Local oceanic CO2 outgassing triggered by terrestrial carbon fluxes during deglacial flooding
Exchange of carbon between the ocean and the atmosphere is a key process that influences past climates via glacial–interglacial variations of the CO2 concentration. The melting of ice sheets during deglaciations induces a sea level rise which leads to the flooding of coastal land areas, resulting in the transfer of terrestrial organic matter to the ocean. However, the consequences of such fluxes on the ocean biogeochemical cycle and on the uptake and release of CO2 are poorly constrained. Moreover, this potentially important exchange of carbon at the land–sea interface is not represented in most Earth system models. We present here the implementation of terrestrial organic matter fluxes into the ocean at the transiently changing land–sea interface in the Max Planck Institute for Meteorology Earth System Model (MPI-ESM) and investigate their effect on the biogeochemistry during the last deglaciation. Our results show that during the deglaciation, most of the terrestrial organic matter inputs to the ocean occurs during Meltwater Pulse 1a (between 15–14 ka) which leads to the transfer of 21.2 Gt C of terrestrial carbon (mostly originating from wood and humus) to the ocean. Although this additional organic matter input is relatively small in comparison to the global ocean inventory (0.06 %) and thus does not have an impact on the global CO2 flux, the terrestrial organic matter fluxes initiate oceanic outgassing in regional hotspots like in Indonesia for a few hundred years. Finally, sensitivity experiments highlight that terrestrial organic matter fluxes are the drivers of oceanic outgassing in flooded coastal regions during Meltwater Pulse 1a. Furthermore, the magnitude of outgassing is rather insensitive to higher carbon-to-nutrient ratios of the terrestrial organic matter. Our results provide a first estimate of the importance of terrestrial organic matter fluxes in a transient deglaciation simulation. Moreover, our model development is an important step towards a fully coupled carbon cycle in an Earth system model applicable to simulations at glacial–interglacial cycles.
(Climate of the Past. vol. 18, n° 1814-9324, pp. 273-292, 13/04/2026)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, MPI-M
Estuarine dissolved speciation and partitioning of trace metals: a novel approach to study biogeochemical processes
Estuaries are complex systems involving numerous biogeochemical gradients and processes that influence the behavior of trace metals. Lead (Pb), cadmium (Cd), and copper (Cu) speciation and partitioning were studied in the Gironde Estuary (SW France), using a multi-method approach in which data from innovative sensors and laboratory-based techniques were combined. For the first time in this system, the so-called dynamic fractions of the target metals (dissolved forms that are potentially bioavailable) were recorded on-board through voltammetry using unique antifouling gel-integrated microelectrode arrays (GIME) incorporated in a submersible sensing probe (TracMetal). Trace metals in the operationally defined dissolved <0.2 μm and <0.02 μm fractions, as well as complexed with suspended particles (collected after centrifugation) were quantified through sampling/laboratory-based techniques. High spatial resolution trace metal concentrations were monitored along the salinity gradient (S = 0.10 to S = 34.0) together with master bio-physicochemical parameters providing robust cruise-specific information on how well-known abiotic and biotic processes control the Gironde estuarine trace element partitioning, (i.e. conservative behavior, addition/removal). Combining conventional methods with GIME measurements showed: (i) the dominance of Cd dynamic species in the intra-estuarine total dissolved fraction (up to 90%), (ii) the importance of small colloids as trace metal carrier phases, desorbing and complexing dynamic fractions of Pb and Cu, and (iii) the potential influence of photo-redox processes remobilizing Pb under their dynamic forms (up to 80%). Data also suggest trace metal release/sorption by phytoplankton with an increase of dissolved Cu concentrations in the riverine branch, as well as Cu and Cd particulate concentrations showing higher levels towards productive coastal waters. This complete approach allowed to monitor key estuarine biogeochemical processes and highlighted the valuable use of the TracMetal to record subtle variations of potentially bioavailable dissolved metal fractions.
(Environmental Research. vol. 208, n° 0013-9351, pp. 112596, 13/04/2026)
UNIGE, UB, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
Multigenerational exposure to gamma radiation affects offspring differently over generations in Zebrafish
Mutigenerational studies have become of great interest in ecotoxicology and previously provided original results on the effects of offspring irradiation in model fish Danio rerio. Here, the irradiation of zebrafish was maintained until F2 larval stage. Two dose rates were selected; the first one (0.05 mGy h-1) was close to the threshold value for the protection of aquatic ecosystems, the second one (5 mGy h-1) previously studied and known to increase morbidity (DCRL). F1 from 30d-irradiated parents were irradiated themselves (irradiated condition) or not (Recovery condition) for 131 days before reproduction. Endpoints concerned reproductive capacity (reproductive success, fecundity, egg fertilization) and larval survival in F0, F1 and F2. Multigenerational irradiation affected F1 parental reproductive capacity mainly over the first reproduction and larval survival rate. Unexpected effects on sex ratio was observed in exposed and non-exposed F1 progeny after parental irradiation (mainly at 5 mGy h-1). The worsening effects over the two generations observed here could partly explain the higher sensitivity of wild populations. Thus, this study confirm that multigenerational studies could be of interest on ecological risk assessment, in particular to determine the benchmark values.
(Aquatic Toxicology. vol. 244, n° 0166-445X, pp. 106401, 13/04/2026)
IRSN/PRP-ENV/SERIS/LECO, IRSN/PRP-ENV/SERIS, IRSN, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
Propagation of Thermohaline Anomalies and Their Predictive Potential along the Atlantic Water Pathway
We assess to what extent seven state-of-the-art dynamical prediction systems can retrospectively predict winter sea surface temperature (SST) in the subpolar North Atlantic and the Nordic seas in the period 1970-2005. We focus on the region where warm water flows poleward (i.e., the Atlantic water pathway to the Arctic) and on interannual-to-decadal time scales. Observational studies demonstrate predictability several years in advance in this region, but we find that SST skill is low with significant skill only at a lead time of 1-2 years. To better understand why the prediction systems have predictive skill or lack thereof, we assess the skill of the systems to reproduce a spatiotemporal SST pattern based on observations. The physical mechanism underlying this pattern is a propagation of oceanic anomalies from low to high latitudes along the major currents, the North Atlantic Current and the Norwegian Atlantic Current. We find that the prediction systems have difficulties in reproducing this pattern. To identify whether the misrepresentation is due to incorrect model physics, we assess the respective uninitialized historical simulations. These simulations also tend to misrepresent the spatiotemporal SST pattern, indicating that the physical mechanism is not properly simulated. However, the representation of the pattern is slightly degraded in the predictions compared to historical runs, which could be a result of initialization shocks and forecast drift effects. Ways to enhance predictions could include improved initialization and better simulation of poleward circulation of anomalies. This might require model resolutions in which flow over complex bathymetry and the physics of mesoscale ocean eddies and their interactions with the atmosphere are resolved.
(Journal of Climate. vol. 35, n° 0894-8755, pp. 2111-2131, 13/04/2026)
NERSC, BCCR, BIO / UiB, UiB, BSC-CNS, GFI / BiU, UiB, MPI-M, LOCEAN-VARCLIM, LOCEAN, MNHN, IRD, INSU - CNRS, SU, CNRS, IPSL (FR_636), ENS-PSL, UVSQ, CEA, INSU - CNRS, X, CNES, SU, CNRS, UPCité, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, DMI, NCAR, CMCC, ISAC, CNR, UNIBO
In-phase millennial-scale glacier changes in the tropics and North Atlantic regions during the Holocene
Based on new and published cosmic-ray exposure chronologies, we show that glacier extent in the tropical Andes and the north Atlantic regions (TANAR) varied in-phase on millennial timescales during the Holocene, distinct from other regions. Glaciers experienced an early Holocene maximum extent, followed by a strong mid-Holocene retreat and a re-advance in the late Holocene. We further explore the potential forcing of TANAR glacier variations using transient climate simulations. Since the Atlantic Meridional Overturning Circulation (AMOC) evolution is poorly represented in these transient simulations, we develop a semi-empirical model to estimate the "AMOC-corrected" temperature and precipitation footprint at regional scales. We show that variations in the AMOC strength during the Holocene are consistent with the observed glacier changes. Our findings highlight the need to better constrain past AMOC behavior, as it may be an important driver of TANAR glacier variations during the Holocene, superimposed on other forcing mechanisms.
(Nature Communications. vol. 401, n° 2041-1723, pp. 108125, 13/04/2026)
CEREGE, IRD, AMU, CdF (institution), INSU - CNRS, CNRS, INRAE, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, SUNY, IGE, IRD, INSU - CNRS, CNRS, Fédération OSUG, UGA, Grenoble INP, UGA, EEOS, UMass Boston, UMASS, UNSW, CRPG, INSU - CNRS, UL, CNRS, ULB, ETH Zürich, DAES, SUNY, TECLIM, ELI, UCLouvain, BC
Architectures 3D et hétérogénéités sédimentaires du réservoir géothermique argilo-sableux de l’Albien d’Île-de-France (Bassin de Paris)
La consommation énergétique en Ile-de-France est majoritairement associée aux besoins en chaleur des bâtiments, puis vient ensuite le secteur des transports. Plus de la moitié de la production de chaleur collective ou individuelle est produite par du combustible fossile. La stratégie énergie-climat de l’Ile-de-France prévoit d’augmenter assez significativement à l’horizon 2030 la production de chaleur par géothermie (x4 par rapport à 2015). Le rythme de développement actuel ne permettra pas d’atteindre cet objectif. Il faudrait atteindre un taux de 6 à 10 fois supérieur. Il devient nécessaire de positionner les doublets de manière optimale en proposant des solutions qui explorent le développement de nouvelles zones. Les réservoirs argilo-sableux du Crétacé inférieur deviennent une cible qu’il convient de mieux caractériser pour optimiser son développement. Récemment (2017) deux doublets géothermiques ont été mis en place dans la nappe de l’Albien sous le plateau de Saclay. Les retours d’expérience sur cette opération ont soulevé des problèmes de forte résistance à la réinjection, ne permettant pas un fonctionnement efficace et durable du système. L’hétérogénéité du réservoir en termes (1) de continuité ou d’épaisseur des niveaux sableux et/ou de niveaux argileux, (2) de minéralogie ou (3) de granulométrie est très peu documentée, ce qui complique son exploitation, et rend incertaine les opérations de ré-injection dans le réservoir. Il devient nécessaire de mieux caractériser ces hétérogénéités dans les réservoirs argilo-sableux du crétacé inférieur (Albien en particulier). Une base de données rassemblant les logs et données pétrophysiques de tous les puits d’Ile- de-France traversant les sables de l’Albien a été organisée sur le géomodelleur Petrel©. Deux cent quarante et un puits, avec diagraphies (avec au moins un Gamma Ray disponible) ou seulement carotté (forage d’Orsay), ont été sélectionnés dans un périmètre allant du nord de la Seine-Saint-Denis jusqu’au sud de l’Essonne et de la Seine et Marne. En incluant le forage carotté historique d’Orsay, ces puits ont été habillés en termes de faciès. Basé sur le rapport BRGM de 2016 (Sévenier et Lasseur, 2016), un ré-examen des faciès et séquences stratigraphiques a été réalisé d’après cette nouvelle base de données. L’étude détaillée permet de reconnaître 7 faciès. Ces faciès ont été attribués à un environnement de dépôt, estuariens à deltaïques en fonction des séquences avec (1) sables grossiers et graviers de la partie chenalisée et influencée par les marées, (2) argiles de replat de marée (mud flat), (3) sables propres de replat sableux (sand flat), (4) sables hétérolithiques de barres sableuses (heterolithic sand bars), (5) sables propres de shoreface, (6) sables argileux d’offshore supérieur et (7) argiles d’offshore inférieur. En tenant compte des concepts de stratigraphie séquentielle et d’empilement vertical des faciès, 3 séquences stratigraphiques de 2nd ordre ont été retrouvées. Douze Maximum Regressive Surfaces et treize Maximum Flooding Surfaces ont été reportées sur les puits et permettent d’illustrer 11 séquences de 3ème ordre, à l’aide de neuf coupes stratigraphiques de corrélation. Ces coupes permettent d’illustrer la géométrie du réservoir. A l’aide de méthodes géostatistiques, plusieurs réalisations numériques rendant compte de l’hétérogénéité 3D des facies ont été proposées. Elles permettent d’identifier les séquences et les localités propices au développement de ce réservoir. Le faciès de sable propre de shoreface de la 3ème séquence 4 et 5 rencontrées dans les Sables de Frécambault présentent une épaisseur d’une trentaine de mètres vers Orsay, et semble une cible idéale pour exploiter le réservoir sur ce site.
(. vol. 82, pp. 6, 13/04/2026)
GEOPS, INSU - CNRS, CNRS, IFPEN, BRGM, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
The Reading Palaeofire Database: an expanded global resource to document changes in fire regimes from sedimentary charcoal records
Sedimentary charcoal records are widely used to reconstruct regional changes in fire regimes through time in the geological past. Existing global compilations are not geographically comprehensive and do not provide consistent metadata for all sites. Furthermore, the age models provided for these records are not harmonised and many are based on older calibrations of the radiocarbon ages. These issues limit the use of existing compilations for research into past fire regimes. Here, we present an expanded database of charcoal records, accompanied by new age models based on recalibration of radiocarbon ages using IntCal20 and Bayesian age-modelling software. We document the structure and contents of the database, the construction of the age models, and the quality control measures applied. We also record the expansion of geographical coverage relative to previous charcoal compilations and the expansion of metadata that can be used to inform analyses. This first version of the Reading Palaeofire Database contains 1676 records (entities) from 1480 sites worldwide. The database (RPDv1b - Harrison et al., 2021) is available at https://doi.org/10.17864/1947.000345.
(Earth System Science Data. vol. 14, n° 1866-3508, pp. 1109-1124, 13/04/2026)
UMR ISEM, Cirad, EPHE, PSL, CNRS, UM, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
Do DOM optical parameters improve the prediction of copper availability in vineyard soils?
Accumulation of copper (Cu) in soils due to the application of fungicides may be toxic for organisms and hence affect winegrowing sustainability. Soil parameters such as pH and dissolved organic matter (DOM) are known to affect the availability of Cu. In this study, we investigated the contribution of chromophoric and fluorescent DOM properties to the prediction of Cu availability in 18 organic vineyard soils in the Bordeaux winegrowing area (France). The DOM parameters, assessed through absorbance and fluorescence analyses, and proxies for Cu availability (total soluble Cu and free ionic Cu2+) were measured in 0.01 M KCl extracts. Total soluble Cu (CuKCl) varied 23-fold while free ionic Cu2+ varied by a factor of 4600 among the soils. DOC concentrations were similar among the soils, but the samples differed in the quality of DOM as assessed by optical spectroscopy. Multilinear regression models with and without DOM quality parameters were investigated to predict Cu availability. The best model for CuKCl successfully explained 83% of variance and included pH, CuT, and two DOM fluorescence quality indices, the FI fluorescence index, which distinguishes between microbial and higher plant origins, and the HIX humification index. For the prediction of Cu2+, pH alone explained 88% of variance and adding DOM parameters did not improve modelling. The two Cu availability proxies were related to pH. This study confirms the prominent role of pH in Cu availability and underlines the importance of DOM quality to better predict Cu solubility
(Environmental Science and Pollution Research, n° 0944-1344, 13/04/2026)
UMR ISPA, Bordeaux Sciences Agro, INRAE, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
Dinoflagellate cysts response to climate change during the MIS 12/11 transition
(13/04/2026)
HNHP, MNHN, UPVD, CNRS, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
Corrigendum to ‘Refinement of an OECD test guideline for evaluating the effects of endocrine disrupting chemicals on aromatase gene expression and reproduction using novel transgenic cyp19a1a-eGFP zebrafish’ [Aquat. Toxicol. 220 (2020) 105403](S0166445X19308392)(10.1016/j.aquatox.2020.105403)
The authors deeply regret that errors occurred in the original above article. Corrections follow below. - In the 2.7. Vitellogenin ELISA section of the Materials and methods section, the sentence “Standard / samples were pre-incubated … overnight at 4°C.” should read as “Standard / samples were pre-incubated with the primary antibody (1:1 with DR-264 zebrafish anti-VTG antibody diluted to 1:500, Biosense Laboratories, Norway) overnight at 4°C.” - In Figure 2, the authors have inadvertently forgot to apply dilution factors to the circulating E2 concentrations. The correct E2 concentrations can be found on the corrected figure bellow. [Formula presented] - In the 3.4. Circulating estradiol concentrations section of the Results section, the sentence “Nevertheless, a 48% inhibition was seen…concentration (172.6 µg/L)” should now read as “Nevertheless, a 40% inhibition was seen between the fish in the different control groups and the fish exposed to the highest concentration (PCZ 172.6 μg/l).” - In the 3.5. Circulating vitellogenin concentrations section of the Results section, the sentence “A significant decrease was measured in fish … (PCZ 172.6 μg/l).” should read as “A significant decrease was measured in fish exposed to the highest concentration of PCZ, with a fall from 23.40 ± 5.11 mg/ml (DMSO) to 6.10 ± 0.74 mg/ml (PCZ 172.6 μg/l).” - In Figure 3, the unit reported on the Y-axis for the vitellogenin concentrations in mg/ml should read as ng/ml. - In the 4.1. Effect of PCZ on classical endpoints of the OECD TG 229 in cyp19a1a-eGFP zebrafish of the Discussion section, the sentence “From a quantitative point of view, the data….(Doering et al., 2019)” should now read as “From a quantitative point of view, the data we obtained in the cyp19a1a-eGFP zebrafish (40 % decrease of estradiol concentration in the high concentration of PCZ compared to control females, leading to a 65 % decrease of circulating VTG and finally to 60 % less eggs produced) are in perfect adequation with the quantitative relationships existing between all key events of the AOP recently described for wildtype zebrafish (Doering et al., 2019).” These corrections do not affect the conclusions of the article in any way. The authors would like to apologise for any inconvenience caused. DOI of original article: https://doi.org/10.1016/j.aquatox.2020.105403 Nathalie Hinfray © 2022
(Aquatic Toxicology. vol. 247, n° 0166-445X, 13/04/2026)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS