeneous grain growth and vertical mass transfer within a snow layer under a temperature gradient
Impact of the sampling procedure on the specific surface area of snow measurements with the IceCube
Wind conditions for snow cornice formation in a wind tunnel
Stochastic analysis of micro-cone penetration tests in snow
A generalized photon-tracking approach to simulate spectral snow albedo and transmittance using X-ray microtomography and geometric optics
Coherent backscatter enhancement in bistatic Ku- and X-band radar observations of dry snow
Effect of snowfall on changes in relative seismic velocity measured by ambient noise correlation
Orientation selective grain sublimation–deposition in snow under temperature gradient metamorphism observed with diffraction contrast tomography
Experimental and model-based investigation of the links between snow bidirectional reflectance and snow microstructure
Impact of water vapor diffusion and latent heat on the effective thermal conductivity of snow
Enhancement of snow albedo reduction and radiative forcing due to coated black carbon in snow
An exploratory modelling study of perennial firn aquifers in the Antarctic Peninsula for the period 1979–2016
Macroscopic water vapor diffusion is not enhanced in snow
Snow albedo sensitivity to macroscopic surface roughness using a new ray-tracing model
A model for French-press experiments of dry snow compaction
Identification of blowing snow particles in images from a Multi-Angle Snowflake Camera
Modeling snow slab avalanches caused by weak-layer failure – Part 1: Slabs on compliant and collapsible weak layers
Modeling the evolution of the structural anisotropy of snow
Motion of dust particles in dry snow under temperature gradient metamorphism
Influence of light-absorbing particles on snow spectral irradiance profiles
Saharan dust events in the European Alps: role in snowmelt and geochemical characterization
On the suitability of the Thorpe–Mason model for calculating sublimation of saltating snow
The influence of layering and barometric pumping on firn air transport in a 2-D model
Lisa Bouvet, Neige Calonne, Frédéric Flin, and Christian Geindreau
The Cryosphere, 18, 4285–4313, https://doi.org/10.5194/tc-18-4285-2024, https://doi.org/10.5194/tc-18-4285-2024, 2024
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Four different macroscopic heat and mass transfer models have been derived for a large range of condensation coefficient values by an upscaling method. A comprehensive evaluation of the models is presented based on experimental datasets and numerical examples. The models reproduce the trend of experimental temperature and density profiles but underestimate the magnitude of the processes. Possible causes of these discrepancies and potential improvements for the models are suggested.
Lou-Anne Chevrollier, Adrien Wehrlé, Joseph M. Cook, Norbert Pirk, Liane G. Benning, Alexandre M. Anesio, and Martyn Tranter
EGUsphere, https://doi.org/10.5194/egusphere-2024-2583, https://doi.org/10.5194/egusphere-2024-2583, 2024
Short summary
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Light absorbing particles (LAPs) are often present as a mixture on snow surfaces, and are important to disentangle because their darkening effect varies, but also because the processes governing their presence and accumulation on snow surfaces are different. This study presents a novel method to retrieve the concentration and albedo reducing effect of different LAPs present at the snow surface from surface spectral albedo. The method is then successfully applied to observations on seasonal snow.
Benjamin Walter, Hagen Weigel, Sonja Wahl, and Henning Löwe
The Cryosphere, 18, 3633–3652, https://doi.org/10.5194/tc-18-3633-2024, https://doi.org/10.5194/tc-18-3633-2024, 2024
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The topmost layer of a snowpack forms the interface to the atmosphere and is critical for the reflectance of solar radiation and avalanche formation. The effect of wind on the surface snow microstructure during precipitation events is poorly understood and quantified. We performed controlled lab experiments in a ring wind tunnel to systematically quantify the snow microstructure for different wind speeds, temperatures and precipitation intensities and to identify the relevant processes.
Ryo Inoue, Teruo Aoki, Shuji Fujita, Shun Tsutaki, Hideaki Motoyama, Fumio Nakazawa, and Kenji Kawamura
The Cryosphere, 18, 3513–3531, https://doi.org/10.5194/tc-18-3513-2024, https://doi.org/10.5194/tc-18-3513-2024, 2024
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We measured the snow specific surface area (SSA) at ~2150 surfaces between the coast near Syowa Station and Dome Fuji, East Antarctica, in summer 2021–2022. The observed SSA shows no elevation dependence between 15 and 500 km from the coast and increases toward the dome area beyond the range. SSA varies depending on surface morphologies and meteorological events. The spatial variation of SSA can be explained by snow metamorphism, snowfall frequency, and wind-driven inhibition of snow deposition.
Kévin Fourteau, Johannes Freitag, Mika Malinen, and Henning Löwe
The Cryosphere, 18, 2831–2846, https://doi.org/10.5194/tc-18-2831-2024, https://doi.org/10.5194/tc-18-2831-2024, 2024
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Understanding the settling of snow under its own weight has applications from avalanche forecasts to ice core interpretations. We study how this settling can be modeled using 3D images of the internal structure of snow and ice deformation mechanics. We found that classical ice mechanics, as used, for instance, in glacier flow, explain the compaction of dense polar snow but not that of lighter seasonal snow. How, exactly, the ice deforms during light snow compaction thus remains an open question.
Anna Braun, Kévin Fourteau, and Henning Löwe
The Cryosphere, 18, 1653–1668, https://doi.org/10.5194/tc-18-1653-2024, https://doi.org/10.5194/tc-18-1653-2024, 2024
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The specific surface of snow dictates key physical properties and continuously evolves in natural snowpacks. This is referred to as metamorphism. This work develops a rigorous physical model for this evolution, which is able to reproduce X-ray tomography measurements without using unphysical tuning parameters. Our results emphasize that snow crystal growth at the micrometer scale ultimately controls the pace of metamorphism.
Kavitha Sundu, Johannes Freitag, Kévin Fourteau, and Henning Löwe
The Cryosphere, 18, 1579–1596, https://doi.org/10.5194/tc-18-1579-2024, https://doi.org/10.5194/tc-18-1579-2024, 2024
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Ice crystals often show a rod-like, vertical orientation in snow and firn; they are said to be anisotropic. The stiffness in the vertical direction therefore differs from the horizontal, which, for example, impacts the propagation of seismic waves. To quantify this anisotropy, we conducted finite-element simulations of 391 snow, firn, and ice core microstructures obtained from X-ray tomography. We then derived a parameterization that may be employed for advanced seismic studies in polar regions.
Stefano Picotti, José M. Carcione, and Mauro Pavan
The Cryosphere, 18, 169–186, https://doi.org/10.5194/tc-18-169-2024, https://doi.org/10.5194/tc-18-169-2024, 2024
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A physical explanation of the seismic attenuation in the polar snow and ice masses is essential to gaining insight into the ice sheet and deeper geological formations. We estimate the P- and S-wave attenuation profiles of the Whillans Ice Stream from the spectral analysis of three-component active-source seismic data. The firn and ice quality factors are then modeled using a rock-physics theory that combines White's mesoscopic attenuation theory of interlayer flow with that of Biot/squirt flow.
Amy R. Macfarlane, Henning Löwe, Lucille Gimenes, David N. Wagner, Ruzica Dadic, Rafael Ottersberg, Stefan Hämmerle, and Martin Schneebeli
The Cryosphere, 17, 5417–5434, https://doi.org/10.5194/tc-17-5417-2023, https://doi.org/10.5194/tc-17-5417-2023, 2023
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Snow acts as an insulating blanket on Arctic sea ice, keeping the underlying ice "warm", relative to the atmosphere. Knowing the snow's thermal conductivity is essential for understanding winter ice growth. During the MOSAiC expedition, we measured the thermal conductivity of snow. We found spatial and vertical variability to overpower any temporal variability or dependency on underlying ice type and the thermal resistance to be directly influenced by snow height.
Lisa Bouvet, Neige Calonne, Frédéric Flin, and Christian Geindreau
The Cryosphere, 17, 3553–3573, https://doi.org/10.5194/tc-17-3553-2023, https://doi.org/10.5194/tc-17-3553-2023, 2023
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This study presents two new experiments of temperature gradient metamorphism in a snow layer using tomographic time series and focusing on the vertical extent. The results highlight two little known phenomena: the development of morphological vertical heterogeneities from an initial uniform layer, which is attributed to the temperature range and the vapor pressure distribution, and the quantification of the mass loss at the base caused by the vertical vapor fluxes and the dry lower boundary.
Julia Martin and Martin Schneebeli
The Cryosphere, 17, 1723–1734, https://doi.org/10.5194/tc-17-1723-2023, https://doi.org/10.5194/tc-17-1723-2023, 2023
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The grain size of snow determines how light is reflected and other physical properties. The IceCube measures snow grain size at the specific near-infrared wavelength of 1320 nm. In our study, the preparation of snow samples for the IceCube creates a thin layer of small particles. Comparisons of the grain size with computed tomography, particle counting and numerical simulation confirm the aforementioned observation. We conclude that measurements at this wavelength underestimate the grain size.
Hongxiang Yu, Guang Li, Benjamin Walter, Michael Lehning, Jie Zhang, and Ning Huang
The Cryosphere, 17, 639–651, https://doi.org/10.5194/tc-17-639-2023, https://doi.org/10.5194/tc-17-639-2023, 2023
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Snow cornices lead to the potential risk of causing snow avalanche hazards, which are still unknown so far. We carried out a wind tunnel experiment in a cold lab to investigate the environmental conditions for snow cornice accretion recorded by a camera. The length growth rate of the cornices reaches a maximum for wind speeds approximately 40 % higher than the threshold wind speed. Experimental results improve our understanding of the cornice formation process.
Pyei Phyo Lin, Isabel Peinke, Pascal Hagenmuller, Matthias Wächter, M. Reza Rahimi Tabar, and Joachim Peinke
The Cryosphere, 16, 4811–4822, https://doi.org/10.5194/tc-16-4811-2022, https://doi.org/10.5194/tc-16-4811-2022, 2022
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Characterization of layers of snowpack with highly resolved micro-cone penetration tests leads to detailed fluctuating signals. We used advanced stochastic analysis to differentiate snow types by interpreting the signals as a mixture of continuous and discontinuous random fluctuations. These two types of fluctuation seem to correspond to different mechanisms of drag force generation during the experiments. The proposed methodology provides new insights into the characterization of snow layers.
Theodore Letcher, Julie Parno, Zoe Courville, Lauren Farnsworth, and Jason Olivier
The Cryosphere, 16, 4343–4361, https://doi.org/10.5194/tc-16-4343-2022, https://doi.org/10.5194/tc-16-4343-2022, 2022
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We present a radiative transfer model that uses ray tracing to determine optical properties from computer-generated 3D renderings of snow resolved at the microscale and to simulate snow spectral reflection and transmission for visible and near-infrared light. We expand ray-tracing techniques applied to sub-1 cm3 snow samples to model an entire snowpack column. The model is able to reproduce known snow surface optical properties, and simulations compare well against field observations.
Marcel Stefko, Silvan Leinss, Othmar Frey, and Irena Hajnsek
The Cryosphere, 16, 2859–2879, https://doi.org/10.5194/tc-16-2859-2022, https://doi.org/10.5194/tc-16-2859-2022, 2022
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The coherent backscatter opposition effect can enhance the intensity of radar backscatter from dry snow by up to a factor of 2. Despite widespread use of radar backscatter data by snow scientists, this effect has received notably little attention. For the first time, we characterize this effect for the Earth's snow cover with bistatic radar experiments from ground and from space. We are also able to retrieve scattering and absorbing lengths of snow at Ku- and X-band frequencies.
Antoine Guillemot, Alec van Herwijnen, Eric Larose, Stephanie Mayer, and Laurent Baillet
The Cryosphere, 15, 5805–5817, https://doi.org/10.5194/tc-15-5805-2021, https://doi.org/10.5194/tc-15-5805-2021, 2021
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Ambient noise correlation is a broadly used method in seismology to monitor tiny changes in subsurface properties. Some environmental forcings may influence this method, including snow. During one winter season, we studied this snow effect on seismic velocity of the medium, recorded by a pair of seismic sensors. We detected and modeled a measurable effect during early snowfalls: the fresh new snow layer modifies rigidity and density of the medium, thus decreasing the recorded seismic velocity.
Rémi Granger, Frédéric Flin, Wolfgang Ludwig, Ismail Hammad, and Christian Geindreau
The Cryosphere, 15, 4381–4398, https://doi.org/10.5194/tc-15-4381-2021, https://doi.org/10.5194/tc-15-4381-2021, 2021
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In this study on temperature gradient metamorphism in snow, we investigate the hypothesis that there exists a favourable crystal orientation relative to the temperature gradient. We measured crystallographic orientations of the grains and their microstructural evolution during metamorphism using in situ time-lapse diffraction contrast tomography. Faceted crystals appear during the evolution, and we observe higher sublimation–deposition rates for grains with their c axis in the horizontal plane.
Marie Dumont, Frederic Flin, Aleksey Malinka, Olivier Brissaud, Pascal Hagenmuller, Philippe Lapalus, Bernard Lesaffre, Anne Dufour, Neige Calonne, Sabine Rolland du Roscoat, and Edward Ando
The Cryosphere, 15, 3921–3948, https://doi.org/10.5194/tc-15-3921-2021, https://doi.org/10.5194/tc-15-3921-2021, 2021
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The role of snow microstructure in snow optical properties is only partially understood despite the importance of snow optical properties for the Earth system. We present a dataset combining bidirectional reflectance measurements and 3D images of snow. We show that the snow reflectance is adequately simulated using the distribution of the ice chord lengths in the snow microstructure and that the impact of the morphological type of snow is especially important when ice is highly absorptive.
Kévin Fourteau, Florent Domine, and Pascal Hagenmuller
The Cryosphere, 15, 2739–2755, https://doi.org/10.5194/tc-15-2739-2021, https://doi.org/10.5194/tc-15-2739-2021, 2021
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The thermal conductivity of snow is an important physical property governing the thermal regime of a snowpack and its substrate. We show that it strongly depends on the kinetics of water vapor sublimation and that previous experimental data suggest a rather fast kinetics. In such a case, neglecting water vapor leads to an underestimation of thermal conductivity by up to 50 % for light snow. Moreover, the diffusivity of water vapor in snow is then directly related to the thermal conductivity.
Wei Pu, Tenglong Shi, Jiecan Cui, Yang Chen, Yue Zhou, and Xin Wang
The Cryosphere, 15, 2255–2272, https://doi.org/10.5194/tc-15-2255-2021, https://doi.org/10.5194/tc-15-2255-2021, 2021
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We have explicitly resolved optical properties of coated BC in snow for explaining complex enhancement of snow albedo reduction due to coating effect in real environments. The parameterizations are developed for climate models to improve the understanding of BC in snow on global climate. We demonstrated that the contribution of BC coating effect to snow light absorption has exceeded dust over north China and will significantly contribute to the retreat of Arctic sea ice and Tibetan glaciers.
J. Melchior van Wessem, Christian R. Steger, Nander Wever, and Michiel R. van den Broeke
The Cryosphere, 15, 695–714, https://doi.org/10.5194/tc-15-695-2021, https://doi.org/10.5194/tc-15-695-2021, 2021
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This study presents the first modelled estimates of perennial firn aquifers (PFAs) in Antarctica. PFAs are subsurface meltwater bodies that do not refreeze in winter due to the isolating effects of the snow they are buried underneath. They were first identified in Greenland, but conditions for their existence are also present in the Antarctic Peninsula. These PFAs can have important effects on meltwater retention, ice shelf stability, and, consequently, sea level rise.
Kévin Fourteau, Florent Domine, and Pascal Hagenmuller
The Cryosphere, 15, 389–406, https://doi.org/10.5194/tc-15-389-2021, https://doi.org/10.5194/tc-15-389-2021, 2021
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There has been a long controversy to determine whether the effective diffusion coefficient of water vapor in snow is superior to that in free air. Using theory and numerical modeling, we show that while water vapor diffuses more than inert gases thanks to its interaction with the ice, the effective diffusion coefficient of water vapor in snow remains inferior to that in free air. This suggests that other transport mechanisms are responsible for the large vapor fluxes observed in some snowpacks.
Fanny Larue, Ghislain Picard, Laurent Arnaud, Inès Ollivier, Clément Delcourt, Maxim Lamare, François Tuzet, Jesus Revuelto, and Marie Dumont
The Cryosphere, 14, 1651–1672, https://doi.org/10.5194/tc-14-1651-2020, https://doi.org/10.5194/tc-14-1651-2020, 2020
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The effect of surface roughness on snow albedo is often overlooked,
although a small change in albedo may strongly affect the surface energy
budget. By carving artificial roughness in an initially smooth snowpack,
we highlight albedo reductions of 0.03–0.04 at 700 nm and 0.06–0.10 at 1000 nm. A model using photon transport is developed to compute albedo considering roughness and applied to understand the impact of roughness as a function of snow properties and illumination conditions.
Colin R. Meyer, Kaitlin M. Keegan, Ian Baker, and Robert L. Hawley
The Cryosphere, 14, 1449–1458, https://doi.org/10.5194/tc-14-1449-2020, https://doi.org/10.5194/tc-14-1449-2020, 2020
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We describe snow compaction laboratory data with a new mathematical model. Using a compression device that is similar to a French press with snow instead of coffee grounds, Wang and Baker (2013) compacted numerous snow samples of different densities at a constant velocity to determine the force required for snow compaction. Our mathematical model for compaction includes airflow through snow and predicts the required force, in agreement with the experimental data.
Mathieu Schaer, Christophe Praz, and Alexis Berne
The Cryosphere, 14, 367–384, https://doi.org/10.5194/tc-14-367-2020, https://doi.org/10.5194/tc-14-367-2020, 2020
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Wind and precipitation often occur together, making the distinction between particles coming from the atmosphere and those blown by the wind difficult. This is however a crucial task to accurately close the surface mass balance. We propose an algorithm based on Gaussian mixture models to separate blowing snow and precipitation in images collected by a Multi-Angle Snowflake Camera (MASC). The algorithm is trained and (positively) evaluated using data collected in the Swiss Alps and in Antarctica.
Philipp L. Rosendahl and Philipp Weißgraeber
The Cryosphere, 14, 115–130, https://doi.org/10.5194/tc-14-115-2020, https://doi.org/10.5194/tc-14-115-2020, 2020
Short summary
Short summary
Dry-snow slab avalanche release is preceded by a fracture process within the snowpack. Recognizing weak layer collapse as an integral part of the fracture process is crucial and explains phenomena such as whumpf sounds and remote triggering of avalanches from low-angle terrain. In this first part of the two-part work we propose a novel closed-form analytical model for a snowpack that provides a highly efficient and precise analysis of the mechanical response of a loaded snowpack.
Silvan Leinss, Henning Löwe, Martin Proksch, and Anna Kontu
The Cryosphere, 14, 51–75, https://doi.org/10.5194/tc-14-51-2020, https://doi.org/10.5194/tc-14-51-2020, 2020
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The anisotropy of the snow microstructure, given by horizontally aligned ice crystals and vertically interlinked crystal chains, is a key quantity to understand mechanical, dielectric, and thermodynamical properties of snow. We present a model which describes the temporal evolution of the anisotropy. The model is driven by snow temperature, temperature gradient, and the strain rate. The model is calibrated by polarimetric radar data (CPD) and validated by computer tomographic 3-D snow images.
Pascal Hagenmuller, Frederic Flin, Marie Dumont, François Tuzet, Isabel Peinke, Philippe Lapalus, Anne Dufour, Jacques Roulle, Laurent Pézard, Didier Voisin, Edward Ando, Sabine Rolland du Roscoat, and Pascal Charrier
The Cryosphere, 13, 2345–2359, https://doi.org/10.5194/tc-13-2345-2019, https://doi.org/10.5194/tc-13-2345-2019, 2019
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Light–absorbing particles (LAPs, e.g. dust or black carbon) in snow are a potent climate forcing agent. Their presence darkens the snow surface and leads to higher solar energy absorption. Several studies have quantified this radiative impact by assuming that LAPs were motionless in dry snow, without any clear evidence of this assumption. Using time–lapse X–ray tomography, we show that temperature gradient metamorphism of snow induces downward motion of LAPs, leading to self–cleaning of snow.
Francois Tuzet, Marie Dumont, Laurent Arnaud, Didier Voisin, Maxim Lamare, Fanny Larue, Jesus Revuelto, and Ghislain Picard
The Cryosphere, 13, 2169–2187, https://doi.org/10.5194/tc-13-2169-2019, https://doi.org/10.5194/tc-13-2169-2019, 2019
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Here we present a novel method to estimate the impurity content (e.g. black carbon or mineral dust) in Alpine snow based on measurements of light extinction profiles. This method is proposed as an alternative to chemical measurements, allowing rapid retrievals of vertical concentrations of impurities in the snowpack. In addition, the results provide a better understanding of the impact of impurities on visible light extinction in snow.
Biagio Di Mauro, Roberto Garzonio, Micol Rossini, Gianluca Filippa, Paolo Pogliotti, Marta Galvagno, Umberto Morra di Cella, Mirco Migliavacca, Giovanni Baccolo, Massimiliano Clemenza, Barbara Delmonte, Valter Maggi, Marie Dumont, François Tuzet, Matthieu Lafaysse, Samuel Morin, Edoardo Cremonese, and Roberto Colombo
The Cryosphere, 13, 1147–1165, https://doi.org/10.5194/tc-13-1147-2019, https://doi.org/10.5194/tc-13-1147-2019, 2019
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The snow albedo reduction due to dust from arid regions alters the melting dynamics of the snowpack, resulting in earlier snowmelt. We estimate up to 38 days of anticipated snow disappearance for a season that was characterized by a strong dust deposition event. This process has a series of further impacts. For example, earlier snowmelts may alter the hydrological cycle in the Alps, induce higher sensitivity to late summer drought, and finally impact vegetation and animal phenology.
Varun Sharma, Francesco Comola, and Michael Lehning
The Cryosphere, 12, 3499–3509, https://doi.org/10.5194/tc-12-3499-2018, https://doi.org/10.5194/tc-12-3499-2018, 2018
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The Thorpe-Mason (TM) model describes how an ice grain sublimates during aeolian transport. We revisit this classic model using simple numerical experiments and discover that for many common scenarios, the model is likely to underestimate the amount of ice loss. Extending this result to drifting and blowing snow using high-resolution turbulent flow simulations, the study shows that current estimates for ice loss due to sublimation in regions such as Antarctica need to be significantly updated.
Benjamin Birner, Christo Buizert, Till J. W. Wagner, and Jeffrey P. Severinghaus
The Cryosphere, 12, 2021–2037, https://doi.org/10.5194/tc-12-2021-2018, https://doi.org/10.5194/tc-12-2021-2018, 2018
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Ancient air enclosed in bubbles of the Antarctic ice sheet is a key source of information about the Earth's past climate. However, a range of physical processes in the snow layer atop an ice sheet may change the trapped air's chemical composition before it is occluded in the ice. We developed the first detailed 2-D computer simulation of these processes and found a new method to improve the reconstruction of past climate from air in ice cores bubbles.
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Short summary
Dry-snow slab avalanche release is preceded by a fracture process within the snowpack. Recognizing weak layer collapse as an integral part of the fracture process is crucial and explains phenomena such as whumpf sounds and remote triggering of avalanches from low-angle terrain. In this second part of the two-part work we propose a novel mixed-mode coupled stress and energy failure criterion for nucleation of weak layer failure due to external loading of the snowpack.
Dry-snow slab avalanche release is preceded by a fracture process within the snowpack....
