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Publications associées (22)

Flash Melting Amorphous Ice

Marcel Drabbels, Ulrich Lorenz, Gabriele Bongiovanni, Constantin Richard Krüger, Nathan Junior Mowry

Water can be vitrified if it is cooled at high rates, which makes it possible to outrun crystallization in so-called no man’s land, a range of deeply supercooled temperatures where water crystallizes rapidly. Here, we study the reverse process in pure wate ...

2024

The molecular scale mechanism of deposition ice nucleation on silver iodide

Athanasios Nenes, Mária Lbadaoui-Darvas

Heterogeneous ice nucleation is a ubiquitous process in the natural and built environment. Deposition ice nucleation, i.e. heterogeneous ice nucleation that - according to the traditional view - occurs in a subsaturated water vapor environment and in the a ...

Royal Soc Chemistry2024

Physicochemical characterization and source apportionment of Arctic ice-nucleating particles observed in Ny-Alesund in autumn 2019

Athanasios Nenes, Ghislain Gilles Jean-Michel Motos

Ice-nucleating particles (INPs) initiate primary ice formation in Arctic mixed-phase clouds (MPCs), altering cloud radiative properties and modulating precipitation. For atmospheric INPs, the complexity of their spatiotemporal variations, heterogeneous sou ...

Copernicus GmbH2023

Deposition freezing, pore condensation freezing and adsorption: three processes, one description?

Athanasios Nenes, Mária Lbadaoui-Darvas

Heterogeneous ice nucleation impacts the hydrological cycle and climate through affecting cloud microphysical state and radiative properties. Despite decades of research, a quantitative description and understanding of heterogeneous ice nucleation remains ...

Copernicus GmbH2023

Highly Active Ice‐Nucleating Particles at the Summer North Pole

Julia Schmale

The amount of ice versus supercooled water in clouds is important for their radiative properties and role in climate feedbacks. Hence, knowledge of the concentration of ice-nucleating particles (INPs) is needed. Generally, the concentrations of INPs are fo ...

2022

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

Michael Lehning, Marc Schneebeli Zeugin, David Nicholas Wagner, Mahdi Jafari, Océane Françoise Madeleine Hames

The remoteness and extreme conditions of the Arctic make it a very difficult environment to investigate. In these polar regions covered by sea ice, the wind is relatively strong due to the absence of obstructions and redistributes a large part of the depos ...

COPERNICUS GESELLSCHAFT MBH2022

The role of air-sea fluxes for the water vapour isotope signals in the cold and warm sectors of extratropical cyclones over the Southern Ocean

Josué Etienne Gehring

Meridional atmospheric transport is an important process in the climate system and has implications for the availability of heat and moisture at high latitudes. Near-surface cold and warm temperature advection over the ocean in the context of extratropical ...

Copernicus Gesellschaft Mbh2021

Radar and ground-level measurements of precipitation collected by the Ecole Polytechnique Federale de Lausanne during the International Collaborative Experiments for PyeongChang 2018 Olympic and Paralympic winter games

Alexis Berne, Anne-Claire Marie Billault--Roux, Nikola Besic, Josué Etienne Gehring, Alfonso Ferrone

This article describes a 4-month dataset of precipitation and cloud measurements collected during the International Collaborative Experiments for PyeongChang 2018 Olympic and Paralympic winter games (ICE-POP 2018). This paper aims to describe the data coll ...

COPERNICUS GESELLSCHAFT MBH2021

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

Michael Lehning, Marc Schneebeli Zeugin, David Nicholas Wagner, Océane Françoise Madeleine Hames, Mahdi Jafari

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 ...

2021

Preferential Deposition of Snow and Dust Over Hills: Governing Processes and Relevant Scales

Marc Parlange, Michael Lehning, Marco Giovanni Giometto, Francesco Comola

Preferential deposition of snow and dust over complex terrain is responsible for a wide range of environmental processes and accounts for a significant source of uncertainty in the surface mass balances of cold and arid regions. Despite the growing body of ...

2019

Cavitation induction by projectile impacting on a water jet

Mohamed Farhat

The present paper focuses on the simulation of the high-velocity impact of a projectile impacting on a water-jet, causing the onset, development and collapse of cavitation. The simulation of the fluid motion is carried out using an explicit, compressible, ...

PERGAMON-ELSEVIER SCIENCE LTD2019

Retrieval of ice-nucleating particle concentrations from lidar observations and comparison with UAV in situ measurements

Athanasios Nenes

Aerosols that are efficient ice-nucleating particles (INPs) are crucial for the formation of cloud ice via heterogeneous nucleation in the atmosphere. The distribution of INPs on a large spatial scale and as a function of height determines their impact on ...

Copernicus Publications2019

Variations in Snow Crystal Riming and ZDR: A Case Analysis

Alexis Berne, Christophe Praz

A case study in terms of variations in differential reflectivity Z(DR) observed at X band and snow crystal riming is presented for a light-snow event that occurred near Greeley, Colorado, on 26-27 November 2015. In the early portion of the event, Z(DR) val ...

2018

Coupled Snow Cover and Avalanche Dynamics Simulations to Evaluate Wet Snow Avalanche Activity

Nander Wever

We present physics-based snowpack simulations for four snow seasons with detailed wet snow avalanche activity records. The distributed, spatially explicit simulations using the Alpine3D and SNOWPACK model show that the simulated snowpack in the release are ...

AMER GEOPHYSICAL UNION2018

Hydration mediated interfacial transitions on mixed hydrophobic/hydrophilic nanodroplet interfaces

Sylvie Roke, Halil Ibrahim Okur, Nikolay Smolentsev, Rüdiger Scheu, Filip Kovacik

Interfacial phase transitions are of fundamental importance for climate, industry, and biological processes. In this work, we observe a hydration mediated surface transition in supercooled oil nanodroplets in aqueous solutions using second harmonic and sum ...

2018

Effects of regional and local atmospheric dynamics on the aerosol and CCN load over Athens

Athanasios Nenes

Aerosol and cloud condensate nuclei (CCN) measurements in the area of Athens during HyGRA-CD campaign (May–June 2014) identified a significant diversity in particle properties. In this study we select two distinct cases in terms of meteorology and air mass ...

Elsevier2018

Impact of Extreme Land Surface Heterogeneity on Micrometeorology over Spring Snow Cover

Michael Lehning, Sebastian Schlögl

The melting mountain snow cover in spring typically changes from a continuous snow cover to a mosaic of patches of snow and bare ground, inducing an extreme heterogeneity of the land surface. A comprehensive measurement campaign, the Dischma experiment, wa ...

American Meteorological Society2017

Fragmentation of wind-blown snow crystals

Michael Lehning, Johan Alexandre Philippe Gaume, Francesco Comola, Enrico Paterna

Understanding the dynamics driving the transformation of snowfall crystals into blowing snow particles is critical to correctly account for the energy and mass balances in polar and alpine regions. Here we propose a fragmentation theory of fractal snow cry ...

2017

Loss of testate amoeba functional diversity with increasing frost intensity across a continental gradient reduces microbial activity in peatlands

Alexandre Buttler, Vincent Eric Jules Jassey, Luca Bragazza, Bjorn Jozef Maria Robroek, Constant Signarbieux, Robert Thomas Edmund Mills

Soil microbial communities significantly contribute to global fluxes of nutrients and carbon. Their response to climate change, including winter warming, is expected to modify these processes through direct effects on microbial functions due to osmotic str ...

Elsevier2016

Wind slab formation in snow: experimental setup and first results

Michael Lehning, Charles Fierz, Christian Gabriel Sommer

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