Publications related to Ice crystal

The molecular scale mechanism of deposition ice nucleation on silver iodide

Athanasios Nenes, Mária Lbadaoui-Darvas, André Welti

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

Simulations of primary and secondary ice production during an Arctic mixed-phase cloud case from the Ny-Ålesund Aerosol Cloud Experiment (NASCENT) campaign

Georgia Sotiropoulou, Paraskevi Georgakaki

The representation of Arctic clouds and their phase distributions, i.e., the amount of ice and supercooled water, influences predictions of future Arctic warming. Therefore, it is essential that cloud phase is correctly captured by models in order to accur ...

Copernicus GmbH2024

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

Athanasios Nenes, Ghislain Gilles Jean-Michel Motos, Jörg Wieder, Guangyu Li

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

Aerosol and dynamical contributions to cloud droplet formation in Arctic low-level clouds

Athanasios Nenes, Ghislain Gilles Jean-Michel Motos, Paraskevi Georgakaki, Jörg Wieder, Guangyu Li

The Arctic is one of the most rapidly warming regions of the globe. Low-level clouds and fog modify the energy transfer from and to space and play a key role in the observed strong Arctic surface warming, a phenomenon commonly termed "Arctic amplification" ...

Copernicus GmbH2023

Spatio-Temporal Dynamics of Snow on Central Arctic Sea Ice and its Implications

David Nicholas Wagner

This thesis presents a comprehensive investigation of the interaction between precipitation and wind-induced erosion and deposition of snow on Arctic sea ice. The study uses observations from the 2019-2020 MOSAiC expedition and makes use of the 3D snow cov ...

EPFL2023

Mixed-Phase Clouds and Precipitation in Southern Ocean Cyclones and Cloud Systems Observed Poleward of 64 degrees S by Ship-Based Cloud Radar and Lidar

Etienne Gabriel Henri Vignon

Mixed-phase clouds (MPCs), composed of both liquid and ice, are prevalent in Southern Ocean cyclones. A characterization of these clouds on fine vertical scales is required in order to understand the microphysical processes within these clouds, and for mod ...

2021

Identification of snowfall microphysical processes from Eulerian vertical gradients of polarimetric radar variables

Alexis Berne, Josué Etienne Gehring, Etienne Gabriel Henri Vignon, Noémie Planat

Polarimetric radar systems are commonly used to study the microphysics of precipitation. While they offer continuous measurements with a large spatial coverage, retrieving information about the microphysical processes that govern the evolution of snowfall ...

COPERNICUS GESELLSCHAFT MBH2021

Secondary ice production in summer clouds over the Antarctic coast: an underappreciated process in atmospheric models

Athanasios Nenes, Alexis Berne, Georgia Sotiropoulou, Etienne Gabriel Henri Vignon

The correct representation of Antarctic clouds in atmospheric models is crucial for accurate projections of the future Antarctic climate. This is particularly true for summer clouds which play a critical role in the surface melting of the ice shelves in th ...

European Geosciences Union2021

Properties of Arctic liquid and mixed-phase clouds from shipborne Cloudnet observations during ACSE 2014

Georgia Sotiropoulou

This study presents Cloudnet retrievals of Arctic clouds from measurements conducted during a 3-month research expedition along the Siberian shelf during summer and autumn 2014. During autumn, we find a strong reduction in the occurrence of liquid clouds a ...

Copernicus GmbH2020

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

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

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

The Microphysics of Stratiform Precipitation During OLYMPEX: Compatibility Between Triple-Frequency Radar and Airborne In Situ Observations

Jussi Sakari Leinonen

The link between stratiform precipitation microphysics and multifrequency radar observables is thoroughly investigated by exploiting simultaneous airborne radar and in situ observations collected from two aircraft during the OLYMPEX/RADEX (Olympic Mountain ...

2019

Observation of methane filled hexagonal ice stable up to 150 GPa

Philippe Gillet, Richard Gaal, Livia Eleonora Bove Kado, Umbertoluca Ranieri

Gas hydrates consist of hydrogen-bonded water frameworks enclosing guest gas molecules and have been the focus of intense research for almost 40 y, both for their fundamental role in the understanding of hydrophobic interactions and for gas storage and ene ...

National Academy of Sciences2019

The effect of secondary ice production parameterization on the simulation of a cold frontal rainband

Athanasios Nenes

Secondary ice production via processes like rime splintering, frozen droplet shattering, and breakup upon ice hydrometeor collision have been proposed to explain discrepancies between in-cloud ice crystal and ice-nucleating particle numbers. To understand ...

Copernicus Publications2018

Implementation of a comprehensive ice crystal formation parameterization for cirrus and mixed-phase clouds in the EMAC model (based on MESSy 2.53)

Athanasios Nenes

A comprehensive ice nucleation parameterization has been implemented in the global chemistry-climate model EMAC to improve the representation of ice crystal number concentrations (ICNCs). The parameterization of Barahona and Nenes (2009, hereafter BN09) al ...

2018

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

Theoretical prediction of the homogeneous ice nucleation rate: disentangling thermodynamics and kinetics

Michele Ceriotti, Bingqing Cheng

Estimating the homogeneous ice nucleation rate from undercooled liquid water is crucial for understanding many important physical phenomena and technological applications, and challenging for both experiments and theory. From a theoretical point of view, d ...

2018

Measurements of precipitation in Dumont d'Urville, Adelie Land, East Antarctica

Alexis Berne, Jacopo Grazioli

The first results of a campaign of intensive observation of precipitation in Dumont d'Urville, Antarctica, are presented. Several instruments collected data from November 2015 to February 2016 or longer, including a polarimetric radar (MXPol), a Micro Rain ...

Copernicus GmbH2017

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

Ice VII from aqueous salt solutions: From a glass to a crystal with broken H-bonds

Livia Eleonora Bove Kado

It has been known for decades that certain aqueous salt solutions of LiCl and LiBr readily form glasses when cooled to below approximate to 160 K. This fact has recently been exploited to produce a "salty" high-pressure ice form: When the glass is compress ...

Nature Research2016