Concept

Atmospheric thermodynamics

Publications associées (20)

The role of secondary ice production in mixed-phase clouds

Clouds are omnipresent in the Earth's atmosphere. Their phase composition significantly modulates their interaction with solar and terrestrial radiation, as well as precipitation formation. Particularly for clouds containing both phases, known as mixed-pha ...

EPFL2023

Assessing the simulation of snowfall at Dumont d'Urville, Antarctica, during the YOPP-SH special observing campaign

Alexis Berne, Etienne Gabriel Henri Vignon

The performance of a set of atmospheric models and meteorological reanalyses in the representation of precipitation days in Antarctica is assessed using ground-based observations such as a precipitation gauge and a Micro Rain Radar during the Year Of Polar ...

WILEY2023

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

Varun Sharma, Michael Lehning, 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

Reducing Aerosol Forcing Uncertainty by Combining Models With Satellite and Within-The-Atmosphere Observations: A Three-Way Street

Athanasios Nenes

Aerosol forcing uncertainty represents the largest climate forcing uncertainty overall. Its magnitude has remained virtually undiminished over the past 20 years despite considerable advances in understanding most of the key contributing elements. Recent wo ...

AMER GEOPHYSICAL UNION2023

Multiphase processes in the EC-Earth model and their relevance to the atmospheric oxalate, sulfate, and iron cycles

Athanasios Nenes

Understanding how multiphase processes affect the iron-containing aerosol cycle is key to predicting ocean biogeochemistry changes and hence the feedback effects on climate. For this work, the EC-Earth Earth system model in its climate-chemistry configurat ...

COPERNICUS GESELLSCHAFT MBH2022

Towards reliable retrievals of cloud droplet number for non-precipitating planetary boundary layer clouds and their susceptibility to aerosol

Athanasios Nenes, Paraskevi Georgakaki, Romanos Foskinis

Remote sensing has been a key resource for developing extensive and detailed datasets for studying and constraining aerosol-cloud-climate interactions. However, aerosol-cloud collocation challenges, algorithm limitations, as well as difficulties in unravel ...

FRONTIERS MEDIA SA2022

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, Irina Gorodetskaya

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

Leveraging meteorological radars to investigate the influence of atmospheric dynamics on snowfall microphysics

Josué Etienne Gehring

Precipitation is the result of a chain of meteorological processes ranging from the large- to the micro-scale. While the transport of moisture and lifting mechanisms leading to cloud formation are mostly governed by dynamical processes, the formation and g ...

EPFL2021

An overview of the ORACLES (ObseRvations of Aerosols above CLouds and their intEractionS) project: aerosol-cloud-radiation interactions in the southeast Atlantic basin

Athanasios Nenes

Southern Africa produces almost a third of the Earth's biomass burning (BB) aerosol particles, yet the fate of these particles and their influence on regional and global climate is poorly understood. ORACLES (ObseRvations of Aerosols above CLouds and their ...

Copernicus GmbH2021

Improved Near-Surface Continental Climate in IPSL-CM6A-LR by Combined Evolutions of Atmospheric and Land Surface Physics

Etienne Gabriel Henri Vignon

This work is motivated by the identification of the land-atmosphere interactions as one of the key sources of uncertainty in climate change simulations. It documents new developments in related processes, namely, boundary layer/convection/clouds parameteri ...

2020

Drivers of cloud droplet number variability in the summertime in the southeastern United States

Athanasios Nenes, André Welti

Here we analyze regional-scale data collected on board the NOAA WP-3D aircraft during the 2013 Southeast Nexus (SENEX) campaign to study the aerosol-cloud droplet link and quantify the sensitivity of droplet number to aerosol number, chemical composition, ...

Copernicus GmbH2020

Constraining the Twomey effect from satellite observations: issues and perspectives

Athanasios Nenes

The Twomey effect describes the radiative forcing associated with a change in cloud albedo due to an increase in anthropogenic aerosol emissions. It is driven by the perturbation in cloud droplet number concentration (Delta N-d, (ant)) in liquid-water clou ...

Copernicus GmbH2020

Improved Representation of Clouds in the Atmospheric Component LMDZ6A of the IPSL-CM6A Earth System Model

Etienne Gabriel Henri Vignon

The cloud parameterizations of the LMDZ6A climate model (the atmospheric component of the IPSL-CM6 Earth system model) are entirely described, and the global cloud distribution and cloud radiative effects are evaluated against the CALIPSO-CloudSat and CERE ...

2020

Microphysics of Snowfall Over Coastal East Antarctica Simulated by Polar WRF and Observed by Radar

Alexis Berne, Josué Etienne Gehring, Nikola Besic, Etienne Gabriel Henri Vignon, Nicolas Jean François Jullien

The current assessment of the Antarctic surface mass balance mostly relies on reanalysis products or climate model simulations. However, little is known about the ability of models to reliably represent the microphysical processes governing the precipitati ...

AMER GEOPHYSICAL UNION2019

A severe hail storm in complex topography in Switzerland-Observations and processes

Nikola Besic, Urs Martin Germann

This paper studies a damaging hail storm that occurred on 6 June 2015 in the complex topography of Switzerland. The storm persisted for several hours and produced large hail resulting in significant damage. Storms of comparable severity occur on average on ...

ELSEVIER SCIENCE INC2018

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

Smooth Shapes with Spherical Topology: Beyond Traditional Modeling, Efficient Deformation, and Interaction

Michaël Unser, Pablo Garcia-Amorena Garcia, Daniel Andreas Schmitter

Existing shape models with spherical topology are typically designed either in the discrete domain using interpolating polygon meshes or in the continuous domain using smooth but non-interpolating schemes such as subdivision or NURBS. Both polygon models a ...

2017

The effect of rounding corners or cutting edges on the absolute/convective instability properties of mixing layers

François Gallaire

We revisit the inviscid spatio-temporal stability properties of mixing layers. Earlier comparisons of the dispersion relations pertaining to the broken line model and the hyperbolic tangent profile have shown that the temporal stability properties are main ...

Elsevier2015

Polarimetric weather radar : from signal processing to microphysical retrievals

Jacopo Grazioli

Accurate modelling of liquid, solid and mixed-phase precipitation requires a thorough understanding of phenomena occurring at various spatial and temporal scales. At the smallest scales, precipitation microphysics defines all the processes occurring at the ...

EPFL2015

The influence of atmospheric circulation on the mid-Holocene climate of Europe: a data-model comparison

Jed Oliver Kaplan, Basil Andrew Stansfield Davis, Pamela Collins, Achille Mauri

The atmospheric circulation is a key area of uncertainty in climate model simulations of future climate change, especially in mid-latitude regions such as Europe where atmospheric dynamics have a significant role in climate variability. It has been propose ...

Copernicus Gesellschaft Mbh2014