Articles | Volume 17, issue 2
https://doi.org/10.5194/tc-17-639-2023
© Author(s) 2023. 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-17-639-2023
© Author(s) 2023. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Research article
| 
08 Feb 2023
Research article |
| 08 Feb 2023
| 08 Feb 2023
Wind conditions for snow cornice formation in a wind tunnel
Hongxiang Yu
College of Civil Engineering and Mechanics, Lanzhou University, Lanzhou, 730000, China
College of Architecture, Civil and Environmental Engineering, Ecole Polytechnique Federal de Lausanne, Lausanne, 1015, Switzerland
College of Atmospheric Science, Lanzhou University, Lanzhou, 730000, China
College of Architecture, Civil and Environmental Engineering, Ecole Polytechnique Federal de Lausanne, Lausanne, 1015, Switzerland
Benjamin Walter
WSL Institute for Snow and Avalanche Research SLF, Davos, 7260, Switzerland
College of Architecture, Civil and Environmental Engineering, Ecole Polytechnique Federal de Lausanne, Lausanne, 1015, Switzerland
WSL Institute for Snow and Avalanche Research SLF, Davos, 7260, Switzerland
Jie Zhang
College of Civil Engineering and Mechanics, Lanzhou University, Lanzhou, 730000, China
Ning Huang
CORRESPONDING AUTHOR
College of Civil Engineering and Mechanics, Lanzhou University, Lanzhou, 730000, China
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The Cryosphere, 18, 4493–4515, https://doi.org/10.5194/tc-18-4493-2024, https://doi.org/10.5194/tc-18-4493-2024, 2024
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Geosci. Model Dev., 16, 5049–5068, https://doi.org/10.5194/gmd-16-5049-2023, https://doi.org/10.5194/gmd-16-5049-2023, 2023
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Geosci. Model Dev., 15, 6429–6449, https://doi.org/10.5194/gmd-15-6429-2022, https://doi.org/10.5194/gmd-15-6429-2022, 2022
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Francesca Carletti, Adrien Michel, Francesca Casale, Alice Burri, Daniele Bocchiola, Mathias Bavay, and Michael Lehning
Hydrol. Earth Syst. Sci., 26, 3447–3475, https://doi.org/10.5194/hess-26-3447-2022, https://doi.org/10.5194/hess-26-3447-2022, 2022
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David N. Wagner, Matthew D. Shupe, Christopher Cox, Ola G. Persson, Taneil Uttal, Markus M. Frey, Amélie Kirchgaessner, Martin Schneebeli, Matthias Jaggi, Amy R. Macfarlane, Polona Itkin, Stefanie Arndt, Stefan Hendricks, Daniela Krampe, Marcel Nicolaus, Robert Ricker, Julia Regnery, Nikolai Kolabutin, Egor Shimanshuck, Marc Oggier, Ian Raphael, Julienne Stroeve, and Michael Lehning
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Atmos. Chem. Phys., 22, 4509–4522, https://doi.org/10.5194/acp-22-4509-2022, https://doi.org/10.5194/acp-22-4509-2022, 2022
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Joel Fiddes, Kristoffer Aalstad, and Michael Lehning
Geosci. Model Dev., 15, 1753–1768, https://doi.org/10.5194/gmd-15-1753-2022, https://doi.org/10.5194/gmd-15-1753-2022, 2022
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The Cryosphere, 15, 3949–3973, https://doi.org/10.5194/tc-15-3949-2021, https://doi.org/10.5194/tc-15-3949-2021, 2021
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A service to enable real-time optimization of grooming and snow-making at ski resorts was developed and evaluated using both GNSS-measured snow depth and spaceborne snow maps derived from Copernicus Sentinel-2. The correlation to the ground observation data was high. Potential sources for the overestimation of the snow depth by the simulations are mainly the impact of snow redistribution by skiers, compensation of uneven terrain, or spontaneous local adaptions of the snow management.
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Atmos. Chem. Phys., 20, 12939–12953, https://doi.org/10.5194/acp-20-12939-2020, https://doi.org/10.5194/acp-20-12939-2020, 2020
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It has been recognized in earlier research that particle size distribution of dust at emission (dust PSD) is dependent on friction velocity. This recognition has been challenged in some recent papers. Based on the analysis of experimental data, we confirm that dust PSD is dependent on friction velocity and atmospheric boundary-layer stability. By theoretical and numerical analysis, we reveal the reasons for this dependency.
Hongchao Dun and Ning Huang
Atmos. Chem. Phys. Discuss., https://doi.org/10.5194/acp-2020-1021, https://doi.org/10.5194/acp-2020-1021, 2020
Revised manuscript not accepted
Benjamin Walter, Hendrik Huwald, Josué Gehring, Yves Bühler, and Michael Lehning
The Cryosphere, 14, 1779–1794, https://doi.org/10.5194/tc-14-1779-2020, https://doi.org/10.5194/tc-14-1779-2020, 2020
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We applied a horizontally mounted low-cost precipitation radar to measure velocities, frequency of occurrence, travel distances and turbulence characteristics of blowing snow off a mountain ridge. Our analysis provides a first insight into the potential of radar measurements for determining blowing snow characteristics, improves our understanding of mountain ridge blowing snow events and serves as a valuable data basis for validating coupled numerical weather and snowpack simulations.
Nander Wever, Leonard Rossmann, Nina Maaß, Katherine C. Leonard, Lars Kaleschke, Marcel Nicolaus, and Michael Lehning
Geosci. Model Dev., 13, 99–119, https://doi.org/10.5194/gmd-13-99-2020, https://doi.org/10.5194/gmd-13-99-2020, 2020
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Sea ice is an important component of the global climate system. The presence of a snow layer covering sea ice can impact ice mass and energy budgets. The detailed, physics-based, multi-layer snow model SNOWPACK was modified to simulate the snow–sea-ice system, providing simulations of the snow microstructure, water percolation and flooding, and superimposed ice formation. The model is applied to in situ measurements from snow and ice mass-balance buoys installed in the Antarctic Weddell Sea.
Varun Sharma, Louise Braud, and Michael Lehning
The Cryosphere, 13, 3239–3260, https://doi.org/10.5194/tc-13-3239-2019, https://doi.org/10.5194/tc-13-3239-2019, 2019
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Snow surfaces, under the action of wind, form beautiful shapes such as waves and dunes. This study is the first ever study to simulate these shapes using a state-of-the-art numerical modelling tool. While these beautiful and ephemeral shapes on snow surfaces are fascinating from a purely aesthetic point of view, they are also critical in regulating the transfer of heat and mass between the atmosphere and snowpacks, thus being of huge importance to the Earth system.
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.
Franziska Gerber, Nikola Besic, Varun Sharma, Rebecca Mott, Megan Daniels, Marco Gabella, Alexis Berne, Urs Germann, and Michael Lehning
The Cryosphere, 12, 3137–3160, https://doi.org/10.5194/tc-12-3137-2018, https://doi.org/10.5194/tc-12-3137-2018, 2018
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A comparison of winter precipitation variability in operational radar measurements and high-resolution simulations reveals that large-scale variability is well captured by the model, depending on the event. Precipitation variability is driven by topography and wind. A good portion of small-scale variability is captured at the highest resolution. This is essential to address small-scale precipitation processes forming the alpine snow seasonal snow cover – an important source of water.
Christian Gabriel Sommer, Nander Wever, Charles Fierz, and Michael Lehning
The Cryosphere, 12, 2923–2939, https://doi.org/10.5194/tc-12-2923-2018, https://doi.org/10.5194/tc-12-2923-2018, 2018
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Wind packing is how wind produces hard crusts at the surface of the snowpack. This is relevant for the local mass balance in polar regions. However, not much is known about this process and it is difficult to capture its high spatial and temporal variability. A wind-packing event was measured in Antarctica. It could be quantified how drifting snow leads to wind packing and generates barchan dunes. The documentation of these deposition dynamics is an important step in understanding polar snow.
Martin Beniston, Daniel Farinotti, Markus Stoffel, Liss M. Andreassen, Erika Coppola, Nicolas Eckert, Adriano Fantini, Florie Giacona, Christian Hauck, Matthias Huss, Hendrik Huwald, Michael Lehning, Juan-Ignacio López-Moreno, Jan Magnusson, Christoph Marty, Enrique Morán-Tejéda, Samuel Morin, Mohamed Naaim, Antonello Provenzale, Antoine Rabatel, Delphine Six, Johann Stötter, Ulrich Strasser, Silvia Terzago, and Christian Vincent
The Cryosphere, 12, 759–794, https://doi.org/10.5194/tc-12-759-2018, https://doi.org/10.5194/tc-12-759-2018, 2018
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This paper makes a rather exhaustive overview of current knowledge of past, current, and future aspects of cryospheric issues in continental Europe and makes a number of reflections of areas of uncertainty requiring more attention in both scientific and policy terms. The review paper is completed by a bibliography containing 350 recent references that will certainly be of value to scholars engaged in the fields of glacier, snow, and permafrost research.
Thomas Grünewald, Fabian Wolfsperger, and Michael Lehning
The Cryosphere, 12, 385–400, https://doi.org/10.5194/tc-12-385-2018, https://doi.org/10.5194/tc-12-385-2018, 2018
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Snow farming is the conservation of snow during summer. Large snow piles are covered with a sawdust insulation layer, reducing melt and guaranteeing a specific amount of available snow in autumn, independent of the weather conditions. Snow volume changes in two heaps were monitored, showing that about a third of the snow was lost. Model simulations confirmed the large effect of the insulation on energy balance and melt. The model can now be used as a tool to examine future snow-farming projects.
Ning Huang and Guanglei Shi
The Cryosphere, 11, 3011–3021, https://doi.org/10.5194/tc-11-3011-2017, https://doi.org/10.5194/tc-11-3011-2017, 2017
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Snow is an important part of the cryosphere, and blowing snow sublimation is an important method to change the snow distribution. However, in the previous studies blowing snow sublimation near surface was ignored. Herein, we built a blowing snow sublimation model to study the sublimation in near-surface region. The results showed that the mass of snow sublimation near surface accounted for even more than half of the total. Therefore, blowing snow sublimation near surface cannot be neglected.
Nander Wever, Francesco Comola, Mathias Bavay, and Michael Lehning
Hydrol. Earth Syst. Sci., 21, 4053–4071, https://doi.org/10.5194/hess-21-4053-2017, https://doi.org/10.5194/hess-21-4053-2017, 2017
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The assessment of flood risks in alpine, snow-covered catchments requires an understanding of the
linkage between the snow cover, soil and discharge in the stream network. Simulations of soil moisture and streamflow were performed and compared with observations. It was found that discharge at the catchment outlet during intense rainfall or snowmelt periods correlates positively with the initial soil moisture state, in both measurements and simulations.
Sebastian Würzer, Nander Wever, Roman Juras, Michael Lehning, and Tobias Jonas
Hydrol. Earth Syst. Sci., 21, 1741–1756, https://doi.org/10.5194/hess-21-1741-2017, https://doi.org/10.5194/hess-21-1741-2017, 2017
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We discuss a dual-domain water transport model in a physics-based snowpack model to account for preferential flow (PF) in addition to matrix flow. So far no operationally used snow model has explicitly accounted for PF. The new approach is compared to existing water transport models and validated against in situ data from sprinkling and natural rain-on-snow (ROS) events. Our work demonstrates the benefit of considering PF in modelling hourly snowpack runoff, especially during ROS conditions.
Anna Haberkorn, Nander Wever, Martin Hoelzle, Marcia Phillips, Robert Kenner, Mathias Bavay, and Michael Lehning
The Cryosphere, 11, 585–607, https://doi.org/10.5194/tc-11-585-2017, https://doi.org/10.5194/tc-11-585-2017, 2017
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The effects of permafrost degradation on rock slope stability in the Alps affect people and infrastructure. Modelling the evolution of permafrost is therefore of great importance. However, the snow cover has generally not been taken into account in model studies of steep, rugged rock walls. Thus, we present a distributed model study on the influence of the snow cover on rock temperatures. The promising results are discussed against detailed rock temperature measurements and snow depth data.
Christoph Marty, Sebastian Schlögl, Mathias Bavay, and Michael Lehning
The Cryosphere, 11, 517–529, https://doi.org/10.5194/tc-11-517-2017, https://doi.org/10.5194/tc-11-517-2017, 2017
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We simulate the future snow cover in the Alps with the help of a snow model, which is fed by projected temperature and precipitation changes from a large set of climate models. The results demonstrate that snow below 1000 m is probably a rare guest at the end of the century. Moreover, even above 3000 m the simulations show a drastic decrease in snow depth. However, the results reveal that the projected snow cover reduction can be mitigated by 50 % if we manage to keep global warming below 2°.
Aurélien Gallice, Mathias Bavay, Tristan Brauchli, Francesco Comola, Michael Lehning, and Hendrik Huwald
Geosci. Model Dev., 9, 4491–4519, https://doi.org/10.5194/gmd-9-4491-2016, https://doi.org/10.5194/gmd-9-4491-2016, 2016
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This paper presents the improvements brought to an existing model for discharge and temperature prediction in Alpine streams. Compared to the original model version, it is now possible to choose between various alternatives to simulate certain parts of the water cycle, such as the technique used to transfer water along the stream network. The paper includes an example of application of the model over an Alpine catchment in Switzerland.
Jie Zhang, Zhenjiao Teng, Ning Huang, Lei Guo, and Yaping Shao
Atmos. Chem. Phys., 16, 15517–15528, https://doi.org/10.5194/acp-16-15517-2016, https://doi.org/10.5194/acp-16-15517-2016, 2016
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In spite of the tremendous efforts, many questions remain unanswered regarding dust emission mechanisms. A series of wind tunnel experiments are carried out on dust emissions from different soil surfaces to better understand relevant mechanisms. Here are some interesting results that demonstrate the importance of surface renewal mechanism, which was normally neglected in previous research and is strongly recommended to be considered in future dust models.
Nander Wever, Sebastian Würzer, Charles Fierz, and Michael Lehning
The Cryosphere, 10, 2731–2744, https://doi.org/10.5194/tc-10-2731-2016, https://doi.org/10.5194/tc-10-2731-2016, 2016
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The study presents a dual domain approach to simulate liquid water flow in snow using the 1-D physics based snow cover model SNOWPACK. In this approach, the pore space is separated into a part for matrix flow and a part that represents preferential flow. Using this approach, water can percolate sub-freezing snow and form dense (ice) layers. A comparison with snow pits shows that some of the observed ice layers were reproduced by the model while others remain challenging to simulate.
Ning Huang, Xiaoqing Dai, and Jie Zhang
Atmos. Chem. Phys., 16, 7523–7529, https://doi.org/10.5194/acp-16-7523-2016, https://doi.org/10.5194/acp-16-7523-2016, 2016
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Drifting snow sublimation (DSS) is of glaciological and hydrological importance. This work is related to the simulation of DSS, which is obviously related to the scientific topics, such as multi-field coupling of wind, snow particles, humidity, etc. Previous studies argued that sublimation will soon vanish in saltation layer. This work shows the sublimation rate of saltating snow can be several orders of magnitude greater than that of the suspended snow due to the impact of moisture advection.
Rebecca Mott, Enrico Paterna, Stefan Horender, Philip Crivelli, and Michael Lehning
The Cryosphere, 10, 445–458, https://doi.org/10.5194/tc-10-445-2016, https://doi.org/10.5194/tc-10-445-2016, 2016
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For the first time, this contribution investigates atmospheric decoupling above melting snow in a wind tunnel study. High-resolution vertical profiles of
sensible heat fluxes are measured directly over the melting snow patch.
The study shows that atmospheric decoupling is strongly increased in topographic sheltering but only for low wind velocities. Then turbulent mixing close to the surface is strongly suppressed, facilitating the formation of cold-air pooling in local depressions.
N. Wever, L. Schmid, A. Heilig, O. Eisen, C. Fierz, and M. Lehning
The Cryosphere, 9, 2271–2293, https://doi.org/10.5194/tc-9-2271-2015, https://doi.org/10.5194/tc-9-2271-2015, 2015
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A verification of the physics based SNOWPACK model with field observations showed that typical snowpack properties like density and temperature are adequately simulated. Also two water transport schemes were verified, showing that although Richards equation improves snowpack runoff and several aspects of the internal snowpack structure, the bucket scheme appeared to have a higher agreement with the snow microstructure. The choice of water transport scheme may depend on the intended application.
W. Steinkogler, B. Sovilla, and M. Lehning
The Cryosphere, 9, 1819–1830, https://doi.org/10.5194/tc-9-1819-2015, https://doi.org/10.5194/tc-9-1819-2015, 2015
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Infrared radiation thermography (IRT) was used to assess the surface temperature of avalanches with high spatial resolution. Thermal energy increase due to friction was mainly depending on the elevation drop of the avalanche. Warming due to entrainment was very specific to the individual avalanche and depends on the temperature of the snow along the path and the erosion depth. The warmest temperatures were located in the deposits of the dense core.
A. Gallice, B. Schaefli, M. Lehning, M. B. Parlange, and H. Huwald
Hydrol. Earth Syst. Sci., 19, 3727–3753, https://doi.org/10.5194/hess-19-3727-2015, https://doi.org/10.5194/hess-19-3727-2015, 2015
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This study presents a new model to estimate the monthly mean stream temperature of ungauged rivers over multiple years in an Alpine country. Contrary to the other approaches developed to date, which are usually based on standard regression techniques, our model makes use of the understanding that we have about the physics controlling stream temperature. On top of its accuracy being comparable to that of the other models, it can be used to gain some knowledge about the stream temperature dynamics
E. Trujillo and M. Lehning
The Cryosphere, 9, 1249–1264, https://doi.org/10.5194/tc-9-1249-2015, https://doi.org/10.5194/tc-9-1249-2015, 2015
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In this article, we present a methodology for the objective evaluation of the error in capturing mean snow depths from point measurements. We demonstrate, using LIDAR snow depths, how the model can be used for assisting the design of survey strategies such that the error is minimized or an estimation threshold is achieved. Furthermore, the model can be extended to other spatially distributed snow variables (e.g., SWE) whose statistical properties are comparable to those of snow depth.
J. Schwaab, M. Bavay, E. Davin, F. Hagedorn, F. Hüsler, M. Lehning, M. Schneebeli, E. Thürig, and P. Bebi
Biogeosciences, 12, 467–487, https://doi.org/10.5194/bg-12-467-2015, https://doi.org/10.5194/bg-12-467-2015, 2015
T. Grünewald, Y. Bühler, and M. Lehning
The Cryosphere, 8, 2381–2394, https://doi.org/10.5194/tc-8-2381-2014, https://doi.org/10.5194/tc-8-2381-2014, 2014
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Elevation dependencies of snow depth are analysed based on snow depth maps obtained from airborne remote sensing. Elevation gradients are characterised by a specific shape: an increase of snow depth with elevation is followed by a distinct peak at a certain level and a decrease in the highest elevations. We attribute this shape to an increase of precipitation with altitude, which is modified by topographical-induced redistribution processes of the snow on the ground (wind, gravitation).
J. Zhang and Y. Shao
Atmos. Chem. Phys., 14, 12429–12440, https://doi.org/10.5194/acp-14-12429-2014, https://doi.org/10.5194/acp-14-12429-2014, 2014
N. Wever, T. Jonas, C. Fierz, and M. Lehning
Hydrol. Earth Syst. Sci., 18, 4657–4669, https://doi.org/10.5194/hess-18-4657-2014, https://doi.org/10.5194/hess-18-4657-2014, 2014
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We simulated a severe rain-on-snow event in the Swiss Alps in October 2011 with a detailed multi-layer snow cover model. We found a strong modulating effect of the incoming rainfall signal by the snow cover. Initially, water from both rainfall and snow melt was absorbed by the snowpack. But once the snowpack released the stored water, simulated outflow rates exceeded rainfall and snow melt rates. The simulations suggest that structural snowpack changes enhanced the outflow during this event.
J. Zhang, Y. Shao, and N. Huang
Atmos. Chem. Phys., 14, 8869–8882, https://doi.org/10.5194/acp-14-8869-2014, https://doi.org/10.5194/acp-14-8869-2014, 2014
N. Wever, C. Fierz, C. Mitterer, H. Hirashima, and M. Lehning
The Cryosphere, 8, 257–274, https://doi.org/10.5194/tc-8-257-2014, https://doi.org/10.5194/tc-8-257-2014, 2014
T. Grünewald, J. Stötter, J. W. Pomeroy, R. Dadic, I. Moreno Baños, J. Marturià, M. Spross, C. Hopkinson, P. Burlando, and M. Lehning
Hydrol. Earth Syst. Sci., 17, 3005–3021, https://doi.org/10.5194/hess-17-3005-2013, https://doi.org/10.5194/hess-17-3005-2013, 2013
C. D. Groot Zwaaftink, A. Cagnati, A. Crepaz, C. Fierz, G. Macelloni, M. Valt, and M. Lehning
The Cryosphere, 7, 333–347, https://doi.org/10.5194/tc-7-333-2013, https://doi.org/10.5194/tc-7-333-2013, 2013
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
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
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 snow slab avalanches caused by weak-layer failure – Part 2: Coupled mixed-mode criterion for skier-triggered anticracks
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.
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.
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
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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 and Philipp Weißgraeber
The Cryosphere, 14, 131–145, https://doi.org/10.5194/tc-14-131-2020, https://doi.org/10.5194/tc-14-131-2020, 2020
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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.
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
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.
Snow cornices lead to the potential risk of causing snow avalanche hazards, which are still...
