Publications de Michael Lehning

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A model study on the impact of climate change on snow cover and runoff has been conducted for the Swiss Canton of Graubünden. The model Alpine3D has been forced with the data from 35 Automatic Weather Stations in order to investigate snow and runoff dynami ...

This study compares the ability of two degree-day models (Poli-Hydro and a degree-day implementation of Alpine3D) and one full energy-balance melt model (Alpine3D) to predict the discharge on two partly glacierized Alpine catchments of different size and i ...

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 ...

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 ...

The longevity of perennial snowfields is not fully understood, but it is known that strong atmospheric stability and thus boundary-layer decoupling limit the amount of (sensible and latent) heat that can be transmitted from the atmosphere to the snow surfa ...

Fluorescent Particle Tracking Velocimetry (FPTV) measurements of the pore-scale water flow through the pore space of a wet-snow sample are presented to demonstrate the applicability of this measurement technique for snow. For the experiments, ice-cooled wa ...

Climate change has already affected many components of our natural environment which are well described in the literature. Water temperature has received less interest despite the fact that it is recognized as key variable for assessing water quality of fr ...

Local wind speed variations influence the energy and mass fluxes over snow through snow accumulation, sublimation of drifting and blowing snow, or variations in turbulent fluxes over static snow and ice surfaces. We use idealized model experiments to analy ...

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 ...

Elevation strongly affects quantity and distribution patterns of precipitation and snow. Positive elevation gradients were identified by many studies, usually based on data from sparse precipitation stations or snow depth measurements. We present a systema ...

As part of its ambitious long term energy strategy, Switzerland plans to phase out nuclear power production and replace most or all of its significant share of national electricity production (40%) by renewables, in particular by photovoltaics (PV) and win ...

Wind energy potential in complex terrain is still poorly understood and difficult to quantify. With Switzerland’s current efforts to shift to renewable energy resources, it is now becoming even more crucial to investigate the hidden potential of wind energ ...

This study presents an inter-comparison of three structurally different electricity system models (EXPANSE, Nexus-e, and OREES) with sub-national spatial resolution in Switzerland in 2035. We analyze technology and regional implications of three targets fo ...

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 ...

High-density snow layers deteriorate grazing conditions for reindeer during winter. We compare two different methods for identifying past winters with difficult grazing conditions for reindeer in Kautokeino, northern Norway. A long-term climate analysis ba ...

Single or a limited number of point observations, such as from index stations, are commonly assumed to be representative for the snow cover of larger areas in many applications. This study presents a systematic investigation of the relationship between poi ...

The destructive power of an avalanche depends, among other things, on the overall mass and the snow conditions in the avalanche path. So far, the knowledge on the effect of snow conditions on avalanche behavior is limited and largely qualitative. We invest ...

We use the latest Coordinated Regional Dynamical Experiment regional climate models over South Asia at 0.22 degrees grid spacing (WAS-22) under two Representative Concentration Pathways scenarios (RCP 2.6 and RCP 8.5) to evaluate their performance against ...

Observations of drifting snow on small scales have shown that, in spite of nearly steady winds, the snow mass flux can strongly fluctuate in time and space. Most drifting snow models, however, are not able to describe drifting snow accurately over short ti ...

This paper presents a spatially-explicit model for hydro-thermal response simulations of Alpine catchments, accounting for advective and non-advective energy fluxes in stream networks characterized by arbitrary degrees of geomorphological complexity. The r ...

Michael Lehning

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Response of snow cover and runoff to climate change in high Alpine catchments of Eastern Switzerland

A comparison of hydrological models with different level of complexity in Alpine regions in the context of climate change

Impact of climate change in Switzerland on socioeconomic snow indices

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

Wind tunnel experiments: cold-air pooling and atmospheric decoupling above a melting snow patch

Measurements of the pore-scale water flow through snow using Fluorescent Particle Tracking Velocimetry

Stream Temperature Evolution in Switzerland: Recent past and future

Sensitivity of turbulent fluxes to wind speed over snow surfaces in different climatic settings

Convection of snow: when and why does it happen?

Elevation dependency of mountain snow depth

Interplay between photovoltaic, wind energy and storage hydropower in a fully renewable Switzerland

Combining Weather Station Data and Short-Term LiDAR Deployment to Estimate Wind Energy Potential with Machine Learning: A Case Study from the Swiss Alps

Inter-comparison of spatial models for high shares of renewable electricity in Switzerland

Influence of sun cups on surface albedo of wet Alpine snowpack

Use of a multilayer snow model to assess grazing conditions for reindeer

Are flat-field snow depth measurements representative? A comparison of selected index sites with areal snow depth measurements at the small catchment scale

Influence of snow cover properties on avalanche dynamics

Future trends in wind resources and their consistency in the Indian sub-continent

Modelling Small-Scale Drifting Snow with a Lagrangian Stochastic Model Based on Large-Eddy Simulations

Thermodynamics in the hydrologic response: Travel time formulation and application to Alpine catchments