Carte 14. Salle Hillaire (Partie sud)
This first volume of Monographie de la grotte Chauvet-Pont d’Arc presents a reasoned inventory of the information contained in the cave in the form of an atlas. While this type of publication may seem unusual, the dimensions of the cave, the morphology of the chambers and galleries that compart-mentalize its space, as well as the inscription of artworks in its underground landscape, are all invitations to reflect upon, study and structure our knowledge of the cave using a cartographic approach. The progressive presentation of the Atlas de la grotte Chauvet-Pont d’Arc enables us to address, in the most neutral manner possible, the complexity and factual richness, often emphasized, of this underground sanctuary.The proposed itinerary, close to that of the current path of the walkways from the entrance to the end of the cavity, invites us to discover the cave via twenty maps extracted from the integrated map of the cave floors. Moving through the cave and into its smallest and most intimate spaces, each person can shape their reading according to their interests. The visit to each of the twenty zones is organized according to the same narrative structure. The first page, accompa-nied by a panoramic photograph, presents the main charac-teristics of the zone and the themes that will be addressed. Depending on the sectors, the archaeology, paleontology, geology, speleogenesis or underground landscape is empha-sized. The second and third pages are positioned opposite each other and are designed to interact. The second page presents the integrated map reproduced at the 1:100 scale. Below it, a thumbnail representation enables the reader to identify the location of the map within the cave. A small map at the 1:300 scale presents the cave floor in 3D and shows the location, feature and artwork designations, the permanent and temporary paths installed for observations, as well as the camera angles and the position of the longitudinal profile of the zone. A synoptic figure shows the relative representation of each of the research domains in the map zone. The pages that follow provide an initial synthesis of the observations and research in progress. These aspects will be presented in detail in the succeeding volumes of the Atlas de la grotte Chauvet-Pont d’Arc.
(. vol. 1, pp. 249-254, 22/06/2026)
TRACES, EHESS, UT2J, Comue de Toulouse, MCC, Inrap, CNRS, MCC, LGL-TPE, ENS de Lyon, UCBL, INSU - CNRS, UJM, UJM EPE, CNRS, PACEA, UB, CNRS, LAMPEA, AMU, CNRS, MC, MSHS-T, CNRS, Comue de Toulouse, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
Reconstructing climatic modes of variability from proxy records using ClimIndRec version 1.0
Modes of climate variability strongly impact our climate and thus human society. Nevertheless, the statistical properties of these modes remain poorly known due to the short time frame of instrumental measurements. Reconstructing these modes further back in time using statistical learning methods applied to proxy records is useful for improving our understanding of their behaviour. For doing so, several statistical methods exist, among which principal component regression is one of the most widely used in paleoclimatology. Here, we provide the software ClimIndRec to the climate community; it is based on four regression methods (principal component regression, PCR; partial least squares, PLS; elastic net, Enet; random forest, RF) and cross-validation (CV) algorithms, and enables the systematic reconstruction of a given climate index. A prerequisite is that there are proxy records in the database that overlap in time with its observed variations. The relative efficiency of the methods can vary, according to the statistical properties of the mode and the proxy records used. Here, we assess the sensitivity to the reconstruction technique. ClimIndRec is modular as it allows different inputs like the proxy database or the regression method. As an example, it is here applied to the reconstruction of the North Atlantic Oscillation by using the PAGES 2k database. In order to identify the most reliable reconstruction among those given by the different methods, we use the modularity of ClimIndRec to investigate the sensitivity of the methodological setup to other properties such as the number and the nature of the proxy records used as predictors or the targeted reconstruction period. We obtain the best reconstruction of the North Atlantic Oscillation (NAO) using the random forest approach. It shows significant correlation with former reconstructions, but exhibits higher validation scores.
(Geoscientific Model Development. vol. 13, n° 1991-9603, pp. 841 - 858, 22/06/2026)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, CQFD, IMB, UB, Bordeaux INP, CNRS, Inria, UOR, LOCEAN-VARCLIM, LOCEAN, MNHN, IRD, INSU - CNRS, SU, CNRS, IPSL (FR_636), ENS-PSL, UVSQ, CEA, INSU - CNRS, X, CNES, SU, CNRS, UPCité
Reconstruction of Holocene oceanographic conditions in eastern Baffin Bay
Baffin Bay is a semi-enclosed basin connecting the Arctic Ocean and the western North Atlantic, thus making out a significant pathway for heat exchange. Here we reconstruct the alternating advection of relatively warmer and saline Atlantic waters versus the incursion of colder Arctic water masses entering Baffin Bay through the multiple gateways in the Canadian Arctic Archipelago and the Nares Strait during the Holocene. We carried out benthic foraminiferal assemblage analyses, X-ray fluorescence scanning, and radiocarbon dating of a 738 cm long marine sediment core retrieved from eastern Baffin Bay near Upernavik, Greenland (Core AMD14-204C; 987 m water depth). Results reveal that eastern Baffin Bay was subjected to several oceanographic changes during the last 9.2 kyr. Waning deglacial conditions with enhanced meltwater influxes and an extensive sea-ice cover prevailed in eastern Baffin Bay from 9.2 to 7.9 ka. A transition towards bottom water amelioration is recorded at 7.9 ka by increased advection of Atlantic water masses, encompassing the Holocene Thermal Maximum. A cold period with growing sea-ice cover at 6.7 ka interrupts the overall warm subsurface water conditions, promoted by a weaker northward flow of Atlantic waters. The onset of the neoglaciation at ca. 2.9 ka is marked by an abrupt transition towards a benthic fauna dominated by agglutinated species, likely in part explained by a reduction of the influx of Atlantic Water, allowing an increased influx of the cold, corrosive Baffin Bay Deep Water originating from the Arctic Ocean to enter Baffin Bay through the Nares Strait. These cold subsurface water conditions persisted throughout the Late Holocene, only interrupted by short-lived warmings superimposed on this cooling trend.
(Climate of the Past. vol. 16, n° 1814-9324, pp. 1075-1095, 22/06/2026)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
The Zebra Mussel (Dreissena polymorpha) as a Model Organism for Ecotoxicological Studies: A Prior 1H NMR Spectrum Interpretation of a Whole Body Extract for Metabolism Monitoring
The zebra mussel (Dreissena polymorpha) represents a useful reference organism for the ecotoxicological study of inland waters, especially for the characterization of the disturbances induced by human activities. A nuclear magnetic resonance (NMR)-based metabolomic approach was developed on this species. The investigation of its informative potential required the prior interpretation of a reference 1 H NMR spectrum of a lipid-free zebra mussel extract. After the extraction of polar metabolites from a pool of whole-body D. polymorpha powder, the resulting highly complex 1D 1 H NMR spectrum was interpreted and annotated through the analysis of the corresponding 2D homonuclear and heteronuclear NMR spectra. The spectrum interpretation was completed and validated by means of sample spiking with 24 commercial compounds. Among the 238 detected 1 H signals, 53% were assigned, resulting in the identification of 37 metabolites with certainty or high confidence, while 5 metabolites were only putatively identified. The description of such a reference spectrum and its annotation are expected to speed up future analyses and interpretations of NMR-based metabolomic studies on D. polymorpha and to facilitate further explorations of the impact of environmental changes on its physiological state, more particularly in the context of large-scale ecological and ecotoxicological studies.
(Metabolites. vol. 10, n° 2218-1989, pp. 256, 22/06/2026)
SEBIO, INERIS, URCA, ULH, NU, URCA, CNRS, LIEC, INSU - CNRS, UL, CNRS, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, TBI, INSA Toulouse, INSA, Comue de Toulouse, CNRS, INRAE, ICMR, URCA, INC-CNRS, URCA, CNRS, URCA, CNRS
Environmental samples of microplastics induce significant toxic effects in fish larvae.
Microplastics (MPs) are present throughout aquatic ecosystems, and can be ingested by a wide variety of organisms. At present, the physical and chemical effects of environmental MPs on aquatic organisms are poorly documented. This study aims to examine the physiological and behavioral effects caused by fish consuming environmental microplastics at different life stages. MP samples were collected from beaches on three islands (Easter Island, Guam and Hawaii) located near the North and South gyres of the Pacific Ocean. Larvae and juveniles of Japanese Medaka were fed for 30days with three doses of MPs (0.01, 0.1 and 1% w/w in fish food) approximate to the concentrations measured in moderately and heavily contaminated ocean areas. Ingestion of MPs by medaka larvae caused (variously) death, decreased head/body ratios, increased EROD activity and DNA breaks and, alterations to swimming behavior. A diet of 0.1% MPs was the most toxic. Two-month-old juveniles fed with 0.01% MPs did not exhibit any symptoms except an increase in DNA breaks. Our results demonstrate ingestion and mainly sublethal effects of environmental MPs in early life stages of fish at realistic MP concentrations. The toxicity of microplastics varies from one sample to another, depending on polymer composition, weathering and pollutant content. This study examines the ecological consequences microplastic build-up in aquatic ecosystems, more particularly in coastal marine areas, which serve as breeding and growing grounds for a number of aquatic species.
(Environment International. vol. 134, n° 0160-4120, pp. 105047, 22/06/2026)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, CNRS, PAnTher, Oniris VetAgroBio, INRAE, APEX, PAnTher, Oniris VetAgroBio, INRAE, ANSES
Field Observations of Wave-induced Headland Rips
Most of rip-current field experiments have focused on persistent rips along rip-channeled sandy beaches or transient rips along reasonably alongshore-uniform surf-zone morphology, while experiments on rip flowing against structures are scarce. In October 2018, a 3-week field experiment was performed at Anglet beach, SW France, aiming at examining the dynamics of high-energy rip currents in complex settings. The beach is barred with prominent inherited geology, characterized by the presence of a 500-m headland and a natural submerged reef. A large array of in-situ instruments was deployed to capture the temporal and spatial variability of rip flow circulations, including ADCPs, surf-zone drifters and video monitoring. The latter allowed to identify a wide range of rip-flow patterns. Among these patterns, a high-intensity rip current flowing against the headland was a dominant feature for obliquely incident waves. Such a boundary rip current was driven by the deflection of the longshore current against the headland, peaking at 0.7 m/s (5-min time-and depth-averaged) 800-m offshore in 12-m depth for a moderate storm event with 4-m obliquely incident waves. Very-lowfrequency (O(1h) and O(30min)) fluctuations of this rip current were observed around low tide. Measurements of the vertical structure of the rip reveal that the deflection rip was more vertically-sheared as the water depth increases, with higher velocities near the surface, which is typical of a theoretical rip head structure.
(Journal of Coastal Research. vol. 95, n° 0749-0208, pp. 578, 22/06/2026)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, SIAME, UPPA, MIO, IRD, AMU, INSU - CNRS, UTLN, CNRS
Bounding Global Aerosol Radiative Forcing of Climate Change
Aerosols interact with radiation and clouds. Substantial progress made over the past 40 years in observing, understanding, and modeling these processes helped quantify the imbalance in the Earth's radiation budget caused by anthropogenic aerosols, called aerosol radiative forcing, but uncertainties remain large. This review provides a new range of aerosol radiative forcing over the industrial era based on multiple, traceable, and arguable lines of evidence, including modeling approaches, theoretical considerations, and observations. Improved understanding of aerosol absorption and the causes of trends in surface radiative fluxes constrain the forcing from aerosol-radiation interactions. A robust theoretical foundation and convincing evidence constrain the forcing caused by aerosol-driven increases in liquid cloud droplet number concentration. However, the influence of anthropogenic aerosols on cloud liquid water content and cloud fraction is less clear, and the influence on mixed-phase and ice clouds remains poorly constrained. Observed changes in surface temperature and radiative fluxes provide additional constraints. These multiple lines of evidence lead to a 68% confidence interval for the total aerosol effective radiative forcing of -1.6 to -0.6 W m-2, or -2.0 to -0.4 W m-2 with a 90% likelihood. Those intervals are of similar width to the last Intergovernmental Panel on Climate Change assessment but shifted toward more negative values. The uncertainty will narrow in the future by continuing to critically combine multiple lines of evidence, especially those addressing industrial-era changes in aerosol sources and aerosol effects on liquid cloud amount and on ice clouds.
(Reviews of Geophysics. vol. 58, n° 8755-1209, 22/06/2026)
IPSL (FR_636), ENS-PSL, PSL, UVSQ, CEA, INSU - CNRS, X, IP Paris, CNES, SU, CNRS, UPCité, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, LMD, INSU - CNRS, X, IP Paris, ENPC, SU, CNRS, ENS-PSL, PSL
Hygroscopic behavior of aerosols generated from solutions of 3-methyl-1,2,3-butanetricarboxylic acid, its sodium salts, and its mixtures with NaCl
Secondary organic aerosols (SOAs), which are formed and transformed through complex physicochemical processes in the atmosphere, have attracted considerable attention over the past decades because of their impacts on both climate change and human health. Recently, 3-methyl-1,2,3-butanetricarboxylic acid (MBTCA), a low volatile, highly oxidized, secondary generation product of monoterpenes, is one of the most relevant tracer compounds for biogenic SOAs. Therefore, MBTCA was selected to understand its hygroscopic properties better. In addition, interactions between the organic acid and inorganic components have been reported, which may alter their hygroscopic properties mutually. In this study, laboratory-generated, micrometer-sized, pure MBTCA, mono-/di-/tri-sodium MBTCA salts, and MBTCA-NaCl mixture aerosol particles of four mixing ratios (molar ratios = 1 : 1, 1 : 2, 1 : 3, and 2 : 1) were examined systematically to observe their hygroscopic behavior by varying the relative humidity (RH) from RH = ~95 % to ~1 % through a dehydration process, followed by a humidification process from RH = ~1 % to ~95 %, using in-situ Raman microspectrometry (RMS) assembled with a see-through impactor where the particles were deposited on a Si wafer. The hygroscopic behavior of pure MBTCA and MBTCA-NaCl mixture aerosol particles of three mixing ratios (molar ratios = 1 : 1, 1 : 2, and 1 : 3) were also examined using a levitation system mounted on in-situ RMS through a humidification process from RH = ~10 % to ~80 % after a quenching process from droplets, followed by dehydration from RH = ~80 % to ~10 %. The pure MBTCA droplets effloresced at RH = ~30–57.8 % and did not dissolve until RH > 95 %. The mono- and di-sodium MBTCA salt aerosols did not show clear efflorescence RH (ERH) and deliquescence RH (DRH). In contrast, the tri-sodium MBTCA salt exhibited ERH = ~44.4–46.8 % and DRH = ~53.1 %, during the hygroscopic experiment cycle. The mixture aerosols generated from solutions of MBTCA : NaCl = 1 : 1 and 2 : 1 showed no visible ERH and DRH in the see-through impactor because of the partial and total consumption of NaCl, respectively, through chemical reactions during the dehydration process. The mixture particles with a 1 : 1 molar ratio in the levitation system exhibited a clear DRH at ~71 % and ERH at ~50 %. This suggests less reaction between the mixtures and a larger portion of NaCl remaining in the levitation system. The other mixtures of MBTCA : NaCl = 1 : 2 and 1 : 3 displayed single-stage efflorescence and deliquescence at ERH = ~45–50 % and DRH = ~74 %, respectively, because of the considerable amount of NaCl present in the mixture aerosols in both systems. Observations and Raman analyses indicated that only monosodium MBTCA salt aerosols could be formed through a reaction between MBTCA and NaCl. The reaction occurred more rapidly with a more elevated concentration of either MBTCA or NaCl, and the controlling factor for the reactivity of the mixtures depended mostly on the availability of H+ dissociated from the MBTCA tricarboxylic acid. The lower degree of reaction of the mixture particles in the levitation system might be caused by the relatively airtight circumstance inside, i.e., the less release of HCl. In addition, the quenching process, i.e., the starting point of the hygroscopicity experiments, induced the solidification of MBTCA, and further, a slow reaction between MBTCA and NaCl. The study revealed that the interactions between the MBTCA and NaCl could modify the properties of the organic acid in the atmosphere, leading to enhanced capability of the probable heterogeneous chemistry in the aqueous aerosols.
(Atmospheric Chemistry and Physics. vol. 20, n° 1680-7316, pp. 14103–14122, 22/06/2026)
ISM, UB, INC-CNRS, CNRS, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
Microbial Communities of the Shallow-Water Hydrothermal Vent Near Naples, Italy, and Chemosynthetic Symbionts Associated With a Free-Living Marine Nematode
Shallow-water hydrothermal vents are widespread, especially in the Mediterranean Sea, owing to the active volcanism of the area. Apart free microbial communities’ investigations, few biological studies have been leaded yet. Investigations of microbial communities associated with Nematoda, an ecologically important group in sediments, can help to improve our overall understanding of these ecosystems. We used a multidisciplinary-approach, based on microscopic observations (scanning electron microscopy: SEM and Fluorescence In Situ Hybridization: FISH) coupled with a molecular diversity analysis using metabarcoding, based on the 16S rRNA gene (V3-V4 region), to characterize the bacterial community of a free-living marine nematode and its environment, the shallow hydrothermal vent near Naples (Italy). Observations of living bacteria in the intestine (FISH), molecular and phylogenetic analyses showed that this species of nematode harbors its own bacterial community, distinct from the surrounding sediment and water. Metabarcoding results revealed the specific microbiomes of the sediment from three sites of this hydrothermal area to be composed mainly of sulfur oxidizing and reducing related bacteria.
(Frontiers in Microbiology. vol. 11, n° 1664-302X, pp. 2023, 22/06/2026)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, LM2E, IFREMER, UBO EPE, CNRS, LEP, EEP, IFREMER, PARTHENOPE
Glacier and ocean variability in Ata Sund, west Greenland, since 1400 CE
To improve knowledge of marine-terminating glaciers in western Greenland, marine sediment cores from the Ata Sund fjord system, hosting two outlet glaciers, Eqip Sermia and Kangilerngata Sermia, were investigated. The main objective was to reconstruct glacial activity and paleoceanographic conditions during the past 600 years. Ice-rafted debris (IRD) was quantified by wet-sieving sediment samples and by using a computed tomography scan. Variability in relative bottom water temperatures in the fjord was reconstructed using foraminiferal analysis. On the basis of this, three periods of distinct glacial regimes were identified: Period 1 (1380–1810 CE), which covers the culmination of the Little Ice Age (LIA) and is interpreted as having advanced glaciers with high IRD content. Period 2 (1810–1920 CE), the end of the LIA, which was characterised by a lowering of the glaciers’ calving flux in response to climate cooling. During Period 3 (1920–2014 CE), both glaciers retreated substantially to their present-day extent. The bottom water temperature started to decrease just before Period 2 and remained relatively low until just before the end of Period 3. This is interpreted as a local response to increased glacial meltwater input. Our study was compared with a study in Disko Bay, nearby Jakobshavn Glacier and the result shows that both of these Greenlandic marine-terminating glaciers are responding to large-scale climate change. However, the specific imprint on the glaciers and the different fjord waters in front of them result in contrasting glacial responses and sediment archives in their respective fjords.
(The Holocene, n° 0959-6836, pp. 095968362095043, 22/06/2026)
GEUS, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS