A5036834271- Geology and Paleoclimatology Research
- Marine and coastal ecosystems
- Isotope Analysis in Ecology
- Oceanographic and Atmospheric Processes
- Methane Hydrates and Related Phenomena
- Marine Biology and Ecology Research
- French Urban and Social Studies
- Marine and environmental studies
- Geochemistry and Elemental Analysis
- Ocean Acidification Effects and Responses
- Paleontology and Stratigraphy of Fossils
- Geological formations and processes
- Groundwater and Isotope Geochemistry
- Radioactive contamination and transfer
- Atmospheric and Environmental Gas Dynamics
- Scheduling and Optimization Algorithms
- Climate Change Policy and Economics
- Climate Change, Adaptation, Migration
- Planetary Science and Exploration
- Advanced Manufacturing and Logistics Optimization
- Archaeology and ancient environmental studies
- Sustainability and Climate Change Governance
- Optimization and Packing Problems
- Field-Flow Fractionation Techniques
- Radioactivity and Radon Measurements
Centre de Recherche et d’Enseignement de Géosciences de l’Environnement
2012-2025
Aix-Marseille Université
2012-2025
Institut National de Recherche pour l'Agriculture, l'Alimentation et l'Environnement
2022-2025
Institut de Recherche pour le Développement
2014-2024
Centre National de la Recherche Scientifique
2003-2024
Utrecht University
2023
Tohoku University
2023
Max Planck Institute for Chemistry
2023
Collège de France
2014-2022
Sustainable Europe Research Institute
2017
Abstract Ecosystem processes are important determinants of the biogeochemistry ocean, and they can be profoundly affected by changes in climate. Ocean models currently express ecosystem through empirically derived parameterizations that tightly link key geochemical tracers to ocean physics. The explicit inclusion will permit ecological taken into account, allow us address several questions, including causes observed glacial–interglacial atmospheric trace gases aerosols, how oceanic uptake CO...
A new model of the marine ecosystem coupled into a global Earth System Climate Model suitable for long‐term (multimillennial timescale) simulations is presented. The based on nitrate as sole limiting nutrient. Prognostic equations nutrients, phytoplankton, zooplankton, and detritus are solved online in three‐dimensional ocean circulation component. Experiments with different parameterizations vertical mixing, including scheme tidally driven changes buoyancy forcing Southern Ocean, particle...
The injection of radiocarbon ( 14 C) into the atmosphere by nuclear weapons testing in 1950s and 1960s has provided a powerful tracer to investigate ocean physical chemical processes. While oceanic uptake bomb‐derived C was primarily controlled air‐sea exchange early decades after bomb spike, we demonstrate that changes are now shallow‐to‐deep exchange, i.e., same mechanism governs anthropogenic CO 2 uptake. This is result accumulated rapidly decreased gradient C/C (Δ shifted main reservoir...
The growing world population increases the demand for water, energy, and land. This natural resources impacts transport of material supply nutrients in coastal ocean by rivers. We assess potential impact river N, Si, Fe, organic carbon (OC) fluxes on global biogeochemistry, using an biogeochemistry model observations, eight different scenarios. two extreme scenarios, one with no nutrients, corresponding to a complete stop nutrient input rivers, high fluxes, 12 billion people. Compared...
Abstract. Carbon isotopes in the ocean are frequently used as paleoclimate proxies and present-day geochemical tracers. In order to allow a more direct comparison of climate model results with this large currently underutilized data set, we added carbon isotope module Community Earth System Model (CESM), containing cycling stable 13C radioactive 14C. We implemented 14C tracer two ways: "abiotic" case, is only subject air–sea gas exchange, physical transport, decay, while "biotic" version,...
This study aims at providing robust temperature reconstructions for a key oceanographic setting in the North Atlantic and understanding nature of signal recorded by two biomarkers Uk′37 TEX86, considering season depth production. To do so, high-resolution signals TEX86 are determined last 70 kyr core MD95-2042, located off Portugal. Signals present tight correlation, demonstrating dominant effect. correspond well to annual mean sea surface (SST), whereas TEXH86-derived temperatures 5.6°C...
CEREGE is a renowned French Research and Teaching Centre for Environmental Geosciences, employing approximately 220 staff members. In 2019, the carbon footprint of CEREGE’s research-related activities was estimated at around 7 tons CO2 equivalent per person. This primarily stems from three sources: 1) purchases that are e.g. necessary various analytical methods, 2) commuting between home remote location, 3) international travel sampling campaigns conferences.Since group about dozen...
Planktonic Foraminifera are unique paleo-environmental indicators through their excellent fossil record in ocean sediments. Their distribution and diversity affected by different environmental factors including anthropogenically forced climate change. Until now, historical changes have not been fully assessed at the global scale. Here we present FORCIS (Foraminifera Response to Climatic Stress) database on foraminiferal species from 1910 until 2018 published unpublished data. The includes...
The coastal ocean provides nutrients to the open in accounts that are poorly quantified. We use an biogeochemistry model assess importance of nutrient supply global biogeochemistry. includes full cycles P, Si, and Fe, as well representation two phytoplankton groups, zooplankton organic detritus pools. When mixing is enhanced reproduce action tides storms, primary production chlorophyll‐a (Chla) concentrations show a large increase at coast smaller ocean. sediment resuspension or river...
Planktonic Foraminifera are ubiquitous marine protozoa inhabiting the upper ocean. During life, they secrete calcareous shells, which accumulate in sediments, providing a geological record of past spatial and temporal changes their community structure. As result, provide opportunity to analyze both current historical patterns species distribution turnover this plankton group on global scale. The FORCIS project aims unlock potential by synthesizing comprehensive database abundance diversity...
Abstract 36 Cl production in the atmosphere is modulated by magnetic field intensity of both Sun and Earth. The record concentration along with that 10 Be ice cores may therefore provide information as to their variability. To better understand signal glaciological archives, we measured its Talos Dome snow samples (mean accumulation rate 8 g cm −2 year −1 water equivalent) spanning 1910 1980 CE period a resolution one sample every 3 years from 1955 C.E., Vostok 1.96 1949 2007 6‐month had...
Abstract Planktonic Foraminifera have been collected from the water column with different plankton sampling devices equipped nets of various mesh sizes, which impedes direct comparison observed quantifications. Here, we use data on community size structure planktonic to assess impact measured abundance (ind m −3 ) Foraminifera. We FORCIS database (Chaabane et al., 2023, Scientific Data 10 : 354) global ocean at depths over past century. find a cumulative increase in size, is best described...
Abstract Soil organic carbon is one of the largest surface pools that humans can manage in order to partially mitigate annual anthropogenic CO 2 emissions. A significant element assess soil sequestration potential age, which evaluated by modelling or experimentally using isotopes. Results, however, are not consistent. The 14 C derived approach seems overestimate a factor 6–10 average age soils estimated modeling and 13 approaches thus potential. fully independent method needed. cosmogenic...
Sediments on the Namibian Margin in SE Atlantic between water depths of ∼1000 and ∼3600 m are highly enriched hydrocarbon‐prone organic matter. Such sedimentation has occurred for more than 2 million years is geographically distributed over hundreds kilometers along margin, so that sediments this region contain a huge concentrated stock carbon. It shown here most variability content due to relative dilution by buried carbonates. This reflects both export productivity diagenetic dissolution,...
[1] Using a regional circulation-ecosystem model subject to set of boundary conditions that reflect present-day (PD) and Last Glacial Maximum (LGM) conditions, we investigate how changes in preformed subsurface nutrient concentrations as opposed local drop sea level or increase wind stress influence the biological productivity off northwest African coastal upwelling area. A reduction concentration at LGM reduced zonally averaged primary production (PP). The change modifies shelf morphology,...
<title>Abstract</title> Anthropogenic activities, in particular rising CO<sub>2</sub> emissions, provoke ocean warming and acidification<sup>1,2</sup>, altering plankton habitats threatening calcifying species<sup>3,4</sup> such as planktonic Foraminifera (PF). Whether they can cope with these unprecedented rates of environmental change, through lateral migrations vertical displacements, is unresolved. Here we show, using over a century data from the FORCIS<sup>5</sup> global census counts,...
The delta(15)N Signal in marine sediments appears to be a good palaeoceanographic tracer. It records biological processes the water column and is transferred preserved sediments. Changes forcing factors upwelling systems may recorded by delta(15)N. These conditions can of biogeochemical nature, such as initial isotopic signal nutrients or trophic structure, physical wind stress, insolation, temperature dynamic recycling. A simple nitrogen-based chain model was used follow development...
Abstract. Carbon isotopes in the ocean are frequently used as paleo climate proxies and present-day geochemical tracers. In order to allow a more direct comparison of model results with this large currently underutilized dataset, we added carbon isotope module Community Earth System Model (CESM), containing cycling stable 13C radioactive 14C. We implemented 14C tracer two ways: "abiotic" case, is only subject air–sea gas exchange, physical transport, decay, while "biotic" version,...
A physical‐biogeochemical model is used to simulate the evolution of δ 15 N signal during last glacial‐interglacial transition in sedimentary cores offshore from Mauritanian upwelling. The biological a classical nitrogen‐based trophic chain model, which also computes nitrogen isotope fractionation. 2D physical primitive equation simulates coastal upwelling circulation and applied for different sea level scenarios. effect rise, inducing shelf immersion, seems be main factor explaining organic...
Abstract. A regional biogeochemical model is applied to the NW African coastal upwelling between 19° N and 27° investigate how a water temperature proxy, alkenones, are produced at sea surface recorded in slope sediments. The has two phytoplankton groups: an alkenone producer group, considered be coccolithophores, group comprising other phytoplankton. Regional Ocean Modelling System (ROMS) used simulate ocean circulation takes advantage of Adaptive Grid Refinement Fortran (AGRIF) package set...
Planktonic Foraminifera have been collected from the water column with different plankton sampling devices equipped nets of various mesh sizes, which impedes direct comparison observed quantifications. Here, we use data on community size structure planktonic to assess impact measured abundance (ind/m 3) Foraminifera. We FORCIS database (Chaabane et al., 2023) global ocean at depths over past century. find a cumulative increase in size, is best described using Michaelis-Menten function. This...