Morphological and ecological responses of a managed coastal sand dune to experimental notches
In northern Europe, coastal dune remobilization by restoring natural processes is considered by some to maintain the coastal dune in chronically eroding sectors by migrating landward and to restore dune ecology. In wet climatic contexts, this nature-based solution has been shown to induce an increase in both sand bare areas and vegetation diversity. However, it has never been tested in the coastal dunes of southern Europe with a drier climate and, thus, more stressful conditions, where disturbance may inversely decrease vegetation diversity. An original experiment was set up in 2018 on a 4-km stretch of coastal dune in southwest France where Experimental Notches (EN) were excavated in the incipient foredune, referred to as West Experimental Notch (WEN), and in the established foredune, referred as to East Experimental Notch (EEN). Morphological and ecological responses were monitored using UAV photogrammetry and vegetation sampling along transects during two years with contrasted winter storm conditions. During the first winter characterized by calm wind conditions, a rapid filling of the WENs and the initiation of deposition lobes landward of the EENs were observed. Stronger winds during the second winter led to the development of deposition lobes of the EENs, increasing both their volume, up to 6 times, and their cross-shore elongation. The increase in disturbance induced by the notches had a significant impact on vegetation. New sandy bares were colonized by pioneer species leading to an increase in species richness and rejuvenation, in particular landward of the EENs. Although longer-term monitoring is required to draw conclusions, these results suggest that the excavation of foredune notches are able to re-establish an ecomorphological dynamic in the dunes of southwest France on the time scales of years, promoting landward sand transport and, thus, the foredune landward translation, while not threatening diversity. Such approach may become a relevant adaptation strategy to sea level rise and increased erosion in this region of the world.
(Science of the Total Environment. vol. 782, n° 0048-9697, pp. 146813, 22/04/2026)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, ONF
Multidecadal Evolution of the Turbidity Maximum Zone in a Macrotidal River Under Climate and Anthropogenic Pressures
Climate and human pressures can influence the evolution of estuarine sediment dynamics concurrently, but the understanding and quantification of their cause–effect relationships are still challenging due to the occurrence of complex hydro-morpho-sedimentary feedbacks. The Garonne Tidal River (GTR, upper Gironde Estuary, France) is a clear example of a system stressed by both anthropogenic and climate change, as it has been subject to decreasing river discharges, natural morphological changes, and gravel extraction. To understand the relative effect of each hydrological and geomorphological pressure on the turbidity maximum zone (TMZ), the sediment dynamics in the GTR over the last six decades was evaluated using the width-averaged idealized iFlow model. Model results show a gradual increase in tidal amplitude and currents over the decades that has led to the upstream shift of the landward sediment-transport capacity components (external M4 tide, spatial settling lag, and tidal return flow). The upstream displacement of the TMZ between the 1950s and the 2010s was estimated to be at least 19 km, of which about three fourth was induced by geomorphological changes and one fourth by hydrological changes. Concerning the geomorphological changes, the natural evolution of the lower Gironde morphology was the main pressure inducing the displacement of the TMZ in the GTR. Anthropogenic and natural changes in morphology and bed roughness in the GTR itself also contributed to this evolution. The natural geomorphological changes were, in turn, probably promoted by the evolution of sediment dynamics, so this study reveals the closed circle that governs the intensification of the TMZ.
(Journal of Geophysical Research. Oceans. vol. 126, n° 2169-9275, pp. e2020JC016273, 22/04/2026)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, TU Delft
Climate and the Evolution of the Ocean: The Paleoceanographic Data
The idea of reconstructing the history of oceans and climates in the past using marine sediment cores arrived quite late after the beginnings of oceanography. It was initiated in the twentieth century, well after the first attempts to measure variations in seawater temperature down the water column, which date back to the eighteenth century with the great circumnavigation expeditions. Land geologists were the first to propose paleoceanographic reconstructions from exposed marine series, limiting the collected information to former coastal waters.
(pp. 225-254, 22/04/2026)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, LSCE, UVSQ, INSU - CNRS, CNRS, DRF (CEA), CEA, IFREMER, PALEOCEAN, LSCE, UVSQ, INSU - CNRS, CNRS, DRF (CEA), CEA, LGO, UBS, IFREMER, UBO EPE, CNRS
Uncertainties in Shoreline Projections to 2100 at Truc Vert Beach (France): Role of Sea‐Level Rise and Equilibrium Model Assumptions
Sandy shorelines morphodynamics responds to a myriad of processes interacting at different spatial and temporal scales, making shoreline predictions challenging. Shoreline modeling inherits uncertainties from the primary driver boundary conditions (e.g., sea-level rise and wave forcing) as well as uncertainties related to model assumptions and/or misspecifications of the physics. This study presents an analysis of the uncertainties associated with future shoreline evolution at the cross-shore transport dominated sandy beach of Truc Vert (France) over the 21st century. We explicitly resolve wave-driven shoreline change using two different equilibrium modeling approaches to provide new insight into the contributions of sea-level rise, and free model parameters uncertainties on future shoreline change in the frame of climate change. Based on a Global Sensitivity Analysis, shoreline response during the first half of the century is found to be mainly sensitive to the equilibrium model parameters, with the influence of sea-level rise emerging in the second half of the century (∼2050 or later), under several simulated scenarios. The results reveal that the seasonal and interannual variability of the predicted shoreline position is sensitive to the choice of the wave-driven equilibrium-based model. Finally, we discuss the importance of the chronology of wave events in future shoreline change, calling for more continuous wave projection time series to further address uncertainties in future wave conditions. Our contribution demonstrates that unmitigated climate change can result in shoreline retreat of several tens of meters by 2100, even for sectors that have been stable or slightly accreting over the last century.
(Journal of Geophysical Research: Earth Surface. vol. 126, n° 2169-9003, pp. e2021JF006160, 22/04/2026)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, BRGM
Satellite-derived shoreline detection at a high-energy meso-macrotidal beach
Publicly available satellite imagery can now provide multi-decadal time series of shoreline data from local to global scale, enabling analysis of sandy beach shoreline variability across a spectrum of temporal scales. Such data can, however, be associated with large uncertainties, particularly for beaches experiencing a large tidal range (>2 m) and energetic incident waves. We use a decade of bi-monthly topographic surveys at the high-energy meso-macrotidal beach of Truc Vert, southwest France, and concurrent wave and water-level hindcast to investigate the uncertainties associated with satellite-derived time series of the shoreline position. We show that consideration of the water level and wave runup elevation is critical for accurately estimating waterline position and, in turn, shoreline position. At Truc Vert, including non-tidal water level residuals (e.g. wind-driven surge) and accounting for time- and elevation-varying beach slope for horizontal correction did not improve satellite-derived shoreline position. A new total water level threshold is proposed to maximize the number of usable images while minimizing errors. Accounting for wave runup and the new water level threshold at Truc Vert, the number of usable satellite images is doubled and shoreline position errors are at least halved compared to previous work at this site. Using the 1984–2019 reconstructed shoreline, we also show that the satellite-derived shoreline trends and interannual variability are in better agreement with field measurements. Although the approach proposed here needs to be tested on other sites in different tidal/wave forcing environments with different morphological and sediment characteristics, we anticipate that it will improve the temporal and spatial description of shoreline change on most surf tidal beaches where accurate continuous water level and wave hindcasts and/or observations are available.
(Geomorphology. vol. 383, n° 0169-555X, pp. 107707, 22/04/2026)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, SBMS
Comparison of five methodologies to apportion organic aerosol sources during a PM pollution event
This study presents a comparison of five methodologies to apportion primary (POA) and secondary organic aerosol (SOA) sources from measurements performed in the Paris region (France) during a highly processed PM pollution event. POA fractions, estimated from EC-tracer method and positive matrix factorization (PMF) analyses, conducted on measurements from PM10 filters, aerosol chemical speciation monitor (ACSM) and offline aerosol mass spectrometry (AMS), were all comparable (2.2–3.7 μg m−3 as primary organic carbon (POC)). Associated relative uncertainties (measurement + model) on POC estimations ranged from 8 to 50%. The best apportionment of primary traffic OA was achieved using key markers (EC and 1-nitropyrene) in the chemical speciation-based PMF showing more pronounced rush-hour peaks and greater correlation with NOx than other traffic related POC factors. All biomass burning-related factors were in good agreement, with a typical diel profile and a night-time increase linked to residential heating. If PMF applied to ACSM data showed good agreement with other PMF outputs corrected from dust-related factors (coarse PM), discrepancies were observed between individual POA factors (traffic, biomass burning) and directly comparable SOA factors and highly oxidized OA. Similar secondary organic carbon (SOC) concentrations (3.3 ± 0.1 μg m−3) were obtained from all approaches, except the SOA-tracer method (1.8 μg m−3). Associated uncertainties ranged from 14 to 52% with larger uncertainties obtained for PMF-chemical data, EC- and SOA-tracer methods. This latter significantly underestimated total SOA loadings, even including biomass burning SOA, due to missing SOA classes and precursors. None of the approaches was able to identify the formation mechanisms and/or precursors responsible for the highly oxidized SOA fraction associated with nitrate- and/or sulfate-rich aerosols (35% of OA). We recommend the use of a combination of different methodologies to apportion the POC/SOC concentrations/contributions to get the highest level of confidence in the estimates obtained.
(Science of the Total Environment. vol. 757, n° 0048-9697, pp. 143168, 22/04/2026)
INERIS, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, PSI, CAE, LSCE, UVSQ, INSU - CNRS, CNRS, DRF (CEA), CEA, UniFI
SNR-Based Water Height Retrieval in Rivers: Application to High Amplitude Asymmetric Tides in the Garonne River
Signal-to-noise ratio (SNR) time series acquired by a geodetic antenna were analyzed to retrieve water heights during asymmetric tides on a narrow river using the Interference Pattern Technique (IPT) from Global Navigation Satellite System Reflectometry (GNSS-R). The dynamic SNR method was selected because the elevation rate of the reflecting surface during rising tides is high in the Garonne River with macro tidal conditions. A new process was developed to filter out the noise introduced by the environmental conditions on the reflected signal due to the narrowness of the river compared to the size of the Fresnel areas, the presence of vegetation on the river banks, and the presence of boats causing multiple reflections. This process involved the removal of multipeaks in the Lomb-Scargle Periodogram (LSP) output and an iterative least square estimation (LSE) of the output heights. Evaluation of the results was performed against pressure-derived water heights. The best results were obtained using all GNSS bands (L1, L2, and L5) simultaneously: R = 0.99, ubRMSD = 0.31 m. We showed that the quality of the retrieved heights was consistent, whatever the vertical velocity of the reflecting surface, and was highly dependent on the number of satellites visible. The sampling period of our solution was 1 min with a 5-min moving window, and no tide models or fit were used in the inversion process. This highlights the potential of the dynamic SNR method to detect and monitor extreme events with GNSS-R, including those affecting inland waters such as flash floods.
(Remote Sensing. vol. 13, n° 2072-4292, pp. 1856, 22/04/2026)
LEGOS, IRD, UT3, Comue de Toulouse, INSU - CNRS, CNES, CNRS, GET, IRD, UT3, Comue de Toulouse, INSU - CNRS, CNES, CNRS, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
Excess protein enabled dog domestication during severe Ice Age winters
Dogs (Canis familiaris) are the first animals to be domesticated by humans and the only ones domesticated by mobile hunter-gatherers. Wolves and humans were both persistent, pack hunters of large prey. They were species competing over resources in partially overlapping ecological niches and capable of killing each other. How could humans possibly have domesticated a competitive species? Here we present a new hypothesis based on food/resource partitioning between humans and incipient domesticated wolves/dogs. Humans are not fully adapted to a carnivorous diet; human consumption of meat is limited by the liver’s capacity to metabolize protein. Contrary to humans, wolves can thrive on lean meat for months. We present here data showing that all the Pleistocene archeological sites with dog or incipient dog remains are from areas that were analogous to subarctic and arctic environments. Our calculations show that during harsh winters, when game is lean and devoid of fat, Late Pleistocene hunters-gatherers in Eurasia would have a surplus of animal derived protein that could have been shared with incipient dogs. Our partitioning theory explains how competition may have been ameliorated during the initial phase of dog domestication. Following this initial period, incipient dogs would have become docile, being utilized in a multitude of ways such as hunting companions, beasts of burden and guards as well as going through many similar evolutionary changes as humans.
(Scientific Reports. vol. 11, n° 2045-2322, pp. 7, 22/04/2026)
LUOMUS, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
Changes in the Intermediate Water Masses of the Mediterranean Sea During the Last Climatic Cycle—New Constraints From Neodymium Isotopes in Foraminifera
The Mediterranean Sea is a semi-enclosed basin characterized by arid conditions and connected to the North Atlantic through the Strait of Gibraltar (sill depth of ∼300 m). This generates a Mediterranean thermohaline circulation where the inflow of relatively fresh and cold surface Atlantic water (AW) is transformed into intermediate and deep waters in the Gulf of Lions, the Adriatic Sea, the Levantine Basin and the Aegean Sea (Robinson et al., 2001; Schroeder et al., 2012). In particular, the Levantine Intermediate Water (LIW) is formed in the Cyprus-Rhodes area from where it spreads westwards into the entire Mediterranean Sea at water depths of between ∼150 and 700 m (Lascaratos et al., 1993; Malanotte-Rizzoli et al., 1999). This overturning circulation is associated with an outflow of saltier and warmer intermediate water into the North Atlantic corresponding to the Mediterranean Outflow Water (MOW) (Robinson et al., 2001; Schroeder et al., 2012). Because the MOW contains up to ∼80% of LIW, the water mass formation in the Levantine Sea plays an important role for the salty outflow to the North Atlantic through the Strait of Gibraltar. A link between the intensification of the MOW and the intensity of the Atlantic Meridional Overturning Circulation (AMOC) has been proposed (
(Paleoceanography and Paleoclimatology. vol. 36, n° 2572-4525, pp. e2020PA004153, 22/04/2026)
GEOPS, INSU - CNRS, CNRS, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, GEOAZUR 7329, INSU - CNRS, UniCA, CNRS, IRD [Occitanie], UniCA, LSCE, UVSQ, INSU - CNRS, CNRS, DRF (CEA), CEA, GEOTRAC, LSCE, UVSQ, INSU - CNRS, CNRS, DRF (CEA), CEA, ISMAR, CNR, SZN, WHOI, CNR-ISP, CNR, LDEO
Timing of Neanderthal occupations in the southeastern margins of the Massif Central (France): A multi-method approach
The middle Rhône valley, located at the southeastern margins of the Massif Central in France, produced a large number of Middle Palaeolithic sites, most of which dated to the Middle and Late Pleistocene. Due to its position, connecting northern Europe and the Mediterranean basin, this corridor and the surrounding plateaus are of particular interest in the study of human cultural evolution, including the emergence of Middle Palaeolithic technology around 300,000 years ago and its variability over time, as well as the subsistence and mobility strategies of Neanderthals. In the last 20 years, several research projects undertaken in this region allowed to revise key Middle Palaeolithic sequences. This work aims at synthesising previous and new chronological data obtained by using uranium-series of speleothems and bones, infrared stimulated luminescence of feldspar and electron spin resonance of tooth enamel and quartz. We review previous ages obtained in the area and present 43 new ages that are discussed together to propose a reliable spatiotemporal framework for Neanderthal occupations. We focus on major sites in the region: Payre, Ranc-Pointu 2, Baume Flandin, Abri du Maras, Grotte des Barasses II, Abri des Pêcheurs, Grotte du Figuier and Grotte de Saint-Marcel. They all provided significant information related to the biological and behavioural evolution of Neanderthal populations on the right bank of the Rhône valley. We present here the updated chronology for the Middle Palaeolithic of this area, ranging from ca. 300,000 to 40,000 years ago.
(Quaternary Science Reviews. vol. 273, n° 0277-3791, pp. 107241, 22/04/2026)
LSCE, UVSQ, INSU - CNRS, CNRS, DRF (CEA), CEA, GEOTRAC, LSCE, UVSQ, INSU - CNRS, CNRS, DRF (CEA), CEA, HNHP, MNHN, UPVD, CNRS, CENIEH, EDYTEM, USMB [Université de Savoie] [Université de Chambéry], CNRS, Fédération OSUG, SCU, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, Xjtu, CAGS, MLR, UQ [All campuses : Brisbane, Dutton Park Gatton, Herston, St Lucia and other locations]