bluuebunny/crossref_metadata_2025 huggingface dataset:
Multidecadal Variability of Ocean Climate and Circulation of the North Atlantic Ocean
Authors: Mishonov Alexey , Seidov Dan , Reagan James
Published: March 2024

The North Atlantic's surface has been heating up for decades. There was concern that the thermohaline circulation and essential climate variables, such as the seawater temperature and salinity, could endure substantial changes in response to this surface warming. The Atlantic Meridional Overturning Circulation (AMOC) has changed noticeably over the last century and possibly slowed down in recent decades. Therefore, concerns about the trajectory of the North Atlantic Ocean climate are warranted. The key to understanding the North Atlantic current climate trajectory is to identify how the decadal climate responds to ongoing surface warming.  We address this issue using objectively analyzed in-situ data from the World Ocean Atlas covering 1955-2017 and from the Simple Ocean Data Assimilation reanalysis data for 1980-2019 as fingerprints of the North Atlantic three-dimensional circulation and AMOC’s dynamics. We have found that although the entire North Atlantic is systematically warming, the climate trajectories in different sub-regions of the North Atlantic reveal diverse regional decadal variability, although the thermohaline geostrophic circulation in the North Atlantic during the most recent decade has slowed down. The warming trends in the subpolar North Atlantic lag behind the subtropical gyre and Nordic Seas warming by at least a decade. The climate and circulation in the North Atlantic remained steady from 1955 to 1994, while the last two decades (1995-2017) demonstrated a noticeable reduction in AMOC strength, which may be closely linked to changes in the geometry and strength of the Gulf Stream system.
An introduction to the concept of Zoohydrology – the interactions between hydrological processes and wild animals
Authors: Cromsigt Joris , Larsen Annegret , Griffioen Jasper
Published: March 2024

Ecohydrology describes the effects of hydrological processes on ecosystem structure and functioning and the effects of biotic processes on hydrological processes. Recently, there is an increasing emphasis on the role of megafauna, large mammals and birds, on earth system processes, such as nutrient cycling, energy flows and vegetation patterns. Ecohydrology as a field, however, has not yet considered megafauna as central drivers of hydrological processes but focused strongly on the interactions between hydrological processes and plants and soils. Here, we introduce zoohydrology to emphasize the importance of considering the interactions between wild animals and hydrological processes. This includes both the effects of hydrological processes on the occurrence, behavior and life history of animals as well as the effects animals have on hydrology. In this introductory talk, we will outline different pathways through which hydrology affects megafauna and through which megafauna affect hydrological processes using a systems approach. We will illustrate these pathways with concrete examples from different parts of the world and on different species. For example, the importance of hydrological processes and hydromorpho-dynamics for shaping habitats of endangered species, such as the Ganges freshwater dolphin and Bengal tigers in northern India and Nepal, but also for structuring megafauna community dynamics, such as the example of Gorongosa National Park in Mozambique. We will also exemplify how wild animals can affect central hydrological processes in diverse ways; directly (e.g., species such as beaver and hippo as ecosystem engineers of aquatic systems) and indirectly (e.g., elephants that reduce woody cover at large scales, affecting evapotranspiration). Many effects of animals on hydrological processes remain understudied and are often lacking from hydrological models. By introducing the concept of zoohydrology, we stress the potentially pivotal interactions between central hydrological processes, wild animals and their habitats. To unravel the full complexity of these interactions and assess their true importance, zoohydrology must be advocated among scientists, policy makers and practitioners in order to better address biodiversity conservation and restoration, make the concept of environmental flow needs more concrete, and investigate the consequences of biodiversity restoration on hydrological systems.
Estimating runoff from pan-Arctic basins through an improved runoff-storage relationship using satellite gravimetry in the GRACE period 2002-2019
Authors: Sneeuw Nico , Yi Shuang , Saemian Peyman , Tourian Mohammad J.
Published: March 2024

Spaceborne gravimetry is the only satellite method that can observe terrestrial water storage at a continental scale. The time variable gravity field, observed by GRACE and GRACE-FO, is a measure of mass transport primarily in the global water cycle. In this contribution we analyse the runoff-storage relationship in the GRACE time frame for the pan-Arctic drainage basins. Over these boreal catchments, the conventional hysteresis-type formulation requires algorithmic adaptations in order to accommodate snowload and base-flow during winter periods. We show that the parameters involved in the pan-Arctic runoff-storage relationships are transferable, albeit with a few exceptions, between the various catchments. This remarkable fact allows us access to determining runoff from ungauged drainage areas across the pan-Arctic. As a result we can quantify the total freshwater flux from pan-Arctic basins into the Arctic Ocean.
Glacier point mass balance modeling using machine learning
Authors: van der Meer Marijn , Zekollari Harry , Huss Matthias , Bolibar Jordi , Hauknes Sjursen Kamilla , Farinotti Daniel
Published: March 2024

Estimations of glacier mass balance are commonly made using field techniques, empirical or physically based models, and remote sensing. More recently, data-driven tools like machine learning have become powerful complements to these conventional techniques. This study explores the potential of using machine learning to simulate the individual point mass balance of 30 sites from 13 glaciers in Switzerland spanning over 60 years, sourced from the Glacier Monitoring Switzerland (GLAMOS) network. To this end, we use two machine-learning models: LASSO regression, a linear regression model with L1-regularisation, and eXtreme Gradient Boosting (XGBoost), a gradient-boosted ensemble of decision trees. The models are driven by temperature and precipitation data at 1 km grid resolution from the Federal Office of Meteorology and Climatology (MeteoSwiss). The seasonal point mass balance data are used to train and test the models for each site individually. A comparative analysis is performed in which the performance of the LASSO regression and XGBoost are compared to a standard approach of calculating mass balance from a temperature-index model. In this analysis, we also explore how different temporal frequencies of climate variables, ranging from annual to monthly, affect the performance of the machine learning methods. Beyond their computational efficiency, these machine learning models are particularly suited to provide valuable insights into feature importance. Harnessing this, we study which months’ temperature and precipitation most significantly contribute to explaining individual stake mass balances and compare these findings with commonly assumed drivers of mass balance.
Development of a water storage toolbox for surface-induced near-nature managed groundwater recharge
Authors: Stautzebach Jan , Steidl Jörg , Merz Christoph
Published: March 2024

Water stress is increasing in Northeast Germany due to climate change. New approaches for water management are needed to mitigate the impacts on the water resources. Therefore, our study deals with the development of a web-based toolbox to manage subsurface water storage by artificial groundwater recharge with focus on the lower catchment of the river Spree in the federal state of Brandenburg.Our approach is based on a systematic combination of site selection criteria and spatial data on land use, soil, groundwater and potential water sources. The aim is to provide relevant information for the preliminary planning of managed groundwater recharge measures by authorities and water suppliers. This includes a wide range of project scales that can be covered by the tool. However, as necessary volumes for large scale recharge projects are unlikely to be found in concentrated form, small scale projects with low demand of infrastructure and energy, are of main concern. Considering surpluses from runoff and surface waters, also caused by extreme weather events, suitable locations for surface-induced recharge will be identified. Thereby, solutions with low environmental impact, like the use of natural depressions for recharge, are highlighted to the user. This will allow for a stabilization of the local water balance, induced by a large number of low impact measures.Supported by additional modelling-based indications for implementation, efficiency and costs, as well as simplified site selection through a query system, the toolbox will offer an initial knowledge for such planning considerations.
Earth-like planets hosting systems: architectures and properties
Authors: Davoult Jeanne , Alibert Yann
Published: March 2024

The search for Earth-like planets is a subject of great importance in the world of planetology today. Detecting such planets is challenging and requires a great deal of observation time. With future missions such as PLATO or LIFE, one of the main objectives of which is to detect small, moderate-temperature planets like the Earth, it is important to understand in what types of systems these plants form and around which stars we can expect to detect them. We present here a theoretical statistical study of the most favorable conditions for a planetary system to host an ELP (Earth-like planet). Based on three populations of synthetic planetary systems generated using the Bern model around three different types of stars, this study aims to create a profile of a typical system that harbors an ELP. By using an observational bias, we generate new populations that can be compared to observed systems. We initially examine the distribution of ELPs across different categories of theoretical and observed architectures. The changes in architecture resulting from the application of a bias are also investigated, highlighting the relationship between "theoretical" and "biased" architectures. A more detailed analysis is then conducted, linking the “biased” architecture of a system with the physical properties of its innermost observable planet, in order to establish the most favorable conditions for the presence or absence of an ELP in a system. Several quantities, such as the mass, radius, period and water fraction of this planet, emerge as correlated with the presence or the absence of an ELP.
Volcanic-hosted Be-(Li-F-REEs-U) mineralization at the world-class Spor Mountain deposit, Utah, USA: Insights into source rocks, geochemical signatures, and macro-to-microscale concentration processes
Authors: Foley Nora K. , Ayuso Robert A. , Jackson John C. , Indela Rani , Bickerstaff Damon P.
Published: March 2024

Beryllium (Be) is among the most important rare metals in the world and is used to produce complex alloys and ceramics critical for the telecommunication, aerospace, medical, and defense industries. Global Be supplies are primarily obtained from bertrandite [Be4Si2O7(OH)2] mined from the Spor Mountain deposit, Utah, U.S.A, in a region dominated by Miocene-Oligocene alkaline rhyolitic tuffs and lavas. Ore occurs primarily in lithic-rich, phreatomagmatic, base-surge deposits containing carbonate debris in a basal tuff. The tuff is part of a package of rare-metal-rich rhyolite lava flows, pyroclastic deposits, and discordant fluorite-bearing pipes. Pb-Nd-Sr isotope and trace element data, together with mineral associations (1) map the flux of Be, Li, F, REEs, and U in the magmatic-to-hydrothermal system, (2) reveal the role of fluid-rock interactions and recrystallization processes in concentrating metals, and (3) place constraints on timescales of bertrandite-fluorite-opal precipitation. Geochemical models indicate that high-grade ore formed under pH-buffered conditions when F-rich fluids leached metals from glassy tuff, reacted with carbonate xenoliths, and deposited Be and other rare metals in complexly layered nodules composed of Mn-oxide, Li-smectite, calcite, fluorite, opal, and bertrandite. U-Pb age dates and coupled 29-element analyses of discrete opal layers by the SHRIMP-RG method show an almost continuous record of opal deposition. The results establish timescales of high-grade opaline ore formation with major influxes of Be, F, REEs, and Li from ~16 Ma to 10 Ma and of Mn and U at
Poleward expansion of North Pacific gyres circulation during the warm early Eocene inferred from inter-model comparisons
Authors: Zhang Yurui , M. de Boer Agatha
Published: March 2024

The larger-scale oceanic gyre circulation regulates temperature, salinity and nutrient flow throughout the ocean, profoundly influencing the biological environment and climate. Here, we investigate the response of the Pacific gyre circulation during the warm climate of the early Eocene in eight models from the Deep-Time model intercomparsion project (DeepMIP). Our DeepMIP results suggest a northward expansion of the North Pacific subtropical gyre by up to 10 degrees latitude in the Eocene, maintaining a similar strength to the present day. This simulated poleward expansion of the North Pacific gyre circulation is corroborated by proxy evidence, including poleward shifts in low sedimentation rate and high clay concentration during the Eocene. In the southern Pacific, the super subtropical gyre is much stronger during the Eocene due to the southward position of Australia that leads to a wide-open Indonesian gateway. The poleward shifted boundary between the subtropical and subpolar gyre in North Pacific occurs as a result of the northward shifted westerly winds maxima, as also corroborated by an analysis of the Sverdrup transport. The Sverdrup transports describes the upper circulation during the Eocene further poleward than modern day mainly due to their continental differences. The upper circulation corresponds to Sverdrup transport up to ~53°N for the North Pacific, slightly further north than modern day of 50°N, and up to ~55°S for the South Pacific that is much further south than in the modern ocean and continents (~45°S).
Size distributions of source-specific risks of atmospheric heavy metals: an advanced method to quantify source contributions to size-segregated respiratory exposure
Authors: Tian Yingze , Li Yixuan , Liang Yongli , Xue Qianqian , Feng Xin , Feng Yinchang
Published: March 2024

Heavy metals in size-segregated particulate matter (PM) were investigated in a Chinese megacity, and an advanced model was developed to quantify source-specific risks focusing on size-segregated respiratory exposure. Incremental lifetime cancer risk (ILCR) and non-cancer risk (hazard quotient: HQ) based on deposition concentrations of heavy metals displayed a peak at 4.7–5.8 µm. The percentage contributions to cancer risk were as follows: industrial emission (IE, 34%) > secondary and transport (ST, 29%) > resuspended dust (RD, 21%) > coal combustion (CC, 11%) > traffic emission (TE, 4%) during spring and summer (SS), and CC (31%) > ST (26%) > IE (21%) > RD (11%) ≈ TE (11%) during autumn and winter (AW). RD (41% of HQ during SS, 28% during AW) and IE (45% of HQ during SS, 35% during AW) dominated non-cancer risk. ILCR and HQ of CC were high at sizes 1.1–2.1 µm and 0.43–0.65 µm; those of RD were high at sizes >3.3 µm; and those of IE were bimodal at fine (<2.1 µm) and coarse (>2.1 µm) sizes, respectively. Cancer risk was more susceptible to small particles than non-cancer risk, partly because higher ILCR was from CC, but higher HQ was attributed by RD.
 The influence of seasonal cropland abandonment on water resources in the humid lowland region, southern China
Authors: Gao Junfeng , Renhua Yan Renhua Yan
Published: March 2024

Seasonal abandonment in the previously rice-based rotation system is increasingly prevalent worldwide particularly in southern China. Assessing the effect of this abandonment on evapotranspiration (ET) and water resources is of major importance for regional water cycle change and agricultural water management. This paper analyzed the ET characterization of rice‐winter rape and rice‐winter fallow rotation systems and its relation to weather factors in a humid lowland region, southern China based on a half-hourly ET measurement with Bowen ratio energy balance system from 2017 to 2020. Then the strategic modelling experiment combining ET and rainfall‐runoff models was used to explore the land abandoning effect on ET and water resources. 
Electromagnetic Insights: 3D Subsurface Modeling of Al-Hassa, Saudi Arabia
Authors: Khogali Abid , Kirmizakis Panagiotis , Chavanidis Konstantinos , Ashadi Abdul Latif , Hanstein Tilman , Stampolidis Alexandros , Candansayar Emin , Soupios Pantelis
Published: March 2024

Al-Hassa area features Saudi Arabia's largest oasis and one of the world's largest naturally irrigated land. Moreover, Al-Hassa area is very close to Ghawar, known as the largest conventional oil-field in the world. Additionally, more than 280 natural springs used in the past to water the farmland where the water in some of the springs, is used to be warm. The quality of water also exhibits spatial variations, hinting at a complex subsurface that must be characterized. Finally, the available geological information from outcrops, are very limited, since the majority of the study area is covered by a sand-layer. Based on the above, it seems that this important for its natural resources (oil & gas, groundwater, low-enthalpy geothermy) area is partly unexplored or the data are not available. The purpose of this work is to reconstruct the 3D subsurface geophysical structure of the study area by combining different geophysical electromagnetic (EM) methods. Thus, three EM geophysical methods to construct a detailed 3D model of the subsurface were applied. Specifically, 46 magnetotelluric (MT) stations, 6 audio magnetotelluric (AMT) stations, and 35 transient electromagnetic (TEM) stations were acquired within Al-Hassa National Park. The data from all these EM soundings were processed and integrated to achieve the highest resolution from the surface to the maximum depth of investigation. 2D and 3D processing, and joint interpretation was applied to all EM data. The EM findings were confirmed by gravity measurement conducted in the same area. The integration of various geophysical data sets, including TEM, MT, AMT and gravity data, uncovers lateral discontinuities in resistivity, a complex structure, and fracture zones acting as pathways or barriers to groundwater flow. This comprehensive modelling approach offers invaluable insights into the subsurface dynamics, enhancing our understanding for the complexity of the study area.
Role of pyrite on oxidative degradation of some chlorophenolic compounds with zero-valent iron/H2O2 system
Authors: Kantar Cetin , Oral Ozlem , Yildiz Ilker
Published: March 2024

The effect of a naturally occurring soil mineral, pyrite, on the degradation of 4-chlorophenol (4-CP) and 2,4-dichlorophenol (2,4-DCP) by Fenton process with micro scale zero-valent iron (ZVI) as the catalyst was studied in batch reactors. Our batch data show that while the CP degradation with ZVI/H2O2 system was adversely affected by the aggregation of ZVP particles, the use of pyrite in systems containing ZVI/H2O2 greatly improved the oxidative degradation of CPs. Surface measurements, including salt titration, Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), scanning electron microscopy (SEM), and X-ray photoelectron spectroscopy (XPS), revealed that the ZVI particles and surface oxidation precipitates dispersed on pyrite particles, thus preventing ZVI particle aggregation, and subsequently promoting iron redox cycling for enhanced ZVI corrosion and surface site regeneration. Following Fenton degradation, the oxidative degradation intermediate species of CPs became significantly more biodegradable relative to their mother compounds. Overall, combining ZVI and pyrite at the optimum dose might be a cost-effective technology for developing novel treatment methods for the treatment of groundwater and wastewater contaminated with chlorophenolic chemicals.
Bespoke simulation capabilities - Digital Twins for Weather-induced Extremes and Climate
Authors: Wedi Nils , Sandu Irina , Hoffmann Joern , Geenen Thomas , Thiemert Daniel
Published: March 2024

The objective of DestinE is to create a highly accurate replica or Digital Twin of the Earth. This constitutes a new type of information system, with unprecedented levels of detail, quality, and interactivity to support EU-policy makers and users who implement these policies to better respond and adapt to the challenges posed by environmental change.Several thematic digital twins of the Earth-system are developed over the course of different phases of DestinE with the first implementations focussing on Extreme Weather and Climate adaptation. DestinE’s digital twins exploit the latest advances in digital technology, science, artificial intelligence, and the huge opportunities offered by the world-leading supercomputing capacities of the European High Performance Computing Joint Undertaking (EuroHPC JU). By combining cutting-edge Earth-system physical and data-driven models and observations DestinE’s digital twins offer bespoke simulation capabilities that accurately simulate natural and human activity and allow to test scenarios that would enable more sustainable development and support European environmental policies. On-demand simulations and a comprehensive distributed data and compute infrastructure tailored to the Big Data needs of Destination Earth for tackling climate and environment-related challenges is located closely to maximise the EuroHPC facilities offered within the strategic allocation in support of the DestinE service.The European Centre for Medium Range Weather Forecast (ECMWF), the European Space Agency (ESA) and the European Organisation for the Exploitation of Meteorological Satellites (EUMETSAT) are the three organisations entrusted by the EU (DG-CNECT) to achieve this unprecedented endeavour for climate, weather and computing sciences. The work involves scientists, computer analysts and domain experts across many contributing institutions and European countries working together on this common goal.
Understanding the multiple linkages between climate risks and water supply: a case study of Southern Sweden
Authors: Fernandez Jeanne , Di Baldassarre Giuliano , Teutschbein Claudia , Mård Johanna
Published: March 2024

There are numerous studies of the impacts of climate-related natural hazards, such as droughts, heatwaves and wildfires, to water supply. These range from the global mapping of water scarcity to local-level evaluations of damages to production and distribution infrastructure. However, comprehensive and dynamic assessments of climate impacts to water supply that consider both fast (e.g., floods, landslides) and slow onset risks (e.g., drought) as well as changes in water consumption are still lacking, especially in regions perceived as “water-rich”.This study reviewed climate change impacts to water supply in northern temperate climates which, in recent years, have been exposed not only to multiple floods but also to seasonal droughts despite predicted increases in average precipitation. By adopting an extended risk framework, we developed a conceptual overview and visualization of the linkages between climate, water, and society in the context of Southern Sweden.The results highlight the multiple knowledge gaps in the Swedish water sector related to climate change uncertainties at local scales, compound and cascading risks, and the challenge of implementing adaptation measures in practice. When acknowledging intersectoral connections, the conceptualization becomes increasingly complex, emphasizing broader implications for a functional society as a whole.This research contributes to a sparse literature on the impacts of climate change to water supply in northern regions. We argue that conceptual and systemic approaches can benefit water utilities and municipalities where drought risk tends to be overlooked and discuss possible venues for moving adaptation forward.
Decoding inter-seismic deformation: Insights from viscoelastic modeling
Authors: Boulze Hugo , Fleitout Luce , Klein Emilie , Vigny Christophe
Published: March 2024

GPS positioning offers millimetric precision in measuring deformation of the lithosphere during the seismic cycle. In particular, during the post-seismic phase, long-lasting and large-scale deformation are measured. They result from the viscoelastic relaxation in the asthenosphere. Consequently, the post-seismic phase is currently modeled using viscoelastic rheologies (e.g., Maxwell or Burgers viscous models). On the other hand, the inter-seismic phase is mainly modeled using purely elastic models. In particular, coupling models, widely used to quantify the accumulation of deformation on the subduction fault, are therefore used to evaluate earthquake hazard. However, such elastic models fail to explain mid-field deformation without the use of an external hypothesis (e.g., a third plate called sliver).The study of post-seismic deformation has provided important insights into the rheological properties of the asthenosphere during the post-seismic phase. For example, viscous creep has been found Newtonian since the cumulative post-seismic displacements normalized by the co-seismic offset, as a function of distance to the trench, superimpose very well for earthquakes of different magnitudes [Boulze et al. 2022]. By incorporating these different results and using the backslip theory [Savage 1983], we model the inter-seismic phase using viscoelastic models. We explore the impact on coupling distribution along the Chilean subduction zone, in particular discussing differences with the elastic model in terms of depth and lateral extension. We also examine the impact of viscoelastic models in a region of Chile (Taltal region, 25.2°S) where elastic models currently fail to reproduce deformation in the near-field [Klein et al. 2018]. Finally, we show that a 2-Burgers viscous model is necessary to reproduce deformation in Argentina in 2010, before the Maule earthquake.
Combined Effect of Wind and Rain on Typhoon-Induced Landslide
Authors: Hsieh Jui-Yun , Lin Yuan-Chien
Published: March 2024

Landslides which cause numerous casualties and property losses are the crucial natural disaster in Taiwan. Traditionally, typhoon-induced landslides studies mainly focused on the triggering factors, such as geological condition, topographic condition and heavy rainfall. However, typhoons often bring sudden maximum wind which sways trees severely, leading to the soil disturbance which decreasing the slope stability. Moreover, some landslide events occurred on borad-leaved forest along the slopes where were only affected by strong winds of the typhoon and were not particularly affecte by heavy rainfall of the typhoon. In this study, data-driven approach is used to prove that strong winds is one of the important trigger factor, especially strong winds lasting for hours. We examed the significance of the combined rain-wind influence on landslides by Three-dimensional (3D) Histogram and Mann-Whitney U test. The results demonstrated that the wind and rain conditions when a typhoon landslide event occurs are both significantly greater than when no landslide event occurs. And a binary machine learning Random Forest model is constructed to predict the occurrences of landslides based on factors, such as heavy rain, strong winds, traditional geological conditions, and topographical factors. The findings of this study infer that  in addition to heavy rainfall, strong winds is also one of the important factor that may increase or trigger the risk of landslides. Therefore, strong winds can not be ignored when investigating the typhoon-induced landslides.
Assessing the uncertainty of the estimation of potential evapotranspiration under climate change using a pseudo-reality approach
Authors: Pastén Zapata Ernesto , Lotsari Eliisa
Published: March 2024

Evapotranspiration is an important process in the water balance. It accounts for water transported from the surface of the Earth to the atmosphere. For practical applications, the estimation of evapotranspiration is limited by the potential evapotranspiration (PET), which is the maximum evapotranspiration that occurs when the availability of water on the surface is unlimited. PET can be estimated based on different climate variables. When assessing climate change projections, different climate models often project different change directions for such variables. Furthermore, the reliability of the climate model projections varies for each variable. Therefore, the uncertainty associated with the estimation of PET can be large. This study assesses this uncertainty by employing ten methods commonly used to estimate PET for ten different locations across Europe, capturing different climate and physical conditions. An ensemble of ten Euro-CORDEX climate models is used to assess projected PET changes through the century under the RCP 8.5 scenario. Different climate model bias correction methods are employed to reduce the biases in the climate model outputs when compared to the reference climate. A pseudo-reality experiment is set where each climate model acts as reference to train the correction methods, which are applied to the climate models that remain in the ensemble. The uncertainty of the projected PET is compared to the reference-climate-PET using evaluation metrics. Results are relevant for decision and policy makers and professionals developing impact studies.
Three-dimensional Structures of Internal Solitary Waves in the Northern South China Sea Revealed by Mooring Array Observations
Authors: Yang Yunchao , Huang Xiaodong , Zhou Chun , Zhang Zhiwei , Zhao Wei , Tian Jiwei
Published: March 2024

The data collected from an array of five subsurface moorings, which are deployed along the direction of internal solitary wave (ISW) crests in the northern South China Sea (SCS) from October 2013 to June 2014, are used to investigate the three-dimensional structures of ISWs and their temporal variabilities. The measurements reveal that the ISWs are asymmetric along their crests, with the average amplitude in the southern portion being 70% larger than that in the northern portion. The observed three-dimensionally integrated energy and flux of ISWs are accurately calculated for the first time, reaching 53 TJ and 0.82 GW, respectively, on average. Over the whole observation period, the pattern of ISW crests was dominantly convex, accounting for 76.2% of all observed episodes. However, due to the changes in propagation speeds along the direction of ISW crests caused by either single or combined effects of mesoscale eddies and intruded Kuroshio, the ISW crests could deform into S-shaped and concave patterns, which accounted for 19.6% and 4.2%, respectively. Moreover, during November and December, the positions of the largest amplitude along ISW crests mostly shifted from the southern portion to the northern portion due to the energy refraction caused by mesoscale eddies, leading to the increase/decrease in wave intensity in the northern/southern portion. In early February, the intruded Kuroshio remarkably shifted ISW energy southward, which increased the wave amplitude in the southern portion by as much as 96%. These results clearly demonstrate that the intensities of three-dimensional ISWs could temporally vary out of phase between the northern and southern portions of crests due to the remarkable modulations by intense background processes.
Estimation of daily NO2 with explainable machine learning model in China, 2007-202
Authors: Shao Yanchuan , Zhao Wei , Liu Riyang , Yang Jianxun , Liu Miaomiao , Fang Wen , Hu Litiao , Adams Matthew , Bi Jun , Ma Zongwei
Published: March 2024

Surface nitrogen dioxide (NO2) is an effective indicator of anthropogenic combustion and is associated with regional burden of disease. Though satellite-borne column NO2 is widely used to acquire surface concentration through the integration of sophisticated models, long-term and full-coverage estimation is hindered by the incomplete retrieval of satellite data. Moreover, the mechanical relationship between surface and tropospheric NO2 is often ignored in the context of machine learning (ML) approach. Here we develop a gap-filling method to obtain full-coverage column NO2 by fusing satellite data from different sources. The surface NO2 is then estimated during 2007-2020 in China using the XGBoost model, with daily out-of-sample cross-validation (CV) R2 of 0.75 and root-mean-square error (RMSE) of 9.11 µg/m3. The back-extrapolation performance is verified through by-year CV (daily R2 = 0.60 and RMSE = 11.46 µg/m3) and external estimations in Taiwan before 2013 (daily R2 = 0.69 and RMSE = 8.59 µg/m3). We explore the variable impacts in three hotspots of eastern China through SHAP (Shapley additive explanation) values. We find the driving contributions of column NO2 to the variation of ground pollution during 2007-2020 (average SHAP = 5.09 µg/m3 compared with the baseline concentration of 33.39 µg/m3). The estimated effect is also compared with ordinary least squares (OLS) model to provide a straightforward understanding. The related health burden is further calculated by using the annual NO2. We demonstrate the employment of explainable ML model is beneficial for comprehend the coupled relationship in surface NO2 change.
Concordant Dilatancy in Stick-Slip Events and Fast/Slow Earthquakes: Insights from High-Resolution Studies
Authors: Ge Yi , Hu Wei , Gou Huaixiao
Published: March 2024

Fast and slow earthquakes represent distinct modes of energy release during tectonic fault rupture. While laboratory stick-slip experiments have observed both fast and slow slips, limitations in sampling rates have obscured detailed insights into fault thickness variation. Specifically, the underlying reasons for a single fault exhibiting different slip modes have remained elusive. In this study, we conducted ring shear experiments employing an ultrahigh sampling rate (10 MHz) to shed light on the contrasting physical processes between fast and slow slip events. Our findings reveal that slip durations varied from dozens to hundreds of milliseconds. Fast slip events exhibit continuous large-amplitude Acoustic Emission (AE) signals alongside complex variations in sample thickness: a brief compaction pulse during rapid stress release, succeeded by sample dilation and thickness vibrations. As the slip concludes, the sample thickness initially undergoes slow compaction, followed by dilation preceding the nucleation of subsequent slip events. Conversely, during slow slip events, shear stress reduction coincides with intermittent bursts of low-amplitude AE and sample dilation. Fast and slow slips have similar AE spectra. Detailed observations of thickness variations during slips indicate that dilation occurs in both fast and slow slips, aligning with natural observations of coseismic dilatation. This study offers insights into the mechanisms governing fault slips during fast and slow earthquakes, potentially explaining their impact on stress redistribution and structural reorganization within faults.
Unraveling antibiotic resistomes associated with bacterial and viral communities in intertidal mudflat aquaculture area
Authors: Wang Linqiong , Zhu Mengjie
Published: March 2024

Coastal tidal flats are intersection zones between terrestrial and marine environments and are considered repositories of pollutants from anthropogenic activities (e.g., fishery and aquaculture). Specifically, the extensive use of antibiotics in intertidal mudflat aquaculture area has substantially increased the dissemination risk of antibiotic resistance genes (ARGs). As hosts of ARGs, bacteria and virus exert vital effects on ARG dissemination. Thus, this study attempts to unravel the occurrence, dissemination, evolution, and driving mechanisms of ARGs associated with bacterial and viral communities using metagenomic sequencing in a typical intertidal mudflat. Abundant and diverse ARGs (22 types and 437 subtypes) were identified and those of ARGs were higher in spring than in autumn. It is worthy noted that virus occupied a more essential position than bacteria for ARGs dissemination through network analysis. Meanwhile, nitrogen exerted indirect effect on ARG profiles by shaping viral and bacterial diversity. According to the results of neutral and null models, deterministic processes dominated the ARG community assembly by controlling sediment nitrogen and antibiotics. Homogeneous and variable selection dominated phylogenetic turnover of ARG community, contributing 46.15% and 45.90% of the total processes, respectively. This study can hence theoretically support for the ARG pollution control and management in intertidal mudflat aquaculture area.
Building and evaluating the high-resolution, integrated groundwater-surface water ParFlow modeling platform of continental China (CONCN): leveraging global datasets in a data-poor region   
Authors: Yang Chen , Condon Laura , Maxwell Reed
Published: March 2024

ParFlow CONCN model is the first integrated groundwater-surface water modeling platform over the mainland of China with a resolution of 30-arcsec and a depth of 492 m. With the flexibility of reconstruction and prediction of groundwater and surface water states and fluxes, it is undoubtedly an efficient tool for scientific understanding on water cycle and decision making on water resources and thus to tackle China’s water crisis in the changing world. Nonetheless, the CONCN model may have broader significances to the hydrologic community. Model evaluation and comparison is a common practice in the geoscientific modeling communities, such as those of land surface and earth system models. Due to the challenges in aquifer parameterization and the expensive computing requirement, high-resolution, large-scale, 3D groundwater modeling or integrated hydrologic modeling with 3D groundwater component is still under development though becoming more active in the past decade. Several national-scale such integrated hydrologic models, for example, ParFlow models over CONUS, west Africa, and Germany, have been built at 1 km resolution or higher with satisfying performances. However, the wide extension of modeling in this category to other places worldwide or to global scale is limitedly explored, preventing the evaluation of modeling workflows at different places and comparison with models using other parameterization schemes. Here, we demonstrate the construction and the first-phase evaluation of CONCN model by leveraging global datasets. Global permeability (GLHYMPS 1.0) and hydrography (MERIT Hydro) products were helpful to build the model while global water table depth (Fan et al., Science, 2013 and Zeng et al., JAMES, 2018) and streamflow (GRADES-HYDRDL and CNRD v1.0) products were adopted to preliminarily evaluate the simulation results. In this data-poor modeling area, both the construction and evaluation of the CONCN model are impossible about five years earlier as most of these global datasets did not exist. Therefore, the CONCN model can be one of the pioneers to evaluate and then to improve the current workflow of the existing models and address the challenges in new modeling areas with hydrogeology, hydrography, and climatology unseen in existing models. We also expect our dilemma caused by lacking observations as many other modelers in China can push the data-sharing to constrain hydrologic models and to motivate the collaboration such as model intercomparison in the Chinese hydrologic modeling community, which are well developed in the global community.
Modelling the Impact of Surfactants on Anthropogenic CO2 Transfer between the Ocean and Atmosphere
Authors: Hu Jianing , Maqueda Miguel
Published: March 2024

During the industrial revolution, anthropogenic carbon dioxide (CO2) emissions have rapidly increased, raising worries about their impact on global climate change. The oceans are an important sink of anthropogenic CO2, taking in about 30% of emissions. Despite the important role of surfactants in reducing gas exchanges between the atmosphere and the ocean, their effect on oceanic intake of CO2 has received limited attention in ocean models. In this exploratory work, we examine the impact of a parameterization of surfactants on CO2 fluxes between the ocean and the atmosphere using the NEMO (Nucleus for European Modelling of the Ocean) ocean engine in the ORCA2-LIM-PISCES configuration. Understanding and quantifying the potential effect of surfactants on the ocean's absorption of anthropogenic CO2 is the main goal of our modelling. Using documented atmospheric CO2 concentrations from 1750 till present, we carried out three simulations of the intake of anthropogenic CO2 by the ocean, one in which the presence of surfactants was ignored and two in which different formulations of the impact of surfactants on air-sea gas exchange were used. According to the simulations, the impact of the presence of surfactant on net, basin-scale anthropogenic CO2 fluxes into the ocean is rather small, on the order of just a few percent. However, in regions where, in the model, the intake of anthropogenic CO2 is largest, such as the Southern Ocean and the Kuroshio and Gulf Stream region, the reduction in these fluxes can attain between 10% and 40%. On seasonal timescales, the global effect of surfactants is to slightly enhance the amplitude of the annual cycle of fluxes by between 10% and 15%. The presence of surfactants leads to a reduction in the total mass of anthropogenic dissolved inorganic carbon (DIC) in the global ocean by about 6% at the end of the integration. Regionally, the concentrations of anthropogenic DIC in the water column (mass of DIC per unit area) are up to 10% lower in the Southern Ocean and in the northern branch of the Kuroshio when surfactants are present.
Can dry get wetter even if rainfall declines?
Authors: Agam Nurit , Kool Dilia
Published: March 2024

Drylands are 57% of the terrestrial area of the world, and are disproportionally affected by climate change. This is particularly pertinent in so-called “climate-change hotspots” such as the Mediterranean, where temperature increases at a rate of up to 0.45 oC/decade and precipitation is expected to decline. Given the sparsity of studies in drylands and the consequent lack of understanding of the unique processes in drylands, the degree to which these projections are accurate for drylands is questionable. The fact that drylands, by definition, are classified according to the aridity index, exposes the inherent assumption that desert hydrology is primarily governed by precipitation and potential evapotranspiration (ET0). There is increasing evidence, however, that non-rainfall water inputs (NRWIs; fog, dew, and water vapor adsorption) are a substantial source of water in multiple desert environments. In arid and hyper-arid drylands, water vapor adsorption is not only the least studied of the three NRWIs, but also likely the most common. In the Negev desert, Israel, the projected decrease in rainfall and increase in temperature, and therefore increase in ET0, is expected to result in drier soils. This potentially will increase the amount of water vapor adsorption. Here we present the actual rate of warming and the corresponding changes in ET0 in the Negev desert. We then elucidate, for the first time, the contribution of water vapor adsorption to desert hydrology and how it might be affected by climate change based on changes observed in the last 20 years.
Dynamic Triggering of Earthquakes in Yunnan, China: Insights into the Influence of Distant M>6 Earthquakes and Geothermal Fluids
Authors: Wang Zhiwei , Lei Xinglin , Ma Shengli
Published: March 2024

This study delves into the phenomenon of dynamic triggering of earthquakes in Yunnan, China, a region renowned for its abundant geothermal activity. Through an extensive analysis spanning from 2006 to 2021, we unveil the impact of 13 distant M>6 earthquakes on seismic clusters in the region, emphasizing the unique clustering of these seismic events at specific fault-related locations. Advanced methods, including the Epidemic-Type Aftershock Sequence (ETAS) model, were employed to identify the spatiotemporal patterns of seismic activity before and after these distant M>6 earthquakes.Noteworthy observations highlight the preferential distribution of earthquake clusters at specific fault-related locations, such as fault ends, bends, intersections, and fault step-overs. Some earthquake clusters exhibit clear fluid diffusion processes, validated by increased water temperature in nearby wells. The applied ETAS model underscores a high proportion of forced seismic activity, elucidating the subtle relationship manifested as delayed triggering effects.The results of our study emphasize the association of dynamic triggering with specific fault-related locations, emphasizing the potentially significant role of subsurface geothermal fluids in this process. This research deepens our understanding of seismic activity patterns in the Yunnan region, revealing the intricate interplay between distant M>6 earthquakes, fault dynamics, and geothermal fluid activity.
Embedding Equity, Diversity and Inclusion into a Professional Geologist's Lifestyle
Authors: Griffin Martín
Published: March 2024

The principles and the values of equity, diversion, inclusion (EDI) should be an as an embedded element into the development of a professionbal geologist within academia, industry or goverment practice. Geoscience as an employment sector lacks diversity and inclusion of under-represented groups, in particular frequently published reports on the demographics of geologists and the skills shortage in the workforce. These reports highlight the under-representation of people of ethnic and minority groups, BAME, or those with a disability or impairment, or those who are LGBTQIA+ within the geoscience sector.  It’s not only morally right to ensure that everyone has equal opportunity, but to improve our world, shape our future and solve complex global challenges we need to include a diversity of talent and knowledge. Furthermore, in the globally we still face a nationwide skills shortage threatening our industry. To address this and ensure the sustainability of our industry we must support equal opportunities for all and be truly inclusive. There is evidence to support the widely accepted view that tackling and managing EDI is a crucial element in increasing productivity and staff satisfaction. Diverse experiences and perspectives bring about diversity of thought which leads to innovation. It allows everybody to be authentic at work and provides the opportunity for their voices to be heard. Consequently, implementing EDI has proven to increase performance, growth, and innovation, as well as improvements in health, safety and wellbeing. EDI will also help to prepare students anmd employees with the fundamental attitudes that are needed as practitioners, and human beings. Hence a good understanding of EDI is of great importance to the success of the engineering sector by driving forward by adopting conscious inclusion, demonstrating equity to attract and retain diverse talent. Likewise, an society will engages the full potential of the individuals where innovation thrives, and views, beliefs and values are integrated.