bluuebunny/crossref_metadata_2025 huggingface dataset:
From raw data to standardized, fully corrected, quality ensured eddy covariance flux data: the ICOS Ecosystem processing pipeline
Authors: Nicolini Giacomo , Sabbatini Simone , Canfora Eleonora , Polidori Diego , Ribeca Alessio , Trotta Carlo , Vitale Domenico , Gielen Bert , Iserbyt Arne , Loubet Benjamin , Michilsens Fana , Op de Beeck Maarten , Papale Dario
Published: February 2023

The eddy covariance is a micrometeorological technique which allows for the estimation of the net fluxes of gases and energy between the atmosphere and an ecosystem. To estimate the net balance, the required input data are high frequency measurements (e.g. 10 or 20 Hz) of wind speed and gas concentration or amount of energy, plus lower frequency measurements (e.g. 1s to 30min ) of some meteorological variables and gas concentration vertical gradients below the measuring point. From these measurements, through a set of processing algorithms and corrections, continuous time series of fluxes are obtained which can be used to, e.g.,  estimate the net ecosystem exchange, as input/validation for modelling purposes, or for eco-physiological analyses. Although the fundamental processing steps and corrections are well established, there is still a discrete margin of subjectivity in the choice of specific operations and corrections which leads to different results even starting from the same set of measured data. The ICOS Ecosystem infrastructure consists of a network of eddy covariance stations equipped with high-level standardized instrumentation, whose data are processed centrally by means of a fully standardized and documented processing pipeline. This allows to obtain robust and consistent datasets, along with sets of metadata (e.g. instruments characteristics and location) and ancillary variables (e.g. meteorological and biometric) that help their interpretation and ensure their traceability and reproducibility. The description of the full processing pipeline is the aim of this contribution. All the data and metadata produced by the ICOS Ecosystem Thematic Centre (ETC) are freely available through the ICOS Carbon Portal as well as the processing codes are available in the ICOS ETC GitHub repository.
Flood modelling using disaggregated rainfall time series and estimating the probability of cholera infection from post-flood ponds in Accra, Ghana
Authors: Jónsdóttir Auður Eva , Müller-Thomy Hannes , Leandro Jorge , Huang Jingshui
Published: February 2023

Extreme weather events magnified by climate change will likely increase the frequency of severe flooding. In this work, we studied the effects of climate change on flooding and cholera infections associated with contaminated floodwater in the Alajo neighbourhood in Accra, Ghana, by considering projected rainfall from different climate scenarios of the GFDL-ESM4 climate model, SSP1-2.6, SSP3-7.0 and SSP5-8.5.Rainfall of daily resolution projected by the climate scenarios was disaggregated into five-minute resolution time series using a multiplicative microcanonical cascade model, and resulting extreme events were simulated using a 1D SWMM model of the subcatchments coupled with a 2D parallel diffusive wave model (P-DWave) of Alajo. The concentration of V. cholerae in the floodwater was further simulated as coming from open drains in the neihbourhood.  Following the flood simulation, the post-flood phase was further simulated, where the V. cholerae concentration was estimated using a constant pathogen die-off rate, and infiltration and evaporation of the post-flood ponds.Using a quantitative microbial risk assessment (QMRA), the probabilities of infection for both adults wading and young children playing or swimming in the post-flood ponds was estimated with a Beta-Poisson dose response model for the El Tor V. Cholera biotype. The QMRA was integrated into the flood risk assessment framework, by replacing the consequence component with infection probability. The expected annual probability of infection (EAPI) for each climate scenario was then found by numerically integrate over the precedence probability.It was found that the mean estimated EAPI is higher for young children than for adults in the study area, but only differs slightly between climate scenarios. This study highlighted the areas most vulnerable to flooding and associated cholera outbreaks, and further development of these techniques could help with decision making on preventative measures for affected areas.
Identification of groundwater recharge zones using comparative analysis of drainage networks
Authors: Das Sourav Sundar , Saraf Arun Kumar , Goswami Ajanta
Published: February 2023

Groundwater, being limited extent in hardrock terrain is undeniably a precious resource for livelihood. In the hardrock terrain of Bundelkhand craton, India where seasonal rainfall is mostly discharged through surface runoff, it is necessary to check and delay the surface runoff to mitigate water table decline caused due to overgrowing demand for groundwater. The objective of this study is to identify suitable places for groundwater recharge where the process of recharge to the groundwater offers better results than the vicinity as per the prevailing hydrogeological conditions. This objective has been achieved employing geospatial  techniques using DEM and toposheet of the Betwa Basin of the Bundelkhand craton. In this present study, a comparative analysis has been carried out by superimposing a drainage network extracted from the toposheet over a simulated drainage network derived from the DEMs such as SRTM, ASTER and ALOS PALSAR to visualise the clustering tendency of the two data sets. The comparative analysis reveals a mismatch of the two datasets at some places which are visible on all the DEMs considered indicating potential groundwater recharge zones. Such mismatch has appeared at places where the degree of infiltration is significant enough to alter the course of the existing drainage network recorded on the toposheet from the simulated one because of the assumption of the surface to be insulated. This study proves to be a quick and reliable method for the identification of groundwater recharge zones for hard rock terrains which are regularly experiencing water scarcity.Keywords: DEM, toposheet, drainage network, hardrock terrain
Assessing long-term climatology of convection permitting simulation of precipitation and associated local circulation over southeastern South America
Authors: Porfírio da Rocha Rosmeri , Silva Leidinice , Bettolli Maria Laura , Reboita Michelle , Llopart Marta
Published: February 2023

The convection permitting (CP) version of Regional Climate Model (RegCM) has been applied to investigate extreme events in southeastern South America in the context of CORDEX collaborative network Flagship Pilot Studies. In this context, we developed a long-term RegCM simulation (from June 2018 to June 2021) at CP resolution (4 km of horizontal grid spacing). RegCM simulation was forced by ERA5 reanalysis and its domain extends from center to southeast (from ~ 15o to 35oS) of South America. In this assessment, simulated daily climatology was compared with both ERA5 reanalysis and with a great number of local stations. These comparisons will help us to understand if CP simulation aggregates relevant information to the ERA5 reanalysis in reproducing local aspects of the climate.  Using the winds from stations,  the ability of CP simulation in reproducing the local circulations, such as sea-breeze, is also investigated. We also discuss how well long-term CP simulation captures long dry and wet periods that were observed in southeastern South America.
SOIL-WATER PROCESSES AND SEDIMENT CONNECTIVITY IN RAINFALL-TRIGGERED LANDSLIDES: A comparative analysis between small catchments in Italy and Brazil
Authors: Schwarz Heron , Comiti Francesco , Michel Gean Paulo , Paul Leonardo Rodolfo
Published: February 2023

Rainfall-induced landslides are natural processes inherent to the sediment dynamics, fundamentally acting in landscape evolution, while favoring the occurrence of hazardous conditions. Given their potential to mobilize large volumes of sediments from the release zones, they play a major role in sediment production in mountain basins, while affecting sediment connectivity through the deformations produced on the landscape.These landslides are triggered out by the imbalance of shear strength and shear stress acting on a soil layer, promoted by the presence of water. The soil wetting through infiltration, namely, the vertical transfer of water from the surface layer of the soil to its interior, during intense precipitation events, has thus historically been associated with landslide triggering.Whereas precipitation intensity and/or volume are recurrently related, the failure of a slope can occasionally be caused by precipitation events with magnitudes that are lower than those that have previously occurred. The triggering is dependent on the overlay of hydrological processes with different spatial and timescales, including the antecedent moisture conditions of the soil and the water storage in the watershed. Thus, different processes that act in the filling, storing, and draining of water in the soil, from seconds to weeks prior to the triggering, as preferential flow or bedrock infiltration and exfiltration are all equally relevant to understand and quantify landslide behavior and sediment connectivity. Furthermore, the soil moisture conditions not only govern landslide triggering but also their potential to fluidize and travel across longer distances, influencing their connectivity.In this way, we analyzed how soil-water processes affect the filling, storing and draining dynamics during landslide triggering and their effects on sediment connectivity. Two study areas with distinct climatic and geomorphological characteristics located in southern Brazil (Mascarada River Catchment, Rio Grande do Sul) and northern Italy (Gadria River Catchment, Autonomous Province of Bozen-Bolzano) were analyzed. Field collected data was used, together with physical-based models to simulate slope stability as well as saturated and unsaturated flow and water retention in the soil layer. Scenarios including infiltration, preferential flow and bedrock exfiltration were simulated to assess whether this increase in uncertainty and complexity brings better results to the representation of the processes.
Interpreting hydrothermal clumped isotope temperatures in the Irish Zn-Pb ore field
Authors: Doran Aileen , Hollis Steven , Menuge Julian , Marca Alina , Dennis Paul , van Acken David
Published: February 2023

With the introduction of climate action plans by many countries globally, the development of green technologies like electric vehicles and renewable infrastructure is expected to increase. These technologies are resource intensive, meaning we will require increased production of metals to meet the growing demands of society. However, discovery and exploration rates are not increasing at the same rate as demand. Improving understanding of ore system formation and evolution is a crucial step in aiding future exploration, to help supply these critical resources.In hydrothermal systems, carbonate minerals (e.g., calcite and dolomite) are often associated with all stages of ore formation, with fluid inclusion thermometry and carbon-oxygen (C-O) isotope ratios traditionally used to study fluid temperature and composition. However, there are several challenges still remaining with these techniques, with fluid inclusions often too small, ruptured or deformed for adequate study. In carbonate minerals, the rare, heavy isotopes 13C and 18O bond or clump more frequently at lower temperatures, with the magnitude of clumping inversely temperature-dependent. Measurement of clumped C-O isotope ratios, using gas source isotope spectrometry, simultaneously yields carbonate δ13C and δ18O values and generates mineral precipitation temperatures, allowing fluid δ18O to be directly calculated. While traditionally applied to low temperate environments, recent applications have included hydrothermal ore systems to study fluid temperature and mixing. When combined with other techniques, such as strontium isotopes, new understanding of the sources, movement and compositional evolution of fluids can be deciphered.Recent clumped C-O and strontium isotope analyses of ore-related carbonates from the Lisheen and Galmoy deposits, southern Irish Zn-Pb ore field, have facilitated the study of fluid sources, temperatures, mixing, and modification. Lisheen and Galmoy are  hosted in a belt of regionally dolomitized Lower Carboniferous (Mississippian) marine limestones, cut by a series of NE-SW-trending ramp-relay normal faults. Study of these deposits reveals that early dolomitizing and later hydrothermal fluids are part of a complex multistage continuum, with phases of fluid mixing, compositional buffering due to dissolution, and isotope resetting. Consequently, studies of carbonates in other deposits may yield new insights into ore formation, ultimately helping exploration for crucial resources.  
Recent magma supply dynamic at Mt Etna volcano inferred from periodic measurements of soil CO2 emissions
Authors: Messina Mirko , Camarda Marco , De Gregorio Sofia , Di Martino Roberto M. R. , Prano Vincenzo
Published: February 2023

Periodic surveys for the measurement of the soil CO2 flux are regularly performed in three peripheral areas of the Mt Etna (Paternò, Zafferana-S. Venerina and Vena-Presa) for a whole of 140 measurement sites. It is widely demonstrated that anomalous emissions of CO2 in these areas are linked to magma supply dynamics. Herein we report the data of soil CO2 flux periodically recorded in these areas from 2015 to 2022. We processed and analyzed the data to reconstruct the magma supply dynamics over the considered period and showed as variations are related to the most significant eruptive phases which occurred through the investigated period.One of the hallmarks eruptive episode occurred on 24th December 2018, from an eruptive fissure which opened on the New Southeast Crater (NCSE) flank. During this event both ash-rich plumes from the summit craters and intense strombolian activity along the fissure were observed. This episode was associated with intense seismic swarms. Mild strombolian activity, ash emission at summit craters, and constant inflation of the volcano edifice during autumn 2018 preceded the eruptive episode. The soil CO2 flux measured in the more distal peripheral areas reveal that, at least three episodes of magmatic supply into the deep system (7-13 km b.s.l.) occur in the Etna feeding system, since 2016. After November 2018, a remarkable increase in the soil CO2 emissions was recorded at Vena-Presa area, along the Pernicana fault, suggesting magma transfer into the shallower portions of the feeding system. The volcanic origin of this degassing event was confirmed also by isotopic signature of carbon of CO2.Another notably eruptive phase occurred on 2021 at the NSEC, with a sequence of seventeen lava fountains from 16 February to 1 April 2021. Some of these events were the most intense among those which occurred at Mt. Etna in the last ten years. A few months earlier (July-December 2020) we detected a huge increase of CO2 emissions in the Paternò area, with the highest value ever recorded over the last 15 years. 
Loss of loess in the geological record due to poor preservation
Authors: Meijer Niels , van der Meulen Bas
Published: February 2023

Loess deposits are widespread in the Quaternary, but relatively rare in older geological records. This disparity is commonly linked to the unique climate conditions of the Quaternary, but those cannot fully explain the scarcity of loess in older records. Instead, we propose that the poor preservation of loess due to its windblown nature also plays an essential role. To test this hypothesis, we assess the preservation potential of loess by quantifying its modern-day distribution in active sedimentary basins. This analysis shows that on the global scale only 20% of loess occurs in basins of which the majority is in a foreland setting, possibly because of the proximity to silt-producing mountains and rain shadow aridity. The other 80% is ultimately either eroded or reworked and therefore poorly preserved in the long term. This conclusion implies that loess deposits may have been more common in pre-Quaternary periods, despite being less abundant in the geological record.
Fault zone complexity naturally produces the full slip spectrum: Insights from numerical models
Authors: Bhat Harsha , Almakari Michelle , Kheirdast Navid , Villafuerte Carlos , Thomas Marion
Published: February 2023

In addition to regular earthquakes, observations of spatiotemporally complex slip events have multiplied over the last decades. These slip events range along different time scales: from creep , slow slip events to LFEs and tremors. At present, these events are generally interpreted by imposed frictional heterogeneities along the fault plane. However, fault systems are geometrically complex in nature over different scales. We aim in this work to investigate the role of “realistic” fault geometry on the dynamics of slip events. We consider a fault system in a 2D quasi-dynamic setting. The fault system consists of a main self-similar rough fault, surrounded by a dense network of off-fault fractures. All fractures are frictionally homogeneous (rate weakening) and can potentially undergo dynamic slip. We aim to understand how the deformation in the volume is accomodated by the off-fault damage zone and the main fault. What fraction of the “supplied” moment rate is hosted by the off-fault fractures during an earthquake cycle?
Pilot-scale application of mobile barrier systems for flood protection of urban areas. Assessment and evaluation of their interoperability in the urban area of Serres, Greece.
Authors: Tzanou Eleni , Chatzigiannis Antonios , Piliouras Michael
Published: February 2023

Urban flooding occurs to  populated and build environments when there is excess water due to intense rainfall, extreme river flows, or storm occurance. Flood protection procedures and processes are  important and critical tools in flood-vulnerable and flood-prone areas. The consequences of the occurrence of such phenomena can have a seriously negative impact on a social, economic and environmental level. The first two categories are particularly affected in urban environments, where flooding might lead to severe casualties. The assessemnt for  optimal use of mobile systems of mobile flood protection dams/barrires as  short-term flood prevention and non-permanent/ nonstructural measures in combination with the permanently existing protection works and infrastructures in the urban environment is the subject of this study.As a field of application (case study) of this research and the evaluation of different flooding and intervention scenarios, a stream section of an important transboundary watercourse that flows through the city of Serres, Greece was chosen. For this stream, the river bed and the surrounding areas as well as the built environment and all the technical works along the stream were measured by land observation methods (topographic and remote sensing data).In order to draw into conclusions, the assessment of the hydrological characteristics and the water flow characteristics of the stream and the catchment area was carried out. Then, the simulation of the hydraulic characteristics for the current state of the stream and for various different flooding scenarios through the use of mobile flood barriers/small dams of different types and geometrical characteristics was applied.The result of the study has led to a “roadmap” of how, when and where non-permanent protection measures and can be implemented in urban environments, useful to local authorities and civil protection in charge.The evaluation of the capacity and performance of mobile barrier systems (based on their characteristics) was carried out, in order to be  effectively used in varying flooding events, with different characteristics and in  site-specific locations in various scenarios, through hydraulic simulations. The results of the hydraulic simulations resulted in the barrier systems’ evaluation and the formation of a methodology, which concerns their application efficiency and their inter-operability in the pilot area, while determining the optimal management and the overall cost at the same time.
Hydrological decision-making systems using high-resolution weather radar observations – a case study from Hungary
Authors: Fehér Zsolt Zoltán , Budayné-Bódi Erika , Nagy Attila , Magyar Tamás , János Tamás
Published: February 2023

According to past observations and long-term forecasts, the Carpathian Basin is distinguished by two precipitation trends. The frequency, length, and severity of periods of precipitation deficit and drought are increasing. Furthermore, as small-scale convective updrafts intensify, heavy thunderstorms become more intense. Both trends pose significant risks from an anthropogenic perspective. The former increases food insecurity due to intensifying droughts, which damages agricultural yields, while the latter mainly increases property damage via heavy hailstorms.The 2022 drought year demonstrated that effective use of available water is the foundation for sustainable growth, which may be supported by well-designed infrastructure investments and smart water management technologies. A rainfall radar system with a high spatial and temporal resolution that contributes to near real-time machine decision-making is one conceivable component of such a complex system.The Furuno WR-2100 precipitation radar, which was deployed on the outskirts of Debrecen in 2020 for benchmarking purposes, is the first component of such an intelligent decision-making system in Hungary. The radar's range comprises both urban and rural areas, allowing it to continually gather high-resolution test data for both urban hydrology and agricultural irrigation system developments.The research presented in the article was carried out within the framework of the Széchenyi Plan Plus program with the support of the RRF 2.3.1 21 2022 00008 project.
Sea-level change along the South American Atlantic coastline
Authors: M.L. Camargo Carolina , Gerkema Theo , Okta Andrawina Yochi , B.A. Slangen Aimée
Published: February 2023

In comparison with the number of tide gauges measuring in-situ sea-level change along the Northern Hermisphere coastlines, the Southern Hemisphere has a poor spatial distribution of stations. For example, along the South American Atlantic coastline, only 12 tide gauges are registered at the Permanent Service for Mean Sea-level (PSMSL), of which only two have been updated in the last three years. While satellite altimetry can be used to provide data in locations where there is no in-situ data, estimating coastal sea-level change using altimetry data is challenging due to the distortion of the satellite signal close to the land. Consequently, sea-level change along the South American Atlantic coastline is still poorly understood. Here, we fill this gap by using coastal altimetry products together with a new network of tide gauges deployed along the coast of Brazil (by the SIMCosta project). Via a sea-level budget analysis, we look at the regional drivers of sea-level change along the coast. Recently, a large effort has been put towards developing algorithms that improve the accuracy of standard radar altimetry in coastal regions. Here, we compare both a coastal altimetry product (XTRACT/ALES) and a standard altimetry product (from CMEMS) to the local tide gauges. Previous studies have shown that, for some regions, coastal sea level is driven by open ocean sea-level change ( e.g., Dangendorf et al, 2021). Following this approach, we use clusters of coherent sea-level variability (Camargo et al., 2022), extracted with a network detection algorithm (delta-Maps), that extend to the open ocean, as proxies of the drivers of sea-level change along the coast.  The northern part of the study region, covering the Amazon Plateau, has a good match between the coastal altimetry-observed sea-level change and the sum of the drivers. The sum of the drivers and coastal altimetry trends also match, considering the uncertainty bars, for the most southern part, covering the Patagonian Shelf. For the other regions, we find a large difference between the coastal altimetry-observed sea-level change and the sum of the drivers. Thus, it is possible that these regions cover large-scale features, which are not strongly correlated with coastal sea level. ReferencesCamargo, C. M. L., Riva, R. E. M., Hermans, T. H. J., Schütt, E. M., Marcos, M., Hernandez-Carrasco, I., and Slangen, A. B. A.: Regionalizing the Sea-level Budget With Machine Learning Techniques, EGUsphere [preprint, accepted], https://doi.org/10.5194/egusphere-2022-876, 2022.
Dangendorf, S., Frederikse, T., Chafik, L., Klinck, J. M., Ezer, T., & Hamlington, B. D.: Data-driven reconstruction reveals large-scale ocean circulation control on coastal sea level. Nature Climate Change, 11, 514-520. https://doi.org/10.1038/s41558-021-01046-1, 2021.
Seasonal dynamics of geomorphic units and denitrification rate in a large lowland tropical river
Authors: Gani Md Ataul , Gettel Gretchen M. , van der Kwast Johannes , van Dam Anne , McClain Michael E. , Irvine Kenneth
Published: February 2023

The present investigation was carried out over a 50 km reach, the Padma River of Bangladesh, downstream of the confluence of the Ganges and Brahmaputra rivers. The study area is highly dynamic, with diverse geomorphic units, with high rates of bank erosion, and sediment abstraction. Sentinel-2 imagery (2019-2020) was processed using NDVI values to classify in-channel geomorphic units (GUs). The identified GUs were categorised as islands (human-dominated and vegetated), bars (side bar and mid bar), primary channel, secondary channels, water depressions and dry channels. Monsoonal water flow was considered an essential factor for reshaping and supplying nutrients to GUs. Based on discharge and the surface area of the identified GUs in different seasons, the dynamics of nutrient-retention-relevant geomorphic units (NRRGUs) were assessed. A field study was carried out to validate the classification of GUs and to measure the potential denitrification rate (PDR) in each type. Results of the analysis showed that changes in the surface area of GUs across seasons influence the rate of PDR significantly. Along the surface area, the number of GUs impacted PDR estimation, mainly regulated by river discharge. This type of systematic investigation of the spatial and temporal distribution of geomorphological and biogeochemical process measuring and monitoring will be useful for planning river restoration and ecosystem management programs.
Do Agri-Environment Schemes have a role for Soil, Water and Soil Organic Matter
Authors: Polakova Jana , Holec Josef , Janku Jaroslava , Maitah Mansoor , Soukup Josef
Published: February 2023

The aim of our study was to review agri-environment (AE) schemes in terms of outcomes for soil water requirements. It should be noted that the implementation of agri-environmental measures in Europe contributes to several ecosystem services and thus has several objectives; of these, the conservation of soil water and soil organic matter is a relevant agenda spearheaded to the heart of research because of the current climatic conditions. The link to carbon storage is relevant although not straightforward. The starting point was a large body of work on agri-environmental measures that examined the effects on biodiversity in narrow geographical areas and the sociology of stakeholder engagement with policy. However, our study proceeded to focus on the effects of agri-environmental measures on soil water and soil organic matter. This study focused on several neighbouring Member States. Two methodological approaches were applied. The quantitative approach was carried out in view of the assessment of expenditure related to agri-environment schemes. The data we used came from the archive of agricultural area per farm in the Eurostat country files, and the expenditure data were reconstrued from the documentation of rural development budget over fifteen years in an in-house archive set up from the sheets by the European Commission. Cost -effectiveness was modelled in a set of two agri-environment schemes. A qualitative approach was used to examine rural development programmes in Central and Eastern Europe ( the Czech Republic, Hungary, Poland, and Slovakia)  and thus to pinpoint the relevant measures for soil water effects. These analyses were anchored in an extensive set of literature reviews on the identification of soils that need to be protected because of inadequate levels of soil water.
We found that the costs of AE measures reflect thecosts of the particular agri-environmental practice and its constraints on commercial performance. It was found that agri-environmental practices with effect on soil water and soil organic matter are likely to be a precursor for fledgling carbon farming schemes in Central and Eastern Europe, although monitoring is much more a crux in carbon farming than in agri-environmental schemes.
Keywords: soil; water; arable farming; agri-environmental measures
The OneGeochemistry initiative as a CODATA Working Group; bringing together international geochemical data systems for easy data discovery
Authors: Prent Alexander , Wyborn Lesley , Klöcking Marthe , Lehnert Kerstin , Elger Kirsten , Hezel Dominik , Profeta Lucia , ter Maat Geertje , Farrington Rebecca , Rawling Tim
Published: February 2023

As geochemical data enable understanding of the Earth system and help to address critical societal issues the organisation thereof is important. Questions asked about processes affecting our environment and geological past become more complex and interdisciplinary in nature as well as multidimensional. To help answer these questions within the geochemistry research capabilities and data compilations are required to be comprehensive and both human and machine readable. Various international organisations are building infrastructure to capture and distribute geochemical data in a consistent manner adhering to the FAIR principles. Since May 2021 the OneGeochemistry initiative has officially started efforts towards aligning these organisations’ data frameworks in order to standardise how geochemical data is reported around the globe. In November 2022 the OneGeochemistry initiative applied and was granted to become the OneGeochemistry CODATA Working Group as part of the International Science Councils Committee on Data. The initiative has now also been endorsed by the Geochemical Society, the European Association of Geochemistry and the Working Group has been endorsed by the IUGS Commission on Global Geochemical Baselines. Coordination of the OneGeochemistry initiative is funded through the WorldFAIR project where it is one of the work packages in the larger ‘WorldFAIR: Global cooperation on FAIR data policy and practice’ project. A FAIR Implementation Profile analyses of the geochemistry communities of Australia (AusGeochem), USA (EarthChem, AstroMat) and Europe (GEOROC-DIGIS, EPOS-MSL, NFDI4EARTH) resulted in recognition of the need for common vocabularies for geochemistry data reporting as one of the most important actions to undertake towards international geochemistry data interoperability. A task adopted by EarthChem-DIGIS(GEOROC)-GFZ(DataSystems) collaboration and Research Vocabularies Australia.Here we will present an overview of the current OneGeochemistry initiative and its preliminary outcomes with regards to FAIR Implementation Profiles and processes that will help enable geochemical data interoperability between various stakeholders.
Rayleigh wave is the coolest – resolving microseismicity of a tidewater glacier in Svalbard
Authors: Gajek Wojciech
Published: February 2023

High-melt areas of glaciers generate a rich spectrum of ambient seismicity. These signals do not only contain information about the source mechanisms (e.g. englacial fracturing, water flow, iceberg detachment, basal stick-slip motion) but also carry information about seismic wave propagation within the glacier ice and, therefore, the mechanical properties of the ice. In the summer of 2021 two seismic arrays were deployed in Southern Spitsbergen at the vicinity of Hansbreen’s terminus, one being placed directly on the glacial ice, yielding an 8-days long time series of glacial seismicity.The direct and scattered wave fields from tens of thousands of icequake records (few thousands per day) were used to determine seismic velocities and monitor structural changes within the ice, while the analysis of the ambient noise was leveraged to constrain the ice thickness. The surface icequakes dominate the seismograms due to an abundance of englacial fracturing. Hence, Rayleigh waves and beam-based techniques were employed to characterise the patterns of microseismicity at the transform junction of two glaciers (Tuvbreen and Hansbreen). Several clusters of various-origin seismicity being active at certain times are identified with a majority of them located on stagnant, fast-melting Tuvabreen.
Holocene Rapid Climate Change: Pervasive Millennial-Scale Climate Variability across the North Atlantic
Authors: Austin William , Howe John , Cage Alix , Smeaton Craig
Published: February 2023

Rapid climate change (RCC) during the Holocene, particularly post-dating the demise of large Northern Hemisphere ice sheets after 8000 cal. yr BP, is a global phenomenon and is almost certainly driven by long-term changes in insolation, upon which solar variability, although a weak direct forcing mechanism, is superimposed. At least five significant intervals are identified in numerous palaeoclimate records since the major 9000-8000 cal. yr RCC, within which the intensively studied 8200 cal. yr ‘event’ is embedded; these are: 6000-5000, 4200-3800, 3500-2500, 1200-1000 and 600-150 cal. yr BP. Most of the Holocene RCCs are associated with bipolar cooling, an expansion-intensification of high latitude circulation systems and drying-aridity at low latitudes.Here, we present proxy-records from a fjord basin located on the Atlantic margins of NW Europe which contain evidence for these combined forcing mechanisms. Giant piston core (MD04-2832) from the main basin of Loch Sunart, Argyll, NW Scotland, is 22 m long and appears to contain a record of continuous sedimentation back to nearly 8000 cal. yr BP. Based upon the age-depth model for core MD04-2832, isotopic shifts recorded in the benthic foraminifera Ammonia beccarii coincide with both the rate and magnitude of the Holocene RCCs. We show that the renewal history of bottom waters in the fjord basins appear to be driven by large-scale atmospheric circulation changes that may have characterised the entire mid-latitude NE Atlantic region.
An exploratory approach to establish baselines and threshold levels for the assessment of floating marine litter in the Black Sea region
Authors: González-Fernández Daniel , Viejo Marín Josué , Quintana  Sepúlveda Rocío , Pérez-López Lucía , Manzano-Medina Sandra
Published: February 2023

The Black Sea region receives significant anthropogenic pollution inputs from rivers, coastal populations, and maritime activities. The use of a harmonized approach for monitoring floating marine litter in the Black Sea has revealed high densities of items in certain parts of the basin, including a predominance of plastic materials and a large number of plastic and polystyrene fragments. Although available data on marine litter are still rather limited in most compartments of the marine environment (beach litter, floating litter, and seabed litter), the European Commission has started to develop guidelines for the establishment of reference values and thresholds for beach litter following statistical approaches. In the case of floating litter, baselines and thresholds have not yet been established. In this study, we explore the statistical approach used by the European Commission to assess potential baselines and thresholds for floating marine litter in the Black Sea. Existing datasets were organized into groups according to distance from the coastline for comparison with basin-wide results. To explore potential baselines levels, the lower percentiles of the different datasets were calculated. For the proposal of potential thresholds, the selected percentiles were compared with different median confidence interval levels to calculate overlapping ranges. Depending on the distance from the coast, the resulting the baselines and thresholds could fluctuate up to six times. These results could be proposed as interim reference levels for further marine litter assessments.
Comparison of two isotope-based methods to quantify nitrification rates in estuaries
Authors: Russnak Vanessa , Kache Sophie , Voss Maren , Dähnke Kirstin
Published: February 2023

Estuaries are important biogeochemical reactors that can remove dissolved inorganic nitrogen (DIN, mostly nitrate) from the water column, but can also generate nitrate via remineralization and subsequent nitrification of organic matter in the water column. To assess this regeneration of nitrate, an important nutrient source for phytoplankton that contributes to eutrophication, various isotope-based laboratory methods are in use.In this study, we compare two commonly used stable-isotope-based techniques to measure nitrification in estuarine water, the isotope dilution method and the addition of 15N-ammonium. Both measure the isotope enrichment in nitrate but have drastically different incubation times. We apply both methods in the estuary of the Elbe River and evaluate the drawbacks and advantages of each method to develop application recommendations.Our results indicate that nitrification measurements using isotope dilution are less variable between stations, but suggest that rates are overestimated at high phytoplankton activity. On the counter side, the addition of 15N-ammonium as a tracer apparently overestimates nitrification in heterotrophic settings, probably because substrate addition stimulates nitrification. The adequate measurement technique must this be carefully chosen depending on the selected study site.Funding information  - This study has been carried out and was financially supported by the BMBF “Blue-Estuaries” project (grant no. 03F0864C)
Modeling of surface displacement and dynamic fracturing during magma emplacement at floor-fractured craters on the Moon and Mars
Authors: Poppe Sam , Morand Alexandra , Cornillon Anne , Harnett Claire
Published: February 2023

Floors of impact craters on rocky planetary bodies in our Solar System are often fractured and bulged. Such deformation features are thought to form by the ascent of impact-generated magma and the inflation of laccolith-shaped magma bodies at a shallow depth below the crater floor. Only the final surface deformation features can be observed from space, and so modeling is the only manner to understand controls on magma emplacement depth and volume, and deformation of the overlying rock. The existing models of crater floor fracturing mostly assume linearly elastic deformation of the shallow planetary crust and are not capable of simulating dynamic opening and propagation of fractures. In contrast, magma-induced deformation on Earth often displays non-elastic deformation features. This mismatch between the realistic mechanical response of planetary crust to magma intrusion and the one assumed by numerical models leads to significant inaccuracies in the modeled magma intrusion characteristics. This has important consequences for volcanic unrest monitoring on Earth and our understanding of structural deformation generated by volcanism throughout the Solar System.We propose a new two-dimensional (2D) Discrete Element Method (DEM) approach to model dynamic fracturing and displacement in a particle-based host medium during the simulated inflation of a laccolith intrusion. The model indicates highly discontinuous deformation and dynamic fracturing and visualizes the localization of subsurface strain. We explored the effect of different gravitational conditions on the Moon, Mars and Earth on the spatial distribution of strain, stress, and fracturing above an inflating laccolith. Moreover, by systematically exploring a range of numerical parameters that govern host rock strength (bond cohesion, bond tensile strength, bond elastic modulus), and intrusion depth, we find complex controls of mechanical properties of planetary crust on the magma intrusion characteristics. Our models help understand fracture distribution patterns above laccolith intrusions in the shallow crust of rocky planetary bodies. We demonstrate that considering dynamic deformation and fracturing mechanisms in numerical models of magma-induced deformation is essential to better understand the formation of floor-fractured craters and the magmatic intrusions that lie beneath.
Physics-based machine learning for modeling thermo-hydraulic processes in a coaxial deep borehole heat exchanger, considering an explicit reservoir-wellbore representation: A case study of Cornwall, UK
Authors: Teza Dimitra , Santoso Ryan , Koltzer Nora , Degen Denise , Bennett Tony , Wellmann Florian
Published: February 2023

Coaxial Deep Borehole Heat Exchanger (DBHE) provides an alternative way to extract geothermal energy by circulating a working fluid without producing geofluids or performing injection processes. It can be used to avoid induced seismicity issues caused by injection operations in hydrothermal doublets or to repurpose damaged or non-productive wells. A detailed numerical model is required to accurately capture as well the thermo-hydraulic processes within the DBHE and the cooling effects in the surrounding reservoir. This numerical model is often high dimensional. For a real-time monitoring purpose and optimization study, a direct numerical simulation with this model is computationally intractable.In this study, we use a physics-based machine learning method to reduce the computational cost of the performed forward model run. The physics-based machine learning method here is based on the non-intrusive reduced-basis method which expresses a physical solution in a linear combination of basis functions and weights. It is a model-order reduction technique that is mathematically proven to produce physically consistent predictions. The structure of the physics is maintained in basis functions and a machine learning model is deployed to calculate the weight for each basis function.We show the advantages of using the physics-based machine learning method by applying it to the planned coaxial DBHE in Eden (Cornwall, UK). The forward simulation is performed using the open-source simulator GOLEM, a finite-element (FE) based simulator that is built within the MOOSE framework. In this study we provide a running time comparison between the FE simulations and the physics-based machine learning simulations. We will also evaluate the accuracy of the physics-based machine learning predictions towards the FE solutions. Here, we would like to emphasize the significant computational speed-up that allow us to obtain new temperature and pressure state predictions in real-time context and to perform optimization with numerous iterations.
Angiosperms leaf evolution and the Cretaceous continental hydrological cycle : accounting for paleotraits in paleoclimate numerical simulations
Authors: Sepulchre Pierre , Bres Julia , Pikeroen Quentin , Viovy Nicolas , Vuichard Nicolas
Published: February 2023

Land cover, and thereby vegetation, can alter climate through biogeochemical and biogeophysical effects. Specifically, plants mediate radiative and turbulent fluxes between the surface and atmosphere and contribute to defining temperature and precipitation patterns in continental areas. In recent decades, pioneering works based both on fossil records and climate modelling have shown that vegetation parameterization is pivotal for accurately simulating past climates. Here, we focused on the Cretaceous, during which the radiation of angiosperms was accompanied by a physiological revolution characterized in the fossil record by an increase in the density of leaf veins and, ultimately, an unprecedented rise in their stomatal conductance. Emulating such an evolution of leaf traits, quantifying their consequences on plant productivity and transpiration, and identifying the associated feedbacks in the Cretaceous climate is a very challenging task. We addressed this triple problem by embedding the reconstruction of physiological paleotraits from the fossil record within the IPSL-CM5A2 earth system model, which land surface scheme allows for the interaction between stomatal conductance and carbon assimilation.
We built and evaluated vegetation parameterizations accounting for the increase in stomatal conductance during angiosperm radiation, which is consistent with the fossil record, by altering the hydraulic and photosynthetic capacities of plants in a coupled fashion. These experiments, combined with two extreme atmospheric pCO2 scenarios, show that a systematic increase in transpiration is simulated when vegetation shifts from a proto-angiosperm state to a modern-like state, and that its magnitude is related to primary productivity modulated by light, water stress, and evaporative demand. Under a high pCO2 scenario, only stomatal conductance plays a role, and the feedback of vegetation change consists mainly of more intense water recycling and rainfall over the continents. At low pCO2, the effect of the high stomatal conductance on transpiration is enhanced by the development of vegetation cover, resulting in more transpiration and higher precipitation rates at all latitudes. Enhanced turbulent fluxes lead to a surface cooling that outcompete the warming linked to the lower surface albedo. Our results suggest a larger impact of angiosperms on climate when atmospheric pCO2 is decreasing, and stresses the importance of accounting for fossil-based paleotraits in paleoclimate simulations.