Publications associées à Régions polaires

Atmospheric isoprene measurements reveal larger-than-expected Southern Ocean emissions

Isoprene is a key trace component of the atmosphere emitted by vegetation and other organisms. It is highly reactive and can impact atmospheric composition and climate by affecting the greenhouse gases ozone and methane and secondary organic aerosol format ...

Nature Research2024

Impact of intercepted and sub-canopy snow microstructure on snowpack response to rain-on-snow events under a boreal canopy

Michael Lehning, Adrien Michel, Nander Wever, Daniel Nadeau, Benjamin Bouchard

Rain-on-snow events can cause severe flooding in snow-dominated regions. These are expected to become more frequent in the future as climate change shifts the precipitation from snowfall to rainfall. However, little is known about how winter rainfall inter ...

2024

Polar oceans and sea ice in a changing climate

Julia Schmale, Hélène Paule Angot, Jenny Thomas

Polar oceans and sea ice cover 15% of the Earth’s ocean surface, and the environment is changing rapidly at both poles. Improving knowledge on the interactions between the atmospheric and oceanic realms in the polar regions, a Surface Ocean–Lower Atmospher ...

2023

Synthesis Report on the Environmental Impacts of Polar Research and Logistics in the Polar Regions

Jérôme Chappellaz

Polar sciences are crucial to understand the effects of climate change. 6 out of 9 eco-tipping points identified by the IPCC are situated in the polar regions. Potential rising sea levels, altered weather patterns and changes in sea-currents are all connec ...

2023

Untangling the influence of Antarctic and Southern Ocean life on clouds

Julia Schmale, Hélène Paule Angot, Jenny Thomas, Markus Frey

Polar environments are among the fastest changing regions on the planet. It is a crucial time to make significant improvements in our understanding of how ocean and ice biogeochemical processes are linked with the atmosphere. This is especially true over A ...

2023

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

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

Widespread detection of chlorine oxyacids in the Arctic atmosphere

Julia Schmale, Ivo Fabio Beck, Hélène Paule Angot

Observations are reported of HClO3 and HClO4 in the atmosphere and their widespread occurrence over the pan-Arctic during spring, providing further insights into atmospheric chlorine cycling in the polar environment. ...

Nature Portfolio2023

Iodine oxoacids enhance nucleation of sulfuric acid particles in the atmosphere

Andrea Baccarini, Imad El Haddad, Mihnea Surdu, Lubna Dada, André Welti, Houssni Lamkaddam

The main nucleating vapor in the atmosphere is thought to be sulfuric acid (H2SO4), stabilized by ammonia (NH3). However, in marine and polar regions, NH3 is generally low, and H2SO4 is frequently found together with iodine oxoacids [HIOx, i.e., iodic acid ...

American Association for the Advancement of Science2023

Investigation of new particle formation mechanisms and aerosol processes at Marambio Station, Antarctic Peninsula

Lubna Dada

Understanding chemical processes leading to the formation of atmospheric aerosol particles is crucial to improve our capabilities in predicting the future climate. However, those mechanisms are still inadequately characterized, especially in polar regions. ...

Copernicus GmbH2022

Convection of water vapour in snowpacks

Varun Sharma, Michael Lehning, Mahdi Jafari

This paper studies numerically the convection of water vapour in snowpacks using an Eulerian-Eulerian two-phase approach. The convective water vapour transport in snow and its effects on snow density are often invoked to explain observed density profiles, ...

Cambridge University Press2022

Radar processing techniques to study summer snowfall in the Sør Rondane Mountains, Antarctica

Alfonso Ferrone

Snowfall is one of the main positive contributors to the surface mass balance of the Antarctic ice sheet. There are several techniques to monitor solid precipitation on the continent. Among them, meteorological radars provide the means to characterize the ...

EPFL2022

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

Varun Sharma, Michael Lehning, 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

Differentiation of coarse-mode anthropogenic, marine and dust particles in the High Arctic islands of Svalbard

Julia Schmale

Understanding aerosol–cloud–climate interactions in the Arctic is key to predicting the climate in this rapidly changing region. Whilst many studies have focused on submicrometer aerosol (diameter less than 1 µm), relatively little is known about the super ...

Copernicus Publications2021

A glacier-ocean interaction model for tsunami genesis due to iceberg calving

Johan Alexandre Philippe Gaume, Ming Gao

Dynamic glacier fracture and the subsequent generation and propagation of iceberg-induced tsunamis are reproduced using a unified numerical glacier-ocean model, in line with observations at the Eqip Sermia glacier in Greenland, as well as laboratory experi ...

SPRINGERNATURE2021

Overview: Integrative and Comprehensive Understanding on Polar Environments (iCUPE) – concept and initial results

Julia Schmale, Imad El Haddad, Jakob Boyd Pernov, Jenny Thomas

The role of polar regions is increasing in terms of megatrends such as globalization, new transport routes, demography, and the use of natural resources with consequent effects on regional and transported pollutant concentrations. We set up the ERA-PLANET ...

Copernicus Publications2020

REMA topography and AntarcticaLC2000 for WRF

Michael Lehning, Franziska Gerber

Reference Elevation Model of Antarctica (REMA) topography and AntarcticaLC2000 landuse dataare now available as static data input for the Weather Research and Forecasting model (WRF). Topographyand landuse are made available at a spatial resolution of 1 km ...

2020

Mountain snow: The source of the mother river—Study of multi-scale and multi-physical process of spatio-temporal evolution of snow distribution

Guang Li

Snow is one of the most active elements on the earth, which is an important mass source of polar ice sheets and alpine glaciers, as well as a main supply for the runoff. Its distribution and evolution have a great impact on global hydrological cycle, ecosy ...

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

Dynamic Differential Reflectivity Calibration Using Vertical Profiles in Rain and Snow

Alexis Berne, Alfonso Ferrone

The accuracy required for a correct interpretation of differential reflectivity (ZDR) is typically estimated to be between 0.1 and 0.2 dB. This is achieved through calibration, defined as the identification of the constant or time-varying offset to be subt ...

2020