bluuebunny/crossref_metadata_2025 huggingface dataset:
Mechanisms for the nucleation and deformation of symplectites during omphacite breakdown     
Authors: Zertani Sascha , Morales Luiz F. G. , Menegon Luca
Published: March 2024

The breakdown of omphacite is one of the first signs of eclogite retrogression, and typically results in the formation of vermicular intergrowths of sodic plagioclase and diopside (± quartz ± amphibole), termed clinopyroxene-plagioclase symplectites. Such symplectites occur in most, if not all, eclogite localities worldwide. The reaction is associated with a substantial grain size reduction, and may thus significantly impact bulk rock rheology during eclogite exhumation. We study a suite of natural clinopyroxene-plagioclase symplectites by electron backscatter diffraction (EBSD). The sample suite comprises symplectites in various stages of their evolution: the beginning stages of nucleation (vermicular symplectites), partially recrystallized symplectites, and completely recrystallized and strongly deformed symplectites. We determine crystallographic relationship between the parent omphacite and the reaction products and interphase misorientation relationships between the reaction products (plagioclase and diopside), to shed light on nucleation and deformation mechanism during eclogite retrogression. We find that the nucleation of diopside and plagioclase in the symplectites is strongly controlled by the crystallography of the parent omphacite, with the diopside copying the crystal lattice of the parent grain, and the plagioclase nucleating in special orientation relationships to the diopside, along planes with favorable interplanar spacing. Initially strong crystallographic relationships are weakened as deformation of the symplectites proceeds by fracturing transitioning into grain boundary sliding accommodated by diffusion creep, i.e., grain-size sensitive (GSS) creep.The results indicate that the formation of clinopyroxene-plagioclase symplectites does not increase permeability in crustal rocks, initially, but that deformation by GSS creep leads to progressive hydration and weakening of eclogites during retrogression. The symplectites thus significantly impact bulk crustal rheology. 
IGS GNSS satellite phase bias products: quality assessment and applications
Authors: Duan Bingbing , Hugentobler Urs , Parra Camille , Liu Yichen , Montenbruck Oliver
Published: March 2024

As part of the International GNSS Service (IGS), several analysis centers (i.e., CODE, CNES/CLS, GFZ, WUHN) provide GNSS (GPS, Galileo, BeiDou) satellite phase bias products to support precise point positioning with ambiguity resolution (PPP-AR). Due to the high correlation with satellite orbits and clock offsets, it is difficult to assess directly the precision of satellite phase bias products. The commonly used approach is to check the positioning performance in PPP-AR applications. However, errors or outliers in phase bias of a specific satellite are not directly visible in this process but lumped into the overall observation residuals. This contribution presents a method independent of ground measurements to detect outliers in satellite phase biases by computing the total Difference of satellite Orbits, Clock offsets and narrow-lane Biases (DOCB) at the midnight epoch between two consecutive days. This method can be also used to assess the consistency of satellite products between two different analysis centers. It is convincing that after removing the detected outliers in individual analysis centers the number of large differences of satellite phase biases between two analysis centers is notably reduced. To show the impact on PPP-AR, we generate a list marking all the outliers in the phase bias products from individual analysis centers, and evaluate the performance in ground-station kinematic positioning and Sentinel-6 satellite orbit determination.
Trade-offs in hydropower reservoir operation under the chain of uncertainty
Authors: Sakki Georgia Konstantina , Castelletti Andrea , Makropoulos Christos , Efstratiadis Andreas
Published: March 2024

The Water-Energy-Food-Ecosystem nexus is characterized by synergies, complementarities and conflicts, and thus its management is a demanding task. This becomes more challenging when socioeconomic influences are embedded. Key components of this nexus are multipurpose water reservoirs that provide drinking water, electricity, agricultural water for food production, and ecosystem services. These systems are driven by inherently uncertain processes, both hydroclimatic and human-induced (e.g., legal regulations, strategic management policies, real-time controls, and market rules), and thus their management should account for them. In this vein, this research proposes an uncertainty-aware methodology for assessing the long-term performance of hydropower reservoirs. Specifically, we investigate and describe in stochastic terms the main uncertain drivers i.e., rainfall, water demands, and energy scheduling, and eventually explore the cascade effects of the uncertainty chain. The modeling framework is stress-tested on a hydropower reservoir in Greece, Plastiras, which has been subject to challenging socioeconomic conflicts during its entire 65-year history. To estimate the water targets, we employ a statistical analysis of historical abstractions, concluding that the irrigation demand is strongly correlated with the reservoir level while it is negatively correlated with antecedent rainfall. For the estimation of the power plant’s energy target, we adopt a copula-based approach, in which the desirable releases for energy production are dependent on day-ahead electricity prices. In particular, we adopt three policies, i.e., conservative, median, and energy-centric, that refer to 95%, 50%, and 5% quantiles of the copula. Finally, to account for the hydroclimatic and market process uncertainties, we are taking advantage of stochastic models for the generation of synthetic rainfall and electricity price data, respectively. Our findings indicate that the cascade effects of the joint uncertainties are crucial for all operation policies. Specifically, in terms of profitability the energy-centric and the median are similar, while from a water supply and irrigation reliability perspective, the uncertainty range of this policy is wider, thus making it unacceptable for some scenarios. Consequently, the conventional approach of ignoring uncertainty in policy selection may result in misleading perceptions for the operator, eventually guiding to sub-optimal reservoir management. 
Positive mitigation effects of glacial rock flour (GRF) addition on ecosystem CO2, CH4 and N2O fluxes – first results from a gradient experiment
Authors: Li Qiaoyan , Larsen Klaus Steenberg , Dietzen Christiana Amalie
Published: March 2024

The application of ground silicate minerals to agricultural ecosystems has recently gained popularity as a mechanism for CO2 removal via enhanced mineral weathering that also has the potential to provide valuable co-benefits, including improved crop yields and reduced emissions of other greenhouse gasses. In Greenland, finely grained glacial rock flour (GRF) is naturally generated in vast amounts by glacier movement causing bedrock erosion and deposition. The natural production of GRF means that less energy is needed for grinding the rock material prior to field application. To quantify the influence of GRF on ecosystem carbon balance and greenhouse gas emissions, we applied 10 to 50 t GRF ha-1 yr-1 to an agricultural field in Denmark in a gradient setup with 5 levels plus combinations with fertilizers. Preliminary results of the CO2 fluxes measured by a combination of automated and manual chamber measurements, show that gross primary productivity (GPP, carbon uptake) and ecosystem respiration (Reco, carbon release) both increased gradually with the increased addition of GRF leading to a slightly increased net ecosystem uptake of CO2. In contrast, CH4 and N2O emissions showed a negative response trend with the increasing addition of GRF. The annual quantifications of ecosystem carbon balance and greenhouse gas emissions need further observations including effects during the non-growing season to be finalized. However, our initial results support the hypothesis that silicate mineral amendment overall may enhance CO2 removal in agricultural settings and reduce greenhouse gas emissions, and therefore may be a useful tool for improving the capacity of farmlands to serve as a greenhouse gas sink.
Multi-case study of particle distribution functions associated with ion cyclotron waves at ballooning-interchange heads
Authors: Panov Evgeny V. , Baumjohann Wolfgang , Hosner Martin , Nakamura Rumi , Sergeev Victor A.
Published: March 2024

Recent THEMIS and MMS spacecraft observations confirmed the kinetic simulations showing that the kinetic Ballooning/Interchange Instability (BICI) may lead to off-equator electromagnetic ion-cyclotron waves.  The ion-cyclotron waves appeared to ripple the growing ballooning-interchange heads and to erode and thin the magnetotail current sheet at ion scales. As this wave activity may be important for initiating magnetic reconnection in the magnetotail, we aim at collecting a number of high-resolution MMS ion observations with clear signatures of the electromagnetic ion-cyclotron waves, and at investigating the particle behavior caused by the waves. Particularly, we analyze the properties of the electromagnetic ion cyclotron waves and search for signatures of wave interaction with resonant particles using partial ion distribution functions and their moments.
Reconstructed global glacier mass change since LIA strongly influenced by the sample of observed glaciers
Authors: Vlug Anouk , Maussion Fabien , Leclercq Paul , van der Laan Larissa , Carrivick Jonathan , Marzeion Ben
Published: March 2024

An accurate global reconstruction of glacier mass change since the Little Ice Age (LIA) is of importance for, e.g., glacier mass change attribution studies and constraining the past sea-level budget. However, there are significant inconsistencies between reconstructions of the global LIA volume derived from (i) glacier length change records and (ii) glacier models that include the build-up to the LIA. The inconsistencies are present in both the magnitude and timing of the LIA maximum. Model reconstructions have shown a smaller peak of glacier volume, occurring many decades later than glacier length records indicate. Furthermore, as the maximum LIA volume did not occur synchronously between glaciers, the sampling choice of glaciers from the global population will have an impact on the total reconstructed LIA volume. Here, we tested the effect of different sampling strategies on reconstructed LIA volume, using a model based reconstruction from the Open Global Glacier Model, forced with the Last Millennium Reanalysis, as a surrogate world. Our analysis shows that glaciers for which length change observations prior to 1945 are available (the “real-world sample”) are not representative of the global signal. This shortcoming has the potential to explain large inconsistencies between the model-based reconstructions of glacier mass and reconstructions from observations. While the real-world sample is skewed, it is still a better representation of the global signal than would be expected from a random sample of the same size.
Improving, evaluating and sharing projections of global mean sea level rise
Authors: Edwards Tamsin , Turner Fiona , Malagon Santos Victor ,   EU PROTECT project
Published: March 2024

Projections of the ice sheet and glacier contributions to sea level rise to 2100 in the Intergovernmental Panel on Climate Change (IPCC) Sixth Assessment Report were made by representing physical models with statistical "emulators" or machine learning techniqes (Edwards et al., 2021). This allowed estimation of the impacts of several kinds of model uncertainty on sea level projections: multiple models for the ice sheets and glaciers, multiple settings determining ice sheet sensitivity to climate change, and multiple estimates of global warming, as well as uncertainty from the emulators themselves.
 
However, there were some limitations, including: predicting each year of the century independently (i.e. not providing smooth timeseries or the possibility to assess rates of change), beginning physical model simulations in 2015 (not allowing evaluation with observations), and exploring a small number of possible model settings. Projections beyond 2100 also had to be estimated for the IPCC with other methods. These limitations presented difficulties for users.
 
We improve on these projections here in their usefulness and robustness for coastal impacts communities and decision-makers. Usefulness: by predicting ice sheet and glacier changes to 2300, not 2100; providing smooth timeseries; and incorporating the emulators into the community FACTS sea level calculation framework (Kopp et al., 2023) for use by others. Robustness: by systematically exploring many more model settings than before (including, for the first time, those for glacier models), and beginning in the past to allow calibration of the projections with observations. The result is more meaningful trajectories of sea level contribution from each land ice source, in which we have greater confidence. We combine these in FACTS with estimates of thermal expansion and land water changes to show new projections of global mean sea level rise. This work was carried out by the EU Horizon 2020 project PROTECT.
 
References:
 
Edwards et al. (2021) Projected land ice contributions to twenty-first-century sea level rise, Nature, 593, 74–82.
 
Kopp et al. (2023) The Framework for Assessing Changes To Sea-level (FACTS) v1.0: a platform for characterizing parametric and structural uncertainty in future global, relative, and extreme sea-level change, Geosci. Model Dev., 16, 7461–7489. 
 
Geogenomics and biogeodynamics in the Northern Apennines and Ligurian Alps (Italy) 
Authors: Vance Gabrielle , Kirschner Dominik , Willett Sean D. , Pellissier Loïc
Published: March 2024

Complex interactions between tectonics and surface processes influence the evolution of aquatic species across orogens. These processes are likely to be important in tectonically active areas where faulting and uplift lead to drainage reorganization. The Northern Apennines are an active orogenic wedge, where horizontal shortening and topographic advection lead to river capture and drainage divide migration, which can separate or connect ecological domains and thus isolate or mix aquatic populations. In contrast, the adjacent Ligurian Alps are a remnant of the Alpine orogen with little modern deformation. In this study, we combine geomorphic analysis with environmental DNA (eDNA) collected from rivers in the Northern Apennines and Ligurian Alps to assess the influence of tectonic advection and subsequent drainage reorganization on the genetic diversity of native freshwater fish. Geomorphic metrics are asymmetric across the main drainage divide (MDD) in both orogens, and divide asymmetry indices based on these metrics suggest an MDD migration direction from Ligurian (coast) to Adriatic (Po Plain), accompanied by river captures. In the Northern Apennines, this suggested drainage divide migration direction is towards the NE, opposite that of the tectonic advection of topography. Geomorphic metrics show greater contrast across the MDD in the Northern Apennines than in the Ligurian Alps. Five native freshwater fish species show statistically significant correlations between genetic distance and divide asymmetry indices across the MDD. Genetic distance is greater across the MDD in the Northern Apennines than in the Ligurian Alps. Endemic species such as Telestes muticellus exhibit greater amplicon sequence variant (ASV) richness on the Ligurian than the Adriatic side of the MDD in both orogens; greater ASV richness in the Northern Apennines than in the Ligurian Alps; and greater ASV richness on the retrowedge of the Northern Apennines than on the prowedge.  Tectonically driven drainage reorganization may promote greater genetic diversity in coastal basins, although we can not rule out anthropogenic population transfer in some cases.
Exploring Thermo-Electrohydrodynamic Flows with DifferentialRotation in AtmoFlow
Authors: Gaillard Yann , Szabo Peter , Egbers Christoph
Published: March 2024

The AtmoFlow experiment is a small-scale,  laboratory experiment  designed to explore idealized large-scale atmospheric flow fields and planned to become operational onboard the International Space Station by 2026. The experiment is composed of two independently rotating spherical shells, mimicking planetary rotation. The temperature on the shell's boundaries is heated at the equator and cooled at the poles to count for the equatorial and polar temperature difference in the presence of solar radiation. An electrical field is applied to a dielectric fluid confined between the shells that serves as an artificial gravity force, known as dielectrophoretic force, inducing the formation of buoyant flow patterns.
Beyond modelling terrestrial or explanatory atmospheres via solid body rotation, the experiment is also able to mimic atmospheric regimes of large celestial bodies by deferential rotation of each shell. The resulting combination of rotational momentum flux and buoyancy force gives rise to distinctive patterns that are dependent on the magnitude of the forcing parameter, enabling to study different regimes. Prior studies have shown that the electric gravity gives rise to a buoyant force leading to plume-like patterns [1,2] in the radial direction, while the Taylor vortices induced by differential rotation maintains an azimuth flow component. The main objective of this study is to investigate the interaction between these two different transport mechanism.
Complementing numerical investigations are therefore performed to model the experiment using the OpenFOAM ecosystem, an open source finite volume solver.  The emerging convective regimes close to the outer shell regions are evaluated. The observed patterns are the classified into these distinct regimes  and presented in a regime diagram showing the transition from different convective states. Beside the pattern analysis, the heat flux through the model is investigated in relation to the forcing strength. This provided  an estimation of the overall heat transported from the inner to the outer shell.  The changes in the thermal transport were also reflected in the kinetic energy, which was monitored for each case and brought in relation to the evaluated heat transfer.

[1] Futterer, B., R. Hollerbach, and C. Egbers, ‘GeoFlow: 3D Numerical Simulation of Supercritical Thermal Convective States’, Journal of Physics: Conference Series, 137/1 (2008), 012026

[2] Futterer, B., A. Krebs, A.-C. Plesa, F. Zaussinger, R. Hollerbach, D. Breuer, and others, ‘Sheet-like and Plume-like Thermal Flow in a Spherical Convection Experiment Performed under Microgravity’, Journal of Fluid Mechanics, 735 (2013), 647–83
An improved suspension system for the observatory variometer
Authors: Pronenko Vira , Marusenkov Andrii , Parylo Igor , Prystai Andrii
Published: March 2024

The observatory variometers have been used for long-term observation of the Earth’s magnetic field for years and more. Because of this, it is necessary to exclude the influence of every external factors at the sensors of these magnetometers. One of the most often ones are tilts of their sensors because of the seasonal tilts of the pears at which they are installed. These variometers are usually equipped with sensors installed on brass or titanium platforms, pendulously suspended for tilt compensation. Here we present a new fiber-suspended sensor that better fits the observatory demands.Usually, the tilt compensation ratio is defined as a relationship between the pendulum and base rotations in the same vertical plane (around the same horizontal axis). We found that at certain conditions a pendulum may rotate around two other axes perpendicular to the base rotation line.  The first effect appears as a pendulum rotation around the horizontal line belonging to the vertical plane in which the sensor base is tilted.  This effect can be seen not only at the inclination of the base but also at the rotation of the sensor around its vertical axis. We used such a rotation in a horizontally directed magnetic field H to match the alignment of the mechanical axes of suspension and the magnetic axes of the sensor.The second detected effect was manifested as the pendulum rotation around the vertical axis during the inclination of the platform in the vertical plane where the upper pair of the fibers lies. The cause of the second effect is the imbalance of the lower part of the pendulum - either due to the uneven distribution of masses or due to different lengths of the lower pair cords.To keep both effects at the lowest possible or negligible level, a new version of the fiber-suspended sensor is designed. This sensor has three supporting feet and a worm drive for fine adjustment of the magnetic components’ orientation and the magnetic axes leveling possibility included in the firmware. The following parameters were obtained: tilt range ±4°, tilt compensation ratio (including off-axis effects) >2000, and thermal factor
Physical characteristics of peat and their influence on peat CO2 emission potential in a drained boreal peatland forest
Authors: Tenhovirta Salla , Palviainen Marjo , Peltomaa Elina , Laurén Annamari
Published: March 2024

Peatlands are a significant global storage of carbon (C), but also major sources of nutrients and dissolved organic carbon (DOC) to surface waters. Export of DOC from peatlands to watercourses cause emissions of  carbon dioxide (CO2) due to degradation of DOC, as well as enhances the brownification of surface waters, altering the ecological networks of the aquatic ecosystems. Managed peatland forests are hotspots for DOC export into downstream water bodies due to forestry practices such as harvesting and drainage. Water table, soil oxygen availability and vegetation control the release and transport of DOC.Drainage of peatlands also alters the physical characteristics of peat (Word et al., 2022). However, the role of these peat characteristics in the processes and release of DOC, as well as their influence on the lateral fluxes of carbon from forested peatlands, remains unknown.In this contribution, we present results from a laboratory experiment where the physical properties of peat and their relationship to peat decomposition are studied in a minerotrophic, nutrient-rich peatland forest that has been drained for ~80 years. The peat for the study was collected from the field site, located in southern Finland, into 50 cm columns along three transects. The transects  extend from 1 to 30 meter distance from the  ditch. In laboratory, the bulk density and water retention characteristics of the peat will first be determined in relation to distance to the ditch. The CO2 emission potential is then defined as the function of these peat properties. This is done by measuring the CO2 fluxes of the peat with a chamber enclosure method, using a Li-7810 online CH4-CO2-H2O analyser.The results of this experiment will increase the process-level understanding of the mechanisms that drive the export of DOC from peatlands. The produced data will be further utilized in an ecosystem model, to be used in assessing and evaluating environmental impacts of forest management practises. ReferencesWord CS, McLaughlin DL, Strahm BD, Stewart RD, Varner JM, Wurster FC, Amestoy TJ, Link NT. 2022. Peatland drainage alters soil structure and water retention properties: Implications for ecosystem function and management. Hydrological Processes 36: e14533.
Exploring the Collisionality of the Icy Galilean Moon Atmospheres.
Authors: Schlarmann Leander , Vorburger Audrey , Carberry Mogan Shane R. , Wurz Peter
Published: March 2024

In this study, we use the Direct Simulation Monte Carlo (DSMC) method [1] to investigate the collisional fraction of the atmospheres of Europa, Ganymede, and Callisto. The extent of the collisional atmosphere of the icy moons is still subject to ongoing debate. While Europa’s atmosphere is tenuous and effectively collisionless, the exobase for Ganymede and Callisto is expected to be located above a thin collision-dominated atmospheric layer [2].In the 2030s, both ESA's Jupiter Icy Moons Explorer (JUICE) and NASA's Europa Clipper mission are set to explore Jupiter's icy moons from up close, using high-resolution mass spectrometers to sample their atmospheres. The Neutral gas and Ion Mass spectrometer (NIM) of the Particle Environment Package (PEP) onboard JUICE [3] and the MAss Spectrometer for Planetary EXploration (MASPEX) onboard Europa Clipper [4] will determine the atmospheric composition of the moons and potentially sample plume material on Europa. The collisional fraction of their atmospheres affects the abundances of the various species that will be measured, and hence also the deduction of the underlying surface composition. Therefore, obtaining a comprehensive understanding of atmospheric structures, including the collisional fraction, is imperative for both missions. This knowledge is essential to ensure the correct interpretation of the measured data once it becomes available.The DSMC method is a computation technique, where rarefied gas flows are simulated by tracking the motion of individual particles, including their collisions and interactions, to provide insight into the macroscopic gas dynamics. Therefore, this method is ideal for studying thin atmospheres that transition from being collisional near the surface to ballistic at higher altitudes, such as the atmospheres of the icy Galilean moons. The model [5, 6] used herein includes different physical and chemical processes that create the atmospheres of the icy moons, such as sputtering due to interactions with Jupiter's magnetosphere, the sublimation of surface ice, and photochemical reactions.[1] Bird, G. A. (1994). Molecular gas dynamics and the direct simulation of gas flows.[2] Schlarmann, L., et al. (2024), in preparation.[3] Grasset, O., et al. (2013). Planetary and Space Science, 78, 1-21.[4] Phillips, C. B., and Pappalardo, R. T. (2014). Eos, Transactions AGU, 95(20), 165-167.[5] Carberry Mogan, S. R., et al. (2021). Icarus, 368, 114597.[6] Carberry Mogan, S. R., et al. (2022). Journal of Geophysical Research: Planets, 127(11).
Body wave retrieval from seismic ambient noise: results validation workflow within a known velocity model
Authors: Riahi Ali , Kazantsev Alexandre , Stutzmann Eleonore , Schimmel Martin , Montagner Jean-Paul , Noble Mark , Metaxian Jean-Philippe
Published: March 2024

We estimated the Empirical Green’s Functions (EGF) from ambient noise cross-correlations using a dense array of 3C broadband seismometers deployed above an anticline structure hosting an underground gas storage in France. In total, 580 recording locations are available. Several array configurations have been used, some of the seismometers being moved to new locations every day. The survey duration was of 16 days, with around 2 days of recording per location, and a typical interstation distance of 400 meters.Our methodology uses polarization characteristics to separate body and surface waves. The approach uses the imaginary part of ZR+RZ cross-coherency (Z: vertical; R: radial) to enable the distinct reconstruction of diving P-waves. In order to enhance the signal-to-noise ratio of the retrieved P-wave, we employed common-offset bin-stacking over all virtual sources and receivers, with an offset bin of 50 meters. Subsequently, we assessed the stability of the extracted P-wave by computing a separate common-offset bin-stack for each recording day and each station couple azimuth interval. The consistent moveout of the extracted P-wave, regardless of various station couple azimuths and recording days, suggested that there was no significant source distribution bias in our EGFs.In the next step, by using the P-wave window from the common-offset bin-stack as a template, we selected only the individual station pairs for which the correlation coefficient between the EGF and the template was above 0.8. This resulted in rejecting about 95% of the station couples. Around 7000 P- arrival times were picked from the selected EGFs in a semi-manual way. The accuracy of these arrival times was validated against the Eikonal solution for the first arrival within the “known” 3D velocity model of the site, based on active seismic and well logging data.Finally, a 3D tomography based on the picked arrivals allowed us to invert for a P-velocity model up to a depth of around 700 meters. The consistency and the limits of the comparison between this inverted model and the known model are discussed.
A Numerical Method for InSAR-Based Estimation of Head Changes using Storativity Parameters
Authors: Khodaei Behshid , Hashemi Hossein , Kompanizare Mazda , Naghibi Amir , Berndtsson Ronny
Published: March 2024

Significant groundwater (GW) head decline due to excessive withdrawal is an essential hydrological concern in several major plains of Iran. The capacity of an aquifer to retain GW can be described through the storativity parameters. Traditional methods to define these parameters are costly, time-consuming, and sometimes ineffective.The storativity of an aquifer, irrespective of its confinement type, is defined as the ratio of land surface deformation caused by GW withdrawal to the corresponding changes in GW head during a specified period. Interferometric Synthetic Aperture Radar (InSAR) is an effective tool to measure the gradual land surface deformation through backscattered radar signals. Additionally, the GW head changes can be monitored using available piezometric wells within the area. Depending on the hydrogeological properties of the aquifer, the GW head changes can lag the deformation by a few days to several years.Previous studies aimed at deriving the aquifer’s storativity parameters by focusing on extracting the storativity coefficient of the confined aquifer based on analyzing the seasonal components of both deformation and GW head signals. In this study, three parameters have been considered as representative indicators of the storativity for each target aquifer, independent of its type and complexity arising from multi-layered structures. These parameters encompass the lag time between the GW head change and induced land surface deformation, which is calculated through cross-correlation analysis. The other two parameters, seasonal and long-term skeletal storage coefficients, are estimated through a joint analysis of the head signal and the deformation signal shifted by the lag-time value. By estimating these parameters at each piezometric well location, a simulation of the GW head signal is feasible using InSAR data. The final year of both signals is isolated to evaluate the method's efficiency for predicting head changes.Our method was implemented on random observation wells across three areas encompassing different aquifer types and geological settings in order to evaluate its performance. The model demonstrated satisfactory performance in simulating and predicting the GW head, as evidenced by the average R-squared values of 0.77 and 0.54, respectively.
Probing the deep Earth interior by a synergistic use of magnetic and gravity fields, and Earth's rotation  
Authors: Mandea Mioara , Dehant Veronique , Cazenave Anny
Published: March 2024

In order to understand the processes involved in the deep interior of the Earth and explaining its evolution, in particular the dynamics of the Earth’s fluid iron-rich outer core, only indirect satellite and ground observations are available. They each provide invaluable information about the core flow but are incomplete on their own. This is the case of (1) the magnetic field, which can be used to infer the motions of the fluid at the top of the core on decadal and sub-decadal time scales, (2) the gravity field variations, which reflect changes in the mass distribution within the Earth, and (3) the Earth's rotation changes (or variations in the length of the day). These variations are occurring at multi-annual timescales and largely related to the core fluid motions. Earth's rotation variations are induced through exchange of angular momentum between the core and the mantle at the core-mantle boundary. We are particularly interested by the 6 and 8-year variations. They are presented together with the main activities proposed in the frame of the GRACEFUL ERC project, which aims at combining all information from observation as well as modelling the core flow in a completely coupled core and mantle system.
 
Non-invasive monitoring of plant root activities in the framework of the Earth’s Critical Zone and soil-plant-atmosphere interactions.
Authors: Cassiani Giorgio , Peruzzo Luca , Censini Matteo , Mary Benjamin , Iván Veronika
Published: March 2024

Bio-geophysics is a very broad discipline, including a variety of physical monitoring techniques applied to biological processes. As such, it is inherently very challenging and, at the same time, very promising. A variety of scales are being investigated, from the cellular scale to the ecosystem scale. More relevant to the latter scale is the investigation of the plants root zone, where the majority of mass and (latent) energy balance takes place between the soil and biota and, from there, to the atmosphere. The response of the soil-water-vegetation system and of the Earth’s critical zone (from the top of the canopy to the bottom of the shallowest aquifer) to climate and land-use change is crucial for the preservation of essential ecosystem services such as carbon storage, primary productivity, food and materials availability, and water and erosion regulation. In addition, the interaction between atmosphere and land surface is one of the most critical points to be resolved to reduce epistemological uncertainties in atmospheric models, both for numerical weather prediction (NWP) and global and regional climate models (GCMs and RCMs). The use of geophysical techniques in this context provides dense high-resolution spatial information as well as, potentially, high temporal resolution monitoring. Two different viewpoints can be taken in this form of “bio-geophysical” monitoring: on one hand, the physical signals of the biological (e.g. root presence and signals) activity can be directly sought; on the other hand, the effects of biological activity (e.g. root water uptake) can be sensed by the resulting changes of the soil/water system state (especially in terms of moisture content, but also temperature, etc.). Examples of both types of approaches, and links to eco-hydrological modelling, will be presented in this contribution, urging towards a more frequent and more accurate applications of these techniques, particularly for their potential contribution towards a better definition of Land Surface Models, i.e. the bottom, critical, and poorly known boundary condition for atmospheric models.
Understanding how sediment movement affects microplastic deposition in sandy streambeds: A modeling study.
Authors: Peleg Eshel , Teitelbaum Yoni , Arnon Shai
Published: March 2024

MP of all sizes and densities have been found deposited in streambeds. Several delivery processes were proposed to explain these observations, especially their dynamics, because most information was based on discrete sampling. Only a few studies have attempted to use a wide range of particle sizes to understand how MP moves in streams and rivers. At the same time, no experiments were conducted during bed motion due to the complexity of running such experiments. This study aimed to quantify the effect of streambed motion on the deposition and accumulation of MP in streambed sediments. We used a numerical model that predicts the flow and transport of particles in a moving streambed to quantify MP deposition. The model was run for streamwater velocities of 0.1- 0.5 m s-1 and median grain sizes of 0.15, 0.3, 0.45, and 0.6 mm. Streambed morphodynamics were estimated from empirical relationships. The flow conditions and sediment types resulted in ripple formation with celerities between 0-2000 cm hr-1. MP propensity to become trapped in porous media was simulated using a filtration coefficient. Various filtration coefficients (0.1-1 [1/cm]) were used in the simulations to predict the fate of particles in the sediment. The maximum deposition efficiency and deposition depth were found for sediment with high hydraulic conductivity and slow-moving stream water velocity conditions. Also, we found that the exchange of water and particles due to sediment motion leads to burial and potentially long-term deposition of MPs that initially were not expected to enter the bed due to size exclusion. However, increasing celerity reduces the depth of MP deposition in the streambed and reduces deposition efficiency due to resuspension. The burial of MP beneath the moving fraction of the bed provides a mechanism for long-term accumulation and may explain resuspension events characterized by high MP loads during floods. The modeling results could also assist in developing strategies for streambed sampling since a horizontal layer of particle deposit is expected to form below the moving fraction of the bed.
Hydrogen supply chain and its impacts on energy storage and carbon neutrality
Authors: Yukihara Tatsuto , Sun Qian
Published: March 2024

As a clean and efficient secondary energy, hydrogen energy is of great significance for energy transition and carbon neutrality. However, hydrogen development faces big challenges of high cost, unclean in production process, insecurity in transportation and storage etc. This paper tries to build a theoretical framework of hydrogen supply chain which contains whole life cycle of production, transportation, storage, utilization, and recycle of end use. Our study shows that a complete and mature hydrogen energy supply chain can enlarge the scale of hydrogen production and reduce the cost, improve its efficient and safety, and obtain a stable, sustainable, and zero-emission energy system. At the same time, a sound hydrogen energy supply chain also plays an important role in ensuring energy security and a bridge for the transition from fossil energy to renewable energy and these will help to reduce CO2 emissions, promote carbon peaking and neutrality through energy technological innovation and rapid energy transition.Key words: Hydrogen energy storage, hydrogen industry supply chain, green hydrogen, energy transition, carbon peaking and neutrality.
Absolute Quantum Gravimeter for Field Applications
Authors: Richard Jérémie , Antoni-Micollier Laura , Vermeulen Pierre , Arnal Maxime , Gautier Romain , Janvier Camille , Ménoret Vincent , Majek Cédric , Desruelle Bruno , Rosenbusch Peter
Published: March 2024

Absolute gravity measurements at the level of 1 µGal using cold atom quantum technology have been demonstrated in the laboratory in 1992 and have ever since received an increasing interest from the geophysics community [1]. In 2015, Exail launched on the marketplace the Absolute Quantum Gravimeter (AQG) [2]. Cutting-edge technology developments brought the necessary easy-of-use, autonomy, and robustness for field deployment. More than 15 units have since been produced for various geophysical applications, including hydrology and volcanology.Designed for field applications with autonomous or remote-controlled operation, the AQG does not require heavy vibration isolation equipment thanks to an integrated real time vibration compensation module which hybridizes the quantum measurement with a built-in classical accelerometer. As a result, all units reproducibly achieve a resolution of 10-9 g after < 2 hours of measurement at our inner-city factory site or after < 40 minutes at a quiet site, as we will demonstrate in this talk [2,4]. Moreover, we will present recent progress on the AQG including a gravity measurement campaign that has been on-going for 3 years now near the summit of Mt Etna [3,4]. Finally, we will detail our study of systematic effects affecting the instrument, whose evaluation is required to build a rigorous accuracy (or trueness) budget.[1] M. Kasevich, S. Chu. Measurement of the gravitational acceleration of an atom with a light-pulse atom interferometer. Applied Physics B, 1992, vol. 54, p. 321-332.[2] V. Ménoret et al, Gravity measurements below 10-9 g with a transportable absolute quantum gravimeter. Scientific Reports, 2018, 8, pp.12300.[3] L. Antoni-Micollier et al Detecting volcano-related underground mass changes with a quantum gravimeter. Geophysical Research Letters, vol. 49, issue 13, e2022GL097814 (2022).[4] L. Antoni-Micollier et al, Absolute quantum gravimeters and gradiometers for field measurements. IEEE Instrumentation & Measurement Magazine (submitted).
The geological record of H2 production in the Archean
Authors: Tamblyn Renée , Hermann Jörg
Published: March 2024

The oxidation of iron from rocks during subaqueous alteration is a key source of the molecular hydrogen (H2) used as an energy source by chemosynthetic organisms, which may represent some of the earliest forms of life on Earth. In the Archean, a potential source of ultramafic material available for serpentinisation reactions that release H2 are komatiites. Komatiites are highly magnesian lavas, which contain evidence of extensive serpentinisation and magnetite (Fe2+Fe3+2O4) production close to the Archean seafloor. H2 production in komatiitic compositions has been modelled and experimentally investigated; however, the natural rock record has remained unexplored. Here, we examine the geological evidence of H2 production from the basaltic to komatiitic rock record held in Archean cratons. From the petrological investigation of thirty-eight samples of komatiitic basalt to komatiite, we identify the unique serpentinisation reaction responsible for H2 production from these lithologies. With support from over 1100 bulk rock geochemical analyses, we directly quantify Fe3+ and therefore H2 production of komatiites in the Archean. The chemical (high Mg) and physical (low viscosity flow) characteristics of komatiite flows allowed for extensive hydration and serpentinisation in oceanic plateaus, and therefore high H2 production available to chemosynthetic early life.
Quantification of the Physical Process Leading to Extreme Day-to-Day Temperature Changes
Authors: Hamal Kalpana
Published: March 2024

Extreme temperature changes from one day to another, either associated with warming or cooling, can have a significant impact on health, environment, and society. Previous studies have quantified that such day-to-day temperature (DTDT) variations and extremes are typically more pronounced in mid-and high latitudes compared to tropical zones. However, the underlying physical processes and the relationship between extreme events and large-scale atmospheric circulation remain poorly understood. Here, such processes are investigated for different locations around the globe based on Observation, ERA5 reanalysis data, and Lagrangian backward trajectory calculations. In the extratropics, extreme DTDT changes are generally associated with changes in air mass transport, in particular shifts from warm to cold air advection or vice versa, linked to regionally specific synoptic-scale circulation anomalies (ridge or through patterns). Lagrangian temperature changes in the advected air masses are due to adiabatic warming, which is dominant in the local winter season, and diabatic warming, most importantly in summer. In contrast, for extreme DTDT changes in the tropics, local processes are more important than changes in advection. For instance, the strongest DTDT decreases over central South America in December-February are linked to a transition from mostly cloud-free to cloudy conditions, indicating an important role of radiative heating. The mechanistic insights into extreme DTDT changes obtained in this study can be helpful for improving the prediction of such events and anticipating future changes in their occurrence frequency and intensity. 
The lethal grip of heat: mapping the heat wave-mortality nexus in Spain (1975-2019)
Authors: Ordanovich Dariya , Casanueva Ana , Tobías Aurelio , Ramiro Diego
Published: March 2024

Nowadays, the rise in the global temperatures are a source of concern, particularly in the Mediterranean region, where Spain is already witnessing notable consequences for its aging population. Predictions for the end of the XXI century reveal a persistent increase in air temperatures along with an increment of extreme episodes. Abnormal heat, once considered an 'environmental accident', is now a serious public threat. This contribution endeavors to quantify the added effects of heat wave exposure on mortality by demographic and socioeconomic strata during the period of 45 years in Spain at the provincial level. Moreover, we aim to explore the temporal evolution in these effects and variations in its spatial patterns, especially focusing on the inequality aspects that shape the health outcomes in an increasingly aging population.Here we leverage daily individual mortality data and other contextual data on population from the National Institute of Statistics of Spain and air temperature estimates from the ERA5 global reanalysis. We also use the historical settlement data as a proxy for population distribution from 1975 onward. To estimate the main and added effects of heat waves we fit a quasi-Poisson time-series regression model using a distributed lag non-linear model with 10 days of lag, controlling for trends and day of the week.We analyze approximately 15.8 million of deaths registered in Spain between 1975 and 2019. During the selected time window, we expect to see a shift in the temperature-mortality association from a V-shape in the first decades of the observation to a U-shape by the end of the period all across the provinces, thus revealing a progressive flattening of the exposure-response curve. We also expect to observe an overall reduction in the mortality burden associated with the temperatures. In particular, we anticipate more significant and rapid decline in the cold-related risks and attributable fractions in comparison with the heat-related ones, with some latitudinal variations across the country.On the other hand, we witness a steady increase in the incidence of the heat wave episodes with time all over the country. We expect to see a positive added effect of heat wave on mortality, however this effect is assumed to be smaller than the primary effect. In addition, we anticipate observing variations in the effect depending on the heat wave order, duration, intensity, geographic location and demographic strata. The largest added effects are expected for the longest and strongest heat waves in the oldest-old population in the less accustomed to extreme heat areas.
Dissolution enables dolomite growth near ambient conditions
Authors: Sun Wenhao
Published: March 2024

Crystals grow in supersaturated solutions. A mysterious counterexample is dolomite CaMg(CO3)2, a geologically-abundant sedimentary mineral that does not readily grow at ambient conditions, not even under highly supersaturated solutions. Using atomistic simulations, we show that dolomite initially precipitates a cation-disordered surface, where high surface strains inhibit further crystal growth. However, mild undersaturation will preferentially dissolve these disordered regions, enabling increased order upon reprecipitation. Our simulations predict that frequent cycling of a solution between supersaturation and undersaturation can accelerate dolomite growth by up to seven orders of magnitude. We validate our theory with in situ liquid cell TEM—directly observing bulk dolomite growth following pulses of dissolution. This mechanism explains why modern dolomite is primarily found in natural environments with pH or salinity fluctuations. More generally, it reveals that the growth and ripening of defect-free crystals can be facilitated by deliberate periods of mild dissolution. [Kim et al., Science: adi3690 (2023)]