Publications de Michael Lehning

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A widely used, yet thus far unproven, fluid dynamical hypothesis originally presented by P. R. Owen 50years ago, states that the surface shear stress induced by a fluid on the ground during equilibrium sediment saltation is constant and independent of the ...

We estimate seasonal drifting snow sublimation at a study site in the Swiss Alps with the numerical model Alpine3D using external wind fields from the Advanced Regional Prediction System on a high-resolution grid (10 m). Novel in the field of snow transpor ...

Drifting and blowing snow are important features in polar and high mountain regions. They control the surface mass balance in windy conditions and influence sublimation of snow and ice surfaces. Despite their importance, model representations in weather an ...

With the perspective of Switzerland’s phase-out from nuclear energy, solar energy potential may take an important role for the country’s future in renewable energy. Based on 12 years of satellite-derived, spatially distributed data of daily average cloud f ...

Modelling and forecasting wind-driven redistribution of snow in mountainous regions with its implications on avalanche danger, mountain hydrology or flood hazard is still a challenging task often lacking in essential details. Measurements of drifting and b ...

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 ...

Most standard air temperature measurements are subject to significant errors mainly due to sensor heating by solar radiation, even when the measurement principle is accurate and precise. We present various air temperature measurements together with other m ...

For a patchy snow cover the advective heat transport and the near-surface boundary layer decoupling, which have an opposite effect on sensible heat transport onto the snow surface, are both expected to increase in magnitude. The main aim of this study is t ...

The rough, steep, and complex terrain in the alpine environment causes a variety of flow patterns such as blocking, speed-up, or flow separation, which influence precipitation, snow deposition, and ultimately snow distribution on the ground. Cloud-terrain ...

Accurately simulating snow-cover dynamics and the snow-atmosphere coupling is of major importance for topics as wide-ranging as water resources, natural hazards and climate change impacts with consequences for sea-level rise. We present a new modelling fra ...

In this study we modelled the influence of the spatially and temporally heterogeneous snow cover on the surface energy balance and thus on rock temperatures in two rugged, steep rock walls on the Gemsstock ridge in the central Swiss Alps. The heterogeneous ...

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, ...

This study presents spatiotemporally-resolved measurements of surface shear-stress tau (s) in live plant canopies and rigid wooden cube arrays to identify the sheltering capability against sediment erosion of these different roughness elements. Live plants ...

We explore the process of modeling aeolian snow transport around buildings by proposing a set of similarity requirements on simulating a single snow fall event with drifting. The similarity criteria are used to guide our wind tunnel tests from the particle ...

The remoteness and extreme conditions of the Arctic make it a very difficult environment to investigate. In these regions, the wind has a substantial effect and redistributes a large part of the snow, which complicates precipitation estimates. Moreover, th ...

The specific surface area (SSA) of snow is a critical structural quantity that controls snow properties and constantly evolves over time. An accurate understanding and modeling of the dynamical evolution of the SSA is thus of primary importance for snowpac ...

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 ...

To retrieve Surface Solar Radiation (SSR) from satellite images, a baseline reflectance of the observed ground in clear-sky conditions, also called background reflectance, is necessary to distinguish atmospheric absorption and scattering effects from surfa ...

Banner clouds are clouds in the lee of steep mountains or sharp ridges on otherwise cloud-free days. Previous studies identified key mechanisms and preferred flow conditions on the basis of idealized Large-Eddy Simulations, but it remained unclear to what ...

Climate change is expected to strongly impact the hydrological and thermal regimes of Alpine rivers within the coming decades. In this context, the development of hydrological models accounting for the specific dynamics of Alpine catchments appears as one ...

Michael Lehning

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Experimental assessment of Owen's second hypothesis on surface shear stress induced by a fluid during sediment saltation

Seasonal simulation of drifting snow sublimation in Alpine terrain

Understanding snow saltation parameterizations: lessons from theory, experiments and numerical simulations

Reliable Averages and Risky Extremes – Analysis of spatiotemporal variability in solar irradiance and persistent cloud cover patterns over Switzerland

Radar measurements of blowing snow off a mountain ridge

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

Albedo effect on radiative errors in air temperature measurements

Relative importance of advective heat transport and boundary layer decoupling in the melt dynamics of a patchy snow cover

A close-ridge small-scale atmospheric flow field and its influence on snow accumulation

Introducing CRYOWRF v1.0: multiscale atmospheric flow simulations with advanced snow cover modelling

Distributed snow and rock temperature modelling in steep rock walls using Alpine3D

Convection of water vapour in snowpacks

Spatio-Temporal Surface Shear-Stress Variability in Live Plant Canopies and Cube Arrays

Similarity conditions and cube model tests of snow drift and precipitation preferential deposition patterns

Modelling the small-scale deposition of snow onto structured Arctic sea ice during a MOSAiC storm using snowBedFoam 1.0

Towards a physically and microstructure-based equation for the evolution of the specific surface area in snow

Evaluating a prediction system for snow management

Retrieval of Surface Solar Radiation through Implicit Albedo Recovery from Temporal Context

Banner Cloud Formation at the Matterhorn: Measurements versus Large-Eddy Simulations

StreamFlow 1.0: an extension to the spatially distributed snow model Alpine3D for hydrological modelling and deterministic stream temperature prediction