Decadal Prediction Centers Prepare for a Major Volcanic Eruption
The World Meteorological Organization’s Lead Centre for Annual-to-Decadal Climate Prediction issues operational forecasts annually as guidance for regional climate centers, climate outlook forums, and national meteorological and hydrological services. The occurrence of a large volcanic eruption such as that of Mount Pinatubo in 1991, however, would invalidate these forecasts and prompt producers to modify their predictions. To assist and prepare decadal prediction centers for this eventuality, the Volcanic Response activities under the World Climate Research Programme’s Atmospheric Processes and Their Role in Climate (APARC) and the Decadal Climate Prediction Project (DCPP) organized a community exercise to respond to a hypothetical large eruption occurring in April 2022. As part of this exercise, the Easy Volcanic Aerosol forcing generator was used to provide stratospheric sulfate aerosol optical properties customized to the configurations of individual decadal prediction models. Participating centers then reran forecasts for 2022–26 from their original initialization dates and, in most cases, also from just before the eruption at the beginning of April 2022, according to two candidate response protocols. This article describes various aspects of this APARC/DCPP Volcanic Response Readiness Exercise (VolRes-RE), including the hypothesized volcanic event, the modified forecasts under the two protocols from the eight contributing centers, the lessons learned during the coordination and execution of this exercise, and the recommendations to the decadal prediction community for the response to an actual eruption.The World Meteorological Organization’s Lead Centre for Annual-to-Decadal Climate Prediction issues operational forecasts annually as guidance for regional climate centers, climate outlook forums, and national meteorological and hydrological services. The occurrence of a large volcanic eruption such as that of Mount Pinatubo in 1991, however, would invalidate these forecasts and prompt producers to modify their predictions. To assist and prepare decadal prediction centers for this eventuality, the Volcanic Response activities under the World Climate Research Programme’s Atmospheric Processes and Their Role in Climate (APARC) and the Decadal Climate Prediction Project (DCPP) organized a community exercise to respond to a hypothetical large eruption occurring in April 2022. As part of this exercise, the Easy Volcanic Aerosol forcing generator was used to provide stratospheric sulfate aerosol optical properties customized to the configurations of individual decadal prediction models. Participating centers then reran forecasts for 2022–26 from their original initialization dates and, in most cases, also from just before the eruption at the beginning of April 2022, according to two candidate response protocols. This article describes various aspects of this APARC/DCPP Volcanic Response Readiness Exercise (VolRes-RE), including the hypothesized volcanic event, the modified forecasts under the two protocols from the eight contributing centers, the lessons learned during the coordination and execution of this exercise, and the recommendations to the decadal prediction community for the response to an actual eruption.
(Bulletin of the American Meteorological Society. vol. 105, n° 0003-0007, pp. E2496-E2524, 01/12/2024)
CCCma, ECCC, ISAS, U of S, MPI-M, NIA, LaRC, BCCR, BIO / UiB, UiB, NERSC, BSC-CNS, GFDL, NOAA, UCAR, 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, LMD, INSU - CNRS, X, IP Paris, ENPC, SU, CNRS, ENS-PSL, PSL, LASG, IAP, CAS, LASW, CAMS, CAMS, MOHC, JAMSTEC, AORI, UTokyo
Environmental changes in the Fleuve Manche paleoriver drainage system (Western Europe) linked to North Atlantic sub-millennial climate variability across Heinrich Stadial 1: Palynological evidence from the Bay of Biscay
Marine microfossils (dinoflagellate cysts and planktonic foraminifera) and geochemical (XRF-Ti/Ca)-based climatic records from a core (MD13–3438) located off the Fleuve Manche (FM) paleo-mouth have revealed that sustained warm summer sea surface temperatures (SSTs) during sub-millennial climate changes within HS1 (~18–14.7 ka) may have played a key role in the FM regime related to the European Ice Sheet (EIS) melting rate. In this study, we have analyzed the MD13–3438 pollen content over the HS1 at a mean resolution of ~50 years to test whether vegetation-based air temperatures were coupled to SSTs face to this rapid climate variability. First, our results highlight two major phases of pollen sources at site MD13–3438, preventing the pollen record to be interpreted as a continuous record of the evolution of vegetation and climate occupying a single watershed across HS1. The first phase, i.e. the HS1-a interval (~18–16.8 ka), is marked by strong occurrences of boreal pollen taxa (especially Picea-Abies). Considering their spatial distribution and the coalescence of the British and Scandinavian ice sheets into the North Sea during the Last Glacial Maximum, these taxa probably originated from the North European Plain, i.e., eastern FM tributaries (east of the Rhine River), where cool-humid conditions generally prevailed. Then, the second phase, i.e. the HS1-b interval (~16.8–14.7 ka BP), is characterized by a deceleration of the EIS retreat and the drop of boreal pollen values at site MD13–3438 further signing a less influence of the upstream FM drainage system and thus a better characterization of pollen sources related with western FM tributaries. Superimposed to these two HS1 main phases, pollen fluctuations are concomitant with sub-millennial variability in the EIS deglaciation intensity. During the early HS1 (HS1-a), we discuss two short-term increases in the ratio between deciduous trees (Quercus-Corylus-Alnus) and herbaceous plants (Plantago-Amaranthaceae-Artemisia). These events are coeval with phases of increasing dinocyst-based SST seasonality (i.e. through summer SST amplification). We associate these events with lower contribution of the upstream FM catchment as well as, possibly, atmospheric warming and regional sea-level positive oscillations. The HS1-b is composed of three main phases that appear more influenced by the downstream FM drainage system. HS1-b1 (16.8–16.3 ka BP) corresponds to the driest and coldest conditions west of the Rhine River. HS1-b2 (16.3–15.5 ka BP) is coeval with large arrivals of iceberg from the Hudson strait in the Bay of Biscay and thus likely to a major sea-level positive oscillation associated with a phase of FM valley reworking. HS1-b3 (15.5–14.7 ka BP) corresponds to persistent arid conditions that preceded the subsequent more humid conditions recorded from 14.7 ka BP at the start of the Bölling-Alleröd.
(Palaeogeography, Palaeoclimatology, Palaeoecology. vol. 655, n° 0031-0182, pp. 112512 (14p.), 01/12/2024)
GEO-OCEAN, UBS, IFREMER, INSU - CNRS, UBO EPE, CNRS, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, EPHE, PSL, IPMA, CCMAR, UAlg
Central-Eastern Europe as a centre of Middle Ages extractive metallurgy
Bohemia to Greece is home to some of the richest ore deposits on earth, with archaeological evidence suggesting a long history of metal use. However, the exact timing and extent of past metal processing activities remains unclear. The Middle Ages and Early Modern period (c. 500-1800 common era (CE)) in Europe, saw the expansion of metal use at an unprecedented scale, continent-wide. Here we analysed rates of past atmospheric lead (Pb) deposition in six peat bogs from Romania, Serbia and Greece. We show that after 1000 CE, the redevelopment of central European mining industry was synchronous with Pb pollution in southeastern Europe, with the onset of metal pollution occurring in the area prior to central Europe. Therefore, southeastern Europe may have led regional mining developments, with technological advances rapidly shifting from east to west through the Middle Ages. This indicates how southeastern Europe should be included in future discussions of Middle Age metallurgy not simply as a contributor, but at times as a leader in metal production.
(Journal of Archaeological Science. vol. 172, n° 0305-4403, pp. 106093, 01/12/2024)
USV, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, ELTE, ELTE, MTA, MTA, ULB
An operational discontinuous Galerkin shallow water model for coastal flood assessment
Hydrodynamic modeling for coastal flooding risk assessment is a highly relevant topic. Many operational tools available for this purpose use numerical techniques and implementation paradigms that reach their limits when confronted with modern requirements in terms of resolution and performances. In this work, we present a novel operational tool for coastal hazards predictions, currently employed by the BRGM agency (the French Geological Survey) to carry out its flooding hazard exposure studies and coastal risk prevention plans on International and French territories. The model, called UHAINA (wave in the Basque language), is based on an arbitrary high-order discontinuous Galerkin discretization of the nonlinear shallow water equations with SSP Runge–Kutta time stepping on unstructured triangular grids. It is built upon the finite element library AeroSol, which provides a modern C++ software architecture and high scalability, making it suitable for HPC applications. The paper provides a detailed development of the mathematical and numerical framework of the model, focusing on two key-ingredients : (i) a pragmatic treatment of the solution in partially dry cells which guarantees efficiently well-balancedness, positivity and mass conservation at any polynomial order; (ii) an artificial viscosity method based on the physical dissipation of the system of equations providing nonlinear stability for non-smooth solutions. A set of numerical validations on academic benchmarks is performed to highlight the efficiency of these approaches. Finally, UHAINA is applied on a real operational case of study, demonstrating very satisfactory results.
(Ocean Modelling. vol. 192, n° 1463-5003, pp. 102447, 01/12/2024)
BRGM, CAGIRE, LMAP, UPPA, CNRS, Inria, LMAP, UPPA, CNRS, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, IMB, UB, Bordeaux INP, CNRS, IMAG, CNRS, UM, CARDAMOM, IMB, UB, Bordeaux INP, CNRS, Inria
Nation-wide monitoring campaign of 49 biocides and surfactants in surface waters and wastewaters
Despite their intensive use and their impact on ecosystems, biocides and surfactants are still poorly regulated and poorly monitored at large scale. In the frame of the revision of the national regulatory surveillance plan of surface waters, France planned in 2018 a monitoring campaign at national scale focused on these two types of substances of very emerging concern. Forty-nine contaminants (32 biocides and 17 surfactants) were investigated in surface water and sediment samples from 91 sampling sites, and in effluent and sludge samples of 7 wastewater treatment plants (WWTP), in mainland France and overseas regions. Between 33 and 52 % of the target contaminants were quantified at least once in water and sediment. High frequencies of quantification were observed for the surfactants (up to 91 % in water samples and up to 57 % in sediment samples for LAS C10-C13) and for the biocides (up to 64 % for fipronil in water samples and up to 90 % for methyl nonyl ketone in sediment samples). The median concentrations of surfactants were up to 2 μg/L in mainland surface water samples and up to 528 μg/kg in sediment samples, and for biocides, the median concentrations were up to 0.18 μg/L in mainland surface water samples and up to 104 μg/kg in sediment samples. PNEC exceedances in water and sediment were determined for both types of substances. The analysis of effluent and sludge suggested significant but not total removal of these substances in the WWTP. Temporal and spatial variations of the concentrations of both types of substances in surface water samples were also observed, suggesting both punctual and diffuse contamination sources of the surface water investigated.
(Science of the Total Environment. vol. 954, n° 0048-9697, pp. 176624, 01/12/2024)
INERIS, CONTEM, HSM, IRD, INSU - CNRS, CNRS, UM, ERT, IMT, HSM, IRD, INSU - CNRS, CNRS, UM, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, ISA, UCBL, INC-CNRS, CNRS
A generative deep neural network as an alternative to co-kriging
In geosciences, kriging is leading spatial interpolation, and co-kriging is the most commonly used method for accomplishing spatial interpolation of a target variable by incorporating information from a secondary variable. Co-kriging relies on the assumption of spatial stationarity, which may not hold true in all geospatial contexts, leading to potential inaccuracies in interpolation. The effectiveness of co-kriging can be compromised in areas with sparse data, impacting the reliability of interpolated results. Moreover, it can be resource-intensive when used for interpolation with a substantial volume of data, especially in the case of 3D interpolation. In this paper, we introduce a new method for spatial interpolation that considers two variables using a generative deep neural network. This approach utilizes a convolutional neural network with an encoder–decoder architecture, featuring a single encoder and two decoders to handle the two variables. Additionally, we introduce a loss function that facilitates the control over the relationships between the two variables. Traditional Deep Learning methods require prior training and labeled data, whereas the proposed approach eliminates this requirement and simplifies the interpolation process. In order to assess the performance of our method, we use two real-world datasets. The first one is a 2D dataset of total soil organic carbon combined with the Normalized Difference Vegetation Index. The second one is a 3D dataset that combines concentrations of Hydrocarbon and Fluoride obtained from hyperspectral analysis of soil cores with very limited number of boreholes. The experimental results demonstrate that the proposed method outperforms ordinary kriging and co-kriging, showing a significant improvement when both variables are used. We also demonstrate how the inclusion of the auxiliary variable serves as a means to mitigate the overfitting of the model.
(Applied Computing and Geosciences. vol. 24, n° 2590-1974, pp. 100198, 01/12/2024)
LITIS - App, LITIS, ULH, NU, UNIROUEN, NU, INSA Rouen Normandie, INSA, NU, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
Southern Ocean Water Mass method: A new statistical approach using microfossil radiolaria for paleoceanographic insights for the Southwest Pacific sector of the Southern Ocean
Ocean circulation and the formation and upwelling of water masses in the Southern Ocean play a critical role in the exchange of heat and carbon with the atmosphere over glacial-interglacial cycles, but the history of the subsurface water masses is poorly understood. Radiolarians inhabit the water column from the surface to the bottom of the ocean, and their distribution is known to be associated with water masses. We use radiolarian abundance census data from the SO-RAD core top dataset to explore the relationship between radiolarian distribution and surface and subsurface water mass structure of the Southwest Pacific Sector of the Southern Ocean. The species distribution was first explored using non-Metric Multidimensional Scaling. Then Multivariate Regression Tree (MRT) analysis was used to understand the relationship between radiolarian distributions and parameters of water mass boundaries (using isopycnal depths) and upwelling (using nutrient data). We identified a series of indicator species associated with oceanographic zones which were used to develop the Southern Ocean Water Mass Index. The contribution of the Index Species Groups provided further information on water column structure and the relative influence of the various water masses. The index was then applied to the radiolarian assemblage data from 2 previously published cores, Y8 and Y9, from the Subantarctic Zone east of New Zealand. The results of the Southern Ocean Water Mass Method showed changes in water mass structure through the last glacial-interglacial cycle at both core sites. The results agree with other proxy data from the region. The SOWM Method provides a new tool for understanding the history of changes in the water mass structure and circulation in the Southern Ocean.
(Quaternary Science Reviews. vol. 346, n° 0277-3791, pp. 109054, 01/12/2024)
UQ [All campuses : Brisbane, Dutton Park Gatton, Herston, St Lucia and other locations], EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, LEMAR, IRD, IFREMER, UBO EPE, CNRS
Comprehensive characterization of European house dust contaminants: Concentrations and profiles, geographical variability, and implications for chemical regulation and health risk
This study investigated the concentration profiles and geographical variability of contaminants in house dust across Europe. A collaborative trial (CT) was organized by the NORMAN network using pooled dust and advanced chromatographic and mass spectrometric techniques combined with suspect screening and non-target screening (NTS). Over 1200 anthropogenic compounds were tentatively identified. Additionally, seventy-five individual samples were subjected to target analysis and NTS. The median concentrations of most contaminants varied <3-fold across Europe, and the contaminant profile of European dust was similar to that of North American dust, which was investigated in a previous CT. This similarity may be attributed to the use of similar consumer articles and building materials throughout the developed world. Multivariate data analysis revealed geographical trends in contaminant distribution, with north-south gradients across Europe. Geographical trends were more frequently found for compounds with rapid release (pharmaceuticals, personal care products, fragrances, pesticides, biocides) and smoke-related compounds. The concentrations of chlorinated paraffins, polycyclic aromatic hydrocarbons (PAHs), perfluorinated alkyl substances and stimulants generally increased from north to south, whereas the biocides levels decreased from north to south. Despite widespread presence of in-use contaminants in dusts, some of the highest risks come from compounds that have been restricted for decades or more. These include di(2-ethylhexyl) phthalate (DEHP), polychlorinated biphenyl (PCB) 118 and polybrominated diphenyl ethers 47, 99, and 153. DEHP remains the most abundant contaminant in European house dust, while the other compounds are classified as persistent organic pollutants (POPs). Moreover, there is a striking lack of reliable toxicity data, particularly for emerging compounds. For instance, although acceptable daily intakes (ADIs) were examined for 202 compounds, only 46 had consensus-based ADI values. The results highlight the need for proactive measures to prevent hazardous chemicals from entering the market and for careful selection of substitute chemicals, when such are needed, to avoid regrettable substitutions.
(Science of the Total Environment. vol. 957, n° 0048-9697, pp. 177639, 01/12/2024)
NKUA, RECETOX / MUNI, SCI / MUNI, MU / MUNI, NILU, INERIS, uni.lu, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, NTNU, NTNU, HECSB, inegi, ERT, IMT, HSM, IRD, INSU - CNRS, CNRS, UM, CONTEM, HSM, IRD, INSU - CNRS, CNRS, UM, Irset, UA, UR, EHESP, INSERM, Biosit : Biologie - Santé - Innovation Technologique, LERES, EHESP, EHESP
Paleoceanography of the Southeast Pacific since the late glacial from diatom and foraminiferal assemblages
(Palaeogeography, Palaeoclimatology, Palaeoecology. vol. 655, n° 0031-0182, pp. 112515, 01/12/2024)
UCSC, LSCE, UVSQ, INSU - CNRS, CNRS, DRF (CEA), CEA, PALEOCEAN, LSCE, UVSQ, INSU - CNRS, CNRS, DRF (CEA), CEA, GEOPS, INSU - CNRS, CNRS, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, UdeC, UMAG, IDEAL
OSL dating as a valuable tool for understanding rapid environmental changes in hypertidal estuaries: A case study from the West coast of France
The last centuries are marked by the Little Ice Age, followed by a global warming period when entering the industrial era, enhanced over the last 50 years due to increased human activities, resulting in an acceleration of sea level rise and a multiplication of extreme events (floods, storms). Global climatic change, coupled with the ongoing urban development of coastal areas, had major impacts on morphosedimentary behaviour of estuarine systems. To precisely track changes due to this climate evolution within sediment archives, a reliable and accurate geochronological framework is crucial. In high energy coastal settings, such as macro- to hypertidal estuaries, hydrodynamic conditions can sometimes render 14C dating method ineffective due to shell reworking. 210Pb and 137Cs are usually reliable but only cover a reduced time frame. In such instances, Optically Stimulated Luminescence (OSL) dating could offer a valuable alternative. Here we present results of a nationwide study of the main tide-dominated estuaries on the west coasts of France. The aim is to compare their morphosedimentary trajectory over the last centuries and thus assess the impact of climate changes and human activities. Sediment cores were taken in the Somme, Orne (English Channel), Loire and Gironde (Atlantic) estuaries to monitor environmental changes through a multi-proxy analysis. To establish an accurate geochronological frame of the cored successions, standard multi-grain quartz SAR OSL dating has been used and compared to 14C dating on recovered shell material and plant debris. Three to five OSL samples per core were collected. The quartz OSL signal is very bright and dominated by a fast component, making it suitable for SAR De measurements. The completeness of the bleaching process was checked by comparing the quartz OSL ages with K-rich feldspar pIRIR50,180 ages. Quartz OSL signals appear to be sufficiently bleached for the Somme, Orne and Loire rivers, but we cannot be fully confident for the Gironde samples (here IR50 ages are few hundred years older than quartz OSL ages). Nevertheless, the top recently buried sediment in the Gironde estuary was dated with quartz to 67±7 years, strongly suggesting that quartz OSL signal was sufficiently bleached at deposition. Our OSL ages are consistent with topo- and bathymetric map analysis, and provide a geochronological framework that underlines a rapid infilling, with rates for example up to 6cm/year in the Loire estuary. Conversely, 14C measurements often provide older ages than OSL values and are not always in stratigraphic order for all the estuaries. Discrepancies sometimes exceed several hundred years, which highlights the limitation of 14C ages to date estuarine sediment successions (Olsen et al. 2017). These encouraging results should enable a more ambitious campaign using OSL dating to quantify in greater detail the rapid evolution of estuarine environments in response to global change. Olsen, Jesper, Philippa Ascough, Bryan Lougheed, et Peter Rasmussen. 2017. « Radiocarbon Dating in Estuarine Environments ». 141‑70. https://doi.org/10.1007/978-94-024-0990-1_7
(27/11/2024)
M2C, UNICAEN, NU, INSU - CNRS, UNIROUEN, NU, CNRS, DTU, IGN, UCPH, UNICAEN, NU, LPG, UM, UA, INSU - CNRS, CNRS, Nantes univ - UFR ST, Nantes Univ, LPG-ANGERS, LPG, UM, UA, INSU - CNRS, CNRS, Nantes univ - UFR ST, BIAF, UA, NOC, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS