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Concept

Échelle de Beaufort

Publications associées (19)

Natural slicks on Lake Geneva: From small-scale effects to large-scale formation and distribution

Mehrshad Foroughan

Low wind speeds (< 4 m/s) are ubiquitous in many water bodies, yet the physical processes occurring at the air-water interface in this range are poorly understood. A notable example is smooth patches on the water surface, known as natural slicks, formed wh ...

EPFL2023

Snow Loss Into Leads in Arctic Sea Ice: Minimal in Typical Wintertime Conditions, but High During a Warm and Windy Snowfall Event

Julia Schmale, Marc Schneebeli Zeugin, Markus Frey

The amount of snow on Arctic sea ice impacts the ice mass budget. Wind redistribution of snow into open water in leads is hypothesized to cause significant wintertime snow loss. However, there are no direct measurements of snow loss into Arctic leads. We m ...

2023

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

Snow transport in extreme environments: from small to large scale modeling

Daniela Brito Melo

The cold regions on Earth, such as the polar and high mountain regions, are snow covered for at least a part of the year. These snow-covered surfaces are highly dynamic, particularly under the influence of strong winds. The aeolian or wind-driven transport ...

EPFL2023

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

Varun Sharma, Michael Lehning, 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

Flushing the Lake Littoral Region: The Interaction of Differential Cooling and Mild Winds

Damien Bouffard, Hugo Nicolás Ulloa Sánchez, Tomy Doda

The interaction of a uniform cooling rate at the lake surface with sloping bathymetry efficiently drives cross-shore water exchanges between the shallow littoral and deep interior regions. The faster cooling rate of the shallows results in the formation of ...

AMER GEOPHYSICAL UNION2022

Wind-tunnel experimental studies of the spatial snow distribution over grass and bush surfaces

Guang Li

The snow is one of the most important water resources in grassland in northern and western China, while the wind blowing snow due to the strong wind there is a common phenomenon, which can lead to heavy disasters to harm the local animal husbandry and tran ...

SPRINGER2022

Inhibited vertical mixing and seasonal persistence of a thin cyanobacterial layer in a stratified lake

Alfred Johny Wüest, Damien Bouffard, Oscar Rodrigo Sepúlveda Steiner, Bieito Fernandez Castro

Harmful blooms of the filamentous cyanobacteria Planktothrix rubescens have become common in many lakes as they have recovered from eutrophication over the last decades. These cyanobacteria, capable of regulating their vertical position, often flourish at ...

2021

Air-flow distortion bias factors of the port and starboard anemometers of the Akademik Tryoshnikov estimated during the Antarctic Circumnavigation Expedition (ACE) legs 0-4 undertaken during the austral summer of 2016/2017

Julia Schmale, Sebastian Johannes Heinz-Josef Landwehr, Sara Oliveira Toscano

Dataset abstract This data set contains the air-flow distortion bias factors of the port and starboard anemometers of the Akademik Tryoshnikov estimated during the Antarctic Circumnavigation Expedition (ACE) legs 0-4 undertaken during the ...

2020

Using global reanalysis data to quantify and correct airflow distortion bias in shipborne wind speed measurements

Julia Schmale, Sebastian Johannes Heinz-Josef Landwehr

At sea, wind forcing is responsible for the formation and development of surface waves and represents an important source of near-surface turbulence. Therefore, processes related to near-surface turbulence and wave breaking, such as sea spray emission and ...

2020

Meridional and vertical variations of the water vapour isotopic composition in the marine boundary layer over the Atlantic and Southern Ocean

Julia Schmale, Sebastian Johannes Heinz-Josef Landwehr

Stable water isotopologues (SWIs) are useful tracers of moist diabatic processes in the atmospheric water cycle. They provide a framework to analyse moist processes on a range of timescales from large-scale moisture transport to cloud formation, precipitat ...

Copernicus GmbH2020

Convection in Lakes

Alfred Johny Wüest, Damien Bouffard

Lakes and other confined water bodies are not exposed to tides, and their wind forcing is usually much weaker compared to ocean basins and estuaries. Hence, convective processes are often the dominant drivers for shaping mixing and stratification structure ...

2019

Nonlinear dynamics of the near-shore boundary layer of a large lake (Lake Geneva)

David Andrew Barry, Ulrich Lemmin, Damien Bouffard, Andrea Cimatoribus

We examine near-shore and pelagic current variability in Lake Geneva, a large and deep lake in western Europe, using observations from several measurement locations and a three-dimensional numerical model for the period 2014-2016. Linear internal seiche mo ...

2018

Windfield: Learning Wind Meteorology with Handheld Haptic Robots

Pierre Dillenbourg, Francesco Mondada, Wafa Monia Benkaouar Johal, Ayberk Özgür

This article presents a learning activity and its user study involving the Cellulo platform, a novel versatile robotic tool designed for education. In order to show the potential of Cellulo in the classroom as part of standard curricular activities, we des ...

ACM2017

Multifractal Analysis of Snowfall Recorded Using a 2D Video Disdrometer

Alexis Berne, Timothy Hugh Raupach

Universalmultifractal (UM) analysiswas used to investigate the scaling properties of snowfall at high temporal and spatial resolutions. Snowfall datawere recorded using a 2Dvideo disdrometer (2DVD) in the SwissAlps. Six 1-h-long periods of snowfall, half i ...

American Meteorological Society2017

How do patchy snow covers affect turbulent sensible heat fluxes? – Numerical analysis and experimental findings

Michael Lehning, Sebastian Schlögl

The surface energy balance of a snow cover significantly changes once the snow cover gets patchy. The substantial progress in knowledge about the surface energy balance of patchy snow covers is a mandatory requirement to reduce biases in flux parameterizat ...

2017

Improving local wind estimation for the automated control of blinds

Jean-Louis Scartezzini, Dasaraden Mauree, Laurent Deschamps, Ali Motamed

Blinds are usually installed on building façade to improve the visual and thermal comfort of the oc-cupants. They are now often linked to an automat-ed system that helps control the glare and decrease overheating. These automated systems are linked to a we ...

2017

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

Michael Lehning, Philip Crivelli, Enrico Paterna

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 ...

Copernicus GmbH2016

Decoupling of mass flux and turbulent wind fluctuations in drifting snow

Michael Lehning, Philip Crivelli, Enrico Paterna

The wind-driven redistribution of snow has a significant impact on the climate and mass balance of polar and mountainous regions. Locally, it shapes the snow surface, producing dunes and sastrugi. Sediment transport has been mainly represented as a functio ...

Amer Geophysical Union2016