bluuebunny/crossref_metadata_2025 huggingface dataset:
Surface sediment permeability and reactivity in a shallow coastal environment
Authors: Forster Stefan , Schade Hanna , Werna Werna
Published: March 2024

Coastal sediments are frequently permeable due to their relatively large grains size. Knowledge on exchange processes across the sediment-water interface and metabolism in these sediments is limited however. We characterize permeable sediments at about 5 m water depth in a coastal stretch of ~3.5 km² at the southern Baltic coast off Germany. Permeability ranged from 1.4 .10-12 m² to 11.3 .10-11 m² (organic content: 0.1% - 0.2% dry mass). We determined total oxygen uptake, TOU, of 10 – 28 mmol O2 m² d-1 from in situ measurements in the dark. Benthic net primary production determined in situ varied between 1 - 14 mmol O2 m² d-1. We observed an increase in volumetric oxygen uptake rates in flow-through experiments when highly reactive glucose was supplied as substrate, pointing to the pivotal role of reactive organic substrate availability. However, we could detect only marginally enhanced TOU (uptake doubled at one out of three locations) when applying stirring rates inducing pore water flow in benthic chambers under natural conditions. We conclude that stimulating effects of permeability associated with pore water flow are not detectable in benthic exchange rates below a threshold of 7 .10-11 m² under field conditions. This threshold is higher than previously reported. Ex situ experiments demonstrated that the distribution of oxygen in the sediment was affected by photosynthetic activity of microphytobenthos and by pore water flow. Benthic primary production determined by the dark-light shift method exceeded the summed fluxes of oxygen into the water and into the sediment driven by concertation gradients, and increased with light intensity as well as with organic substrate availability. These findings indicate that calculated net ecosystem metabolism can shift from autotrophy to heterotrophy owed to an increased consumption within the sediment during advection. We argue that under advective conditions the export flux of photosynthetically produced oxygen may differ from the flux under diffusive conditions. This may seriously impair photosynthesis rate determinations obtained from incubation experiments.
Litho-structural framework of the Eoarchean Tussaap supracrustal belt, Itsaq gneiss complex, southwestern Greenland
Authors: Haproff Peter , Webb Alexander , Leung Chit Yan Eunice , Hauzenberger Christoph , Zuo Jiawei , Ramírez-Salazar Anthony
Published: March 2024

The Isua and Tussaap supracrustal belts of the Itsaq gneiss complex, southwestern Greenland, form the largest and best-preserved exposure of Eoarchean supracrustal materials on Earth. Previous studies have almost exclusively focused on the ∼35-km-long, arc-shaped Isua supracrustal belt and adjacent ca. 3.8–3.7 Ga meta-tonalite bodies, which are the basis for competing Archean tectonic regime interpretations (i.e., plate versus heat-pipe tectonics). In this study, we performed geologic field mapping of the seldom-explored Tussaap supracrustal belt, located ~11 km south of the Isua supracrustal belt, to better constrain its litho-structural framework and test the predictions of existing Eoarchean tectonic models. Observations from this study and previous works show that the Tussaap supracrustal belt consists of a east-northeast-striking, ~12-km-long and
Disaggregation bands as indicator for active blind faults
Authors: Brandes Christian , Tanner David , Fossen Haakon , Halisch Matthias , Müller Katharina
Published: March 2024

The identification of active faults is an important step in the seismic hazard evaluation process. However, this task is often difficult because many faults are unknown, buried below younger sediments. Especially in slowly-deforming intraplate areas with long recurrence intervals between individual seismic events, the detection of hidden blind faults is a major challenge. Furthermore, active faults can undergo long episodes of aseismic creep and thus do not produce typical earthquake-related, soft-sediment deformation structures, which also hinders the detection of these faults. Consequently, there is the demand for a robust universal geological indicator for active blind faults. Based on outcrop studies, we are able to show that disaggregation bands (near-surface deformation bands that develop in unconsolidated sediments due to reorganization of the grain fabric) are such an indicator. Disaggregation bands are developed at several locations in Central Europe and Scandinavia, in near-surface sandy sediments above the tip lines of blind faults. The strike of these bands is parallel to the strike of the underlying faults, which indicates that the disaggregation bands formed as a consequence of fault movement. The disaggregation bands internally show a pore-space reduction and in some cases a clear alignment of elongated grains. The thickness of the disaggregation bands increases with the amount of offset along the bands. Based on these observations, we infer that the bands formed in the process zone of propagating faults due to a shear-related reorganization of the grain fabric that leads to strain-hardening and a growth of the bands into centimetre-thick tabular structures. With analogue shearing experiments we show that disaggregation bands can form at a wide range of deformation speeds, even down to speeds several orders of magnitudes lower than seismogenic fault-slip velocities. Thus, disaggregation bands are key structures that record large parts of the seismic cycle and represent a very suitable indicator for active blind faults, even if the related fault creeps without emitting seismic waves. Disaggregation bands can easily be recognized in outcrops and artificial trenches, and previous studies showed that it is possible to even image them with ground-penetrating radar.
Environmental Monitoring with Q8 datalogger and Quanterra Mesh Extension (QME)
Authors: Parapuzha Arvind , Oncescu Lani , Frank Mathias
Published: March 2024

The versatile Q8 datalogger is telemetry ready, but using very low power (~300mW) is suitable for portable applications, such as On-Site-Inspections or seismo-acoustic arrays. Q8 features six or seven high resolution channels, plus an internal +/-2g accelerometer with additional three high resolution channels. The new Quanterra Mesh Extension (QME) allows for simplified integration of up to 16 one-sample-per-second environmental sensors, analog and digital. QME uses a modern IEEE wireless protocol, eliminating the management of multiple cables, ground loops, conduits, trenching, while adding freedom in sensors positioning. QME improves environmental data quality, lowers installation costs and time, and does not require specialized software. The environmental sensors tested so far were for temperature, relative humidity, barometric pressure, wind speed and direction, tilt, strain, external voltage, and intrusion.
Oligotrophic Trend following surface freshening in the western Arctic Ocean basin    
Authors: Zhuang Yanpei , Jin Haiyan , Qi Di , Chen Jianfang
Published: March 2024

Observations between 1994 and 2018 show that nitrate-depleted waters thickened and expanded northward in the western Arctic Ocean during this time, following a freshening trend in surface waters. Abrupt deepening of nitrate-depleted waters occurred in the Beaufort Gyre during 2005–2009 and throughout the western Arctic Ocean during 2008–2010. Owing to freshwater convergence associated with the anticyclonic Beaufort Gyre, the expansion of nitrate-depleted water is estimated to have occurred earlier in the Beaufort Gyre than in the western Arctic Ocean. The oligotrophic trend would have had a profound influence on observed ecosystem trends and related biogeochemical processes. This means that the Beaufort Gyre can be referred to as the “precursor” for the biogeochemical events response to freshening in the western Arctic Ocean.
Lessons learned developing a regionally-consistent exposure database for Central Asia
Authors: Scaini Chiara , Tamaro Alberto , Peresan Antonella
Published: March 2024

The Central Asia region encompasses a wide variety of climatic areas and geological settings. It is therefore prone to multiple hazards which can affect different parts of the region, including trans-boundary areas. Earthquakes, in particular, are a known threat for the region, and caused substantial damages and financial losses in the past. Here, we develop the first high-resolution regionally-consistent exposure database for Central Asia, encompassing multiple asset types including residential and non-residential buildings and transportation. The dataset was assembled using both global and regional-scale data and country-based information provided by local experts and authorities (e.g. building census, national statistics). This information includes also reconstruction costs, which are usually difficult to retrieve at country level, and images for different building typologies, which could serve as input for the development of image-based classification systems. Country-based data was collected interacting with local experts, and was supported by 5 workshops, one for each country, which fostered data sharing and knowledge transfer. Finally, the residential buildings exposure layer was used as a basis to estimate the projected exposure in 2080 under different Shared Socioeconomic Pathways. The lessons learned while developing the exposure database for Central Asia will be discussed in order to provide insights for developing similar datasets in other areas.
Volatile Organic Compounds: mediators of forest-atmosphere interactions and indicators of forest vulnerability
Authors: Gomes Alves Eliane
Published: March 2024

Volatile organic compounds (VOCs) are important mediators of forest-atmosphere interactions, regulating plant performance and atmospheric processes. Amazonian forests comprise the dominant source of VOCs to the global atmosphere. Yet, there is a poor understanding of how VOC emissions vary in response to ecophysiological and environmental controls in Amazonian ecosystems and even less understanding of how ecosystem emissions respond to climate extremes and land use change. I will summarize my work on VOC emissions from different ecosystems and scales in the Amazon and point out that VOCs can be indicators of forest stress and, therefore, a possible metric of forest vulnerability. First, I will present the state-of-the-art of VOC emissions and their interactions with the climate system in the Amazon. Next, I will demonstrate how these interactions can differ when considering different forest types and environmental stresses, including extremes of heat and drought. Finally, I will highlight the recent progress of VOC emissions investigated in the so-called "Amazon arc of deforestation" and indicate the potential of VOCs as a metric of forest vulnerability in climate modeling.
Retrieving the irrigation actually applied at district scale: assimilating high-resolution Sentinel-1-derived soil moisture data into a FAO-56-based model
Authors: Laluet Pierre , Olivera-Guerra Luis Enrique , Altés Víctor , Paolini Giovanni , Ouaadi Nadia , Rivalland Vincent , Dorigo Wouter , Jarlan Lionel , Villar Josep Maria , Merlin Olivier
Published: March 2024

Irrigation is the most water consuming activity in the world. Knowing the timing and amount of irrigation that is actually applied is therefore fundamental for water managers. However, this information is rarely available at all scales and is subject to large uncertainties due to the wide variety of existing agricultural practices and associated irrigation regimes (full irrigation, deficit irrigation, or over-irrigation). To fill this gap, we propose a two-step approach based on 15 m resolution Sentinel-1 (S1) surface soil moisture (SSM) data to retrieve the actual irrigation at the weekly scale over an entire irrigation district. In a first step, the S1-derived SSM is assimilated into a FAO-56-based crop water balance model (SAMIR) to retrieve for each crop type both the irrigation amount (Idose) and the soil moisture threshold (SMthreshold) at which irrigation is triggered. To do this, a particle filter method is implemented, with particles reset each month to provide time-varying SMthreshold and Idose. In a second step, the retrieved SMthreshold and Idose values are used as input to SAMIR to estimate the weekly irrigation and its uncertainty. The assimilation approach (SSM-ASSIM) is tested over the 8000 hectare Algerri-Balaguer irrigation district located in northeastern Spain, where in situ irrigation data integrating the whole district are available at the weekly scale during 2019. For evaluation, the performance of SSM-ASSIM is compared with that of the default FAO-56 irrigation module (called FAO56-DEF), which sets the SMthreshold to the critical soil moisture value and systematically fills the soil reservoir for each irrigation event. In 2019, with an observed annual irrigation of 687 mm, SSM-ASSIM (FAO56-DEF) shows a root mean square deviation between retrieved and in situ irrigation of 6.7 (8.8) mm week-1, a bias of +0.3 (-1.4) mm week-1, and a Pearson correlation coefficient of 0.88 (0.78). The SSM-ASSIM approach shows great potential for retrieving the weekly water use over extended areas for any irrigation regime, including over-irrigation.
A comparison of two causal methods in the context of climate analyses
Authors: Docquier David , Di Capua Giorgia , Donner Reik V. , Pires Carlos A. L. , Simon Amélie , Vannitsem Stéphane
Published: March 2024

Correlation does not necessarily imply causation, and this is why causal methods have been developed to try to disentangle true causal links from spurious relationships. In our study, we use two causal methods, namely the Liang-Kleeman information flow (LKIF) and the Peter and Clark momentary conditional independence (PCMCI) algorithm, and apply them to four different artificial models of increasing complexity and one real-case study based on climate indices in the North Atlantic and North Pacific. We show that both methods are superior to the classical correlation analysis, especially in removing spurious links. LKIF and PCMCI display some strengths and weaknesses for the three simplest models, with LKIF performing better with a smaller number of variables, and PCMCI being best with a larger number of variables. Detecting causal links from the fourth model is more challenging as the system is nonlinear and chaotic. For the real-case study with climate indices, both methods present some similarities and differences at monthly time scale. One of the key differences is that LKIF identifies the Arctic Oscillation (AO) as the largest driver, while El Niño-Southern Oscillation (ENSO) is the main influencing variable for PCMCI. More research is needed to confirm these links, in particular including nonlinear causal methods.
Do observations support ideas behind common mass flux closures?
Authors: Vogel Raphaela , Mellado Juan Pedro
Published: March 2024

Determining the mass flux at cloud base is the principle closure needed in convective parameterizations. Here we evaluate if observations from the EUREC4A field campaign support ideas behind common shallow-convective mass flux closures. All parameters of the closures are diagnosed at the mesoscale (200km, 3h) from dropsonde data and turbulence measurements. The closure models are compared to a reference mass flux estimated as a residual of the sub-cloud layer mass budget from the same circular dropsonde arrays. We find that a closure using the subcloud convective velocity scale (w*) captures the magnitude but underestimates the variability of the reference mass flux. A closure using a  turbulence kinetic energy (TKE) based velocity scale instead explains 78% of mass flux variability. These results suggest that (1) the full TKE needs to be considered rather than just the convective contribution represented by w*, and (2) the TKE may contain information about the area fraction of thermals, which makes a separate cloud area fraction scale unnecessary to explain mass flux variability during EUREC4A.
A Replicable Multi-Cloud Automation Architecture for Earth Observation
Authors: Karatosun Armagan , Pisa Claudio , Kaprol Tolga , Baousis Vasileios , Albughdadi Mohanad
Published: March 2024

The EO4EU project aims at making the access and use of Earth Observation (EO) data easier for environmental, government and business forecasts and operations.To reach this goal, the EO4EU Platform will soon be made officially available, leveraging existing EO data sources such as DestinE, GEOSS, INSPIRE, Copernicus and Galileo, and offering advanced tools and services, based also on machine learning techniques, to help users find, access and handle the data they are interested in. The EO4EU Platform relies on a combination of a multi-cloud computing infrastructure coupled with pre-exascale high-performance computing facilities to manage demanding processing workloads.The EO4EU multi-cloud infrastructure is composed by IaaS resources hosted on the WEkEO and CINECA Ada clouds, leveraged by a set of Kubernetes clusters dedicated to different workloads (e.g. cluster management tools, observability, or specific applications such as an inference server). To automate the deployment and management of these clusters, with advantages in terms of minimisation of dedicated effort and human errors, we have devised an Infrastructure-as-Code (IaC) architecture based on the Terraform, Rancher and Ansible technologies.We believe that the proposed IaC architecture, based on open-source components and extensively documented and tested on the field, can be successfully replicated by other EO initiatives leveraging cloud infrastructures.
Does an anthropogenically induced subsurface temperature hotspot affect groundwater ecology?
Authors: Noethen Maximilian , Becher Julia , Menberg Kathrin , Blum Philipp , Schüppler Simon , Metzler Erhard , Bayer Peter
Published: March 2024

Worldwide shallow groundwater is increasingly exposed to anthropogenic impacts. The thermal state of this important resource is affected not only by global warming but also by various local structures that release heat into the subsurface. This additional heat can accumulate and lead to local hotspots or - mostly urban - areas of elevated groundwater temperatures. The consequences of this warming for groundwater quality and ecology are widely unknown. Groundwater ecosystems are embedded in a naturally relatively stable environment, where temperature changes can affect the highly specialized, cold-stenotherm invertebrate community and meso- to psychrophilic microorganisms. In this study, we examine whether and how a groundwater temperature hotspot impacts groundwater ecology. We identified such a thermal anomaly in Hockenheim, Germany, caused by a water park with heated swimming pools and basements. The thermal impact was monitored over the course of a year by temperature data loggers in nine wells – four upstream and downstream of the structure each and one inside the basement. The same wells were sampled for chemical and microbiological parameters, such as the microbial total cell count and the cellular ATP content, as well as groundwater fauna. We additionally tested three wells in a nearby forest to obtain reference values that are mostly unaffected by anthropogenic interference. The measurements were repeated every three months in order to account for seasonal variations. The preliminary results show a local heat plume and an increase in groundwater temperatures by up to 8 K. However, there is no significant deterioration in the ecological parameters. Regarding the fauna, which generally shows low abundance due to oxygen depletion in the study area, we observed only a minor decrease within the thermally affected zone. Finally, the outcome of this study will improve our understanding of the vulnerability of groundwater ecosystems in the context of subsurface warming.
Extreme and compound ocean events are key drivers of projected low pelagic fish biomass 
Authors: Le Grix Natacha , Cheung William , Reygondeau Gabriel , Zscheischler Jakob , Frölicher Thomas Frölicher
Published: March 2024

Ocean extreme events, such as marine heatwaves, can have harmful impacts on marine ecosystems. Understanding the risks posed by such extreme events is key to develop strategies to predict and mitigate their effects. However, the underlying ocean conditions driving severe impacts on marine ecosystems are complex and often unknown as risks to marine ecosystems arise not only from hazards but also from the interactions between hazards, exposure and vulnerability. Marine ecosystems may not be impacted by extreme events in single drivers but rather by the compounding effects of moderate ocean anomalies. Here, we employ an ensemble climate-impact modeling approach that combines a global marine fish model with output from a large ensemble simulation of an Earth system model, to identify the key ocean ecosystem drivers associated with the most severe impacts on the total biomass of 326 pelagic fish species. We show that low net primary productivity is the most influential driver of extremely low fish biomass over 68% of the ocean area considered by the model, especially in the subtropics and the mid-latitudes, followed by high temperature and low oxygen in the eastern equatorial Pacific and the high latitudes. Severe biomass loss is generally driven by extreme anomalies in at least one ocean ecosystem driver, except in the tropics, where a combination of moderate ocean anomalies is sufficient to drive extreme impacts. Single moderate anomalies never drive extremely low fish biomass. Compound events with either moderate or extreme ocean conditions are a necessary condition for extremely low fish biomass over 78% of the global ocean, and compound events with at least one extreme variable are a necessary condition over 61% of the global ocean. Overall, our model results highlight the crucial role of ex-treme and compound events in driving severe impacts on pelagic marine ecosystems.
Depletion of a Mineral Water Aquifer – Implications on Sustainable Groundwater Management
Authors: Hegels Marlis , Baumann Thomas
Published: March 2024

Deep groundwater extraction alters both the reservoir's hydraulic and hydrochemical state. Although deep groundwater is part of the hydrologic cycle, it is considered a limited resource regarding the original hydrochemical composition and age structure. Mineral water producers share the privilege to use this resource for commercial purposes. Here, geological protection against surface influences and highly constant hydrochemical conditions are legally required.This study evaluates the development of a deep groundwater aquifer that has been used for bottled water production since the 1900s. Production stopped in late 2019, offering the unique opportunity to study the recovery of the aquifer. Detailed data from the past 40 years show a hydrochemical stratification in the mineral water aquifer with salinity and age increasing with depth. The saltwater horizon seems to have been lowered significantly due to extraction, and the hydraulic potential has also decreased. A connection to shallow groundwater was confirmed through the detection of herbicide metabolites. Isotope activities and metabolite concentrations indicate that the travel times are between 5-10 years.After the shutdown of the operation, the hydraulic potential increased and some of the wells are now again artesian. In the first analyses of the hydrochemical conditions the deepest wells reveal increasing salinity and CO2 concentrations. This indicates that the saltwater horizon is now moving upwards. The shallower wells, however, still show slightly decreasing salinity and are far away from the original hydrochemical composition. This indicates that the water extraction at this site has to be considered a mining operation.The measurements of the hydraulic and hydrochemical development together with an investigation of the flow paths for the recharge will allow an assessment of the sustainability of the groundwater extraction at this and other sites.
An Integrated GNSS-SAR Approach to Improve Ground Deformation Analysis in the Field of Geo-energies: activities planned within the SMILE project
Authors: Aponte Osmari , Gatti Andrea , Realini Eugenio , Barzaghi Riccardo , Sansò Fernando
Published: March 2024

The SMILE network, part of the Marie Sklodowska-Curie doctoral network funded by the Horizon Europe (2021-2027) program, undertakes an innovative role in addressing geo-energy project challenges while promoting net-zero greenhouse gas emissions in line with global sustainability goals.A segment of the SMILE network is dedicated to addressing the issue of ground deformation analysis. This research aims to develop a software tool that capitalizes on Global Navigation Satellite System (GNSS) data, coupled with Synthetic Aperture Radar (SAR) inputs and ground modeling information. This abstract outlines the methodological framework for the anticipated software development.In the initial phase, we aim to integrate the high temporal resolution GNSS data with the high spatial resolution of SAR data. The goal of this process is to combine the advantages of both data types while minimizing their limitations. SAR provides extensive spatial detail but has limited temporal frequency and directional sensitivity. On the other hand, GNSS data provides comprehensive three-dimensional vectors with high temporal frequency, but spatially limited to the points where GNSS stations are located.Merging the displacement measurements from GNSS and SAR requires temporal synchronization and the reconciliation of their different displacement vectors: GNSS captures vertical, east, and north components, and SAR measures in the line-of-sight direction. The optimal joint operation for this task is proposed through a Kalman filter. Due to the complexity of building a joint filter, the proposed method seeks to first analyze by considering the projected displacements only in the vertical direction. In this case, the measure in the line-of-sight of the SAR satellite will be projected in the vertical direction.The next phase will focus on an innovative approach to enhance the covariance matrix within the Kalman filter algorithm. Instead of using a homogeneous and isotropic constant covariance in time, this enhancement strategy will harness observed data as input. Primarily, it will smooth the covariance evolution in time, exploiting past observations; this may improve the stability of the outcomes. The method under development proposes to improve the covariance modeling further by enabling the consideration of anisotropic and non-homogeneous scenarios. Finally, the proposed method aims to integrate the monitoring data into Thermo-Hydro-Mechanical (THM) modeling.The proposed expansion is expected to bring significant advancements in ground deformation analysis, improving its resolution and precision. The tool will integrate GNSS and SAR datasets into a comprehensive ground deformation analysis suitable for geomatics applications within geo-energy projects.
From Global Mean Temperature to Regional Climate Impacts
Authors: Wells Christopher , Smith Christopher
Published: March 2024

There is strong motivation in Integrated Assessment Modelling to generate methods for quickly approximating regional climate impacts. Here, we use climate impacts from the Inter-Sectoral Impacts Model Intercomparison Project phase 2b (ISIMIP2b) to emulate impacts based on global mean surface temperature anomaly, beginning with crop yields and extending the analysis to other sectors. Unlike many existing methods, we emulate impacts directly, rather than first emulating regional climate. We find that a second order polynomial function of global mean temperature is a very good predictor of changes in regional crop yield, in line with existing research on damage function literature. Socio-economic and other drivers must be treated with care in the process. By using multiple driving climate models and impact models that are available for many impacts in ISIMIP, we are also able to sample uncertainty in the severity in changes in impacts with increasing warming.We built our climate impacts emulator for the 10 regions considered by the IPCC for the Sixth Assessment Working Group 3 report, but the selection of regions is flexible, and could be applied to any existing IAM. Our impacts emulator can also be used to construct updated damage functions for use in economic models and cost-benefit IAMs.This approach will be used to generate climate impact functions within the newly created FRIDA integrated assessment model, which seeks to account for feedbacks between all components of the human-Earth system – such as the climate, food systems, and energy production – as these are key drivers of the response to anthropogenic forcing.
Radionuclide sorption in the far field: Geostatistical simulation of crystalline rock to assess uncertainties due to heterogeneities
Authors: Duckstein Alexandra , Pospiech Solveig , Tolosana-Delgado Raimon , Brendler Vinzenz
Published: March 2024

In the event of radionuclides leaking from a deep geological repository for radioactive waste, they can reach the ecosphere through fluid migration pathways in the rock and aquifers. Retention mechanisms such as the sorption of radionuclides on the minerals along such pathways influence the migration patterns and are thus an essential part of the safety requirements. Consequently, determining the mineral composition and its spatial distribution of a crystalline host rock is an important task in the safety assessment for potential repositories.In the SANGUR project (Systematic sensitivity analysis for mechanistic geochemical models using field data from crystalline rock) we aim to determine which parameters and their uncertainties are essential for developing models for the simulation of radionuclide retention in crystalline rock. Radionuclide retention is substantially affected by sorption processes on the mineral surfaces, described by distribution coefficients (Kd values). A subsequent sensitivity analysis will help to identify the most influential parameters.In addition to the groundwater composition and the thermodynamic sorption data, the mineralogy and its heterogeneity of the host rock play an important role in establishing the model. For the sensitivity analysis, in turn, it is vital to be able to describe the uncertainties of the individual parameters in the model.To quantify the uncertainties, we simulate crystalline rock based on MLA (Mineral Liberation Analyzer image) data using Multinary Random Fields geostatistics. The focus is not only on the mineral composition of the bulk rock as a function of number of mineral phases and variability in grain sizes, but above all on the determination of the mineral composition of the exposed surfaces with which the aqueous phase comes into contact and on which sorption processes will  thus preferentially take place.Besides the question of how detailed the rock must be modeled in order to adequately capture the heterogeneities, the question of the model scale or the size of the representative volume element is also addressed.In addition to the discussion of the methodology and the results of the host rock simulations, we show the results of an initial study that enables us to determine what size the representative volume element should have in order to best describe the heterogeneities of the host rock for the subsequent calculation of the Kd values and their uncertainties.
Future drought changes in Australia from multiple projections
Authors: Ukkola Anna , Vogel Elisabeth , Thomas Steven , Bende-Michl Ulrike , Pitman Andy , Abramowitz Gab
Published: March 2024

Australia suffers from frequent droughts but future drought changes have remained stubbornly uncertain over the continent, with CMIP projections indicating low model agreement across most regions. Here we constrain future changes in drought over Australia by combining a hierarchy of projections from coupled global and regional climate models and several offline hydrological models that are widely employed in Australia. We analyse changes across multiple types of droughts (meteorological, hydrological and agricultural) to understand robustness of trends across drought types. Using this multi-projections approach, we identify robust future increases in drought across key agricultural and densely populated regions that are consistent across different drought types. Our study demonstrates value in analysing multiple projections together to build confidence in future changes in other regions of the world where model uncertainty is high.
Resuspended sediment exchange between the north and south Yellow Sea in the north of Chengshantou
Authors: Li Bowen , Jun Xiongxue , Duan Baichuan , Wang Daolong , Yu Long
Published: March 2024

Due to the regional differences between the North and South Yellow Sea, and under the influence of winter winds, the relative changes of the coastal current and the Yellow Sea warm current will lead to the instability of the front, which will lead to the cross-front transport of sediment. Therefore, the study of sediment exchange between the North and South Yellow Sea has become an indispensable part of the study of the Yellow Sea environment. In this paper, the current field and sediment concentration in the sorthern part of Chengshantou, a representative area of the Yellow Sea, were observed in winter in order to analyze the sediment exchange process between the North Yellow Sea and the South Yellow Sea in winter. The results show that in the north of Chengshantou sea area in winter, the current velocity does not change with the water depth when the water depth is more than 20 m, and the variation range is less than 5 cm/s, and the tides are regular semi-diurnal tides. The resuspension of sediments in the sea area is not controlled by the current velocity, but the sediment transport per unit width is mainly affected by the current velocity. Under the Shandong peninsula coastal current effect, suspended sediment is mainly transported from the north Yellow Sea to the South Yellow Sea, and the total difference between the southward and northward sediment is 442500 NTU×m2 during the observation period of about one month. The largest two-day transport volume accounted for 41.2% of the total transport flux.
A numerical model of microplastic transport for fluvial systems
Authors: Armitage John , Rohais Sébastien
Published: March 2024

Rivers are the primary pathway of microplastic pollution from source to the eventual sink in the marine environment. However, like sediments, microplastic will become trapped within the fluvial system as it makes its way from source-to-sink. There is therefore the potential that rivers are an important reservoir of microplastic pollution globally. To explore the transport of microplastic through the fluvial system we develop a reduced complexity model of microplastic erosion, transport, and deposition that builds on methods developed for the transport of sediment. We apply this model to the river Têt, France, where there has been punctual monitoring of the flux of microplastic at the outlet. We find that the reduced complexity model captures the observed quantity of microplastic under reasonable assumptions of the relationship between microplastic sources and population density. The model that best matches observed fluxes of microplastic at the outlet of the Têt river requires between 1 and 10 ppm volume concentration of microplasitc per 200 × 200 m in the top half a meter of soil. This concentration of microplastic then travels within the river network with a settling velocity of between 10-4 and 10-6 m/sec. The model results imply that a large proportion of microplastic will become entrained within the sediments along the fluvial system. This model is a first step in assessing where to sample for microplastic pollution within river networks and points to regions susceptible to microplastic pollution.
Case studies towards cryosphere digital twin applications
Authors: Liinamaa Iiris , Aalto Tero , Haapala Jari , Zhang Xinfang , Rasmussen Till , Wang Keguang , Arneborg Lars , Carlstedt Linn , Uiboupin Rivo , Maljutenko Ilja
Published: March 2024

The NOrdic CryOSphere Digital Twin (NOCOS DT) project aims to explore and pilot digital twin technology opportunities and showcase how output from key initiatives such as the Destination Earth (DestinE) Climate Change Adaptation Digital Twin (Climate DT) could be leveraged for key sea-ice impact sectors in the Arctic and Baltic.By enabling simulations at an unprecedented scale and resolution, DestinE and Climate DT aim to provide a more detailed representation of the Earth system. While awaiting the Climate DT data, NOCOS DT has done preparatory work using existing data sets in order to calculate novel navigational risk indicators, user-relevant  sea-ice climatologies and modeling of sea ice breakup and ridges. Additionally, the project looks at the potential use of this new information system and other climate data in marine spatial planning. NOCOS DT provides a Nordic perspective and insight that can inform Destination Earth in its future phases.The presentation provides an overview of the project and its main outcomes with informative animations. It hopes to spark open conversation around further ways to benefit from emerging digital twin technologies and ways to leverage international initiatives such as Destination Earth for specific impact sector needs in the Baltic Sea area.CSC – IT Center for Sciences coordinates the NOCOS DT consortium which brings together the Danish Meteorological Institute (DMI), the Finnish Meteorological Institute (FMI), the Norwegian Meteorological Institute (MetNo), the Swedish Meteorological and Hydrological Institute (SMHI) together with Tallinn University of Technology, Department for Marine Systems (TalTech). The project is funded by the Nordic Council of Ministers.
The Isotope and REY geochemistry of fault-related calcites document syn-kinematic fluid distribution along the Val d’Agri faults (southern Italy)
Authors: Schirripa Spagnolo Giulia , Bernasconi Stefano , Aldega Luca , Castorina Francesca , Agosta Fabrizio , Billi Andrea , Prosser Giacomo , Smeraglia Luca , Carminati Eugenio
Published: March 2024

Calcite is a common syn-kinematic precipitate in upper crustal fault zones coating slickensides, forming slickenfibers, and infilling veins. Structural and geochemical analyses of fault-related calcites can be used to unravel the source, distribution, and mixing of parental fluids in association with past fault activity. Identifying deeply sourced fluids through syn-kinematic calcites is of paramount importance, as the correlation of the ascent of deep sourced fluids with strong earthquakes, may allow using hydrogeochemical modifications in groundwater as potential seismic precursors. In this study, we investigate the origin of syn-kinematic paleo-fluids that circulated along the Val d’Agri faults, in southern Italy. These faults bound an intermontane basin topping the largest onshore oil field in Western Europe. Since the Val d’Agri Basin is affected by natural seismicity and low magnitude oil production induced earthquakes, it is necessary to assess the potential threats of hydrocarbon fault leakage at shallow crustal levels. With this aim, we collected about 350 syn-tectonic calcites along high-angle extensional-transtensional fault zones. By combining macro- and micro- scale structural observations with carbonate isotopes (C, O, clumped, and Sr) and rare earth elements and yttrium (REY) geochemistry, we identified 5 fluid sources: (1) meteoric waters in geochemical and thermal disequilibrium with the host rocks, which interacted with superficial soil; (2) meteoric waters in geochemical disequilibrium and thermal equilibrium with the host rocks, which had limited interaction with the host rocks; (3) buffered fluids in geochemical and thermal equilibrium with the host rocks; (4) high temperature fluids in geochemical equilibrium and thermal disequilibrium with the host rocks, which ascended from the carbonate hydrocarbon reservoir; (5) hot meteoric waters in thermal and geochemical disequilibrium with the host rocks, which mixed with the deeply sourced fluids. The presence of multiple fluids is consistent with an open fault-related circulation system, which allowed mixing of shallow and deep fluids through the high-angle extensional-transtensional Val d’Agri faults. Given the societal and economic issues of this area, the recognized involvement of deep fluids during past fault activity is crucial for the context of oil exploration and production as well as for environmental monitoring. Furthermore, this suggests that the Val d’Agri Basin is an ideal region to explore fluid-fault relationships throughout the entire seismic cycle through local seismicity records and continuous groundwater monitoring.
Ion escape processes in the solar system and beyond 
Authors: Dandouras Iannis , Yamauchi Masatoshi
Published: March 2024

Understanding the evolution of planetary atmospheres, and particularly the evolution of their composition and eventual habitability, is a major challenge. The evolution of an atmosphere is driven by its interactions with the planetary surface and interior, the influx from space (e.g. meteors), and the atmospheric escape to space in the form of neutral or ionised atoms/molecules, upwelling from the atmosphere and escaping to space. For a planet like Earth, atmospheric escape in the form of neutrals concerns essentially hydrogen whereas heavier species, such as oxygen and nitrogen which constitute 99% of the mass of the terrestrial atmosphere, need to be accelerated as ions in order to reach escape velocities. The ions that outflow from the ionosphere are successively accelerated through a series of energisation mechanisms and can eventually reach velocities above the gravitational escape velocity. Missions like Cluster, MAVEN and Cassini and associated modelling efforts have advanced our understanding of the ion acceleration, circulation in the magnetosphere and escape mechanisms operating on different planetary objects of our solar system, magnetised or unmagnetised. However, several questions remain open, as: (i) What is the exact composition of the escaping populations and how does it change in response to the different driving conditions?  How does it affect the long-term evolution of the composition of a planetary atmosphere and its habitability? (ii) What is the exact degree of plasma recirculation for each ion species, after it has left the ionosphere, versus direct or indirect escape, and what is its dependence on the solar and geomagnetic activity conditions? (iii) What is the effect of a planetary magnetic field on the different escape mechanisms, particularly in view of the conjugate effect of different magnetospheric size / solar wind dynamic pressure / exobase altitude / solar irradiance? (iv) The discovery in recent years of a large number of exoplanets, several of them in the "habitable" zone, raises the question of atmospheric escape mechanisms operating in these environments. Could exoplanets orbiting active K-M stars undergo massive atmospheric escape, removing the constituents of water from their atmospheres under XUV irradiation and making them uninhabitable within a few tens to hundreds of Myr, as some models suggest?   
An operational way of SAR feature creation to facilitate machine learning analyses
Authors: Zhang Xu , Chang Ling , Stein Alfred
Published: March 2024

Satellite missions have delivered a wealth of SAR images for Earth monitoring applications since the 1990s. Due to the complex nature of SAR images and a limited amount of accessible SAR labeling data, these images remain underutilized in providing reference information for machine learning. In response to this gap, we designed a SAR feature creation workflow in an operational framework by releasing Jupyter tools to the public.  The workflow is developed upon Doris-5 and consists of two streams. The first stream utilizes SAR images to generate basic SAR and SAR interferometric and polarimetric features. The second stream capitalizes on other available geospatial datasets, such as optical images, cadastral and geological maps, to generate additional features for SAR data that can be treated as reference data. They are first radar-coded to align with the extracted SAR features and then geo-coded in geographic coordinates. All SAR features are concatenated as separate layers in the NetCDF data format, which contains STAC (spatio-temporal asset catalogs) for the data querying.For the demonstration, an area in the province of Groningen, the Netherlands, was selected as the test site. Seven ascending Sentinel-1A images in VV and VH modes on track 15 between January and March 2022 were used, along with the topographic base map – TOP10NL dataset as a reference. The extracted features encompass VV amplitude, VH amplitude, VV interferometric phase, VV coherence, intensity summation, intensity difference, intensity ratio, cross-pol correlation coefficient, cross-pol cross product, entropy, buildings, roads, water and railways. The first ten features were created via the first stream, while the last four features via the second stream. By applying a random forest classifier to these fourteen SAR features, the model resulted into four types of classified SAR images: building, road, water and railway. The overall accuracy was 0.8558, 0.9939, 0.9065, and 0.8191, with corresponding F1-scores of 0.9191, 0.9669, 0.9490, and 0.9006, respectively.We conclude that the created SAR features well facilitate machine learning, and that even a simple random forest classification can yield relatively high-accuracy results. In addition, our workflow to create SAR features is well suited to prepare labeled features for machine learning analyses that are even friendly to a user with limited knowledge of SAR.  
Coastal Convective Clouds: Gulf-/Bay-Breezes and TRACER Insights
Authors: Wang Dié , Chen Jingyi , Jensen Michael
Published: March 2024

This study delves into the characteristics of convective clouds induced by Gulf-Breeze Circulations (GBCs) and Bay-Breeze Circulations (BBCs) in the Houston-Galveston region. By using a machine learning method, we find that anticyclonic synoptic patterns prevalent during the summer months significantly contribute to the formation and development of GBC/BBC-induced convective clouds, constituting 71% of cases. Leveraging data from the TRacking Aerosol Convection interactions ExpeRiment (TRACER), we discover that the main site at LaPorte, TX experiences the influence of both GBC and BBC, with frontal passages primarily occurring around 1300 LT. These frontal passages trigger boundary layer updrafts, fostering isolated convective cores characterized by short durition (63 min) and slow movement (5 m/s), particularly within 20-40 km from the coast, and maturing around 80 km inland. In addition to observations, we simulate these convective cases using the WRF model, demonstrating good agreement with TRACER data. Various urban schemes are then explored to probe the impact of the urban heat island effect on the evolution of GBC/BBC structures and subsequent convective cloud development.