Publications associées à Environmental isotopes

The isotopic signature of U(V) during bacterial reduction

Marinella Mazzanti, Rizlan Bernier-Latmani, Margaux Camille Andréa Molinas, Radmila Faizova, Ashley Richards Brown

The two-step electron transfer during bacterial reduction of UVI to UIV is typically accompanied by mass-independent fractionation of the 238U and 235U isotopes, whereby the heavy isotope accumulates in the reduced product. However, the role of the UV inte ...

2024

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

A 2000-year temperature reconstruction on the East Antarctic plateau from argon-nitrogen and water stable isotopes in the Aurora Basin North ice core

Jérôme Chappellaz

The temperature of the Earth is one of the most important climate parameters. Proxy records of past climate changes, in particular temperature, represent a fundamental tool for exploring internal climate processes and natural climate forcings. Despite the ...

COPERNICUS GESELLSCHAFT MBH2023

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

Sonja Wahl

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 ...

Amer Geophysical Union2023

Persistence of the isotopic signature of pentavalent uranium in magnetite

Rizlan Bernier-Latmani, Barbora Bártová, Zezhen Pan

Uranium isotopic signatures can be harnessed to monitor the reductive remediation of subsurface contamination or to reconstruct paleo-redox environments. However, the mechanistic underpinnings of the isotope fractionation associated with U reduction remain ...

2022

Detritus-hosted methanogenesis sustains the methane paradox in an alpine lake

Damien Bouffard, Oscar Rodrigo Sepúlveda Steiner

Accumulation of methane in oxic waters of lakes and the ocean has been widely reported. Despite the importance for the greenhouse gas budget, mechanistic controls of such "methane paradox" remain elusive. Here, we use a combination of CH4 concentration and ...

American Society of Limnology and Oceanography2022

Plant and root‐zone water isotopes are difficult to measure, explain, and predict: some practical recommendations for determining plant water sources

Charlotte Grossiord, Jana Freiin von Freyberg

Stable isotope ratios of water (𝛿 18O,𝛿 2H) have long been used to study a core question in plant ecology and ecohydrology: “From where do plants take up water?” Indeed, decades of research has involved sampling potential plant water sources in the subsurf ...

2020

Effect of fuel isotope mass on q-profile formation in JET hybrid plasmas

Matteo Fontana

The initial current ramp phase of JET hybrid plasmas is used to optimise the target q-profile for main heating to allow access to high beta and avoid MHD instabilities. Mixed protium-deuterium experiments, carried out at JET since the installation of the b ...

IOP Publishing Ltd2020

Dissolution-reprecipitation reaction of dolomite: investigation of self- and tracer-diffusion using SIMS mini-spot and NanoSIMS profiles

Anders Meibom, Stéphane Laurent Escrig, Lukas Baumgartner

Recrystallization of minerals due to fluid infiltration modifies their original chemical and isotopic signature. Such processes are sought after as they give access to timescales of geologic processes, which are commonly quantified using diffusion chronome ...

2019

Importance of the advection scheme for the simulation of water isotopes over Antarctica by atmospheric general circulation models: A case study for present-day and Last Glacial Maximum with LMDZ-iso

Etienne Gabriel Henri Vignon

Atmospheric general circulation models (AGCMs) are known to have a warm and isotopically enriched bias over Antarctica. We test here the hypothesis that these biases are partly consequences of a too diffusive advection. Exploiting the LMDZ-iso model, we sh ...

2019

Investigation of subglacial weathering under the Greenland Ice Sheet using silicon isotopes

Tyler Joe Kohler

Subglacial chemical weathering plays a key role in global silicate weathering budgets, contributing to the cycling of silicon (Si) in terrestrial and marine systems and the potential drawdown of carbon dioxide from the atmosphere. Here, we use data from tw ...

2019

Modelling of C/Cl isotopic behaviour during chloroethene biotic reductive dechlorination: Capabilities and limitations of simplified and comprehensive models

Julien Maillard, David Hunkeler

Predicting the fate of chloroethenes in groundwater is essential when evaluating remediation strategies. Such predictions are expected to be more accurate when incorporating isotopic parameters. Although secondary chlorine isotope effects have been observe ...

2018

Comment on “Origin of water in the Badain Jaran Desert, China: New insight from isotopes” by Wu et al. (2017)

David Andrew Barry, Ho Ling Li, Jiaqi Chen

Precipitation isotope data were used to determine the origin of groundwater in the Badain Jaran Desert (BJD) in the study of Wu et al. (2017). Both precipitation and its isotope composition vary seasonally, so arithmetic averages of precipitation isotope v ...

2018

Ideas and perspectives: Tracing terrestrial ecosystem water fluxes using hydrogen and oxygen stable isotopes - challenges and opportunities from an interdisciplinary perspective

Paolo Benettin, Natalie Claire Ceperley, Jana Freiin von Freyberg

In this commentary, we summarize and build upon discussions that emerged during the workshop "Isotope-based studies of water partitioning and plant-soil interactions in forested and agricultural environments" held in San Casciano in Val di Pesa, Italy, in ...

Copernicus GmbH2018

Observation of enhanced ion particle transport in mixed H/D isotope plasmas on JET

Olivier Sauter, Ambrogio Fasoli, Basil Duval, Stefano Coda, Martinus Gijs, Jonathan Graves, Yves Martin, Duccio Testa, Patrick Blanchard, Bruno Emanuel Ferreira De Sousa Correia, Alessandro Pau, Pierre-Thomas Paul Brun, Cristian Sommariva, Henri Weisen, Michele Marin, Richard Pitts, Sun Hee Kim, Yann Camenen, Jan Horacek, Marco Wischmeier, Javier García Hernández, Mikhail Maslov, Miguel Fernández Ruiz, Nicola Vianello, Antonio José Pereira de Figueiredo, Federico Nespoli, Liang Yao, Dalziel Joseph Wilson, Yao Zhou, Robin Humphry-Baker, David Pfefferlé, José Pedro Rebelo Ferreira Marques, Davide Galassi, Ana Francisca Leal Silva Soares, Daniel Scott Alessi, Jonathan Marc Philippe Faustin, Arnout Lodewijk M Beckers, Julio Rodriguez, Jonnathan Cesar Hidalgo Acosta, Hamish William Patten, , , , , , , , ,

Clumped isotope fractionation during phosphoric acid digestion of carbonates at 70°C

Marie Estelle Solange Violay

The application of clumped isotopes (Delta(47)) in carbonate minerals as a sensitive temperature proxy in paleo-environments depends on a well-constrained clumped isotope fractionation for the necessary step of phosphoric acid digestion of the carbonate mi ...

Elsevier2016

Silicon isotopes in angrites and volatile loss in planetesimals

James Badro

Inner solar system bodies, including the Earth, Moon, and asteroids, are depleted in volatile elements relative to chondrites. Hypotheses for this volatile element depletion include condensation from the solar nebula and volatile loss during energetic impa ...

National Academy of Sciences2014

A multi-proxy, high-resolution record of peatland development and its drivers during the last millennium from the subalpine Swiss Alps

Edward Mitchell, Mariusz Lamentowicz

We present a record of peatland development during the last 1000 years from Mauntschas mire in the eastern Swiss Alps (Upper Engadine valley; 1818 m a.s.l.) inferred from testate amoebae (pH and depth to the water table (DWT) reconstructions), stable oxyge ...

2011

Distributed, high-resolution modelling of 18O signals in a meso-scale catchment

Laurin Wissmeier

A combined simulation of runoff dynamics and distributed transport of the stable isotope oxygen-18 (18O) was performed in the mountainous Dreisam basin (258 km2) in the southwest of Germany. For this purpose, a mixing cell solute routing scheme was impleme ...

2007