Publications by Charles Fierz | EPFL Graph Search

Representation of Horizontal Transport Processes in Snowmelt Modeling by Applying a Footprint Approach

Michael Lehning, Sebastian Schlögl, Charles Fierz

The energy balance of an alpine snow cover significantly changes once the snow cover gets patchy. The local advection of warm air causes above-average snow ablation rates at the upwind edge of the snow patch. As lateral transport processes are typically no ...

FRONTIERS MEDIA SA2018

Investigation of a wind-packing event in Queen Maud Land, Antarctica

Michael Lehning, Christian Gabriel Sommer, Nander Wever, Charles Fierz

Surface snow in polar and mountainous regions is often mobile and this mobility influences surface mass balance and isotopic composition before final deposition, which is poorly understood thus far. In December 2016 and January 2017, during a field campaig ...

COPERNICUS GESELLSCHAFT MBH2018

ESM-SnowMIP: assessing snow models and quantifying snow-related climate feedbacks

Tao Wang, Xing Fang, Nander Wever, Huanyuan Shan, Charles Fierz

This paper describes ESM-SnowMIP, an international coordinated modelling effort to evaluate current snow schemes, including snow schemes that are included in Earth system models, in a wide variety of settings against local and global observations. The proj ...

COPERNICUS GESELLSCHAFT MBH2018

Wind Tunnel Experiments: Influence of Erosion and Depositionon Wind-Packing of New Snow

Michael Lehning, Christian Gabriel Sommer, Charles Fierz

2018

Wind tunnel experiments: saltation is necessary for wind-packing

Michael Lehning, Christian Gabriel Sommer, Charles Fierz

Wind-packed snow in the form of slabs or crusts is an important part of alpine and polar snow covers. Yet, the formation process of such layers is poorly understood. For example, it remains unclear whether drifting snow is necessary for wind-packing or not ...

International Glaciological Society2017

Impact of climate change in Switzerland on socioeconomic snow indices

Michael Lehning, Charles Fierz

Snow is a key element for many socioeconomic activities in mountainous regions. Due to the sensitivity of the snow cover to variations of temperature and precipitation, major changes caused by climate change are expected to happen. We analyze the evolution ...

Springer Verlag2017

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

Wind slab formation in snow: experimental setup and first results

Michael Lehning, Christian Gabriel Sommer, Charles Fierz

Geophys . Res. Abstr. 18: EGU2016‐11274. The formation of wind-hardened surface layers, also known as wind slabs or wind crusts, is studied. Better knowledge about which processes and parameters are important will lead to an improved understanding of the m ...

2016

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

A new ring‐shaped wind tunnel facility to study wind‐packing of snow

Michael Lehning, Christian Gabriel Sommer, Charles Fierz

A new wind tunnel was designed and built at SLF. The facility is ring-shaped to simulate an infinite fetch. This is important for experiments where the observed processes have a slow time scale (minutes to hours). The wind tunnel was developed to study the ...

University de Genève2016

Verification of the multi-layer SNOWPACK model with different water transport schemes

Michael Lehning, Nander Wever, Charles Fierz

The widely used detailed SNOWPACK model has undergone constant development over the years. A notable recent extension is the introduction of a Richards equation (RE) solver as an alternative for the bucket-type approach for describing water transport in th ...

2015

Simulations of 21st century snow response to climate change in Switzerland from a set of RCMs

Michael Lehning, Charles Fierz

Twenty-first century snow depth and snow water equivalent (SWE) changes are assessed for three time periods (2020-2049, 2045-2079 and 2070-2099) at 11 stations in Switzerland with the physics-based snow model SNOWPACK and meteorological input data perturbe ...

Wiley-Blackwell2015

Evaluation of modelled snow depth and snow water equivalent at three contrasting sites in Switzerland using SNOWPACK simulations driven by different meteorological data input

Michael Lehning, Charles Fierz

The knowledge of certain snow indices such as the number of snow days, maximum snow depth and snow water equivalent or the date of snow disappearance is important for many economical and ecological applications. However, snow data are frequently not availa ...

Elsevier2014

Model simulations of the modulating effect of the snow cover in a rain-on-snow event

Michael Lehning, Nander Wever, Tobias Jonas, Charles Fierz

In October 2011, the Swiss Alps underwent a marked rain-on-snow (ROS) event when a large snowfall on 8 and 9 October was followed by intense rain on 10 October. This resulted in severe flooding in some parts of Switzerland. Model simulations were carried o ...

European Geosciences Union2014

Solving Richards Equation for snow improves snowpack meltwater runoff estimations in detailed multi-layer snowpack model

Michael Lehning, Nander Wever, Charles Fierz

The runoff from a snow cover during spring snowmelt or rain-on-snow events is an important factor in the hydrological cycle. In this study, three water balance schemes for the 1 dimensional physically-based snowpack model SNOWPACK are compared to lysimeter ...

European Geosciences Union2014

Event-driven deposition of snow on the Antarctic Plateau: analyzing field measurements with SNOWPACK

Michael Lehning, Charles Fierz

Antarctic surface snow has been studied by means of continuous measurements and observations over a period of 3 yr at Dome C. Snow observations include solid deposits in form of precipitation, diamond dust, or hoar, snow temperatures at several depths, rec ...

Copernicus Gesellschaft Mbh2013