bluuebunny/crossref_metadata_2025 huggingface dataset:
Coupling OpenFOAM and PhreeqC to quantify local disruptions of hydrochemical equilibria due to bubble formation and stripping of CO2
Authors: Omidi Mohamad , Baumann Thomas
Published: March 2024

Scaling refers to the accumulation of solid precipitates on the surfaces of pipes, heat exchangers, and other equipment across various industrial processes, notably within geothermal systems. This process can lead to decreased efficiency and increased maintenance needs, highlighting the importance of accurate prediction and control methods.Hydrogeochemical models tend to overestimate the extent of scalings, especially if the scalings are caused by a disruption of the lime-carbonic acid equilibrium due to degassing in the geothermal fluid. This is because the models are not capable to describe diffusion-limited crystal growth, partial volume effects, and local saturation states adequately. In this study we introduce a novel approach by coupling a multiphase CFD-model (OpenFOAM) for the description of the gas phases in the produced geothermal fluids with PhreeqC to simulate the hydrochemical effects of the stripping of CO2 by the gas phase. This results in a model with high spatial and temporal resolution which allows to quantitatively differentiate between processes in the fluid and the processes taking place at the solid interfaces (pipe walls or matrix).The code is validated with published experiments in bubble columns. The coupling results in a highly flexible model which can account for different hydrochemical conditions, different matrix, and varying gas composition using a well established thermodynamic database. Transfer to other hydrochemical conditions is therefore facilitated.
Understanding Social Vulnerability to Climate Change-Modified Water Hazards in the Vietnamese Mekong Delta Coastal Zone
Authors: Phan Trung , Van Tri , Downes Nigel , Thai Trong
Published: March 2024

Concern for climate change impacts to the Vietnamese Mekong Delta is rapidly increasing due to the compound risks of a changing climate, environmental change and sensitivity and social-economic transformation. The Delta, located in the downstream section of the Mekong River is considered globally as one of the three most vulnerable deltas to climate change. Variations in precipitation, temperature changes, sea-level rise, progressive saline instructions, riverbank erosion, flooding and extreme weather events all aggravate the risk to the existing socio-ecological system.Using Ben Tre Province as an in-depth case study, this paper develops a social vulnerability index (SVI) to understand the water hazards-modified by climate change in terms of their association between vulnerability, existing infrastructures and socio-economic patterns. A mix-method of qualitative and quantitative approaches was framed to procure and analyse data. This consisted of group discussions, individual surveys and key informant panel interview. Spatially mapped results of cluster analysis showed a strong spatial trend of SVI increasing from upstream to the downstream areas The multivariate regression model found linear correlations between the SVI and the proximity to the dike system and waterways. Additionally, the Moran’s I autocorrelation indicated the statistically significant difference between the SVI spatially of various household clusters. These findings contribute y to the understanding of the array of biophysical and socio-ecological impacts, their variability and their interlinkages.
A consolidated 30 Arc-second Global Digital Elevation Model for Geodesy and Geophysics
Authors: Förste Christoph , Abrykosov Oleh , Ince Elmas Sinem
Published: March 2024

We have analysed the digital elevation models (DEMs) published in recent years and merged them to create a new elevation grid together with complementary Earth’s relief model for bedrock, surface, bathymetry, ice surface, and ice thickness. Although each model is unique in its own, the merged grid is able to provide seamless elevation information based on a common reference surface globally with high spatial resolution as required for various geoscience applications. We present how the merging procedure was carried out, how the accuracy of the model was evaluated and for which application areas it is intended. Our aim is to disseminate the use of a homogeneous and a consistent elevation model that is particularly suitable for geodetic applications in all parts of the world, including global and regional geoid calculations. The DEMs and associated auxiliary files included in the merged product are: TanDEM-X 90m over all dry land and ice-covered regions, ETOPO2022, GEBCO-2022 and GEBCO-2023 over land and ocean, BedMachineGreenland-v5 over Greenland, BedMachineAntarctica-v3 over Antarctica, GLOBathy (the Global Lakes Bathymetry Dataset) over lakes globally. Masks for ocean, dry land, lakes, islands in the lakes, ponds on the islands, ice-covered land, ice-covered shelves, the area outside Greenland and the ice-covered lake Vostok (Antarctica) were taken into account in the merging. This complete model is anticipated to provide a standardized DEM for various applications in geodesy and geophysics.  Our future plans include high resolution topographic gravity field modelling using this consolidated 30 arc-second digital elevation model and laterally varying global density data.
Geological activities at Galilei Science Department (Liceo Scientifico Statale "Galileo Galilei" - Potenza, Italy)
Authors: Cantarelli Valentina , Ierardi Irene , Zaza Serena , Girolamo Lucia , Pandolfi Luca
Published: March 2024

Since September 2023, the high school Liceo Scientifico “Galileo Galilei”, located in Potenza (Southern Italy), has been leading a project in collaboration with the Basilicata University aimed at promoting knowledge of geo sciences among high school pupils at a national level. The main objective is to enable the development of skills in the geological, geophysical and geochemical fields via the adoption of teaching practices that include laboratory-based work, with the aim to encourage high schoolers to continue their studies in these fields.The project will increase exposure to geological and environmental topics by covering not only classical geological aspects like lithogenesis, continental drift and geological time, but also current challenges such as territorial planning, environmental problems, natural and anthropic risks and the exploitation of renewable energy sources. The project will last three years (40 hours annually for a total of 120 hours) and involve 11th graders and above. Each year, students will spend 17 hours at the Liceo Galilei, 15 hours at the laboratories of the University of Basilicata, and 8 hours in field excursions to the geosites of the Basilicata region (including the Latronico geothermal power plant, the Vulture volcano and Aliano's gullies among others).At the end of this project, the expectation is that students will have expanded their understanding of Earth Sciences and will have increased their awareness of the central role that this discipline plays in political decisions concerning territorial planning and the management and use of natural resources.
Subway Flooding Simulation with US EPA SWMM: A Case Study of the Tamsui-Xindian Line During Taiwan's 2001 Typhoon Nari
Authors: Lin Yong-Jun , Chang Hsiang-Kuan , Lai Jihn-Sung , Tan Yih-Chi
Published: March 2024

There have been frequent reports of subway station flooding incidents in recent years. For instance, on October 30, 2012, Hurricane Sandy in the United States caused a storm surge combined with astronomical tide that submerged seven subway lines in New York City. It was the most severe disaster in the New York City subway system. On July 20, 2021, a flooding incident occurred in Zhengzhou, Henan Province, China, with a record hourly rainfall of 201.9mm. The heavy rain caused severe water accumulation at the Wulongkou yard of Zhengzhou Metro Line 5 and its surrounding areas. The temporary flood barrier was breached, allowing water to flood into the subway, with a maximum water depth of 1.75 meters inside the carriages and the flooding length extending approximately 1 kilometer.In 2001, Typhoon Nari caused flooding at the Taipei Station, with 16 MRT stations also inundated. Surface roads were extensively flooded, and the Taiwan Railways Administration stations in Taipei, Wanhua, and Banqiao were submerged, resulting in a 90-day suspension of the Taipei MRT station. How to quickly evaluate the impacts of subway station flooding is crucial for the extreme weather in the future. Therefore, this study utilized the US EPA SWMM to simulate the flooding situation of the Tamsui-Xindian line during Typhoon Nari in 2001. The SWMM calculations showed varying degrees of flooding at different stations at different times. For example, Guting Station was not affected by human intervention, while the simulated flooding depth at Taipei Station was only 0.09 m different from the actual depth. Additionally, the September 17, 2001 flood profile at 17:34 showed that Taipei Station was submerged, with water flowing to Zhongshan and Shuanglian stations. The National Taiwan University Hospital station experienced minimal flooding due to its higher elevation. The simulation also displayed the water ingress situation at different stations at various times. However, there were some inaccuracies due to the lack of detailed flood progression and inflow data and the use of a simplified station model. Nonetheless, the overall simulation results reflected the related flooding process.
Collisional effects on relativistic magnetic reconnection
Authors: Schoeffler Kevin , Deisenhofer Magnus , Finke Martha , Jeß Emanuel , Köhne Sophia , Innocenti Maria Elena
Published: March 2024

In extreme astrophysical environments around compact objects such as neutron stars and black holes, magnetic reconnection is expected to occur in the relativistic magnetically dominated regime, where the magnetization σ >> 1. These regimes have previously been studied using particle-in-cell (PIC) simulations showing hard power-law spectra, that can help to explain radiation spectra. While kinetic simulations are typically small-scale and collisionless, in realistic astronomical scales, collisional effects also should play a role. In this study, we reproduce the hard power-laws using 2D PIC simulations, and investigate the effects of Coulomb collisions which are taken into account self-consistently using Monte Carlo methods. A large body of research has investigated how the spectra is generated via reconnection in such relativistic systems, but the mechanism remains under debate. Understanding the differences in the energetic particle spectra at large collisional scales, may help shed light on this debate, and provide more accurate spectra to compare with astronomical observations.
Identifying probable signatures of hydrothermal activity from the Carlsberg ridge sediments using rock magnetic properties
Authors: Lenka Sambhabana , Kessarkar Pratima , Fernandes Lina , Gomes Concy
Published: March 2024

The Carlsberg Ridge (CR) is a slow-spreading ridge occurs along divergent plate boundary, with the reports of three active and one extinct hydrothermal vent sites. For the present study eight spade cores (SCs) were collected from the CR, of which three are in the vicinity of Tianxiu hydrothermal field and one on the ridge flank. The hydrothermal sites are known to be associated with metalliferous sediments with Fe being the one of the dominant element. We measured rock magnetic properties of sediments that depend on iron bearing minerals, along with X-ray diffractometry (XRD), and microscopic observations to distinguish metalliferous sediments, that may be associated with the active/extinct hydrothermal activity at the CR. Magnetic susceptibility (χlf) of sediments ranges between 1.3 and 37.1 x10-8 m3kg-1. Low χlf signatures suggesting low metalliferous sediments are observed on flank and two cores from the ridge valley indicating, the absence of hydrothermal activity. Whereas sediments closer to the Tianxiu hydrothermal vent field are associated with high χlf, signifying higher metalliferous sediments and are also having high satuaration isothermal remanent magnetization (SIRM), hard isothermal remanent magnetization (HIRM), and low anhysteretic remanent magnetic susceptibility (χARM)/SIRM, coarse stable single domain (SSD)  and fine SSD & mixture grains characteristics. Two more spade cores ~ 250 km south of the Tianxiu vent field also showed similar signatures indicating new active/relict site/sites in the vicinity. Identifying/locating metalliferous hydrothermal sediment/sites along extensive Mid Ocean Ridge (MOR) is expensive and time-consuming; rock magnetic could be a non-destructive method to shortlist the areas for detailed studies.
Estimating the heat transfer capability of fractured geothermal systems
Authors: Heinze Thomas
Published: March 2024

The heat transfer capability of any geothermal system is an essential characteristic deciding about its productivity, lifetime, and sustainability. Common attempts assuming thermal equilibrium between hot rock and injected fluid have shown to be a poor proxy for the thermal field in the subsurface. More detailed models at the laboratory scale based on explicit heat transfer between phases provide much better estimates but require a priori information concerning fracture geometry and network connectivity that is commonly not available at field scale applications.Based on these single and discrete fracture models, this work presents an effective heat transfer model upscaled for fracture networks. Using a realistic parameter set including fracture orientation, fracture density, and the permeability distribution, the developed approach determines the heat transfer coefficient and heat transfer area to be subsequently used in a coupled thermo-hydraulic model to simulate the evolution of the temperature field. The heat transfer coefficient is derived from a semi-empirical approach using the dimensionless Nusselt, Prandtl, and Reynolds numbers, and based on over 240 experiments. The heat transfer area is analytically derived from geometrical constraints. This approach achieves good agreement with single fracture experiments as well as with an analytical solution for an equally spaced fracture network. Its full capabilities are demonstrated with a complex three-dimensional simulation of a doublet system in a heterogeneous fracture network including anisotropy.
Source characteristics of the adakitic lavas and intrusions in Fildes Peninsula, King George Island (South Shetland Islands, Antarctica)
Authors: Ünal Alp , Altunkaynak Şafak , Nývlt Daniel
Published: March 2024

South Shetland Islands (western Antarctica) host widespread magmatism through the Meso-Cenozoic as a result of the subduction of the Phoenix plate along the South Shetland trench. With the logistical support of the Czech Antarctic Research Center and in-kind assistance from TÜBİTAK MAM Polar Research Institute, geological fieldwork was conducted on the Fildes Peninsula in order to understand the magma evolution beneath western Antarctica. This study presents preliminary results from field, petrographic and geochemical studies obtained from the volcanic and intrusive rocks in Fildes Peninsula- King George Island.Fildes Peninsula represents the southwestern parts of King George Island which is located at the northeastern tip of the South Shetland Islands. The dominant lithologies in the study area are Paleocene- Eocene volcanic and intrusive rocks, with a minor presence of sedimentary rocks. The volcanic rocks cropping out on Fildes Peninsula are referred to as the Jasper Hill, Agate Beach, Block Hill and Long Hill formations. They mostly display similar compositions changing from basalt to basaltic andesite lavas and accompanied by pyroclastic rocks (tuffs and volcanic breccias). Intrusive rocks are composed of gabbro-micro gabbro stocks and diabase dykes. Petrographic investigations show that volcanic and intrusive rocks in the area mostly display disequilibrium textures such as sieve textures and embayments in plagioclase and pyroxenes, patchy and oscillatory zoning in different generations of plagioclases. Geochemically, all volcanic rocks show similar characteristics; they are represented by basic rocks that mostly display tholeiitic affinity. Their MgO and SiO2contents range from 3.04 to 6.18 and 44.80 to 48,47wt. %, respectively. The samples are slightly enriched in large ion lithophile elements (LILE) and light rare earth elements (LREE) compared to N-MORB and they display depletions in Nb and Ti elements which are the typical indicators of subduction zone magmatism. All volcanic rocks display low Y and high Sr/Y contents which are typical for adakites.  These adakites are specifically represented by “low-silica adakites” due to their low SiO2 (
Predisposition and triggering conditions at a permafrost-affected rock avalanche site in the French Alps (Étache, June 2020)
Authors: Cathala Maëva , Bock Josué , Magnin Florence , Ravanel Ludovic , Ben-Asher Matan , Astrade Laurent , Bodin Xavier , Chambon Guillaume , Deline Philip , Faug Thierry , Genuite Kim , Jaillet Stephane , Josnin Jean Yves , Revil André , Richard Jessy
Published: March 2024

Permafrost-affected rockwalls are highly sensitive to rapid climate change, sometimes leading to rock slope failures threatening human lives and activities. Many studies have demonstrated a link between permafrost degradation and rockwall instability, but there is still a need to document destabilization events to improve the understanding of triggering mechanisms to ultimately develop relevant approaches for hazard assessment. Our study investigates the little rock-avalanche (c. 229,000 m3) that occurred in the Vallon d'Étache (Savoy, France) on June 18, 2020, after several days of heavy precipitation. We try to decipher the preconditioning and triggering factors of the rock avalanche by combining ground surface temperature monitoring, numerical modelling of permafrost evolution, energy balance modelling and geoelectrical survey interpreted with a petrophysical model to bring a detailed description of the hydrological and thermal mechanisms. The results show an intense permafrost warming especially since 2012 (annual trend: +0.06 °C a-1 at 30 m depth), with permafrost transitioning from cold to warm permafrost along the scar plan at a depth of c. 45 m when the event occurred. This warming may have preconditioned the rock avalanche. The geoelectrical soundings (240 to 640m long profiles) confirm that the crest around the scarp is still largely frozen with possible ice-rich layers (high resistivity values; 360 kΩ m). Furthermore, the energy balance model shows that the event occurred during the highest water input from rain and snowmelt, since at least 1985 which may have played as a triggering factor.  It also shows that the ground surface temperature experienced its highest winter and spring values before the event. This multi-method approach shows that this rock avalanche occurred in still largely frozen bedrock but subject to recent and very intense warming, and that water infiltration may have played a key-role in its triggering, either due to the development of high hydrostatic pressure or to accelerated permafrost thawing along fractures.
Mapping the water-economic cascading risks within a multilayer network of supply chains
Authors: Li Jinling , Wu Kehan , Liu Miaomiao , Yang Jianxun , Shan Yuli , Bi Jun
Published: March 2024

      Trade linkages within the supply chain can be mapped onto a complex network. Disruptions in regional resource supplies (i.e., water scarcity) have the potential to generate industrial losses in remote areas due to the interconnected flow of goods and services. While numerous studies have assessed the economic and virtual water supply networks, they assumed rapid and linear transmission of industrial risks in the network, without modeling the transmission process and vulnerability between nodes. Such oversights can lead to the misestimation of risks, especially in the context of climate change. Therefore, it is urgent to construct a cascading model for the supply economic and water supply network that consider step-by-step avalanche in nodes, to help identify vulnerable sectors and mitigate economic risks.      In this research, we utilize the 2017 multi-region environmental multiregional input-output (E-MRIO) table in China to construct a comprehensive multilayer network. Each province is represented as a distinct layer within this network, incorporating 42 economic sectors(nodes). These layers and nodes are interconnected through trade linkages. To simulate the cascade process, we introduce the concept of net fragility for a node, calculated as the difference between the ratio of the sum of net inflows and net outflows of a node to its own total output and the threshold. Once a node fails (i.e., net fragility less than 1) the cascade process is triggered, then we quantify the total number of collapsed adjacent nodes, i.e., avalanche size. The bigger avalanche size refers to the province-sector higher vulnerability to economic shocks. Furthermore, we use the risk probability of province-sectors suffering from water scarcity as external shocks to describe the supply network response process under different water quantity and quality constraints. By comparing with the economic impact results, we can further identify vulnerable nodes affected by the dual restraints of water scarcity and economic shocks.
Effect of bedload shape on the signal characteristics of a hybrid impact plate 
Authors: Sahu Bidhan Kumar , Mohapatra Pranab Kumar
Published: March 2024

Understanding bedload dynamics is critical for insights into erosion, sedimentation, and channel evolution of river systems. Designing hydraulic structures and validating existing sediment transport models need accurate bedload data. Bedload measurement is done using direct methods involving physical samplers or indirect devices with various acoustic sensors. One widely used indirect method is the impact plate system, which houses an acoustic sensor under it to detect bedload particles. Impact plate systems have been tested under varying velocity, bed roughness and bedload grain sizes. However, the influence of bedload particle shape on the signal characteristics in impact plate systems has yet to be investigated in detail. In the present study, an impact plate system with a hybrid sensor (accelerometer and geophone) attached to the plate's underside is used to understand the role of the shape of the bedload in an experimental flume. Five different particle sizes (4 to 40 mm) are grouped into three classes based on their sphericity index (0.45-0.6, 0.6-0.75, and 0.75-0.9), creating a total of fifteen classes. Ten bedload particles from each class are manually released over the impact plate for 20 runs, and the signals are recorded. It is found that the bedload shape significantly affects the signal characteristics, and with increasing sphericity, the mean maximum amplitude of the signal increases while the centroid frequency decreases. A calibration equation is thus developed between the signal parameters and the sphericity of the bedload grains.
Probabilistic Assessment of Exposure to Coastal Hazards at a Nuclear Power Station Development Site in the UK
Authors: Zhong Zehua , Kassem Hachem , Haigh Ivan , Sifnioti Dafni , Gouldby Ben
Published: March 2024

A fundamental requirement for the development of nuclear power stations is an evaluation of the risk and exposure to external hazards that may challenge nuclear safety. These hazards are often driven by a wide range of meteorological, oceanographic, and geomorphological processes which act on varying spatial and temporal scales. For coastal flooding and erosion, assessing the hazard potential requires consideration of both the local wave and water level variations and the associated regional weather conditions. Fortunately, the development of downscaling techniques offers useful tools for transferring large-scale climate forcings to local impacts. This research aims to conduct probabilistic assessments of coastal hazard exposure at a nuclear power station in the UK by using a hybrid downscaling framework. First, a weather typing method is employed to statistically downscale from regional atmospheric conditions to coastal waves and storm surges at the Hartlepool nuclear power station, which will be further downscaled to coastal flooding and erosion using physics-based dynamical models. We performed a sensitivity analysis to determine what parameters are significant in weather typing to downscale waves and storm surges. The resulting weather types and their associated wave climate and surge conditions are useful in identifying weather patterns related to extreme wave and surge events, which helps to reduce the computational effort in dynamical downscaling by focusing on those coastal-risk weather types and investigating their impacts. The sensitivity analysis reveals that the inclusion of the gradient of sea level pressure as the predictor and the use of local predictands to guide the classification of weather types are important to improve the model performance. 
Risk Communication as part of European civil protection mechanism. Roadmap basis from a national to a European Union Civil Protection communication and awareness.  
Authors: Mantini Marina , Rebora Nicola , Polo Lara , Andreaggi Margherita , Gioia Antonio , Franciosi Chiara , Ferraris Luca , Morando Marina
Published: March 2024

Risks know no borders, as climate change taught us in the last years,. Also, risks increased in frequency and intensity. Europe is experiencing multiple types of disasters that affect communities in different countries and it requires a coordinated, cross-country, inclusive, and international response. Consequently, communication and awareness campaigns have been increasing proportionally. However, it is difficult to know what different countries are carrying on, there is no database aimed to systematically collect and categorize practices implemented across Europe.  

To increase preparedness and improve the cooperation inter-states and inter European citizens, it is essential to assess communication initiatives across Europe and to build a common culture of risk preparedness. Obviously, it is necessary to maintain the differences and specificities of different communities and cultural contexts.  

The challenge is indeed to communicate something that could happen to anybody, but in a completely different context from a social, linguistic, economic and cultural point of view.  

 This research study, realised as part of preparEU European flagship initiative, has the aim to collect the risk communication good practices already existent in Europe, finding gaps, needs and challenges. It’s a preliminary study essential to find an effective and participatory way to enhance the culture of risk prevention amongst the EU, putting in common knowledge and experiences across different territories.  

 The study involved 25 EU Civil Protection Mechanism participant states through desk research, high level interviews and a questionnaire directed to the Institutions and experts committed to risk preparedness and communication. Useful data and patterns have been collected until now but also questions and challenges about the main concepts and tools that should be put in place to raise a common European preparedness culture, that focuses on a community response and solidarity, respecting at the same time differences and specificities.  
Understanding the performance of three 1-D lake models over Yangtze River Basin
Authors: Obulkasim Omarjan , Zhang Shulei , Dai Yongjiu
Published: March 2024

Lake thermal processes greatly impact the local climate and environment and are sensitive to climate change and human interference. The Yangtze River Basin has the highest lake density in China, boasting diverse natural and artificial water bodies; however, there is still a lack of comprehensive understanding and effective simulation approaches for the thermal processes of the various lakes in this area. This study, utilizing observed lake surface temperatures, thermal stratification data, and evaporation data from lakes in the region, provides key parameters for three one-dimensional lake models (namely, Simstrat, CoLM-Lake, and Flake) and comprehensively assesses their performance in the region. The findings indicate that all three models demonstrate robust accuracy in simulating shallow lakes (primarily natural lakes) but show substantial differences in performance when simulating deep lakes (mainly reservoir water bodies). Specifically, Simstrat excels in reproducing the thermal stratification of deep lake. It also demonstrates good performance in simulating lake surface temperature and evaporation, which is primarily attributed to the integration of Monin-Obukhov similarity theory into Simstrat. However, its ability to model temperature diffusion during the colder seasons requires further improvement. CoLM-Lake, while capable of simulating thermal stratifications, shows limitations in maintaining stability in deeper stratifications. Flake, on the other hand, encounters substantial challenges in accurately estimating turbulence effects in deeper lakes, particularly in autumn and winter. This study provides valuable insights for improving the simulation of lake thermal processes, particularly for deep artificial water bodies, which will enhance our understanding of lake thermal changes and their impacts in the Yangtze River Basin.
Towards Sustainable Futures in Tree Assessment using Ground Penetrating Radar: Insights, Developments and Novel Perspectives
Authors: Lantini Livia , Tosti Fabio
Published: March 2024

The global impact of diseases and environmental pressures on trees and forests has resulted in the decay and loss of a significant portion of the Earth’s natural heritage. Responding to this challenge, Ground Penetrating Radar (GPR), a well-established and reliable non-destructive testing (NDT) method, emerges as a fundamental assessment technique with vast potential. Its efficacy spans various domains, from Earth sciences to engineering, making GPR uniquely suited for forestry applications and offering a sustainable and non-invasive alternative to destructive methods like coring.Within forestry applications, GPR assumes a critical role in optimising economic expenditure for tree maintenance while simultaneously enhancing public safety. Swift and reliable detection of subsurface anomalies make GPR essential in safeguarding natural heritage and facilitating early identification of tree decay, ultimately supporting effective tree disease control.The present work explores the extension of GPR's capabilities to evaluate critical parameters in tree health, focusing on the assessment of root systems and the identification of potential structural weaknesses within tree trunks.The study introduces a series of recent experimental-based and theoretical models, each contributing to the understanding and enhancement of tree assessment. These models refine the interpretation of intricate reflection patterns, providing a refined understanding of tree trunk conditions. Additionally, models for the early detection of decays and cavities in tree trunks are presented, offering valuable insights into the internal structure of trees and enhancing the sensitivity and precision of GPR for proactive tree health management.In terms of assessing and monitoring tree roots, the study introduces methodologies designed to enhance the understanding of below-ground ecosystems. Developed algorithms for root detection and tracking, along with methodologies for estimating root mass density, offer insights into growth patterns and contribute to sustainable tree management practices. Furthermore, recent methodologies focus on understanding interconnections within tree root systems and the surrounding environment, identifying buried structures within the root system, addressing unique challenges faced by street trees in urban environments, refining the analysis of tree root systems using frequency spectrum-based processing, and integrating artificial intelligence for automatic recognition to enhance the efficiency of root system assessment.Finally, unique case studies are presented, showcasing the methodology, survey planning, and site procedures. These case studies add depth to the exploration, reflecting the practical application of the research in diverse and challenging scenarios.
Lagged Synchronizations of Hydroclimatic Extremes and Their Propagation Dynamics Revealed by Complex Event Coincidence Networks
Authors: Wang Hui-Min , He Xiaogang
Published: March 2024

Extreme droughts and pluvials are recurrent natural hazards that often lead to disastrous socio-economic impacts. These hydroclimatic extremes are generally characterized by large-scale spatial-temporal patterns spanning thousands of kilometres with time-evolving features of expansion or shrinkage. The spatial-temporal dynamics of these hydroclimatic extremes can pose compound impacts across multiple locations. Understanding the propagation behaviour, including movement and propagation, is crucial for disaster response and mitigation. The spatial propagation dynamics of droughts/pluvials are inherently complex as they are often associated with and modulated by natural climate variability, such as El Niño-Southern Oscillation (ENSO), North Atlantic Oscillation (NAO), and atmospheric dynamics like Rossby waves. However, the specific influences of these drivers on the spatial propagation pathways of droughts and pluvials remain elusive. Here, we conduct a multi-layer complex network-based analysis to explore the interactions between drought/pluvial propagation pathways and potential modulating mechanisms with a focus on the conterminous United States. We first identify extreme drought and pluvial occurrences using self-calibrated Palmer Drought Severity Index (scPDSI) and Standardized Precipitation Index (SPI) during 1948–2016. We then apply event coincidence analysis (ECA) for all location pairs to construct fully-connected drought and pluvial complex networks, based on which we identify the spatial-temporal propagation pathways through community analysis. Subsequently, partial event coincidence analysis is carried out to elucidate the direct links from potential climate modulators (e.g., ENSO, NAO, and Rossby waves) to extreme event propagation. Our results provide insights into how climate variability and large-scale circulation patterns affect the spatial propagation of droughts and pluvials, offering valuable information for pre-emptive actions to mitigate remotely synchronized extreme events.
Accurate mean-field micromechanical modelling of the nonlinear anisotropic response of polycrystalline aggregates
Authors: Castelnau Olivier , Ponte Castañeda Pedro
Published: March 2024

Rocks from the Earth mantle and polar ices have in common a nonlinear rheology and low crystal symmetries leading often to a limited number of independent slip systems for the glide or climb of dislocations. Both deform at elevated homologous temperatures, mostly under creep. Very large plastic deformation occurs during large scale geophysical flows, leading to pronounced crystallographic texture and an associated anisotropic rheology. Polar ice is a pure material, whereas several mineral phases are present simultaneously the mantle. The mantle deforms at extremely slow strain-rates, 10 orders of magnitude smaller than standard laboratory strain-rates, and thus the estimation of the mantle behaviour requires a drastic extrapolation from lab data. A consequence of the features outlined above is that deformation of mantle rocks or polar ices leads to a strong heterogeneity of the stress and strain-rate fields inside the polycrystalline aggregates, at the intragranular (micron) scale. This field heterogeneity has strong implication in terms of texture evolution, recrystallization, but also on the effective flow stress. Another consequence is that simple or ad-hoc micromechanical models are often inaccurate when the goal is to estimate the in situ nonlinear and anisotropic rheology, and the microstructure evolution at large strain, as the activation of slip systems is highly sensitive to stress fluctuations. In this presentation, we will review existing mean-field models for polycrystalline aggregates, show their capabilities / limitations with respect to reference full-field solutions, and show the benefit of the fully-optimized second order self-consistent scheme recently proposed by Song and Ponte Castañeda [2018]. Examples for ice and few mantle minerals will be given for illustrative purpose. D. Song and P. Ponte Castañeda, Fully optimized second-order homogenization estimates for the macroscopic response and texture evolution of low-symmetry viscoplastic polycrystals, Int. J. plasticity 110 (2018), 272–293
Measurements of ultra-relativistic electrons during solar energetic particle events - Results from the Ulysses Kiel Electron Telescope
Authors: Köberle Marlon , Heber Bernd , Jöhnk Carlotta
Published: March 2024

Solar energetic particle (SEP) events are increases of ions and electrons causedby solar activity namely flares and coronal mass ejections. While the mostenergetic ion population is well studied, SEP events accelerating electrons above20 MeV have only been reported from measurements by ISEE III in the 1980’sand the Kiel Electron Telescope (KET).The KET aboard Ulysses launched in 1990 and measured the electron flux inthe energy range from 4 MeV to above 6 GeV. Here we report on observationsof ultra-relativistic electrons and show spectra of electron events during solarcycle 22 and 23 until the end of 2008. The maximum electron energy exceeded100 MeV during the August 16, 2001 SEP event.This study has received funding from the European Union’s Horizon 2020research and innovation programme under grant agreement No. 101004159(SPEARHEAD).
Evaluation of the Copernicus Atmosphere Monitoring Service Cy48R1 upgrade of June 2023
Authors: Eskes Henk , Tsikerdekis Thanos ,   CAMS global developers and validation team
Published: March 2024

The Copernicus Atmosphere Monitoring Service (CAMS) is providing daily analyses and forecasts of the composition of the atmosphere, including the reactive gases such as ozone, CO, NO2, HCHO, SO2, aerosol species and greenhouse gases. The global CAMS analysis system (IFS-COMPO) is based on the ECMWF Integrated Forecast System (IFS) for numerical weather prediction (NWP), and assimilates a large number of composition satellite products on top of the meteorological observations ingested in IFS. The global CAMS system is regularly upgraded, and the upgrades are simultaneous with the upgrades of NWP-IFS. The upgrade to Cy48R1, operational since 27 June 2023, introduced a large number of code changes and improvements, both for COMPO and for NWP. The COMPO innovations include the introduction of full stratospheric chemistry, a major update of the emissions, of the aerosol model, including the representation of secondary organic aerosol, several updates of the dust life cycle and optics, and inorganic chemistry in the troposphere. Concering data assimilation, the assimilation of VIIRS AOD and TROPOMI CO were implemented in 2023. The CAMS Cy48R1 upgrade was evaluated using a large number of independent measurement datasets, including surface in situ, surface remote sensing, routine aircraft and balloon and satellite observations. In our contribution we present the validation results for Cy48R1. The new cycle is compared with the previous operational system (Cy47R3), with the independent observations as reference. Results are provided for the period October 2022 to June 2023 for which daily forecasts from both cycles are available. Major improvements in skill are found for the ozone profile in the lower-middle stratosphere and for stratospheric NO2 due to the inclusion of full stratospheric chemistry. Stratospheric trace gases compare well with ACE-FTS observations between 10-200 hPa, with larger deviations between 1-10 hPa. The impact of the updated emissions is especially visible over East Asia and is beneficial for the trace gases O3, NO2, and SO2. The CO column assimilation is now anchored by IASI instead of MOPITT which is beneficial for most of the CO comparisons, and the assimilation of TROPOMI CO data improves the model CO field in the troposphere. In general the aerosol optical depth has improved globally, but the dust evaluation shows more mixed results. In summary, 83% of the evaluation datasets show a neutral or improved performance of Cy48R1 compared to the previous operational CAMS system, while 17% indicate a (slight) degradation, which shows the overall success of this upgrade. This presentation summarises the results achieved by a large consortium of scientists working on CAMS, including the ECMWF staff, the developers of the global CAMS modelling system, the data assimilation team at ECMWF, and the CAMS validation teams. We acknowledge their contributions to this work.
Many shades in three dimensions and parallel universes of causality analysis
Authors: Palus Milan
Published: March 2024

Many approaches to infer causal relations from time series in Earth sciences have been proposed and applied in order to identify diverse interactions, such as the influence of large-scale circulation modes on local temperature and precipitation, variability of Euroasian winters due to changing Arctic Sea ice cover, or interactions of solar activity and interplanetary medium conditions with the Earth’s magnetosphere-ionosphere systems. The methods usually depend on “dimensions” in which the understanding of underlying phenomena is located: The phenomena or processes can be linear or nonlinear; deterministic, or random. The third abstract “dimension” is the actual dimensionality of the problem, given either by the dimension of the state space of the underlying mechanism or the number of involved variables. We will conduct a short flight inside these “dimensions,” shedding light on some of the shades, comparing some of the causality inference methods using model and real data from the Earth sciences.This study was supported by the Czech Academy of Sciences, Praemium Academiae awarded to M. Paluš and the Czech–Chinese Academies of Sciences Mobility Plus Project NSFC-23-08.
Patterns of volcanic eruptions in connection to sea-level change
Authors: Scala Margherita , Neves Maria C , Dumont Stéphanie
Published: March 2024

Understanding the relationships between the onset of volcanic eruptions and external forcings, such as solid Earth and ocean tides, can help us to understand the underlying dynamics of volcanic processes and have implications for volcanic monitoring and prediction efforts.Many studies that explored the relationship between tidal forces and volcanic activity have shown that certain phases of tidal cycles are associated with an increased likelihood of eruptions. At longer-time scales of hundreds of thousands of years, pronounced sea level variations related to ice melting or climatic and astronomical periodic variations have also been associated with pulses of volcanic activity.Oceans participate in significant redistributions of mass that can affect the stress field within the Earth’s crust over different time scales. Considering that most volcanoes lie near, within or beneath the oceans we hypothesize that stresses induced by ocean loading participate in destabilizing volcanic dynamical systems and ultimately contribute to eruption triggering.In a previous study we analyzed the worldwide number of monthly volcanic eruptions from the Global Volcanism Program and the global mean sea level between 1880 and 2009 using the Singular Spectrum Analysis time-series analysis technique. We found common periodicities and particularly multi-decadal components of similar periodicities of 20, 30 and 50 years present in both time-series.In this work we further explore the connection between volcanic activity and sea level by mapping the spatial patterns of volcanic eruptions at the previously identified temporal scales of correlation, ranging from the fortnightly tide to cycles of approximately 100 years. Geographical Information System tools are used to create spatial data layers, perform spatial analysis, and provide geographical visualization. The analysis might reveal global conditions and space-time patterns favorable to eruption triggering.This work was funded by the Portuguese Fundação para a Ciência e a Tecnologia (FCT) I.P./MCTES through national funds (PIDDAC) –UIDB/50019/2020 (https://doi.org/10.54499/UIDB/50019/2020),UIDP/50019/2020 (https://doi.org/10.54499/UIDP/50019/2020) andLA/P/0068/2020(https://doi.org/10.54499/LA/P/0068/2020).
Observed weakening of glacier ice-bed interface caused by climatic and hydro-mechanical feedbacks: towards glacier-wide acceleration?
Authors: Schuler Thomas Vikhamar , Nanni Ugo , Bouchayer Coline , Åkesson Henning , Lefeuvre Pierre-Marie , Mannerfelt Erik , Köhler Andreas , Schmidt Louise Steffensen , Hulth John , Renard Francois
Published: March 2024

 Stronger and more widespread surface melt may alter the flow of glaciers and ice sheets and trigger instability. However, observational deficiencies hamper our ability to better understand and thus predict such responses. We deployed surface and borehole seismometers along the centerline of a High Arctic glacier in Svalbard. The records span over six years and are analyzed in relation to the measured increase of surface velocity. We complement our seismic analysis (icequakes and seismic noise) with long-term measurements of glacier-surface velocity, surface-elevation changes, and runoff modeling. Since 2000, we observe glacier thinning and steepening, coinciding with acceleration of up to 1000%. In response, new crevasses have opened and provide access pathways for surface melt water to the base of the glacier, affecting the ice-bed coupling. This mechanism represents a positive hydro-mechanical feedback that fuels further acceleration and crevassing. This feedback may have wider implications for triggering of glacier-wide instabilities, increasing short-term sea-level rise and local hazards. Beyond the Arctic, we suggest that, under a warming atmosphere, glaciers may transition from stable to unstable flow through such a mechanism.  
VTEC Estimation Performance of Real-Time PPP with Galileo High Accuracy Service
Authors: Gul Caneren , Warnant René
Published: March 2024

Precise positioning with Global Navigation Satellite Systems (GNSS) requires a significant amount of effort for deliberate modeling of various effects on transmitted signals. Among these error sources, the ionosphere has a special place with its daily variations of total electron content (TEC), disrupting signals and degrading positioning performance. Some attempts to remove ionospheric effects, such as forming ionosphere-free combinations in Precise Point Positioning (PPP) can cause the amplification of observation noise. Using data-driven Global Ionospheric Maps (GIM) from GNSS analysis centers could be an alternative solution. However, precise GIMs are available after 10-11 days from the observation campaign and are not accessible in real-time. Therefore, the demand for real-time and reliable solutions is a hotspot research field in precise positioning.Real-time PPP (RT-PPP) with undifferenced and uncombined observables can convert the limitations of the ionosphere into an opportunity to make GNSS a versatile tool that is capable of monitoring the ionosphere and achieving high-accuracy positioning in real time. Our work focuses on the performance of ionospheric delay estimation with RT-PPP, using a newly developed real-time correction service, Galileo High Accuracy Service (Galileo HAS). First, International GNSS Service (IGS) stations from low, mid, and high latitudes for day-of-year 140,141, and 143 were selected for RT-PPP data processing. Next, we performed station-based Vertical TEC (VTEC) modeling and compared the results with GIM from the Centre for Orbit Determination in Europe (CODE). In addition, we processed the data from two receivers co-located on the rooftop of the University of Liège Sart Tilman campus B5a building. Finally, characteristics of the between-receiver single difference of estimated ionospheric delays are presented to assess the precision of slant ionospheric delays.