bluuebunny/crossref_metadata_2025 huggingface dataset:
The role of anthropogenic forcing on Australia’s Tinderbox (2017-19) Drought and its future likelihood 
Authors: Rauniyar Surendra , Power Scott , Hope Pandora , Bende-Michl Ulrike
Published: March 2024

During the 2017-2019 period, a large region of the Murray Darling Basin in Australia received the lowest three-year rainfall resulting in an unprecedented drought, known as the Tinderbox Drought. The cool season (Apr-Sep) rainfall declined by more than 54% of the 1901-1960 average. An analysis of the observed rainfall records (1900 – 2020) shows that it was exceptionally unlikely that a decline of this magnitude could occur from internal climate variability alone. In this study, we analysed outputs from CMIP5 and CMIP6 climate models under different forcing conditions (i.e., pre-industrial, historical-all forcings and different future emissions pathways) to estimate the relative contribution of anthropogenic forcing and internal variability to the observed 2017-2019 cool season rainfall reduction and the future likelihood of three-year rainfall change as dry or drier than the Tinderbox Drought under different emission pathways. According to the models, taken at face value, the Tinderbox Drought is an extremely unlikely event, but the likelihood of its occurrence is being increased from virtually impossible to extremely unlikely by the anthropogenic forcing. This suggests that the Tinderbox Drought was largely dominated by internal climate variability, however, it would not have been as dry without the influence of anthropogenic forcing. We found that the likelihood of a three-year drought as dry or drier than the Tinderbox Drought is going to increase by 15% towards the end of the twenty-first century under a high-emission scenario. Even with a marked reduction in emissions, its likelihood will be still around 5 % which is 10 times higher than the pre-industrial climate. Only a few ensemble members simulate a drying as large or larger than the observed 2017-2019 drying. The inability of most models to fully replicate the large drying seen so far leads to two possible conclusions: the rainfall in this region is more sensitive to greenhouse gas concentrations than is currently modelled, or factors other than climate change have coincidentally reduced rainfall during the recent period of anthropogenic climate change. 
A missing Cretaceous magmatic arc of Neo-Tethys in Iran
Authors: Lei Yiyang , Chu Yang , Wan Bo , Lin Wei , Chen Ling , Xin Guangyao , Talebian Morteza
Published: March 2024

Magmatic arcs are generally considered to be the direct record of subduction zone. Magmatic activity can start with subduction initiation until the end of oceanic subduction. In the Neo-Tethys tectonic domain, arc magma gaps in Alps and Iran prove that arc magmatism and oceanic subduction are not always coupled.Unlike the Alps, where arc magmatism is absent, or the Gangdese, where arc magmatism is continuous, Iran exhibits an intermittent arc magma record. Since the subduction of the Neo-Tethys Ocean in the Jurassic, Iran has recorded two phases of magmatic activities: the Middle Jurassic (200-140 Ma, with a peak at ~170 Ma) and the Eocene (55-25 Ma, with a peak at ~40 Ma), which are attested by the age peaks of detrital zircons from Mesozoic-Cenozoic clastic rocks. The Cretaceous magma record is sparse, but Cretaceous detrital zircons are abundant (120-65 Ma, with a peak at ~90 Ma). Regarding this mismatched age record of detrital zircons and magmatic rocks, we choose the Makran forearc basin deposits as the target because it receives thick detritus from Eurasia to form a tens of kilometer thick sedimentary sequence. We conducted a detrital zircon study from the Makran to explore the magmatic evolution of the Iranian Tethys zone.Euhedral zircon grains, obvious oscillatory zoning, low zircon Th/U>0.1, and trace element geochemistry indicate Cretaceous magmatic zircons sourced from the continental magmatic arcs rather than ophiolites. Positive zircon Hf isotopes excludes the source region of the Gangdese arc which is more depleted. We further used machine learning to confirm our provenance results, that reveal Cretaceous (120-65 Ma) magmatism by the Neo-Tethys Ocean subduction in Iran.The decreasing trend of Cretaceous zircons U-Pb in Late Cretaceous to Pliocene strata indicates gradual denudation of the Cretaceous magmatic arc from deep to shallow. Cretaceous zircon peaks disappears abruptly in the Pliocene rocks, implying that the Cretaceous magmatic arc was completely denuded. Thus, we confirm that since the subduction initiation, magmatic activity was continuous in Iran but the “missing” was due to the denudation process. This works also highlights the importance of comprehensive analysis before discussing subduction geodynamics based on the record of magmatic outcrops.
Turbulent structure of CME-driven sheath regions and their role as energizing charged particles in interplanetary space
Authors: Kilpua Emilia , Good Simon , Vainio Rami , Ala-Lahti Matti , Dresing Nina , Gieseler Jan , Koikkalainen Venla , Osmane Adnane , Ruohotie Julia , Soljento Juska , Trotta Domenico , Cohen Christina , Horbury Timothy , Bale Stuart
Published: March 2024

Fast Coronal Mass Ejections (CMEs) gather compressed and heated solar wind ahead of them to for turbulent sheath regions. In this presentation we will first demonstrate with recent examples (using e.g. Parker Solar Probe and Solar Orbiter measurements) and the results from a statistical analysis (the ACE spacecraft data) that CME-driven sheath regions can significantly contribute to the acceleration of charged particles in interplanetary space, independent from the effect of the leading shock wave.  Then, we will present the key characteristics of sheath regions, e.g., variations of magnetic fied fluctuation and key turbulent properties across the sheath, that can have the key importance for the particle energization.   
The summer marine heatwaves in the North Sea in 2023
Authors: Mohamed Bayoumy , Barth Alexander , Alvera-Azcárate Aida
Published: March 2024

Marine heatwaves (MHWs) have increased worldwide in recent decades and are considered one of the most pressing challenges of climate change due to their dramatic environmental and socio-economic impacts. This study examines the occurrence of MHW in the North Sea over more than four decades (1982-2023) by analyzing the long-term trends and interannual variations of MHW characteristics. The study also investigates the role of atmospheric and large-scale climate modes on MHW generation. We find that the accelerated SST warming trend (0.38 ± 0.04 °C/decade) was accompanied by an increase in MHW frequency by 1.0± 0.3 events/decade and in MHW days by 17± 6 days/decade over the entire period. In the summer of 2023, several extreme climate events were observed worldwide, including terrestrial and oceanic heatwaves. This triggered strong media interest and public concern about the causes and links to climate change. In the North Sea, the average SST value broke the record in June and September 2023 with several extreme MHWs. In June 2023, the northwestern part of the North Sea experienced the strongest MHW since 1982, which lasted three weeks (from June 13 to July 4, 2023) and was attributed to changes in atmospheric circulation.Keywords: North Sea; SST; marine heatwaves; ERA5.
Station versus reanalysis-based proxies for the Quasi-Biennial Oscillation (QBO): How do they differ – and does it matter?
Authors: Braesicke Peter , Ertl Benjamin , Kerzenmacher Tobias
Published: March 2024

The Quasi-Biennial Oscillation (QBO) has long been recognized as an important factor shaping hemispheric large-scale dynamics, in particular serving as a sort of switch for polar vortex dynamics in the Northern Hemisphere (NH). When calculating (extratropical) correlations or composites for different phases of the QBO some subjective choices have to be made, including “Which timeseries should be used?” or “How to define the phasing?”.Here, we will examine - from a historical perspective - the differences between a traditional station based QBO timeseries (specifically, the “Singapore” zonal wind timeseries provided by the Free University of Berlin and currently continued at the Karlsruhe Institute of Technology) in contrast to reanalysis based timeseries (specifically, zonal mean zonal wind timeseries from ERA5, and near station profiles from ERA5 corresponding to the station’s location).We explore the climatological properties of the QBO, including composites and phase transitions. Additionally, we examine how the choice of QBO proxy relates to and influences the perception and interpretation of the Holton-Tan relationship, which describes the potential link between the phases of the QBO and the strength of the stratospheric polar vortex – in particular during NH winter.Data and tools are accessible via the ATMOHub at https://www.atmohub.kit.edu/.
Pore Structure Affecting the NMR Relaxation in Unsaturated porous media 
Authors: Zhou Junwen , Zhang Chi
Published: March 2024

Nuclear magnetic resonance (NMR) uniquely reveals pore water properties due to the magnetization and relaxation dynamics of water molecule hydrogen atoms. Importantly, the correlation between NMR signals (amplitude and relaxation times) and water content and distribution aids in discerning water retention patterns in porous media. While this relationship is well understood in saturated media, comprehending water dynamics under unsaturated conditions using NMR datasets is a considerable challenge, owing to the complexities of the pore environment (e.g. pore structure and interactions between different phases and components). In many previous studies, an increased amplitude of shorter relaxation T2 time distribution components has often been associated with enhanced water bound in micropores in unsaturated versus saturated media. The interpretation is counterintuitive as smaller pores cannot exceed their saturation water capacity, implying a potential misinterpretation of water distribution dynamics and pore structure within unsaturated media. To address this misinterpretation, our study develops a model to simulate the T2 peak shift from unsaturated to saturated pore states. The simulations successfully reconcile these anomalies, indicating that unsaturated macropores can display short relaxation times akin to saturated micropores and demystifying the decrease in shorter relaxation time components in T2 distributions of non-expansive, multi-pore-sized media from saturated to unsaturated states. By establishing different models to idealize pore structure characteristics (e.g. size and shape), the simulated NMR relaxation can clarify how pore structure affects the NMR relaxation, and how information about water distribution and pore structure are interpreted from NMR outcomes in unsaturated porous media.Keywords: Nuclear magnetic resonance; porous media; water distribution; pore structure
Towards Parameterizing Eddy-Mediated Transport of Circumpolar Deep Water across Antarctic Continental Slopes
Authors: Dettling Nicolas , Losch Martin , Pollmann Friederike , Kanzow Torsten
Published: March 2024

The onshore transport of warm Circumpolar Deep Water (CDW) is associated with a heat flux onto the Antarctic continental shelves and strongly contributes to Antarctic ice shelf decline. On the continental shelf of the Weddell Sea, dense water forms through interactions with sea and shelf ice and subsequently propagates down the continental slope. The descent of dense water simultaneously produces an onshore transport of CDW. Here, mesoscale eddies drive a vertical momentum flux that is necessary to overcome the potential vorticity gradient imposed by the continental slope. The resolution of current climate models, however, is too coarse to resolve the Rossby Radius of deformation at high latitudes so that eddies need to be parameterized.In an idealized model setup (MITgcm) representing the continental slope and shelf of the Weddell Sea, we show that eddy-driven shoreward CDW transport can be parameterized using the classical Gent-McWilliams and Redi (GM/Redi) parameterization for mesoscale eddies. In particular, the coarse resolution model with the GM/Redi parameterization simulates an onshore heat flux that is comparable to a high-resolution reference simulation. In contrast, no shoreward heat flux is observed without the eddy parameterization. When parameterizing eddies, the isopycnal slopes and the hydrographic mean fields also strongly improve compared to the runs without the parameterization. We further show that the parameterization works best when the GM transfer coefficient strongly decreases over the continental slope, representing the eddy-suppressive effect of steeply sloped topography. Motivated by this observation, we propose a simple modification to the GM/Redi scheme that reduces the coefficients in the presence of sloping topography. Only this „slope-aware“ version of the GM/Redi parameterization yields coefficients suitable for the continental shelf and slope and the open ocean and produces the best fit to the high-resolution model fields. We expect this addition to also be beneficial for modelling other parts of the ocean where eddy effects are moderated by topographic slopes. We therefore discuss the application of the modified parameterization to a regional model of the Cape Darnley region, East Antarctica, where dense water flows down realistic topography and drives an onshore flow of CDW at high resolution.
Laser Ranging Interferometry for the next gravity missions
Authors: Müller Vitali , Bekal Pallavi , Misfeldt Malte , Müller Laura , Sudha Reshma , Weberpals Martin , Nicklaus Kolja , Voss Kai , Heinzel Gerhard
Published: March 2024

The Laser Ranging Interferometer (LRI) on board the GRACE Follow-On spacecraft has successfully demonstrated for the first time interferometric laser ranging between satellites with a noise level below 1 nm/rtHz. In addition, the LRI’s steering mirror information provides attitude information that enable inter-comparisons with the conventional star cameras. Two new twin-satellite missions are now under development: the Next Generation Gravity Mission (NGGM) by ESA and the GRACE-C mission by a US-German partnership. Both missions rely on laser interferometry as the primary and only means of measuring the distance variations between the spacecraft.In this presentation, we introduce the measurement concept and design principles, report on the current status of the ranging instruments and explain the changes to be implemented with respect to GRACE-FO, mainly related to redundancy and lessons learned.
In-situ sample handling and chemical analysis of lunar regolith by laser ablation ionisation mass spectrometry
Authors: Keresztes Schmidt Peter , Boeren Nikita J. , Gruchola Salome , Tulej Marek , Riedo Andreas , Wurz Peter
Published: March 2024

With NASA's emphasis on lunar exploration through the Artemis program, novel scientific objectives have been formulated to enhance our understanding of the Solar System's historical context, particularly the evolution of the Earth-Moon system. Simultaneously, the establishment of a permanent human presence on the Moon is proposed as a primary objective within the Artemis program, with the achievement of this goal hinging on in-situ resource utilization (ISRU) of lunar materials. Effective ISRU needs methodologies for chemical analysis and selecting appropriate lunar materials in-situ. To facilitate these tasks, the deployment of sensitive instrumentation capable of determining the element and isotope composition of lunar materials is imperative.In this contribution, we present the current progress in developing a reflectron-type time-of-flight laser ablation ionisation mass spectrometer (RTOF-LIMS) to allow for direct sensitive chemical microanalysis of lunar regolith grains in-situ on the lunar surface. This LIMS system will operate in the lunar south pole region on a CLPS mission within NASA’s Artemis program.The contribution will provide a general overview of the instrument and focus primarily on the design and operations of the sample handling system (SHS). Furthermore, we will discuss the results of experiments conducted on lunar regolith simulant. These experiments were performed using a prototype LIMS system to validate the feasibility of the SHS. This prototype system has capabilities representative of the flight instrument currently in development regarding the mass analyser and optical sub-system. The laboratory and flight optical sub-systems are based on a microchip Nd:YAG laser system (~ 1.5 ns pulse width, λ = 532 nm, 100 Hz laser pulse repetition rate, laser irradiance ~ 1 GW/cm2), and custom-made laser optics to achieve a focal spot on the sample surface of ~20 μm. Consequently, the conducted measurements can serve as a qualification baseline for the flight instrument during ground-based tests.(1) P. Keresztes Schmidt et al., Sample handling concept for in-situ lunar regolith analysis by laser-based mass spectrometry, IEEE Aerospace Conference, 2024, submitted(2) P. Wurz et al., In Situ Lunar Regolith Analysis by Laser-Based Mass Spectrometry, IEEE Aerospace Conference, 2023, 1-10(3) P. Keresztes Schmidt, A. Riedo, P. Wurz, Chimia 2022, 76, 257(4) A. Riedo, A. Bieler, M. Neuland, M. Tulej and P. Wurz, J. Mass Spectrom., 2013, 48, 1-15(5) P. Wurz, M. Tulej, A. Riedo, V. Grimaudo, R. Lukmanov, and N. Thomas, IEEE Aerospace Conference, 2021, 50100, 1-15.
Improving the effectiveness of citizen science projects for environmental monitoring through the targeted activation of selected stakeholder groups
Authors: Koedel Uta , Schuetze Sofia , Liang Christine , Hermann Thora , Dietrich Peter , Schuetze Claudia
Published: March 2024

The understanding the motivations and benefits of potentially participating individuals in citizen science (CS) is a key element in the success of CS projects This knowledge is essential for developing effective strategies to recruit, engage and retain CS participants, and ultimately to increase the data quality in environmental science projects. Marketing tools such as stakeholder analysis and Value Proposition Canvas (VPC) are recognised as valuable tools in CS. Similar to a customer-focused approach in a business context, these tools are able to improve the efficiency, effectiveness, engagement and evaluation of CS initiatives, when integrated into recruitment and communication processes. The presented poster highlights the use of quantitative measures, specifically key performance indicators (KPI's), to measure inputs, activities and outputs in CS projects. KPIs provide quantitative evidence of project success and play a critical role in helping stakeholders trust the reliability of citizen science data. The poster presentation shows the applicability of marketing tools in CS projects using exemplarily a case study focusing on the observation of urban climate effects. By involving diverse groups and taking into account their everyday activities, CS projects can broaden their data sources and increase their impact. It also highlights the need for continuous adaptation to ensure the relevance and success of CS initiatives, as future analyses of urban climate impacts may require targeting new groups to fill data gaps.
Surface deformation along the Nile Delta, Egypt: From monitoring towards prediction
Authors: Zaki Amira , Manzella Irene , Lazecky Milan , Hooper Andy , Chang Ling , Meijde Mark van der , Fadel Islam
Published: March 2024

The Nile Delta represents the most critical part of Egypt, hosting more than 50% of the population and approximately two-thirds of the nation’s agricultural lands. During the last decades, the Nile Delta has suffered from significant surface deformation that has led to damage to transport networks and infrastructures, thus becoming a significant risk in the area. This deformation is mainly due to environmental changes and anthropogenic activities such as the over-extraction of groundwater for different purposes and the building of dams inside and outside Egypt along the river Nile. These activities have led to shortage of water inflow, changing the discharge rates, reduced sedimentation in the delta and changes in the water recharge rates of the Nile, the primary source of water for the Nile Delta aquifers. Regarding the environmental changes, the shifts in climate patterns, including variations in precipitation, rising temperatures, and rising sea levels, have all altered the hydrological balance of the Nile Delta, consequently leading to variations in surface deformation patterns. Many studies have studied the rate and patterns of land deformations in the Nile Delta based on geodetic tools such as Global Positioning System (GPS) and Interferometric Synthetic Aperture Radar (InSAR). But still, there is a gap in understanding the relationship between surface deformation rates and the causative factors. Such understanding could potentially enable the estimation of system response for future scenarios.In this research, we present the results of a system that uses Sentinel-1 SAR data characterized by VV polarization, with ascending and descending orbital directions, acquired between 2015 and 2023 along the Nile Delta. We utilized open-source LiCSBAS tools to analyze the surface deformation rates from InSAR Sentinel-1 data. Then, we calculated the vertical deformation velocity over time by decomposing the ascending and descending LOS data. Then, we analyzed the surface deformation results obtained with the present methodology against the freely available geospatial data, which represents the possible causative factors (such as rainfall, water body change, total terrestrial water storage, land use-landcover, temperature, etc.), to understand their relations and their impact. By linking the surface deformation to its causative factors through machine learning techniques such as Random Forest, our research aims to provide a better understanding of the system dynamics and an appropriate model for prediction. This model can be utilized by decision-makers to consider and manage risks associated with severe surface deformation for possible future scenarios. The results should enable the design of future mitigation actions to protect Egyptian society and make it more resilient to the consequences of land deformation over the Nile Delta.
Improvement of ONERA Electrostatically suspended torsion pendulum
Authors: Portier Nolwenn , Christophe Bruno , Dalin Marine , Lebat Vincent , Liorzou Françoise , Rodrigues Manuel
Published: March 2024

In order to meet the objectives of the Next Generation Gravity Mission (NGGM), the French Aerospace Lab ONERA is developing a new accelerometer concept MicroSTAR with three sensitive linear and three true angular acceleration measurements (Dalin et al., session G4). This instrument benefits from previous developed accelerometers which flew in the well-known gravity space missions: CHAMP, GRACE, GOCE, GRACE-FO.The principle of operation of these accelerometers is to maintain motionless a proof-mass with respect to the surrounding electrodes using a control loop. The applied electrostatic forces needed for this control, are proportional to the accelerations suffered by the proof-mass. The proof-mass is polarized with a very thin (few micrometer) wire in order to measure precisely its position by capacitive detection with the electrodes and to avoid charging in orbit. The stiffness and damping induced by the polarization wire impact the performance of the accelerometer at low frequencies. To quantify on-ground the performance limitation due to the wire, an electrostatically suspended torsion pendulum (PTSE) is used (Willemenot 1997, Willemenot and Touboul 2000).The PTSE is a six-axes servo-controlled accelerometer, optimized for the measurement of angular accelerations about the vertical axis. The torque noise spectral density is 1.3 10-14 Nm/√Hz  around 0.05 Hz with a 1/√f increase at lower frequency, corresponding to 10-8 rad/s²/√Hz , and 2 10-10 ms-2/√Hz with a lever arm of 2cm. For instance, regarding a gold wire of 7.5µm diameter and 1.7cm length, we use it to measure theoretical stiffness of 2.5 10-5 N/m i.e. a torsion of 10-8 Nm/rad. In our presentation, this instrument will be described before sharing ideas for its improvement. Willemenot, P. Touboul; Electrostatically suspended torsion pendulum. Rev Sci Instrum 1 January 2000a; 71 (1): 310–314. https://doi.org/10.1063/1.1150198Willemenot, P. Touboul; On-ground investigation of space accelerometers noise with an electrostatic torsion pendulum. Rev Sci Instrum 1 January 2000b ; 71 (1): 302–309. https://doi.org/10.1063/1.1150197Willemenot, Pendule de torsion à suspension électrostatique, très hautes résolutions des accéléromètres spatiaux pour la physique fondamentale. Ph.D. thesis, Université Paris 11, France, 1997
Strategies for assimilating GRACE/-FO terrestrial water storage anomalies into hydrological models
Authors: Springer Anne , Ewerdwalbesloh Yorck , Gerdener Helena , Schulze Kerstin , Kusche Jürgen
Published: March 2024

After more than 15 years of experience with GRACE/-FO data assimilation (DA) into hydrological models, numerous studies have conducted various tests on GRACE product and preprocessing options as well as DA strategies. However, a commonly accepted standard procedure has yet to emerge. This contribution comprises (1) a review on the prevalence of GRACE-DA options based on existing studies together with (2) insights from applying two GRACE assimilating frameworks: the high-resolution CLM-DA framework over Europe and the global WGHM-based calibration and data assimilation framework.We discuss the selection of different GRACE/-FO products for DA into hydrological models, including spherical harmonics, MASCONS, level 3 products, and the recently evolved along-orbit line-of-sight gravity differences. Additionally, we explore processing choices such as filtering and rescaling, possible corrections for phenomena like glacial isostatic adjustment, large lakes and reservoirs or earthquakes, observation grid representation, and various approaches to handle observation errors. We evaluate the impact of these processing strategies on simulated water storage trends and the representation of selected extreme events.Through this research, we contribute to understanding optimal strategies in assimilating GRACE/-FO data, addressing critical aspects influencing hydrological model reliability.
Chlorophyll-a satellite climate time series: How machine learning can help distinguish between bias and consistency
Authors: Pauthenet Etienne , Martinez Elodie , Gorgues Thomas , Roussillon Joana , Drumetz Lucas , Fablet Ronan , Roux Maïlys
Published: March 2024

Phytoplankton sustains marine ecosystems and influences global carbon dioxide levels through photosynthesis. To grow, phytoplankton rely on nutrient availability in the upper sunlit layer, closely related to ocean dynamics and specifically ocean stratification. Human-caused climate change is responsible, among others, for an increase in global temperature and regional modifications of winds, thus affecting the stratification of the ocean's surface. Consequently, phytoplankton biomass is expected to be impacted by these environmental changes. While most existing studies focus on one or two satellite products to investigate phytoplankton trends in the global ocean, in this study, we analyze surface chlorophyll-a concentration (chl-a), a proxy for phytoplankton biomass, using six merged satellite products from January 1998 to December 2020. Significant regional discrepancies are observed among the different products, displaying opposing trends. To distinguish trends arising from changes in the physical ocean from those potentially resulting from sensor biases, a convolutional neural network is employed to examine the relationship between chl-a and physical ocean variables (sea surface temperature, sea surface height, sea surface currents, wind, and solar radiation). The training is conducted over 2002-2009 when the number of merged sensors is constant, and chl-a is reconstructed over 2010-2020. Our results suggest that the merging algorithm of the Globcolour Garver, Siegel, Maritorena (GSM) bio-optical model is not reliable for trend detection. Specifically, changes in chl-a after 2016 are not supported by changes in the physical ocean but rather by the introduction of the VIIRS sensor. These results emphasize the need for a careful interpretation of chl-a trends and highlight the potential of machine learning to study the evolution of marine ecosystems.
Effects of root-derived organic acids on sorption of pharmaceuticals in cultivated sandy soil
Authors: Szabó Lili , Vancsik Anna , Bauer László , Kondor Attila Csaba , Jakab Gergely , Szalai Zoltán
Published: March 2024

Pharmaceutically active compounds (PhACs) in cultivated areas have become an important issue and have received significant public attention because of their availability to plants during nutrient uptake. This study highlights the effects of low-molecular-weight organic acids (LWMOAs) generated in the root environment on the sorption processes of PhACs in cultivated sandy soil. Sorption experiments are conducted using three PhACs characterised by different physicochemical properties: carbamazepine (CBZ), 17α-ethynylestradiol (EE2), and diclofenac-sodium (DFC). The results suggest that the adsorption of EE2 is more intense than the other two PhACs, whereas DFC and CBZ are primarily dominated by desorption. Additionally, LMWOAs mainly provide additional low-energy adsorption sites for the PhACs, and slight pH changes do no significantly affect the sorption mechanism. During competitive adsorption, the high-energy sites of the adsorbents are initially occupied by EE2 owing to its high adsorption energy. In addition, during multicomponent adsorption, new low-energy binding sites enhance the adsorption of DFC and CBZ. Our results show that LMWOAs promoted the adsorption of PhACs into the root environment, thus rendering PhACs available to plants.This research was supported by the National Research, Development, and Innovation Office (NKFIH), Hungary (project identification number: 2020–1.1.2-PIACI-KFI-2021-00309; 2021–1.2.4-TÉT-2021-00029, and K-142865). Project no. KDP-1015196 has been implemented with the support provided by the Ministry of Culture and Innovation of Hungary from the National Research, Development and Innovation Fund, financed under the KDP-2020 funding scheme. This study has also been supported by the Doctoral Excellence Program (DKOP-23) of the Ministry for Culture and Innovation, Hungary, from the source of the National Research, Development and Innovation Fund.
Monitoring and Benchmarking of Earth System Model Simulations with ESMValTool
Authors: Schlund Manuel , Lauer Axel , Bock Lisa , Hassler Birgit
Published: March 2024

Earth system models (ESMs) are important tools to improve our understanding of present-day climate and to project climate change under different plausible future scenarios. For this, ESMs are continuously improved and extended resulting in more complex models. Particularly during the model development phase, it is important to continuously monitor how well the historical climate is reproduced and to systematically analyze, evaluate, understand, and document possible shortcomings. For this, putting model biases relative to observations into the context of deviations shown by other state-of-the-art models greatly helps to assess which biases need to be addressed with higher priority. Here, we introduce the new capability of the Earth System Model Evaluation Tool (ESMValTool) to monitor running or benchmark existing simulations with observations in the context of results from the Coupled Model Intercomparison Project (CMIP). ESMValTool is an open-source community-developed diagnostics and performance metrics tool for the evaluation and analysis of ESMs. To benchmark model output, ESMValTool calculates metrics such as root mean square error (RMSE) or the coefficient of determination (R2) relative to reference datasets. This is directly compared to the same metric calculated for an ensemble of models such as CMIP6, which provides a statistical measure for the range of values that can be considered typical for state-of-the-art models. Results are displayed in different types of plots such as map plots (using stippling and hatching) or time series (via uncertainty bands). Automatic downloading of CMIP results from the Earth System Grid Federation (ESGF) makes application of ESMValTool for benchmarking of individual model simulations, for example in preparation of CMIP7, easy and very user friendly.
A GPS hydro-geodesy dataset for monitoring changes in terrestrial water storage during drought and flood periods in California: assessment, validation, and application
Authors: Ding Xin , Li Zhao , Jiang Weiping
Published: March 2024

The continuously distributed changes in water storage in hydrosphere deform the shape of the Earth’s surface, which can be recorded by GPS position time series. However, GPS stations that exhibit poroelastic behavior located on aquifer systems are excluded from largely previous studies so that terrestrial water storage variations can be estimated by elastic loading, which leads to biases in results. We proposed a novel approach to classify GPS stations whose vertical displacement time series are significantly correlated with hydrological loading variations to construct hydro-geodesy datasets, including elastic response (positive), poroelastic response (negative), and aquifer compaction. Using the wavelet analysis method, we further identified 569 GPS vertical displacement time series from California provided by the Nevada Geodetic Laboratory between 2007 and 2017 into the pre-defined temporal-scales of long-term, seasonal, and short-term. We calculated and evaluated elastic deformation induced by hydrological loading variations, including GRACE, WaterGAP, GLDAS, NLDAS, ERA5, and ERA5-land, and the HYDL product provided by GFZ. The results show that most/several GPS stations located outside/within the Central Valley are under the control of the elastic response. We also used a poroelastic half-space model to validate that most GPS stations located within the Central Valley are simultaneously affected by surface subsidence and controlled by poroelastic response. Our results show that the hydro-geodetic datasets we constructed enable the use of previously and widely neglected GPS stations, such as those that may observe poroelastic response and those affected by surface subsidence, to accurately monitor changes in terrestrial water storage during droughts and floods.
3D Least-squares Migration of Receiver Function
Authors: Zuo Pengfei , Chen Yunfeng
Published: March 2024

Receiver function (RF) imaging is a crucial method that employs converted teleseismic waves to characterize discontinuities in the Earth's interior. The proliferation of dense areal seismic arrays has necessitated developing advanced imaging techniques to effectively utilize the increasing seismic data. In this study, we develop a 3D regularized least-squares migration (LSM) method for RF imaging, which allows for imaging subsurface structures using teleseismic waves incident from arbitrary directions. We employ the Split-step Fourier algorithm to solve the acoustic wave equation, resulting in the construction of forward and adjoint operators for wavefield propagation. These operators facilitate the transformation of the seismic migration into an inverse problem in a least-squares sense, which enables suppressing the strong acquisition footprints and compensating for inadequate illumination. Tikhonov regularization is performed to generate preconditioned images with higher resolution than standard migration algorithms. To assess the performance of the proposed method, we conduct synthetic experiments by simulating teleseismic recordings using the SPECFEM3D code. The input model incorporates undulated and step Moho interfaces. The obtained migration images demonstrate that the capability of the developed LSM method to accurately recovers the 3D geometry of the Moho interfaces. The current study only considers the P-to-S converted waves, and future research will focus on utilizing free-surface multiples to obtain higher-resolution subsurface structures.
How much microplastic reaches the stratosphere? The example of road traffic-related emissions
Authors: Tatsii Daria , Evangelou Ioanna , Bucci Silvia , Bakels Lucie , Stohl Andreas
Published: March 2024

Depending on their size and shape, microplastic particles have the potential to be transported over great distances in the atmosphere, both vertically and horizontally. Recent studies have shown that they can even reach the stratosphere. However, there is a lack of information on the distribution and amount of microplastics in the stratosphere.Here, we estimate how much of microplastics from the second largest primary source can be found in the stratosphere. To investigate this, we use global road traffic-related emissions of microplastics - from tyres, road markings and polymer-modified bitumen - to simulate the atmospheric transport of particles of different sizes and spherical and cylindrical shapes using the Lagrangian particle dispersion model FLEXPART (Pisso et. al, 2019).When exposed to the ultraviolet (UV) light, microplastic particles degrade and can release halogen-containing gases such as chlorine and bromine. Forexample, neoprene, aka polychloroprene, which is present in tyres, contains around 40% chlorine by weight.The released bromine and chlorine compounds could be involved in the catalytic destruction of ozone, similar to the release of chlorofluorocarbons andhalons under the Montreal Protocol. Therefore, in addition to quantifying the amount of microplastics reaching the stratosphere, we also estimate the amount of chlorine and bromine that can potentially be released during UV degradation of microplastics.
Assessing earthquake focal mechanisms in the North Sea for risk mitigation of large-scale CO2 injections
Authors: Martuganova Evgeniia , Naranjo Hernandez David F. , Kühn Daniela , Barnhoorn Auke
Published: March 2024

Decarbonisation of the European economy represents one of the current challenges to both society and the energy sector. The advancement and further application of carbon capture and sequestration (CCS) technologies are crucial components of the EU’s effort to become climate-neutral by 2050. The success of CCS depends heavily on understanding the present-day stress field to anticipate reservoir and cap rock response to fluid injection. Despite its importance, many proposed carbon storage sites in the North Sea are located in areas with little to no borehole stress data available, presenting a significant challenge.Within the ACT project SHARP Storage framework, we have addressed this gap by generating a comprehensive earthquake bulletin for the North Sea, revealing spatial clusters of seismic events with the majority of earthquakes with ML < 4. Focal mechanisms of earthquakes are excellent indicators of crustal dynamics, which are essential for assessing the present-day stress field. Therefore, to improve the understanding of the in-situ stress conditions, we created a comprehensive workflow to evaluate focal mechanisms based on data from the North Sea (Kettlety et al., 2023). First, we developed a routine for the seismological bulletin to aggregate the recorded earthquakes from international seismological centres. The following step included retrieval of the waveforms from data centres and quality control routines, which included dead channels check, exclusion of files with significant recording gaps and low signal-to-noise ratio, and corrections of errors in the station XML files. Then, a subset of data traces with sufficient quality was selected for moment tensor computations using a Bayesian bootstrap-based probabilistic inversion scheme (see Heimann et al., 2018). Using existing focal mechanism solutions for the North Sea region, we calibrated our processing routine and then applied it to selected earthquakes (after 1990, M > 3.5) to expand the existing focal mechanisms database.The newly computed focal mechanism solutions provide valuable insight into the present-day stress field in areas outside the main hydrocarbon provinces and improve the risk assessment of ongoing and future CCS projects. Furthermore, we will release our processing workflow as an open-source package and a new focal mechanisms database of the North Sea to establish a standard processing routine that can be readily utilised for similar seismological studies.
Passive seismic imaging for CO2 geological storage in the Sudret area of Gotland, Sweden
Authors: Wang Zhihui , Juhlin Christopher , Hedin Peter , Erlström Mikael , Sopher Daniel
Published: March 2024

Carbon capture and storage (CCS) is a strategy that can be employed to reducing human impact on climate change In the 21st century. Geological storage has been currently considered the most promising strategy. It is reported that there is a large theoretical capacity to store CO2 in the Precambrian sedimentary succession of the Baltic Basin. To aid in surveying and evaluating the potential storage reservoirs in the Baltic Sea, a seismic survey was performed over similar geology in the Sudret area of Gotland. Part of the survey consisted of 14-hours passive data, recorded along a 2.8 km profile with 10m receiver spacing and 1ms sample rate using 329 5Hz SmartSolo nodal units in the vicinity of two boreholes that had been drilled earlier. We retrieved body wave and surface wave virtual shot gathers after applying signal separation and cross correlation calculations. For the body waves, conventional seismic data processing was conducted to obtain a stacked profile; for the surface waves, we could determine the dispersion curve in the frequency range 0.5 to 5.5 Hz and inverted these curves to obtain a velocity model from the ground surface down to c. 1500m depth. Both the body waves and surface waves provide a high quality and high resolution image of the top of the Ordovician formation and have a good consistency with active seismic data in the same location. Moreover, they revealed some reliable deep geological information which active data cannot provide because of the limited source energy. Compared with active seismic exploration, passive seismic is friendly to the environment and cost effective. In some cases, it is an important complementary or alternative method to active seismic for CO2 storage and monitoring.
Tectonic geomorphology and morphostratigraphy applied to the study of the evolution of fault systems at different scales
Authors: Racano Simone , van der Beek Peter , Schildgen Taylor , Buleo Tebar Victor , Bonasera Mauro , Cosentino Domenico , Tallini Marco
Published: March 2024

In active tectonic areas, fault systems represent one of the main structural elements in shaping landscapes. Thus, the study and dating of landforms and continental deposits affected by tectonic deformation, such as river profiles and knickpoints, paleosurfaces, strath and alluvial terraces, are crucial to assess the activity state of the faults and how they evolved over time. Some features may provide a time-averaged history of deformation (e.g., deformed geomorphic markers), while others have the potential to record a continuous history of deformation (e.g., rock-uplift histories from inversions of river profiles). In this work, we present three case studies where we reconstruct the history and characteristics of fault systems at different scales through a combination of geomorphological and morphostratigraphical analyses. At a regional scale, we present the case study of the North Anatolian Fault (NAF). We reconstructed a spatio-temporal history of rock-uplift by inverting river profiles from 19 different catchments draining the northern part of the Central Pontides, a mountain belt uplifted by the transpression produced by the NAF. We found that uplift migrated westward over time, and combining our results with other published data, we proposed a model describing the age and propagation rates of the NAF from the nucleation point in the Eastern Pontides to the Marmara Sea. The second case study investigates, at a meso-scale, the Quaternary evolution of the northwestern sector of the Apennine Chain (Italy). By combining the rock-uplift history inferred from the inversion of river profiles from 6 catchments draining the Apennine Belt and the morphostratigraphy of the youngest marine units uplifted during the Pliocene in the Po Plain, we inferred the main activity phases of the thrust-top/compressive arc system of the Alessandria Basin and Monferrato Arc, one of the outermost arcs of the northern Apennines. The third case study is a local investigation into identifying the master faults in the Aterno River Valley, one of the most active tectonic intramontane basins in the Central Apennines (Italy). Because the tectonic complexity of the area makes it unsuitable for reconstructing a continuous deformation history by the inversion of river profiles, we applied a different approach by combining the deformation of dated paleosurfaces and fluvial terraces with the present characteristics of the topography (slope, relief, present elevation of deformed paleosurfaces and terraces) and drainage system (channel steepness index, knickpoints). We identified two opposite fault segments (Monte Marine Fault in the Upper Aterno Valley and Bazzano-Monticchio-Fossa Fault in the Lower Aterno Valley), respectively dipping SW and NE, representing the master faults of two different half-grabens.
Unraveling anthropogenic impact on Mawmluh Cave Speleothems: Insights from high-resolution analysis of aragonite formations
Authors: Dildi Dildi , Weber Michael , Vonhof Hubert B. , Scholz Denis
Published: March 2024

Geochemical anomalies within speleothems serve as crucial indicators of environmental changes. While research predominantly focuses on calcite-dominated formations, understanding the significance of aragonite is essential for a comprehensive grasp of past climate dynamics. This study presents high-resolution records, based on 230Th/U dating, stable isotopes (δ13C) and trace elements analysis in recent aragonite growth lamina near the calcite top in three speleothems from Mawmluh Cave, Meghalaya, India. Covering a total of 163 years (2022 to 1859 CE), the research explores the environmental impact on the cave system, especially in relation to nearby industrial activities. Laser Ablation-Inductively Coupled Plasma Mass Spectrometry (LA-ICP-MS) was utilized to analyze trace elements (e.g., Mg, Sr, Ba, U, P, Y, Pb, Al, Th, etc.) in the recent aragonite growth lamina. Detected trace elements (Pb, Zn, Mn, etc.) at trace concentrations, alongside current δ13C values, may be linked to emissions from a nearby cement plant and open-cast mining activities, acting as potential indicators of anthropogenic influence. All three speleothems displayed transitions from calcite to aragonite near the top, suggesting a significant alteration in the cave system over time, potentially induced by human activities. Anthropogenic factors may contribute to this transition, with specific elements acting as key markers. Future studies on the geochemical signatures of aragonite formations promise to fill existing gaps, offering a nuanced perspective on paleoclimatic and paleoenvironmental conditions.Keywords: speleothems, aragonite formations, trace elements, stable isotopes, anthropogenic impact, Mawmluh Cave.