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Michael Lehning

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Publications associées (173)

Large eddy simulation of near-surface boundary layer dynamics over patchy snow

Michael Lehning, Océane Hames, Dylan Stewart Reynolds, Michael Haugeneder

The near-surface boundary layer over patchy snow is highly heterogeneous and dynamic. Layers of opposing stability coexist within only a few horizontal meters. Conventional experimental methods to investigate this layer suffer from limitations related to t ...

FRONTIERS MEDIA SA2024

A Case Study on Drivers of the Isotopic Composition of Water Vapor at the Coast of East Antarctica

Michael Lehning, Armin Sigmund, Riqo Chaar

Stable water isotopes (SWIs) contain valuable information on the past climate and phase changes in the hydrologic cycle. Recently, vapor measurements in the polar regions have provided new insights into the effects of snow-related and atmospheric processes ...

AMER GEOPHYSICAL UNION2023

Evidence of Strong Flux Underestimation by Bulk Parametrizations During Drifting and Blowing Snow

Michael Lehning, Wolf Hendrik Huwald, Varun Sharma, Francesco Comola, Koichi Nishimura, Jérôme François Sylvain Dujardin, Daniela Brito Melo, Armin Sigmund

The influence of drifting and blowing snow on surface mass and energy exchange is difficult to quantify due to limitations in both measurements and models, but is still potentially very important over large areas with seasonal or perennial snow cover. We p ...

SPRINGER2023

Wind conditions for snow cornice formation in a wind tunnel

Michael Lehning, Hongxiang Yu

Snow cornices growing on the leeward side of mountain ridges are common in alpine and polar regions during snow seasons. These structures may crack and fall, leading to an increase in avalanche danger. Although cornice formation has been observed in wind t ...

COPERNICUS GESELLSCHAFT MBH2023

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

Michael Lehning, Tobias Jonas, Dylan Stewart Reynolds, 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

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

Michael Lehning, Varun Sharma, Franziska Gerber

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 ...

2023

Southward migration of the zero-degree isotherm latitude over the Southern Ocean and the Antarctic Peninsula: Cryospheric, biotic and societal implications

Michael Lehning

The seasonal movement of the zero-degree isotherm across the Southern Ocean and Antarctic Peninsula drives major changes in the physical and biological processes around maritime Antarctica. These include spatial and temporal shifts in precipitation phase, ...

Elsevier2023

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

Michael Lehning, Wolf Hendrik Huwald, Franziska Gerber, Jérôme François Sylvain Dujardin, Fanny Kristianti

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 ...

2023

Decentralized green energy transition promotes peace

Michael Lehning, Nicolas Tétreault, Julia Steinberger

FRONTIERS MEDIA SA2023

Reproducibility Dataset for CRYOWRF v1.0

Michael Lehning, Varun Sharma, Franziska Gerber

This repository contains data required for reproducibility of the results to be published in the associated manuscript. Apart from reproducibility, the attached datasets also serve as templates for new users to adopt CRYOWRF in their research. The datasets ...

2023

A Database of Snow on Sea Ice in the Central Arctic Collected during the MOSAiC expedition

Michael Lehning

Snow plays an essential role in the Arctic as the interface between the sea ice and the atmosphere. Optical properties, thermal conductivity and mass distribution are critical to understanding the complex Arctic sea ice system's energy balance and mass dis ...

NATURE PORTFOLIO2023

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

Michael Lehning, Varun Sharma, 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

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

Michael Lehning, Jérôme François Sylvain Dujardin

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 ...

ELSEVIER SCI LTD2023

Determining return levels of extreme daily precipitation, reservoir inflow, and dry spells

Michael Lehning, Tatjana Milojevic

Return level calculations are widely used to determine the risks that extreme events may pose to infrastructure, including hydropower site operations. Extreme events (e.g., extreme precipitation and droughts) are expected to increase in frequency and inten ...

FRONTIERS MEDIA SA2023

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

Modeling Snow Saltation: The Effect of Grain Size and Interparticle Cohesion

Michael Lehning, Varun Sharma, Francesco Comola, Daniela Brito Melo, Armin Sigmund

The surface of the Earth is snow-covered at least seasonally over large areas. This snow surface is highly dynamic, particularly under the influence of strong winds. The motion of snow particles driven by the wind not only changes the snow cover but has im ...

2022

Sources of Primary Electricity Supply

Michael Lehning, Aleksandra Kim, Annelen Kahl

This synthesis report provides an overview of primary electricity supply sources, including power generation potentials and costs as well as the as- sociated environmental burdens of electricity pro- duction in Switzerland. It gives a synthesis of the main ...

ETH Zurich2022

Wind-Topo: Downscaling near-surface wind fields to high-resolution topography in highly complex terrain with deep learning

Michael Lehning, Jérôme François Sylvain Dujardin

Predicting wind flow in highly complex terrain like the Alps is a challenge for all models. When physical processes need to be resolved in a spatially explicit manner, grids with high horizontal resolution of a few hundred meters are often required and dra ...

WILEY2022

Dataset for: Future water temperature of rivers in Switzerland under climate change investigated with physics-based models

Bettina Schaefli, Michael Lehning, Wolf Hendrik Huwald, Nander Wever, Adrien Michel

This work presents the first extensive study of climate change impacts on rivers temperature in Switzerland. Results show that even for low emissions scenarios, water temperature increase will lead to adverse effect for both ecosystems and socioeconomic se ...

Zenodo2022

Snowfall and snow accumulation during the MOSAiC winter and spring seasons

Marc Oggier, Michael Lehning, Marc Schneebeli Zeugin, David Nicholas Wagner, Markus Frey

Data from the Multidisciplinary drifting Observatory for the Study of Arctic Climate (MOSAiC) expedition allowed us to investigate the temporal dynamics of snowfall, snow accumulation and erosion in great detail for almost the whole accumulation season (No ...

COPERNICUS GESELLSCHAFT MBH2022

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