Publications associées à Manteau neigeux

Good enough: Intermediate complexity atmospheric models improve the representation of processes affecting seasonal snow

Snow plays a crucial role in processes regulating ecosystems, the climate, and human development. Mountain snowpack in particular has great relevance for downstream communities. Knowledge about the distribution and properties of the snowpack thus help in p ...

EPFL2024

Influence of sun cups on surface albedo of wet Alpine snowpack

Michael Lehning, Mathias Thierry Pierre Bavay, Francesca Carletti

In high elevation Alpine areas, characterised by high snow accumulation and radiation-driven melt processes, the formation of peculiar ablation features called sun cups can be observed. Sun cups likely influence the energy and mass balance of the wet snowp ...

2024

Convection of snow: when and why does it happen?

Michael Lehning, Mahdi Jafari

Convection of water vapor in snowpacks is supposed to have a major impact on snow density and microstructure profiles with strong implications for the thermal regime and snow stability. However, the process has never been directly measured and only recentl ...

FRONTIERS MEDIA SA2023

CRYOWRF—Model Evaluation and the Effect of Blowing Snow on the Antarctic Surface Mass Balance

Varun Sharma, Michael Lehning, Franziska Gerber

The surface mass balance (SMB) of large polar ice sheets and of snow and ice surfaces in general are incompletely understood because of the complexity of processes involved. One such process, drifting and blowing snow, has only been considered in a very si ...

AMER GEOPHYSICAL UNION2023

Convection of water vapour in snowpacks

Varun Sharma, Michael Lehning, Mahdi Jafari

This paper studies numerically the convection of water vapour in snowpacks using an Eulerian-Eulerian two-phase approach. The convective water vapour transport in snow and its effects on snow density are often invoked to explain observed density profiles, ...

Cambridge University Press2022

Water vapor transport in snowpacks

Mahdi Jafari

This thesis is an in-depth treatment of water vapor transport in snowpacks and its impacts on snow structure. The aim is to better understand this transport process and to lay the basis for a model representation in physics-based multi-layer snow models. O ...

EPFL2022

A Novel Method to Quantify Near-Surface Boundary-Layer Dynamics at Ultra-High Spatio-Temporal Resolution

Michael Lehning, Dylan Stewart Reynolds, Tobias Jonas, Michael Haugeneder

The lateral transport of heat above abrupt (sub-)metre-scale steps in land surface temperature influences the local surface energy balance. We present a novel experimental method to investigate the stratification and dynamics of the near-surface atmospheri ...

SPRINGER2023

Evaluating a prediction system for snow management

Michael Lehning

The evaluation of snowpack models capable of accounting for snow management in ski resorts is a major step towards acceptance of such models in supporting the daily decision-making process of snow production managers. In the framework of the EU Horizon 202 ...

COPERNICUS GESELLSCHAFT MBH2021

Simulation of long-term spatiotemporal variations in regional-scale groundwater recharge: contributions of a water budget approach in cold and humid climates

Emmanuel Qays Dubois

Groundwater recharge (GWR) is a strategic hydrologic variable, and its estimate is necessary to implement sustainable groundwater management. This is especially true in a global warming context that highly impacts key winter conditions in cold and humid cl ...

2021

Version 1 of a sea ice module for the physics-based, detailed, multi-layer SNOWPACK model

Michael Lehning, Katherine Colby Leonard, Nander Wever

Sea ice is an important component of the global climate system. The presence of a snowpack covering sea ice can strongly modify the thermodynamic behavior of the sea ice, due to the low thermal conductivity and high albedo of snow. The snowpack can be stra ...

COPERNICUS GESELLSCHAFT MBH2020

The Impact of Diffusive Water Vapor Transport on Snow Profiles in Deep and Shallow Snow Covers and on Sea Ice

Michael Lehning, Varun Sharma, Adrien Michel, Mahdi Jafari, Margaux Caroline Patricia Couttet, Nander Wever, Isabelle Amandine Gouttevin

Water vapor transport has been highlighted as a critical process in Arctic snowpacks, shaping the snow cover structure in terms of density, thermal conductivity, and temperature profile among others. Here, we present an attempt to describe the thermally-in ...

2020

Coupled Snow Cover and Avalanche Dynamics Simulations to Evaluate Wet Snow Avalanche Activity

Nander Wever

We present physics-based snowpack simulations for four snow seasons with detailed wet snow avalanche activity records. The distributed, spatially explicit simulations using the Alpine3D and SNOWPACK model show that the simulated snowpack in the release are ...

AMER GEOPHYSICAL UNION2018

Snowpack runoff formation processes during rain-on-snow events

Sebastian Würzer

Rain-on-snow (ROS) events cause repeated flooding in many mountainous regions with a seasonal snow cover. The complex interaction of processes across spatial scales makes it difficult to accurately predict the effect of snow cover on runoff formation for a ...

EPFL2018

A mechanically-based model of snow slab and weak layer fracture in the Propagation Saw Test

Johan Alexandre Philippe Gaume, Lorenzo Benedetti

Dry-snow slab avalanche release is the result of failure initiation in a weak snowpack layer buried below a cohesive snow slab, which is then followed by rapid crack propagation. The Propagation Saw Test (PST) is a field experiment which allows to evaluate ...

2018

Small-scale spatio-temporal dynamics of snowmelt and its influence on runoff generation in a high Alpine catchment

Tristan Jonas Brauchli

Snow is one of the most complex materials occurring in nature. In clouds, it can be seen either as a crystal with various shapes or as a freshwater resource that will fall down to the Earth's surface. Once on the ground, it can be described as a thermodyna ...

EPFL2018

Wind-packing of snow: How do wind crusts form?

Christian Gabriel Sommer

Wind-packing of snow is the process responsible for the formation of wind slabs and wind crusts. These are hard layers of well-sintered snow often found in the snowpack in mountains as well as in polar regions. Wind-packing affects the local mass balance, ...

EPFL2018

Upscaling the evolution of snow microstructure : from 4D image analysis to rigorous models

Quirien Eibhilín Krol

Snow microstructure and its evolution play an important role for various applications of snow physics in cryospheric sciences. The main modes of microstructure evolution in snow are referred to as isothermal and temperature gradient metamorphism. The forme ...

EPFL2017

Assessing snow instability in skier-triggered snow slab avalanches by combining failure initiation and crack propagation

Johan Alexandre Philippe Gaume

Dry-snow slab avalanches start with a local failure in a weak snowpack layer buried below cohesive snow slab layers. If the size of the failed zone exceeds a critical size, rapid crack propagation occurs possibly followed by slab release if the slope is st ...

2017

Assessing wet snow avalanche activity using detailed physics based snowpack simulations

Nander Wever, Charles Fierz

Water accumulating on microstructural transitions inside a snowpack is often considered a prerequisite for wet snow avalanches. Recent advances in numerical snowpack modeling allow for an explicit simulation of this process. We analyze detailed snowpack si ...

American Geophysical Union2016

Simulating ice layer formation under the presence of preferential flow in layered snowpacks

Michael Lehning, Nander Wever, Sebastian Würzer, Charles Fierz

For physics-based snow cover models, simulating the formation of dense ice layers inside the snowpack has been a long-time challenge. Their formation is considered to be tightly coupled to the presence of preferential flow, which is assumed to happen throu ...

Copernicus GmbH2016