Concept

Paléoclimatologie

Publications associées (52)

Snow-Atmosphere Humidity Exchange at the Ice Sheet Surface Alters Annual Mean Climate Signals in Ice Core Records

Surface processes alter the water stable isotope signal of the surface snow after deposition. However, it remains an open question to which extent surface post-depositional processes should be considered when inferring past climate information from ice cor ...

Washington2023

Wind, Hail, and Climate Extremes: Modelling and Attribution Studies for Environmental Data

Ophélia Mireille Anna Miralles

This thesis presents work at the junction of statistics and climate science. We first provide methodology for use by climate scientists when performing fast event attribution using extreme value theory, and then describe two interdisciplinary projects in c ...

EPFL2023

A Snapshot on the Buildup of the Stable Water Isotopic Signal in the Upper Snowpack at EastGRIP on the Greenland Ice Sheet

Sonja Wahl

The stable water isotopic composition in firn and ice cores provides valuable information on past climatic conditions. Because of uneven accumulation and post-depositional modifications on local spatial scales up to hundreds of meters, time series derived ...

AMER GEOPHYSICAL UNION2023

Northern Hemisphere atmospheric history of carbon monoxide since preindustrial times reconstructed from multiple Greenland ice cores

Jérôme Chappellaz

Two Himalayan ice cores display a factor-two decreasing trend of air content over the past two millennia, in contrast to the relatively stable values in Greenland and Antarctica ice cores over the same period. Because the air content can be related with th ...

Copernicus GmbH2022

The Biogeochemical Legacy of Arctic Subglacial Sediments Exposed by Glacier Retreat

During past periods of advance, Arctic glaciers and ice sheets overrode soil, sediments, and vegetation and buried significant stores of organic matter (OM); these glaciers are now shrinking rapidly due to climate warming. Little is known about the biogeoc ...

2022

Annual aerosol chemical composition retrieved from an aerosol mass spectrometer in the central Arctic

Ivo Fabio Beck, Benjamin Jérémy Laurent Heutte, Hélène Paule Angot, Lubna Dada

The Arctic environment is transforming rapidly due to climate change, which induces several feedback processes such as retreating sea ice, changing atmospheric transport patterns and cloud formation. In addition, more local pollution due to shipping and re ...

2022

Surface snow isotopic composition: Post-depositional processes in an alpine snowpack

Michael Lehning, Luca Bianchi, Yoann Nicolas Sadowski

Stable water isotopes are natural tracers allowing to reconstruct the history of a water parcel. They are used as climate proxies and to better understand the hydrological cycle. The snow isotopic composition is directly influenced by temperatures and atmo ...

2022

CH4 and N2O fluctuations during the penultimate deglaciation

Jérôme Chappellaz

Gas is trapped in polar ice sheets at ∼50-120m below the surface and is therefore younger than the surrounding ice. Firn densification models are used to evaluate this ice age-gas age difference (Δage) in the past. However, such models need to be validated ...

Copernicus GmbH2021

Abrupt CO2 release to the atmosphere under glacia and early interglacial climate conditions

Jérôme Chappellaz

Gas is trapped in polar ice at depths of ∼50-120 m and is therefore significantly younger than the ice in which it is embedded. The age difference is not well constrained for slowly accumulating ice on the East Antarctic Plateau, introducing a significant ...

American Geophysical Union (AGU)2020

A Reassessment of of the geochemical and isotopic fidelity of biogenic carbonates

Anders Meibom, Jaroslaw Hubert Stolarski, Arthur Adams, Deyanira Graciela Cisneros Lazaro, Jinming Guo, Tarek Axel Vennemann

Oxygen isotope compositions of calcite foraminifera tests are considered to be a robust palaeotemperature proxy at earth-surface conditions, where diffusion is slow. Recrystallization of tests during diagenesis may be optically identified and is often the ...

2019

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