bluuebunny/crossref_metadata_2025 huggingface dataset:
Creating a Pseudo-Deterministic Forecast for Surface Transport from an NWP Ensemble with Consistency Across Multiple Variables using KDE
Authors: Wiggs Joshua , Eyles Joe , Lake Alice
Published: March 2024

In modern forecasting it is now a common technique to use an ensemble of forecasts generated by Numerical Weather Prediction (NWP) models. This necessitates a statistical approach be taken when using these weather predictions to inform decision-making and leveraging probabilities in the production of forecasts. It is often required to take the spread of predictions made by NWPs in the ensemble and reduce these to a single value, a pseudo-deterministic forecast, analogous to a forecast made be a traditional deterministic NWP, in order to allow end users to make binary decisions often defined at a definite threshold. These values may be representative of a single physical parameter modelled (e.g. road surface temperature) or may combine multiple parameters in a physically consistent manner (e.g. the road surface temperature coupled to the depth of water on the road for calculating road state), and are used by stakeholders in a number of sectors often to inform safety critical decision making. Therefore, it is important to ensure that the methodology used to reduce the ensemble of predictions to a pseudo-deterministic forecast is as accurate as possible and can retain information related to the ensemble spread , whilst ensuring consistency in parameters through the spatial and temporal domain.The Surface Transport Forecast (STF) system produces forecasts for different transport surfaces in response to NWP outputs. The STF system is architected such that it runs simultaneously for each member of the NWP forecast ensemble, producing a corresponding ensemble of STF predictions. This enables the computation of a pseudo-deterministic forecast, which retains the maximum amount of information provided by the NWP ensemble.To reduce the STF ensemble to a pseudo-deterministic forecast a Kernel Density Estimation (KDE) is utilised to build Probability Density Functions (PDFs), which can be readily interrogated using standard statistical techniques. It is found that pseudo-deterministic forecasts, which are consistent across a combination of physical modelled parameters, can be determined using covariant techniques, ensuring the ensemble is reduced as late as possible in the forecast production keeping the maximum benefit provided by the forecast spread. We will present the numerical and computational implementation of the described method in our STF system. Further, we will analyse the pseudo-deterministic forecasts produced and verify the validity of results at specific locations using multiple years of road observations.
Dynamic changes in depositional patterns and glaciotectonic deformations revealed by high-resolution 3D seismic data in the Northern North Sea.
Authors: Kurjanski Bartosz , Lee Nick , MacKay Allan , Powell Bill , Oukili Julien
Published: March 2024

During the Last Glacial Maximum (LGM), the British-Irish ice sheet is known to have been coalescent with the Fennoscandian ice sheet. Some models indicate that this might have been rather short-lived, whereas other reconstructions indicate an early and long-lasting coalescence of the ice sheets which, together reached the Northern North Sea continental shelf edge around 27,000 years ago. To date, the lack of empirical data, in the form of boreholes or high and ultra-high resolution seismic data has hindered efforts to validate the reconstructions and identify ice flow directions, drainage patterns, and chronology. Little is also known about the nature of the deglaciation and unzipping of the two ice sheets  which would  have likely comprised  multiple ice re-advances, stillstands, and retreats as well as an unknown duration of ice grounding which, based on experience, will result in complex and heterogeneous stratigraphy, vertically and horizontallyIn this study, a unique 3D seismic dataset with bin spacing of 3.125m x 3.125m and a frequency range of ~10-160Hz will be used to reconstruct the depositional history and sequence of events in the shallow subsurface(~ 200m below sea bed) including but not limited to processes responsible for tunnel valley formation and infill, large scale glaciotectonic deformation or postglacial deposition. This will be juxtaposed against known paraglacial reconstructions to propose preliminary timing of events. Implications for offshore infrastructure projects will be subsequently discussed in the context of ground conditions identified over the site.
GNSS Precipitable Water Vapour for Climate Monitoring
Authors: Dick Galina , Zus Florian , Wickert Jens , Männel Benjamin , Ramatschi Markus
Published: March 2024

Aside from main geodetic applications, the Global Navigation Satellite System (GNSS) is now an established observing system for atmospheric water vapour which is the most important greenhouse gas as it is responsible for around 60% of the natural greenhouse effect. Water vapour is under-sampled in the current climate-observing systems. Obtaining and exploiting more high-quality humidity observations is essential for climate research.Established in 2006, the Global Climate Observing System (GCOS) Reference Upper-Air Network (GRUAN), is an international reference observing network of sites measuring essential climate variables above the Earth's surface. Currently, this network comprises more than 30 reference sites worldwide, designed to detect long-term trends of key climate variables such as temperature and humidity in the upper atmosphere. GRUAN observations are required to be of reference quality, with known biases removed and with an associated uncertainty value, based on thorough characterization of all sources of measurement. A complementary small scale regional climate station network is the Austrian WegenerNet, which provides since 2007 measurements of hydrometeorological variables with very high spatial and temporal resolution. GNSS precipitable water vapour (GNSS-PWV) measurement has been included as a priority one measurement of the essential climate variable water vapour to both GRUAN and WegenerNet climate station networks.GFZ contributes to climate research within GRUAN and WegenerNet with its expertise in processing of ground-based GNSS network data to generate precise PWV products. GFZ is responsible for the installation of GNSS hardware, data transfer, processing and archiving, derivation of GNSS-PWV data products according to GRUAN and WegenerNet requirements including PWV uncertainty estimation. GNSS-PWV products and results of selected validation studies will be presented.
Refining Regional Climate Projections for Louisiana and Mississippi: Dynamical Downscaling with WRF Model in the Face of Projected Sea Level Rise
Authors: Ishmam Zuhayr Shahid , Miller Paul , Rohli Robert , Mostafiz Rubayet Bin
Published: March 2024

Global climate models (GCMs) lack the necessary spatial resolution to accurately depict the atmospheric and land surface processes that define the regional climate of any particular location. In contrast, regional climate models (RCMs) explicitly capture the interactions between the broad-scale weather patterns simulated by global models and the specific characteristics of the local terrain. In this work, the Weather Research and Forecasting (WRF) model is used for dynamical downscaling simulations for a historical period (2001-2005) and the future (2095-2099) forced by the NCAR’s Community Earth System Model, version 1 (CESM1), for Louisiana and Mississippi, United States. The future RCM was run with both a present-day and future land-sea mask, considering model projections of sea level rise along the Gulf of Mexico coast. The convection-permitting, high-resolution (4 km) model performs more satisfactorily for temperature than rainfall when validated against observations from meteorological stations and gridded rainfall data. The future RCM runs demonstrate significant projected changes in average and extreme temperatures and rainfall from the current climate over the model domain. The probable retreat of the coastline shifts the sea breeze landward from its present-day area, which generates heavier rainfall and more moderate temperatures at places presently relatively distant from the Gulf of Mexico. This study enhances the existing dynamical downscaling methodology by incorporating the impacts of anticipated sea level rise on the regional climate.
Midlatitude cirrus cloud investigations from ground-based lidar and ERA-5 re-analysis
Authors: Mandija Florian , Alraddawi Dunya , Keckhut Philippe , Khaykin Sergey
Published: March 2024

Cirrus as high-altitude clouds are formed at the highest layers of the troposphere, usually at the altitude range 5,000 – 14,000m. Cirrus clouds are composed mainly by asymmetric ice crystals, which are formed during the freezing process of the water vapor at the regions of very low temperature. In global scale, over land, their frequency of occurrence ranges between 28 and 42%, depending on the geographic location and season.Cirrus clouds are classified with respect to optical thickness into four major classes; thick cloud (τ > 3), opaque cirrostratus (0.3 < τ < 3), transparent or thin cirrus (0.03 < τ < 0.3), and subvisible cirrus (τ < 0.03). Another classification of cirrus comes from their origin; in-situ and liquid origins.This cloud type plays a key role in the Earth’s radiation budget. In general, cirrus has a net warming effect (21 W/m2), due to the warming LR and cooling caused by SR reflection. However, difficulties to investigate optically very thin cirrus clouds with satellite observations, don’t allow to have the whole picture of the cirrus radiative forcing. Local investigations, engaging  ground-based lidar measurements enable the detection of cirrus clouds of optical depths down to 10-3 and hence a better quantification of the effect of the thin clouds.In this study, we have investigated the cirrus cloud geometrical properties, during the period 2020 – 2023, based on the nocturnal measurements of the high-resolution Rayleigh/Mie lidar at the  Observatory of Haute Provence (OHP) in France (43.9°N, 5.7°E). The analysed parameters are the top/base/mid- cloud heights, mid-cloud altitude and geometrical thickness .Coincident meteorological parameters Data, such as  mid-cloud temperature and relative humidity are provided by ERA-5 (climate reanalysis produced by ECMWF).Clouds are then considered as cirrus based on the following  criterias: In-cloud temperature must be as lower than −25 ◦C,  the Scattering Ratio SR, must be above its average plus three times its standard deviation in the 17–19 km altitude range.Multivariate analysis combining the principal component analysis and cluster methods are used to classify cirrus cloud with respect of their geometrical properties. Overall results of these analysis indicate three major cirrus cloud classes; mid-troposphere thin cirrus, thick upper-troposphere cirrus and thin-tropopause cirrus. These cirrus classes have different geometrical thickness and mid-cloud altitude. These classes differ also in terms of meteorological parameters, such as relative humidity and In-cloud temperature.This study is done in the framework of the project CONTRAILS funded by MEFR/BPI France under the contract number DOS0182436/00. 
Exploring soil organic carbon dynamics through a multi-model simulation of multiple long-term experiments 
Authors: Longo Matteo , Piccoli Ilaria , Berti Antonio , Farneselli Michela , Tabaglio Vincenzo , Ventrella Domenico , Trestini Samuele , Morari Francesco
Published: March 2024

Agricultural system models are widely recognized as valuable tools for identifying best management practices and addressing the challenges posed by climate change. In this context, the use of model ensembles has been recently recommended for their enhanced performance and accuracy. However, assessing their effectiveness over a large geographical area, such as national scale is often currently lacking. This study focuses on simulating soil organic carbon (SOC) dynamics using an ensemble of models comprising DSSAT, CropSyst, EPIC, and APSIM models, utilizing data derived from five Long-Term Experiments (LTEs) spread across a north-to-south pedoclimatic range transect in Italy. This region is of particular importance as it represents a significant hotspot for climate change. The LTEs featured a robust array of 63 unique experimental protocols, incorporating variation effect in fertilization rates, cropping rotations, and tillage prescriptions. This resulted in a total of 2184 years of simulated data for each model. The dataset employed included SOC stocks and crop yield and biomass. Models underwent independent calibration, with crop and SOC parameters selected based on expert knowledge. Main crop cultivars, such as maize, soybean, sugarbeet, and wheat, were further categorized and calibrated by maturity classes. A similar approach was used for cover crops. The extensive dataset enabled a nuanced exploration of the models’ performance across varied agro-ecological contexts. The models proved capable of accurately reproducing the varied pedo-climatic conditions of the Italian peninsula, contributing to the advancement of our understanding of SOC dynamics.
The e3HOPE service: a high-resolution forecasting system for the hydrodynamics in Fangar Bay (Ebro Delta, NW Mediterranean Sea)
Authors: López Pérez Tania , Balsells Fernández-Pedrera Marta , Fernández Tejedor Margarita , García-Valdecasas Jose María , Grifoll Manel , Ballesteros Óscar , Bielsa Ernesto , Mestres Marc , García-León Manuel , Espino Manuel , G Sotillo Marcos
Published: March 2024

The Ebro Delta (EU Natura 2000 site and Natural Park and Biosphere Reserve (UNESCO)) is a complex area that faces a set of challenges mainly due to anthropogenic pressure and climate change related risks. The two Ebro embayments (i.e. Fangar and Alfacs) are natural protected areas of value for the survival of many species, such as the critically endangered Pinna nobilis. Likewise, these bays are two of the most productive aquaculture areas along the NW Mediterranean Sea.
The e3HOPE Service, led by NOW Systems (Nologin), provides a coastal operational forecast for the Ebro Delta. The system is based on a coastal downscaling of the Copernicus Marine Mediterranean regional solution, generating daily forecasts at 350 m resolution for the whole Ebro Delta and products at even higher resolution (around 70 m) for the Fangar Bay. A high-resolution ROMS model application, developed and tested by the LIM/UPC and integrated into the NOW operational framework, contributes to a seamless modelling in the area, filling the gap between the existing Copernicus regional forecast products and the local needs for a higher resolution model prediction.
The e3HOPE coastal service is completed with a tailor-made visualization service layer co-designed with IRTA. The new NAUI web service deployed by NOW for the Delta and Fangar Bay is a highly customizable tool that allows visualization of both met-ocean observations (including additional local monitoring routinely performed at specific fixed CTD stations) and the e3HOPE model forecasts at selected locations. This new NAUI deployment at the Ebro Delta certainly eases, and enhances, the IRTA uses of (new and existing) operational forecasting capabilities, making coastal data more actionable and transferred into fit-for-purpose applications for management, supporting sustainable aquaculture activities and biodiversity conservation.
This contribution is mainly focused on the skill of the current e3HOPE model release, being the model solution validated along 1 year with available in-situ observations (for temperature, salinity, sea level and surface and bottom water currents). Some insights into the operational forecast products delivered by the e3HOPE service, as well as into the planned service evolution (for 2024) is provided. Next e3HOPE operational release will include: (i) upgrade of the model system (to a wave-current coupled system, using COAWST), (ii)  improvement of the fresh water forcing (substituting climatological approaches by predicted data for the Ebro river, and some local channels discharges), and (iii) improvement in the initialization (using CTD data), in the Fangar Bay domain.
Source-to-sink weathering response to the Paleocene-Eocene Thermal Maximum (PETM) in the Southern Pyrenees
Authors: Jaimes-Gutierrez Rocio , Puceat Emmanuelle , Wilson David J. , Adatte Thierry , Prieur Marine , Musajo Claire , Pogge von Strandmann Philip , Braun Jean , Castelltort Sebastien
Published: March 2024

Global warming and the associated hydrological cycle variations are known to disrupt the weathering regime over geological timescales. Enhanced weathering and erosion, which constitute denudation, are important feedback mechanisms for regulating Earth’s temperature over multi-million-year timescales. Weathering can draw down CO2 from the atmosphere, while enhanced physical transport can accelerate organic carbon sedimentation and sequestration. This study aims to uncover changes to the denudation regime accompanying a massive climatic disturbance in deep time, the Paleocene-Eocene Thermal Maximum (PETM). The global warming of 5-8 °C due to the PETM has been documented to have increased the magnitude and intensity of precipitation events in the Spanish Pyrenees. But how did weathering respond to such a climatic and hydrological disturbance?We investigated the lithium (Li), hafnium (Hf), and neodymium (Nd) isotopic composition of the
Sensitivity analysis of a shallow-water model for landslide-generated tsunamis in Mayotte
Authors: Marboeuf Alexis , Poulain Pablo , Mangeney Anne , Le Friant Anne , Silver Maxwell , Fernandez Nieto Enrique , Moatty Annabelle
Published: March 2024

Since May 2018, Mayotte Island has been experiencing seismo-volcanic activities which may trigger submarine landslides and tsunamis. Numerical models are a powerful tool to build tsunami hazard maps and to establish evacuation plans, improving early-warning systems. However, a lot of uncertainties still remain in model parameters making it difficult to reproduce the landslide dynamics and the generated waves. In this work, we perform a sensitivity analysis using the multilayer HySEA shallow water model [1, references therein]. HySEA simulates both a landslide and a generated tsunami. We focus on a scenario posing the greatest threat to the local community, involving a submarine landslide on the eastern side of Mayotte's lagoon at a shallow water depth [2]. Hydrostatic and non-hydrostatic results are compared and several numeric and physical parameters are investigated: grid resolution, number of water layers in the vertical direction, rheological laws, friction coefficients and grain sizes.Our results show that using non-hydrostatic conditions, increasing the grid resolution and the number of water layers greatly impacts the computed waves. Increasing these parameters is worth the larger computational cost. Physical parameters related to the landslide also affect the dynamic and the final deposit of the granular mass. While the choice of the grain size, the used rheological law or the friction angles may lead to different results, almost no change was observed over an hour of simulation when the Manning coefficient is modified. In all our test cases, the differences appear mainly at the early stages of the simulations. Numerical gauges placed at locations of interest on Mayotte's coast allow a closer look at the numerical waves for a finer sensitivity analysis.References[1] J. Macìas, C. Escalante, M. J. Castro. Multilayer-HySEA model validation for landslide-generated tsunamis - Part 2: Granular slides. Natural Hazards and Earth System Sciences, Volume 21 (2021).[2] A. Lemoine; R. Pedreros; A. Filippini. Scénarios d’impact des tsunamis pour Mayotte. BRGM Report BRGM/RP-69869-FR (April 2020).  
Measuring flow resistance in rough-bed rivers using flume and CFD approaches
Authors: Yamasaki Taís , Houseago Robert , Hodge Rebecca , Hardy Richard , Rice Stephen , Ferguson Robert , Hackney Christopher , Yager Elowyn , Johnson Joel , Hoey Trevor
Published: March 2024

Accurate predictions of river channel flow resistance are necessary for estimating flow depth and/or velocity, and so are needed for predicting sediment transport and flood risk, river restoration and in-channel engineering. Standard approaches typically predict resistance as a function of the channel bed grain size distribution (GSD). However, in rough-bed rivers that comprise much of the river network (i.e. rivers where flow depth is not much greater than channel roughness elements), the sediment GSD is not the main factor that controls the channel shape, and so GSD does not provide a good predictor of flow resistance. In these channels, predictions need to instead account for the influence of multiple scales and shapes of roughness, including boulders, sediment patches, exposed bedrock and irregular banks, but we do not yet have suitable methods for making these predictions.  

We present initial results from flume and CFD modelling experiments that have been designed to identify how irregular river-beds affects the spatial pattern of form drag and determine overall flow resistance. Both experiments take advantage of high-resolution topographic data that has been collected from field locations using new survey techniques (terrestrial laser scanning and structure from motion photogrammetry). In the flume experiments, we used the data to create 1:10 scale 3D reproductions of three different river beds. For each bed we incrementally add sediment cover, boulders, and rough walls, and measured changes in channel topography. For each configuration we then measure how water depth varied across a range of discharges to evaluate bulk flow resistance. In the CFD experiments, we simulate a range of flows over the field topography to evaluate the spatial pattern of form drag across the bed. In subsequent experiments the topography will be manipulated to retain specific topographic scales, in order to assess how form drag changes. From both sets of experiments, we will identify which topographic (surface roughness) metrics best represent the effect of the differing river bed properties on bulk flow resistance, and hence offer most promise for improved predictive equations. 
Influence of climate and land management on water, carbon and nitrogen cycling in grasslands of the pre-alpine region of southern Germany
Authors: Kiese Ralf , Schlingmann Marcus , Schneider Katrin , Reinermann Sophie , Schucknecht Anne , Han Jincheng , Koellner Thomas , Boos Carolin , Dannenmann Michael
Published: March 2024

Pre-alpine grasslands provide important economic value through forage for milk and meat production. Grassland soils also support ecosystem services such as carbon and nitrogen storage, water retention, erosion control and biodiversity. These functions are currently threatened by climate change, which is likely to accelerate in the coming decades. In addition to climate change, management decisions such as mowing and fertilisation frequency have a major impact on grassland yields, biodiversity and soil C and N dynamics. In this presentation we will summarise results from long-term monitoring of control and translocated grassland soil monoliths (1m2; 1.4m height) as operated in TERENO and studied in detail in the SUSALPS project.From 2012, moderate climate change (plus 2°C) has increased grassland productivity, unless water stress has reversed the temperature stimulating effect. However, this increase in plant growth is only possible because increased N mineralisation rates under climate change allow increased N demand to be met. As plant N uptake is already in the range of total N fertilisation rates under current climate conditions, N losses to the environment, such as microbial N2O emissions and nitrate leaching from montane grassland soils, are comparatively low. If other ecosystem N losses such as NH3 and N2 emissions are considered, it becomes clear that even under the present climatic conditions substantial N has to be provided by mineralisation of soil organic N, indicating soil N (and C) mining. As the latter is associated with negative effects on soil fertility/productivity, C sequestration and GHG exchange, as well as filtering functions to protect water bodies, this trend poses risks to key soil functions in the long term. The detailed investigations from long-term monitoring sites were essential for testing a process-based model (LandscapeDNDC), which was used together with remote sensing information for spatial and temporal upscaling of the results.
Turbulence statistics of terrestrial Mars-analog and Martian dust devils
Authors: Temel Orkun , Karatekin Ozgur , Apéstigue Palacio Víctor , Daniel Toledo , Arruego Ignacio , Franchi Fulvio , Martinez German , Senel Cem Berk
Published: March 2024

Convective instabilities in the lowermost part of the atmosphere, so called the planetary boundary layer, can lead to the formation of convective vortices and form dust devils both on Earth and Mars. We performed mesoscale simulations for a Mars-analog terrestrial site, Makgadikgadi Pan - Botswana [1,2], where a state-of-the art field campaign was conducted to investigate the terrestrial dust devils, and the InSight landing site [3] using WRF/MarsWRF models [4,5]. We then combined our atmospheric modeling with in-situ observations of wind and pressure to perform a comparative boundary-layer meteorology study. We focused on the length and time of scales of turbulence and investigated the turbulent spectrum.[1] Toledo, D., Apéstigue, V., Arruego, I., Montoro, F., Martinez-Oter, J., Serrano, F., Yela, M., Carrasco-Blázquez, I. and Franchi, F., 2022, September. Investigating dust devils on Mars through the Makadikadi Salt Pans analogue (Botswana). In European Planetary Science Congress (pp. EPSC2022-485).[2] Toledo, D., Apéstigue, V., Martinez-Oter, J., Franchi, F., Serrano, F., Yela, M., De La Torre Juarez, M., Rodriguez-Manfredi, J.A. and Arruego, I., 2023. Using the Perseverance MEDA-RDS to identify and track dust devils and dust-lifting gust fronts. Frontiers in Astronomy and Space Sciences, 10, p.1221726.[3] Lorenz, R.D., Spiga, A., Lognonné, P., Plasman, M., Newman, C.E. and Charalambous, C., 2021. The whirlwinds of Elysium: A catalog and meteorological characteristics of “dust devil” vortices observed by InSight on Mars. Icarus, 355, p.114119.[4] Temel, O., Senel, C.B., Porchetta, S., Muñoz-Esparza, D., Mischna, M.A., Van Hoolst, T., van Beeck, J. and Karatekin, Ö., 2021. Large eddy simulations of the Martian convective boundary layer: towards developing a new planetary boundary layer scheme. Atmospheric Research, 250, p.105381.[5] Temel, O., Bricteux, L. and van Beeck, J., 2018. Coupled WRF-OpenFOAM study of wind flow over complex terrain. Journal of Wind Engineering and Industrial Aerodynamics, 174, pp.152-169.
Inter-annual and long-term variability in streamflow elasticity to precipitation reveal bias in estimates of hydrological sensitivity
Authors: Anderson Bailey , Slater Louise , Rapson Jessica , Brunner Manuela , Dadson Simon , Yin Jiabo , Buechel Marcus
Published: March 2024

Empirically derived sensitivities of streamflow to precipitation are often assumed to be temporally unchanging. This assumption may be unrealistic because changes in climate and storage are known to alter this relationship. We present a non-stationary regional regression approach which is functionally similar to typical elasticity estimation approaches. This is applied to 2967 catchments in the United States to estimate variability in interannual, and trends in long-term, streamflow elasticity to precipitation over a 39-year period. We show that interannual elasticity is highly variable in water-limited catchments, indicating that these are especially sensitive to year-to-year climate variability, as compared to other regions. Interannual elasticity is more often correlated with the one-year lagged standardized precipitation index than with temperature or in-phase standardized precipitation index, suggesting that antecedent soil moisture, groundwater storage, and precipitation seasonality influence streamflow sensitivity. Finally, statistically significant long-term trends in elasticity exist in some regions, but trend magnitude is generally small. These findings suggest that an assumption of stationarity in long-term average elasticity may still be appropriate at the regional scale, however, year-to-year variation in streamflow responsiveness to precipitation is often substantial.    
Spatio-temporal evolution and source tracking of arsenic in surface waters of an old mining district (Orbiel Valley, France)
Authors: Heydon Marie , Resongles Eléonore , Casiot-Marouani Corinne , Schreck Eva , Behra Philippe , Freydier Rémi , Marie Mylène , Causserand Carole , Delpoux Sophie , Roddaz Martin , Pages Alain , Viers Jérôme
Published: March 2024

Past mining activities in the Orbiel Valley pose a significant risk of As contamination to its ecosystems and inhabitants. Approximately 12 million tons of tailings from last century's As and Au mining operations remain on site. Rehabilitation works have been implemented to store mining wastes and treat leaching waters. However recent studies have revealed that contamination is still present in water and sediments (Khaska et al., 2015; Delplace et al., 2022). The complexity of the area and previous findings have shown the importance of a more in-depth study of As sources and fate in the watershed, including 1/ characterizing As contamination levels in the Orbiel River and its tributaries during different hydrological periods, 2/ identifying the main sources of As and 3/ distinguishing the natural geochemical baseline from anthropogenic inputs.Water samples ( 52 %). The anthropogenic origin of this contamination was confirmed by the 87Sr/86Sr ratio, which is less radiogenic than in the upstream pristine area, in relation with lime treatment implemented in the mine waste area. However, some valley limestones exhibit a Ca-arsenate-like isotopic ratio, highlighting the need to use complementary tracers to distinguish between anthropogenic and lithological sources. Finally, the mining-impacted tributaries are identified as significant contributors of As to the Orbiel River.The present study will serve as a reference to interpret the origin, transport, and fate of metal(loid)s during future extreme flood events characteristic of this Mediterranean river. Delplace, G., Viers, J., Schreck, E., Oliva, P., Behra, P., 2022. Pedo-geochemical background and sediment contamination of metal(loid)s in the old mining-district of Salsigne (Orbiel valley, France). Chemosphere 287 (2).Khaska, M., Le Gal La Salle, C., Verdoux, P., Boutin, R., 2015. Tracking natural and anthropogenic origins of dissolved arsenic during surface and groundwater interaction in a post-closure mining context: isotopic constraints. J. Contaminant Hydrol. 177–178, 122–135.
Potential methanogenic evidence related to the transportation of anthropogenic elements in semi-closed estuarine system (Masan-Jinhae Bay, South Korea) 
Authors: Lee Dong-Hun , Jeong Chang-Bum , Kim Seung-Hee , Shin Kyung-Hoon
Published: March 2024

We investigated water chemical properties (chlrolophyll a, nutrients), particulate/dissolved organic carbon (POC, DOC) and methane in water columns of the semi-closed estuarine system (Masan-Jinhae Bay, South Korea). Together with the overall OM increase in upper boundaries (chlrolophyll a; 13.3±2.3 μg/L, POC and DOC; 0.2-2.1 mg/L) of Masan-Jinhae Bay, methane profiles within water columns showed the distinct predominance (101.2±7.6 nM) near surface layers. Considering OC isotopic compositions (δ13CPOC; -19.4±0.6 ‰, δ13CDOC; -22.5±0.4 ‰) may reflect the decomposition of autochthonous OC sources, the methane production near surface seems to be potentially related to chemical reactions (e.g., demethylation and OM aggregates) of biological sources. Specifically, methane concentrations at adjacent terrestrial realm (inner Masan Bay) showed the most increased patterns (401.5±47.3 nM), indicating significant correlations with dissolved nitrogen and DOC. Together with the substantial transport of anthropogenic derived-nitrogen (δ15NNO3,δ18ONO3; 4.3±0.3 ‰, 6.0±1.0 ‰), our results infer that methanogenic process may be potentially influenced from the predominant OC production/decomposition under increased discharge of domestic wastewater. In near future, the additional analysis of methane isotopes may provide important clues for effectively understanding methane dynamics such as production and removal.
The impact of mid Holocene Saharan greening on the Euro-Atlantic climate variability
Authors: Gaetani Marco , Messori Gabriele , Pausata Francesco S.R. , Tiwari Shivangi , Alvarez Castro M. Carmen , Zhang Qiong
Published: March 2024

During the first half of the Holocene (11,000 to 5,000 years ago) the Northern Hemisphere experienced a strengthening of the monsoonal regime, with climate reconstructions robustly suggesting a greening of the Sahara region. Paleoclimate archives also show that this so-called African Humid Period (AHP) was accompanied by changes in the climate conditions at mid to high latitudes. However, inconsistencies still exist in reconstructions of the mid-Holocene (MH) climate at mid-latitudes, and model simulations provide limited support to reduce these discrepancies. In this study, a set of simulations performed with an Earth System Model is used to investigate the hitherto unexplored impact of the Saharan greening on mid-latitude atmospheric circulation during the MH. Numerical simulations show a year-round impact of the Saharan greening on the main circulation features in the Northern Hemisphere, especially during boreal summer when the African monsoon develops. In particular, a westward shift of the global Walker Circulation leads to a modification of the North Atlantic jet stream. The Saharan greening also modifies the atmospheric synoptic circulation over the North Atlantic, changing the North Atlantic Oscillation phase from prevailingly positive to neutral-to-negative, and significantly modifying the occurrence of blocking events. This study provides a first constraint on the Saharan greening influence on northern mid-latitudes, indicating new opportunities for understanding the MH climate anomalies in the Euro-Atlantic sector.
Increasing intermittence of the UK’s chalk streams into the future 
Authors: Magee Eugene , Sefton Catherine , Parry Simon , Allen Stuart , England Judy
Published: March 2024

The chalk streams of the UK are globally rare, strongly intermittent in their upper reaches, and highly valued for their biodiversity and historical provision of water resources. Recent projections of river flows and groundwater levels under climate change in the UK, coupled to existing statistical models of hydrological state, enable the projection of spatiotemporal intermittence patterns into the near- and far-future.  

Catchments were selected for the study based on the availability of data and the performance of statistical models in the historical period.  Cumulative logit models, previously trained on historical data, were used in conjunction with state-of-the-art ensemble projections of future river flows and groundwater levels to simulate future hydrological state at multiple sites along chalk streams in the south-east of England.  Heatmaps visualise spatiotemporal variations in state, and intermittence metrics quantify the variability.   

The results show projected increases in drying into the future, both temporally, with greater duration of drying, and spatially, with intermittence extending downstream.  Some sites are likely to alter substantially, for example, on the river Chess with notable decreases in modelled flow permanence projected, from 75% in the baseline period (2005-2020) to 25% in the far future (2065-2080). 

This research provides quantifiable spatiotemporal dynamics of intermittence, informing water resource decisions, drought management and engagement activities on these high-profile streams.  The methods developed are adaptable for transfer to other catchments for which spatiotemporal mapping of intermittence patterns and future projections of driving variables exist. 
Monitoring the greening of mountain pasture habitats based on satellite image analysis in response to elevation and seasonal weather change.
Authors: Oriani Fabio , Aasen Helge , Schneider Manuel K.
Published: March 2024

Mountain pastures host rich plant biodiversity organized in various distinct habitats. An accurate long-term monitoring, going beyond the sole ground survey, is of primary importance for nature conservation and forage production planning. We develop here a novel analytical framework to identify and monitor plant communities in mountain pastures based on the joint statistical analysis of ground data and satellite imagery. We use commonly available satellite imagery (Sentinel-2) to track, for the first time to our knowledge, spatial and temporal changes of individual habitats composing the mountain pasture ecosystem, in relation to interannual hydroclimatic variations.We consider as study zone the mid-to-high elevation mountain pastures surrounding the Swiss National Park in the Grisons canton, Switzerland (approx. 100 sq. km), including fertile pastures, wetlands, dry plant communities, and shrubs. We couple the habitat map to the NDVI spectral index (Sentinel-2 images, ESA) to retrieve a proxy for living vegetation and its productivity. Then, by computing statistical parameters of the NDVI curves, we characterize the annual greening season for the different habitats, taking into account elevational changes and interannual variations of snow persistence, depending on autumn and winter rainfall.The different habitats show a marked difference in their productivity in function of their wetness until 2400 m a.s.l, while they seem to homogenize at higher altitudes. The greening in the 1-st season half is strongly controlled by snow persistence variations and partially compensated by an after-snowmelt quick growth. Conversely, the 2-nd half season greening is mainly linked to the season maximum NDVI. This workflow presents as an effective strategy to monitor the seasonal and long-term evolution of mountain pasture vegetation in the complex alpine domain.
Concrete application in enhanced weathering: Investigating the effect of concrete on barley and oat under field conditions
Authors: Chondrogiannis Christos , O’Dea Katie , Bryson Maurice , Magee Ruadhan , McDermott Frank
Published: March 2024

Weathering, the breakdown of rock into its elements, is a carbon sequestering process and a significant component of the Earth’s long-term carbon cycle. As rock is weathered, atmospheric CO2 reacts with elements released, forming bicarbonates. These compounds are transported to the ocean where they are stored for thousands of years.The above mechanism has garnered much attention in recent years for its use as a potential negative emissions technology to advance efforts in climate change mitigation. Enhanced weathering (EW) aims to accelerate carbon sequestering reactions of rock weathering by applying crushed rock onto vegetated surfaces. It’s also believed this practice could provide secondary benefits of improving crop yields and soil conditions. A variety of rocks, such as basalt and olivine, have been applied to different crops all over the world in an attempt to test their potential as a CO2 removal technique and natural fertilizer.This study aims to build upon previous attempts by employing a novel material, crushed concrete. Concrete is abundant in fast-weathering minerals such as portlandite and amorphous calcium silicates, making it an ideal candidate for EW. By harnessing the same bicarbonate forming and carbon sequestering reactions but using a waste by-product of the construction industry, the sustainability and circularity of EW technology could be further increased.In this study, crushed concrete was applied to fields of oat (Avena sativa) and barley (Hordeum vulgare) in Co. Wexford, Ireland, during the spring growing season. Physiological (chlorophyll fluorescence and stomatal conductance) and morphological (dry mass and plant height) parameters were measured through multiple stages of the plant growth to assess the impact of concrete application on crop health and yield. Our results showed an increase in the dry mass (specifically seed dry mass) of barley, suggesting that barley may benefit from concrete application. No significant changes were observed in oat. Our results suggest that concrete does not negatively impact crop yields and could even improve yields in certain crop species.
Supraglacial Lake Drainage: from process puzzle to subglacial diagnostic
Authors: Stevens Laura A. , Banwell Alison F. , Behn Mark D. , Chase Danielle L. , Das Sarah B. , Dell Rebecca L. , Falconer Emily , Joughin Ian R. , Lai Ching-Yao , Larochelle Stacy , Lu George J. , McGuire Jeffrey J. , Nettles Meredith , Okal Marianne , Rines Joshua , Willis Ian C.
Published: March 2024

Supraglacial lake drainages are isolated events that deliver the largest observable fluxes of surface melt to the ice-sheet bed. This talk will present advances in the study of these lake drainages, through which we piece together an empirical understanding of glacier hydrology. We examine the ways in which lakes both respond to, and determine, the hydrologic and glaciologic conditions under which they exist. We begin with the process puzzle of what mechanisms drive the opening of fractures within the compressive regions where lakes form, allowing hydro-fracture-driven drainages to occur. Next, we follow drained lake water in time and space, using the natural experiments provided by the drainages to infer subglacial-drainage-system transmissivity and structure beneath kilometer-thick ice flowing at rates of tens to thousands of meters per year in Greenland. In widening our view to previous subglacial-flood events observed at other ice-sheet locations—as well as at alpine, valley, and tidewater glaciers—we observe surprising similarities across a wide range of ice thicknesses, flow speeds, and types of flood events. The similarities we observe are encouraging because they suggest that information on drainage-system structure and evolution gleaned from these episodic events can be used to understand the wider picture. Finally, we examine current challenges: how do we move from the observed mechanisms of individual lake drainages to an integrated understanding of the importance of hundreds of drainages for long-term ice-sheet response and ice-shelf collapse? Progress will require the combination of geodetic observations, hydrologic simulations, and geophysical models to deconvolve the differing mechanisms that result in clusters of drainages in the multiple settings in which lakes form.
CataEx: How to get started with JavaScript in Google Earth Engine?
Authors: Domej Gisela , Pluta Kacper
Published: March 2024

Google Earth Engine offers a multitude of options for retrieving and analyzing satellite imagery from various satellite missions, which optimizes GIS studies, especially in the aspect of download and storage of extensive data volumes.However, the compatibility with traditional desktop or web-based GIS software remains a gap that was attempted to overcome with the JavaScript code CataEx – a multi-functional tool that exemplifies several essential types of computations and finally exports imagery and its additionally created layers as GeoTIFFs. We presented several basic functionalities of CataEx: identifying images out of collections (e.g., the least cloudy image in a time frame), the definition of a location of interest (as coordinates and/or as a polygon), cloud masking for different collections, evaluation of satellite band properties and their projections, layer creation in Google Earth Engine, index computation, pixel-based statistics and histogram plotting, layer visualization and export to Google Drive.CataEx is available in six versions for Landsat 4/5/7, Landsat 8/9, and Sentinel-2, each separated for top-of-atmosphere reflectance and surface reflectance collection. The code is deliberately kept simple to allow for easy brick-like recombination, adaption, and customization of code sections, and, hence, can be used as an example toolkit for students or beginners writing their first JavaScript routines for Google Earth Engine.This work is funded by the Polish National Science Center (no. 2021/42/E/ST10/00186); the code is available on Zenodo (https://doi.org/10.5281/zenodo.8407939). 
Global expression of bomb radiocarbon in Earth's surface carbon reservoirs
Authors: Eglinton Timothy ,   Bomb-spike team
Published: March 2024

The Earth’s carbon cycle encompasses myriad processes that connect different reservoirs containing diverse forms of carbon that turnover and exchange on a wide range of spatial and temporal scales. Increased atmospheric CO2 from anthropogenic perturbation of the carbon cycle associated with fossil fuel combustion and land-use change reflects the release of carbon from stable, slow-cycling reservoirs.  Much current research seeks to quantify carbon transfer from slow to fast cycling reservoirs, as well as the ability of different carbon reservoirs, particularly the terrestrial biosphere and the oceans, to compensate for these increased CO2 emissions through carbon uptake and storage. Determination of the turnover time and rate of transfer of carbon between reservoirs is crucial in this regard. Radiocarbon, 14C, represents a powerful tool to address this question by virtue of its ~ 5700-year half-life that allows processes occurring on centennial to millennial timescales to be resolved. Superimposed on natural abundance 14C variations, above-ground nuclear weapons testing during the mid-20th Century created an abrupt spike in atmospheric radiocarbon (“bomb spike”) that has subsequently permeated into and moved through various Earth surface carbon reservoirs, serving as a useful tracer of carbon cycle processes occurring on annual to decadal timescales. Numerous studies have exploited this signal for assessment of turnover or transit times within and through carbon pools, atmospheric and oceanic circulation, ecosystem functioning and source attribution. However, much 14C data currently tends to be compartmentalized, with a focus on specific reservoirs or geographic locations.In this study, we evaluate the global expression of the radiocarbon bomb spike across the different Earth surface active carbon reservoirs (terrestrial biosphere, soils, freshwater aquatic systems, and marine carbon reservoirs). We compile 14C data from existing and nascent databases as well as new measurements, including direct observations and records from natural archives spanning the pre-bomb period to the present, to develop an overview of the general features of 14C (timing, amplitude and character of the bomb peak) within each reservoir over this time interval.  In addition to using this information to refine our understanding of the interactions between different reservoirs, this study seeks to (i) identify gaps and biases in data with a view to motivating further 14C studies, (ii) underline the value of systematic data reporting, as well as careful archiving of samples for future 14C analysis, (iii) inform isotope-enabled carbon cycle and earth system models, and (iv) serve as benchmark against which to gauge future carbon cycle changes.