bluuebunny/crossref_metadata_2025 huggingface dataset:
Determinants of soil field-saturated hydraulic conductivity across sub-Saharan Africa: texture and beyond
Authors: Bargués Tobella Aida , Winowiecki Leigh A. , Sheil Douglas , Vågen Tor G.
Published: March 2024

Soil infiltration is a critical hydrological process governing water security and related ecosystem services. The infiltration capacity of soils is largely controlled by their hydraulic conductivity. Hence, understanding soil hydraulic conductivity is critical for effective soil and water management. Despite recent efforts in assembling measurements of soil hydraulic conductivity, global databases and derived pedotransfer functions lack coverage in the tropics. Africa, in particular, remains sparsely represented in these global databases, and representative observations of soil hydraulic properties are few and of mixed form and quality.In this presentation, we introduce a new dataset of soil infiltration measurements and accompanying indicators of soil and land health collected systematically using the Land Degradation Surveillance Framework (LDSF) in 3573 plots from 83 100 km2 sites across 19 countries in sub-Saharan Africa and present the results from a recent study* where we used these data to (a) determine field-saturated hydraulic conductivity (Kfs) and (b) explore which variables best predict variation in Kfs.Our results show that sand content, soil organic carbon (SOC), and woody cover had a positive relationship with Kfs, whereas grazing intensity and soil pH had a negative relationship. Our findings highlight that, despite soil texture being important, structure also plays a critical role. These results suggest significant opportunities to improve soil hydrological functioning through management and restoration practices that protect and enhance soil structure. Enhancing SOC content, limiting livestock stocking rates, promoting vegetation cover, particularly woody vegetation, and preventing and halting soil erosion can increase Kfs. This evidence can guide sustainable land management practices and restoration interventions across the region for improved soil health and water security.Our dataset expands existing regional and global databases of soil hydraulic properties, improving coverage for Africa and providing field data for underrepresented land uses and soils. As such, we envision that this dataset can contribute to improved understanding and prediction of soil hydraulic properties and to improved Earth system and land surface models for applications in Africa. * Bargués-Tobella, A., Winowiecki, L.A., Sheil, D., and Vågen, T.G. Determinants of soil field-saturated hydraulic conductivity across sub-Saharan Africa: texture and beyond. Water Resources Research. DOI 10.1029/2023WR035510. In-press.
Evolution of paleohydrological pathways at Nettilling Lake, Baffin Island (Nunavut, Canada) since deglaciation
Authors: Pienitz Reinhard , Labrie Rachel , Narancic Biljana , Saulnier-Talbot Emilie , Meyer Hanno
Published: March 2024

Paleohydrological connections and pathways within Nettilling Lake, the largest lake in the Canadian Arctic Archipelago (Baffin Island, Canada), remain poorly known. This knowledge gap hinders our ability to reliably infer past environmental changes that could provide clues to the future evolution of this region with rapid environmental change at high latitudes. The lake is currently fed by freshwaters from its catchment and drains westward into the Foxe Basin via the Koukdjuaq River. However, its early hydrological connections following the last deglaciation are thought to have been complex, when marine waters from the postglacial Tyrell Sea initially invaded the Nettilling basin from the west, followed by a brief reversal when Atlantic waters fed the basin from the east via the Cumberland Sound and Nettilling Fjord. To test this hypothesis, we investigated the lithology, sedimentology and geochemistry of various sediment archives from the easternmost sector of the lake. The multi-proxy data revealed three successive phases: an initial glaciomarine phase (8300 - 7300 cal. BP), a brackish phase (7300 - 6000 cal. BP) and a lacustrine freshwater phase (6000 - present). Our results support the hypothesis formulated by Blake (1966) of temporary hydrological connectivity between the Foxe Basin in the west, followed by a link with the Atlantic Ocean in the east via the Cumberland Sound before marine waters retreated due to differential glacio-isostatic uplift that forced the basin to be progressively occupied by the fresh waters of the present-day Nettilling Lake.
Controls on soil moisture variability on two Mediterranean hillslopes during dry and wet periods using wavelet coherence analysis
Authors: Murgia Ilenia , Kaffas Konstantinos , Verdone Matteo , Manca di Villahermosa Francesca Sofia , Dani Andrea , Preti Federico , Massari Christian , Segura Catalina , Penna Daniele
Published: March 2024

Although topography and evapotranspiration rates are the main determinants of soil moisture, climatic forcings play a crucial role. In the Mediterranean climate, the marked sensitivity of soil moisture to alternations between wet and dry periods exerts a strong control on hydrological and ecohydrological processes at the hillslope and catchment scales.We monitored soil moisture in two hillslopes in the Re della Pietra experimental catchment, Appennine mountains, Tuscany, central Italy. The two hillslopes (HS1 and HS2) show different morphological characteristics, such as elevation (≅ 670m asl for HS1 and 940m asl for HS2), slope (≅ 26° for HS1 and 36° for HS2), and tree composition (fruit chestnut grove converted into coppice in HS1 and pure beech forest in HS2). For two years, soil moisture was measured in each hillslope, at three different positions and two different depths (15 and 30 cm) along a longitudinal transect. We used wavelet coherence analysis to evaluate the dominant factors controlling soil moisture variability in the two hillslopes during dry and wet periods.Preliminary results reveal a clear coupling of soil moisture at 15 cm and 35 cm on both hillslopes during wet periods, indicating a relatively homogeneous soil water content across the two depths. Conversely, a decoupling occurs during dry periods when soil moisture values at 35 cm are greater than those at 15 cm, reflecting significant solar radiation, atmospheric demand, and tree water uptake from shallow soil layers. During dry periods, we observed significant differences in soil moisture between the two depths in HS1 compared to HS2, suggesting that local conditions affect hillslope-scale soil moisture response.Ongoing analyses investigate the role of rainfall, solar radiation, vapor pressure deficit, and tree transpiration on soil moisture spatio-temporal variability on the two hillslopes.
Communicating uncertainties in flood early warnings
Authors: Stefanova Anastassi , Sallwey Jana , Philipp Andy , Mueller Uwe
Published: March 2024

A key problem in flood early warnings for small catchments is the increasing forecast uncertainty associated with decreasing catchment size. Forecasts for small catchments often are based on rainfall-runoff models and quantitative precipitation estimation, both of which are subject to considerable uncertainties. In the case of a flood event, these uncertainties must be communicated to the responsible authorities along with the actual flood alert, in order for them to respond appropriately.This requires a reliable warning system that can easily adapt to the different needs of its users. Within the HoWa-PRO project (howa-pro.sachsen.de) an information platform (howapro.de) was developed meeting exactly these requirements. The platform is an interactive web-based application providing flood early warnings for small catchments (for now only in Saxony) along with forecast uncertainties. It uses a hydrological ensemble forecast system to calculate hourly predictions and presents these as coloured symbols and plots with uncertainty bands or data layers with various information on probabilities and daily sums.The users of the HoWa information platform are flood risk managers at municipal and district level, who often have no scientific background and certainly, no knowledge of the uncertainties in hydrological forecasts. For this reason, we developed a modular training concept that takes into account the heterogeneous level of knowledge of various user groups, such as employees of water authorities or members of the water brigade and enables a flexible and user-adapted implementation of the training courses. Additionally, a serious game on flood forecasting was designed aiming to convey important key-massages in a playful way. The game can be played during the trainings or just for fun when browsing through the HoWa information platform.Both, the information platform and the training concept were developed in collaboration with the target groups through workshops with intensive discussions and iterative improvements. Consequently, the products on the HoWa platform are visualized and explained in a user-oriented manner. Users' preferences and suggestions were considered in the presentation of warnings (What is presented? How is it presented?) and in communicating uncertainties (Which formulations are also understood by laypersons?). Subsequent to the user workshops, the training concept and information platform were gradually adapted.This contribution provides an overview of the visualization of uncertainties on the HoWa information platform, the training modules on the topic of uncertainties, and the iterative adaptation process by means of a continuous user dialogue.
Promoting Carbon Storage and Health in Urban Soils through Sustainable Management Practices  
Authors: Movassagh Atefeh , Betancur Corredor Bibiana , Hamer Martin
Published: March 2024

Sustainable urban soil management is becoming increasingly crucial due to its vital role in climate and water regulation and its significant potential for storing soil organic carbon (SOC). This significance is emphasized considering the ongoing urbanization and climate change issues. Although SOC is influenced by many factors, such as soil type and climate fluctuations (temperature, precipitation patterns), on a regional scale, land use and management practices (e.g., fertilization, irrigation) can have a more significant impact on SOC storage and the balance of soil-atmosphere carbon fluxes. However, there is still a limited understanding of the amount of humus content in urban soils and the effects of urban development and management practices on soil health and carbon storage. We investigated how management practices in urban green spaces influence soil carbon storage as the primary indicator of soil health.The present study was carried out in the Bonn-Rhein-Sieg area, as the region is vital in terms of sustainable urban and regional development with a high population density (Rhein-Sieg district: 338.4, Bonn: 520.9 inhabitants/km2) in Germany. A survey was conducted with owners and managers of urban private (e.g., allotment and backyard garden) and public green spaces on the practices for the most common vegetation types (e.g., lawn, vegetable, ornamental). In the autumn and winter of 2022, 248 soil samples (0–20 cm depth) were collected from 95 private and public green spaces in the study area and analyzed for physiochemical and biological properties. Multivariate Analysis of Variance (MANOVA) was performed to assess the effects of different management practices on soil properties.Our results indicate that the average SOC stock in public green areas (94.67 Mg ha-1) is substantially higher than in private ones (house garden 67.72 Mg ha-1, allotment garden 73.15 Mg ha-1). Moreover, urban green spaces with vegetables (91.66 Mg ha-1) and ornamentals (85.05 mg ha-1) show greater SOC stock levels when comparing vegetation types (lawn 62.48 Mg ha-1). Significant differences in SOC are also found for various management practices. Specifically, the monthly fertilization schedule resulted in higher SOC levels (127.37 Mg ha⁻¹) compared to the yearly fertilization schedule (76.88 Mg ha⁻¹). Additionally, the use of organic fertilizers contributed to increased SOC levels (84.40 Mg ha⁻¹) in contrast to mineral fertilizer applications (65.31 Mg ha⁻¹). The average SOC stock in all the studied urban green spaces (85 mg ha-1) was higher than the average SOC stock in arable soils in Germany (47.30 Mg ha-1). The higher SOC in the region could be due to vegetation types and fertilization frequencies, which show statistically significant effects (p-value
Turbulent dynamics and energetics of anticyclonic submesoscale headland wakes
Authors: Chor Tomás , Wenegrat Jacob
Published: March 2024

Both submesoscale flows and interactions with topography have been posited to be important factors driving dissipation and mixing in the ocean. However, since their in-situ measurement is difficult and numerical approaches do not typically resolve the turbulent processes responsible for the irreversible mixing and dissipation, the dynamics and energetics of submesoscale flows generated by topography are not currently well-understood.In this work we attempt to clarify the topic by investigating a series of realistic Large-Eddy simulations of submesoscale flows past a headland where the turbulence is fully resolved, allowing us to probe into the small-scale processes responsible for the energy cascade. Consistent with previous studies, we find strong evidence of submesoscale centrifugal-symmetric instabilities (CSIs) in the wake, with most of the wakes being energized mainly via horizontal shear production (i.e., centrifugal instabilities). We also find that the mixing efficiency (the fraction of total energy extracted from the flow spent mixing buoyancy) within CSI regions in the wake varies between approximately 0.1 and 0.3, consistent with previous studies that found similar variability in CSI mixing efficiency values.Finally, despite our simulations spanning a wide range of parameter space and at least three different dynamical regimes (namely regimes with detached eddy formation, attached boundary layers and tridimensional wake turbulence), we show that some quantities of interest can be predicted by simple scalings. As examples, the kinetic energy dissipation and buoyancy mixing rates scale with the Slope Burger number, and the vertical eddy diffusivity scales with the Rossby number times the Froude number.
Assessing Gol-e-Zard Cave (GZS) and Bergen Speleothem Standards (BSS) for U/Th Geochronometry Using MC-ICP-MS
Authors: Hasözbek Altug , Jiménez-Barredo Fernando , Sharifi Arash , Pourmand Ali , Mertz-Kraus Regina , Weber Michael , Scholz Denis , Lauritzen Stein-Erik , M. Parés Josep , Constantin Silviu
Published: March 2024

Recent advancements in MC-ICPMS technology have significantly enhanced the application of U/Th geochronometry in both biogenic and chemically precipitated carbonate rocks of almost middle Pleistocene to upper Holocene. This burgeoning use, particularly in the study of late Pleistocene earth surface processes, underscores the need for standardized reference materials with a broad age spectrum with different uranium and thorium concentrations. Addressing this need, our study evaluates speleothem specimens, Gol-e-Zard Cave Standard (GZS) and Bergen Speleothem Standard (BSS), as potential reference materials.BSS-2 was processed as a homogenized powder and dissolved aliquot for U-Th dating using MC-ICP-MS analysis. We employed various digestion and ion-resin chromatography separation methods, followed by U-Th dating using MC-ICP-MS at CENIEH, University of Miami, and University of Mainz. The ion chromatography protocols yielded recovery rates ranging from 85% to over 95%. U-series analyses of powdered BSS-2 indicated uncertainties between 0.2-1.5%, attributed to variations in the Beta-factor and the specific U and Th standard bracketing procedures used across laboratories. The dissolved BSS-2 aliquots yield between 1.5-2% of uncertainty. Obtained U-Th ages were 122.8 ± 3.3 ka (University of Miami), 124.5 ± 0.3 ka (University of Mainz), and 123.9 ± 3.2 ka (CENIEH) in the powdered samples. Furthermore, in dissolved samples, the Th-ages vary between 126.9 ± 2.9 to 127.9 ± 3.1 (CENIEH & University of Miami). GZS was prepared as a dissolved standard and the Th-date results obtained from this stalagmite are 3967 ± 0.1 to 3988 ± 0.1 (University of Miami), and 3967 ± 0.1 to 4060 ± 0.4 (CENIEH).All Th-dates required no correction as activity ratios [230Th/232Th] exceeded 500 and 150 for BSS-2 and GZS, respectively. The consistency of these preliminary results across different laboratories suggest that GZS and BSS-2 are promising reference materials for U-Series analysis of calcium carbonate.
The Urban Flooding Open Knowledge Network: From Real-Time Flood Forecasts to Cascading Failures Through Infrastructure, Ecosystems, Communities and Economy
Authors: Yeghiazarian Lilit ,   Lilit Yeghiazarian
Published: March 2024

Floods impact a series of interconnected urban systems (referred to as the Urban Multiplex) that include the power grid and transportation networks, surface water and groundwater, sewerage and drinking water systems, inland navigation and dams – all intertwined with the natural environment and socioeconomic and public health sectors. While the Urban Multiplex is physically and functionally connected, the data produced within its individual sectors are not. This is the core reason why we still do not fully understand the total impact of floods on cities.The Urban Flooding Open Knowledge Network (UFOKN) is an information infrastructure that (i) integrates Urban Multiplex data, (ii) produces real-time and long-term flood forecasts across the continental U.S., and (iii) serves as the foundation to evaluate the total impact of floods on cities. The latter includes assessment of cascading economic impacts of floods across multiple sectors, as well as cascading failures across infrastructure, ecosystems, and communities.UFOKN aims to provide actionable answers to questions such as: Real-time flood mitigation and response: Will my house or place of business flood? Will I have access to water and power? Which district to evacuate first? When? Which traffic routes are safe? Will this storm disrupt the power grid, drinking water treatment plant, or a bridge?
Long-term design, planning and research: Which critical urban infrastructure will likely fail in a future flood? Which failures will affect the most people or the most vulnerable people? Which areas will experience repeated flooding? Which houses should the city buy out? Should a hospital be built at location X? What are the common triggers of Urban Multiplex failures?
The interdisciplinary team behind this project has brought together academic researchers, industry, federal government, U.S. National labs and local stakeholders. UFOKN is funded by the U.S. National Science Foundation’s Convergence Accelerator Program that is structured to enable rapid advancement in highly complex problems of critical societal importance.
Rare Earth Elements Concentration Patterns in Surface Waters of Lakes Ontario, Erie, and Huron (North America)
Authors: Junqueira Tassiane , Vriens Bas
Published: March 2024

The North American Great Lakes constitute a distinctive hydrological system comprising five interconnected lakes (Superior, Michigan, Huron, Erie, and Ontario) that together represent one of the planet's most significant freshwater reserves. Extensive environmental surveillance by federal, state, and provincial governments targets major water quality parameters such as temperature, pH, total dissolved solids, electrical conductivity, and dissolved oxygen, as well as concentrations of nutrients and major ions. However, trace element concentrations are more scarcely measured, and the comparatively little available data on trace element concentrations in the Great Lakes is typically older, discontinuous, or focused on historically contaminated areas. Consequently, the myriad of processes and sources involved in the distribution patterns of trace elements is poorly studied, and there remains a lack of understanding the natural baselines for these elements, including for the Rare Earth Elements (REE). The REE play a crucial role in various technological applications, including electronics, renewable energy technologies, and other high-tech industries. Because of their increasingly applications, REE are currently a significant concern, particularly in mining and industrialized areas, due to their enduring toxicity, radioactive properties, and the potential for bioaccumulation.To understand the REE distribution pattern in the North American Great Lakes, we assessed REE concentrations in >70 surface water samples from Lakes Huron, Erie, and Ontario. The concentrations of dissolved REE, filtered at
Intercomparison of Landsat OLI and Sentinel 2 MSI performance
Authors: Micijevic Esad , Anderson Cody , Barsi Julia , Rengarajan Rajagopalan , Haque MD. Obaidul , Mann Joshua
Published: March 2024

For Landsat 8 and Landsat 9 (L8 and L9), the radiometric stability of the Operational Land Imager (OLI) is monitored using two solar diffusers, three sets of stimulation lamps, and regular lunar collects. Consistent response to the multiple calibrators provides high confidence in the radiometric characterization of the imagers over time and calibration parameters needed to maintain the stability of image products. After 11 years on orbit, all spectral bands in Landsat 8 OLI are stable within 1.5%, while Landsat 9 OLI degradation over its 2.5 years of life remains within 0.3% across all bands.The MultiSpectral Instruments (MSIs) onboard Sentinel 2A and 2B (S2A and S2B) satellites were designed with 8 similar spectral bands (out of 13) as the OLIs, which created opportunities to combine data from both types of instruments and obtain higher temporal frequency of Earth observations. To ensure proper interoperability among the different instruments, they need to be radiometrically cross-calibrated and consistently georeferenced. We use coincident acquisitions over Pseudo Invariant Calibration Sites (PICS) to monitor the radiometric calibration consistency and stability of the instruments over time. For geometry, Landsat and Sentinel 2 images acquired within a month of each other over the same ground targets were used to assess the co-registration accuracy between the sensor products.Our results show a general agreement in radiometry of all four instruments over their lifetimes to within 1%. Following the launch of MSI instruments, the initial geometric co-registration assessment between the MSI instruments and the Landsat 8 OLI instrument showed more than 12 m Circular Error (CE90), larger than a Sentinel 2, 10m, pixel. To further improve co-registration and, thus, interoperability of the four instruments, Landsat Collection-2 products use a geometric reference that was harmonized using the Global Reference Image (GRI). The GRI is a dataset consisting of geometrically refined Sentinel 2 images with an absolute accuracy better than 6 m globally. After adopting a common geometric reference in the generation of Landsat and Sentinel 2 products, our assessment of geometric co-registration of the Landsat and Sentinel terrain-corrected products shows a CE90 error of less than 6 m.Multiple efforts have also been made to validate the accuracy of surface reflectance products from both Landsat and Sentinel 2. In-situ measurements have been made during overpasses of L8, L9, S2A, and S2B using various methods. These measurements also show consistency between all the sensors and can also be used for other missions.
Climate, fire, and vegetation history from loess-palaeosol sequences in Southern Tajikistan, Central Asia during early Palaeolithic: Reconstruction using organic biomarkers and stable isotopes
Authors: Chirakkal Aljasil , K Wright David , Constantin Stiendal Calin , Jonathan Birk Jago , Kurbanov Redzhep , Buylaert Jan-Pieter
Published: March 2024

We reconstruct palaeoenvironmental conditions with multi-proxy records from loess-palaeosol settings in Tajikistan, Central Asia. Landscape conditions in this area are poorly characterised, ambiguous, and difficult to determine, which confounds models of human dispersal out of Africa. This region has been the focus of Russian-Tajik archaeological projects since the 1970s, as it contains evidence of some of the earliest (~600-400 ka) hominin occupations in Central Asia and has yielded numerous Lower Palaeolithic artifacts. In the present study, fire and vegetation biomarkers and stable isotopes have been used to reconstruct fire and vegetation histories in loess-palaeosol samples of early Palaeolithic sites in the vicinities of the Obi-Mazar River in the Khovaling district of southern Tajikistan. Samples from four loess-palaeosol documented profiles were analysed for linear chain alkanes (n-alkanes) and polycyclic aromatic hydrocarbons (PAHs) together with soil stable isotopes (δ13C, δ15N). The fluctuations in the values of n-alkane derived indices showed vegetation changes in concert with glacial-interglacial variability. The δ13C values fell between -20‰ and -25‰ (vs. PDB) and revealed mixed input of C3 and C4 plant organic matter into loess-palaeosol sediments, while δ15N values varied between 3.5‰ and 6.5‰ (vs. AIR) indicating high litter content and tree abundance. The fluctuations in total PAH abundance and increased low to high molecular weight ratio values revealed fire activity and lower temperature burning events during interglacial periods relative to glacial periods.  Moreover, the strong positive correlation between PAHs and deposits that hosted the densest artifact assemblages signals early hominin use of fire in the catchment during MIS 11, 13, and 15. Therefore, our study demonstrates substantial hominin influences on the environment dating to over 500 ka indicating human-ecological processes far predate the modern era.
Analysis of Cluster data with the publicly available GRMB (Geospace Region and Magnetospheric Boundary) dataset
Authors: Grison Benjamin , Darrouzet Fabien , Maggiolo Romain , Hayosh Mykhaylo , Taylor Matthew
Published: March 2024

The Cluster mission consists of 4 identical spacecraft, each carrying 11 scientific experiments. The spacecraft were launched in July and August 2000 into near polar inclined, 19x4 RE elliptic orbits. All four spacecraft are still in operation 23 years later. The magnetosphere environment is highly dynamic and its regions cannot be accessed by the orbital information alone. The purpose of this study is to develop a comprehensive dataset, providing information on Geospace Region and Magnetospheric Boundaries (GRMB) crossed by each of the four Cluster spacecraft, and to deliver it to the Cluster Science Archive (CSA).The GRMB dataset provides a classification useful for the scientific community. Therefore, the methodology does not define what is a bow shock or what is a magnetopause. The goal is to have labeled regions that contain the bow-shocks or magnetopauses. And then each user can apply its own definition on the appropriate label subset.The GRMB list contains two kinds of items:
Regions: Magnetosphere, Magnetosheath, Lobe, Solar wind / Foreshock, Plasmasheet, Plasmasphere

Transition regions: Bow shock TR, Magnetopause TR, Polar regions, Plasmasheet TR, Plasmapause TR

Transition regions can include properties matching several regions. For example, a bow shock TR can include short periods of solar wind or magnetosheath. Solar wind and magnetosheath should not include bow shock crossings.The GRMB dataset is based on more than 40 data products available at CSA, taken from 7 instrument suites. The methodology relies on the visual identification of the boundaries between two consecutive GRMB items. The methodology, the criteria applied for the boundary identification, and the dataset validation are presented. The dataset is not yet fully completed but the Cluster location is already available for more than 5 years per spacecraft.The visualization of the regions, and their physical properties, crossed by the Cluster spacecraft during several years, illustrates the scientific interest of this dataset.
Crustal Structure of Continental Margin and Oceanic Basin at the Southern Mozambique Margin
Authors: Wang Wei , Singh Satish , Wang Zhikai , Ruan Aiguo , Tang Yong , Dyment Jérôme , Leroy Sylvie , Watremez Louise , Wu Zhaocai , Li He , Dong Chongzhi
Published: March 2024

During the Jurassic period, the Gondwana Continent progressively rifted from north to south along three huge transform faults (Davie Fracture Zone (DFZ), Mozambique Fracture Zone (MFZ) and Agulhas-Falkland Fracture Zone (AFFZ)), forming the northern, central and southern continental margins along Mozambique, producing a series of divergent and strike-slip margins. These margins are crucial areas for understanding the evolution of Gondwana as their crustal nature and geometry have strongly impacted the kinematic reconstruction of Gondwana. Especially, the debate about continental or oceanic crust for the Mozambique Coastal Plain (MCP) and North Natal Valley (NNV) at the southern Mozambique margin led to tens of kinematic reconstruction models of Gondwana. Based on the OBS and MCS data results of PAMELA MOZ3/5 Cruises, MCP and NNV were identified as continental crust. This has led the scientific community to reconsider the issue, for example, the opening time of the oceanic basin, the movement direction of rifting, and the intense magmatism during the rifting and break-up of Gondwana.In June 2021, the Second China-Mozambique Joint Cruise was conducted onboard the R/V “Dayang hao”. Three wide-angle seismic OBS profiles were acquired where 70 four-component OBSs were deployed along profiles DZ02 and DZ04 oriented nearly W-E and DZ01 oriented nearly N-S. Four Bolt air guns with a total volume of 8000 in3 in total were towed at ~100 m behind the R/V “Dayang hao” at ~10 m below the sea surface. The shot interval was 200 m.Here, we present the tomographic results of P-wave velocity along 442 km long profile DZ02, where 21 OBSs were deployed. It traverses through the Continent Ocean Transition (COT) and extends into the Mozambique ocean basin. Approximately 19,000 P-wave arrivals were manually picked, using the travel-time tomography inversion to get the velocity model. The tomographic result shows an apparent decrease in crust thickness from COT to the ocean basin, and the thickness of the oceanic crust is about 8 km. We also observe high-velocity anomalies up to 7.4 km/s in the lower crust above Moho, suggestive of more primitive melt. We will also present the S-wave velocity model for DZ02.  
Integrating a Blowing Snow Module for Enhanced Representation of Snow Dynamics and Surface in the HydroBlocks modeling framework
Authors: Cai Jiaxuan , Chaney Nathaniel
Published: March 2024

To maintain computational efficiency and avoid adding too many uncertainties into Land Surface Models (LSMs) with fine-scale parameterization, many efforts have been made to improve sub-grid representations of heterogeneous landscapes. HydroBlocks LSM stands out as a model that employs advanced hierarchical clustering methods, utilizing field-scale satellite-derived data to construct sub-grid tiles or clusters. The Noah-MP land surface model is applied within each tile. Unlike conventional tiling approaches, knowing the spatial location of the clusters provides the opportunity to incorporate the interactions across the distinct clusters. Presently, they interact through the subsurface flow processes. Despite the comprehensiveness of these models, both Noah-MP and HydroBlocks lack consideration for the wind-induced snow transport which plays a pivotal role in snow-related hazards. Other than that, the sublimation and redistribution of wind-blown snow in exposed environments contributes significantly to variations in snow depth. It not only exerts local influence on surface water and energy balance, but also can have expansive impact since the snowmelt is critical for the water availability of downstream basins. To address this limitation, we propose the integration of a blowing snow module into HydroBlocks. This module, inspired by the Prairie Blowing Snow Model, consists of physical-based wind transport and sublimation algorithms. Clusters will be categorized into source and sink regions considering their topography and vegetation. The redistribution of snow mass at every timestep will be calculated based on the wind condition and the adjacent borders between clusters. This research seeks to pave the way for modeling other mass transport processes between tiles which considers the complex interactions within heterogeneous landscapes.
Nitrous oxide dynamics in the Arctic Siberian shelves of the North Kara Sea during summer 202
Authors: Muller Sofia , Fripiat François , Martínez-Garcia Alfredo , Jaccard Samuel L. , Hölemann Jens A. , Delille Bruno
Published: March 2024

Nitrous oxide (N2O) distribution in the North Kara Sea during summer 2021 shows elevated N2O concentrations in shelf water masses, highlighting the significance of coupled benthic-pelagic and nitrification-denitrification processes. In surface waters, temperature emerges as the primary driver of N2O concentrations, with a clear negative correlation between both parameters. Most surface waters are near saturation for N2O, and the saturation deficit exhibits an inverse relationship with temperature. Under-ice water influx originating from the open ocean exhibits strong under-saturation (80%), attributed to the limited air-sea exchange in sea ice covered waters. Contrary to expectations, river supply does not exert a discernable influence on N2O concentrations in the studied area. This study reveals the potential of the Arctic Siberian shelves for the uptake of atmospheric N2O during summer.
Abiotic soil matrix, rather than microbial community composition, determines litter C cycling
Authors: Mason-Jones Kyle , Ingenhoven Kira , Hannula S. Emilia , Veen G. F. (Ciska) , van der Putten Wim H.
Published: March 2024

Microorganisms are the primary agents of litter decomposition in the detritusphere, and are considered potentially powerful levers for influencing soil biogeochemical transformation of plant C into soil organic matter (SOM). However, it remains unclear whether soil microbial activity is primarily constrained by the microbial community composition or by the abiotic soil habitat in which they live. We explored the relative importance of abiotic and biotic factors in litter carbon (C) cycling by reinoculating five sterilized agricultural soils from the Netherlands with six contrasting soil microbial communities from a gradient of land-use intensity. Admixing of subsurface horizons (representing older SOM) and the addition of synthetic ferrihydrite (as an iron oxide representative) were included as additional abiotic manipulations. 16S and ITS amplicon sequencing confirmed that the contrasting communities successfully colonized the sterilized soils and retained strong signatures of their source inoculum during a laboratory incubation of nine months. Nevertheless, basal respiration of SOM and the mineralization of isotopically (13C) labelled litter (Lolium perenne) was overwhelmingly determined by the abiotic soil matrix, most notably the source soil and mixing of subsurface horizons. Ferrihydrite, in contrast, had little effect. These observations were extended by quantification of mineral nitrogen as well as 13C incorporation into particulate and mineral-associated SOM fractions. The findings provide strong experimental support for the responsiveness of C cycling to soil abiotic habitat factors, irrespective of community structure.
From Field to Flow: Assessing River-Aquifer Dynamics in Tropical Regions with In-Situ Dataset Insights
Authors: Sousa Mota Uchôa José Gescilam , Tarso S. Oliveira Paulo , S. Ballarin André , Almagro André , A. Meira Neto Antônio , Gastmans Didier , Jasechko Scott , Fan Ying , C. Wendland Edson
Published: March 2024

In recent years, the scientific community has directed significant attention towards understanding river-aquifer interactions due to their pivotal role in hydrological and biogeochemical processes with implications for solving diverse engineering challenges. Despite the growing focus on these interactions, most studies remain confined to local scales, hindering their incorporation into comprehensive continental-scale water resources management. Addressing this gap, our study pioneers the empirical verification of river-aquifer flow directions (characterizing losing or gaining rivers) in a tropical context. We leveraged an extensive database comprising approximately 150 thousand wells spanning the entirety of Brazil, and we developed empirical power equations using data from around 500 river gauge stations to estimate river water levels under low-flow conditions. To ascertain the flow direction of river-aquifer interactions, we compared hydraulic gradients between groundwater levels of wells and their nearest rivers. A river was classified as losing when its water levels were above those of neighboring wells, indicating potential water loss to underlying aquifers. Stringent connectivity criteria were applied, including a maximum distance of 1 km between wells and rivers, well depth not exceeding 100 meters, and exclusion of wells in confined aquifers. Our study conducted systematic robustness checks, exploring the sensitivity of the data to chosen time intervals, variations in river water levels under low-flow conditions, and the inclusion of confined aquifers. Our findings reveal that more than half of Brazilian rivers are prone to losing water to underlying aquifers. The results underscore the significance of our in-situ data-driven methodology, indicating that losing rivers, widespread throughout Brazilian territory, may serve as potential points of groundwater contamination. Particularly crucial in tropical regions with elevated organic matter input into rivers, given the inadequate wastewater treatment. The findings emphasize the critical necessity of analyzing river-aquifer interactions for effective water resource management on both local and continental scales.
Characterizing Land Subsidence Using Random Forest Algorithm in Taiwan
Authors: Ku Cheng-Yu , Liu Chih-Yu
Published: March 2024

In light of the increasing frequency of severe droughts linked to climate change in central and southern Taiwan, the Choshui delta in central Taiwan has witnessed a notable surge in land subsidence. Consequently, the pace of land subsidence has peaked at 7.8 cm per year as of 2021 in the Choshui delta, Taiwan. The process of soil compaction in the Choshui delta primarily unfolds as a time-dependent geological phenomenon. A comprehensive understanding and characterization of this process are essential for the formulation of effective mitigation and adaptation strategies. This study presents a pioneering approach to characterize land subsidence in the Choshui delta, utilizing a random forest algorithm (RFA).The random forest is an ensemble machine learning algorithm known for its versatility and effectiveness in various predictive modeling tasks. It is widely used due to its ability to handle complex relationships for tasks such as classification, regression, and feature selection in land subsidence. By leveraging this advanced modeling technique, we aim to identify and analyze the underlying causes of land subsidence, providing valuable insights into the dynamic interplay of environmental factors. This research contributes to a more comprehensive understanding of land subsidence patterns by incorporating a multi-factorial perspective in the face of changing climatic conditions. Using the RFA, we may identify and analyze the dominant factors affecting land subsidence. Subsequently, a land subsidence prediction model is established based on the RFA, considering the multi-factorial perspective, include cumulative compaction, groundwater levels, electricity consumption for pumping, and rainfall.The RFA is utilized to identify the temporal patterns from historical time-series data spanning from 2008 to 2021, which is specifically associated with the land subsidence site in the study area. To validate the proposed model, we compare its predictions to the historical time-series data, utilizing metrics such as root mean square error, correlation coefficient, and coefficient of determination. Results demonstrate that, the optimal RMSE, R, and R2 values during the prediction phase. The RFA in the context of land subsidence prediction performs exceptionally well, exhibiting high accuracy in predicting land subsidence patterns in the rapidly subsiding areas of the Choshui delta.Keywords: land subsidence; climate change; random forest algorithm; groundwater; Choshui delta.
FVM: A Good Match to Airborne Gravimetry?
Authors: Li Xiaopeng , Cunderlik Robert , Lin Miao , Macak Marek , Zahorec Pavol , Papco Juraj , Minarechova Zuzana , Krcmaric Jordan , Roman Daniel
Published: March 2024

Numerical methods like the Finite Element Methods (FEM) or Finite Element Methods (FVM) are widely used in many engineering applications to solve boundary value problems that are hard to find rigorous analytical solutions. These numerical methods have been also applied in geodesy in many previous studies regardless of its huge computation demands. They have arisen due to the fact that the upper boundary condition was usually set up at the satellite orbit level, hundreds of kilometers above the Earth. The relatively large distances between the bottom boundary Earth' s surface, and the upper boundary even exacerbates the computation loads because of the required discretization in between. Considering that many areas such as the US have uniformly distributed airborne gravity data that are just a few kilometers above the topography, we propose to move the upper boundary from the satellite orbit level to the mean flight level of the airborne gravimetry. The significant reduction in altitudes, dramatically saves the large computation demands in previous FEM or FVM computations. This paper demonstrates this benefit by using FVM for both simulated data and real data in the target area. In the simulated case, the FVM numerical results show that about an order of magnitude precision improvement can be obtained when moving the upper boundary from 250km to 10km, the maximum altitude of GRAV-D. For the real data sets, 2-3 cm level of accurate quasi geoid model can be obtained depending on different schemes used to model the topographic mass. The paper also demonstrates how to find the upper layer in case no airborne data is available. Last but not the least, this study provides a 3D representation of the entire local gravity field instead of a single 2D surface, the (quasi) geoid.
Inverse Radius Weighting (IRW) interpolation model: A new interpolation considering morphology
Authors: Sadeghi Behnam , Morrison Shaunna , Eleish Ahmed , Klump Jens
Published: March 2024

Geochemical sampling has limitations due to budget constraints and restricted access to certain areas. This results in some regions being unsampled, making it difficult to generate comprehensive geochemical anomaly maps and distinguish between background values and anomalies. To address this, different interpolation models have been developed, such as inverse distance weighting (IDW) and kriging techniques. However, both IDW and kriging only consider the horizontal distance between samples and ignore elevation changes, which is important in real-world terrains. This effect is most pronounced in mountainous terrains. To address this, we propose a new interpolation technique called Inverse Radius Weighting (IRW). IRW factors in both horizontal distance and elevation changes between sample pairs, resulting in more accurate predictions. Detailed elevation data is available for the entire globe in the form of digital elevation maps from the Shuttle Radar Topography Mission (SRTM) and other sources. In this research, both IDW and IRW models were applied to soil samples in Cyprus. A comparative analysis between IDW and IRW models showed that IRW gives more accurate predictions, especially in terrains with complex morphologies. IRW's ability to account for topographical influences makes it the preferred choice in such scenarios.
Ultra-relativistic 7 MeV electron acceleration during intense and long-duration substorm activity
Authors: Hajra Rajkumar , Tsurutani Bruce , Lu Quanming , Lakhina Gurbax , Du Aimin
Published: March 2024

Substorms and strong convection events occurring during high-intensity long-duration continuous auroral electrojet (AE) activity (HILDCAA) events are associated with acceleration of magnetospheric relativistic electrons. From an analysis of Van Allen Probe satellite measurements, it is shown that ~7 MeV electrons are accelerated during ~3.4–4.1 days-long HILDCAA events. The dominant acceleration process is due to wave-particle interactions between magnetospheric electromagnetic chorus waves and substorm injected ~100 keV electrons. The longer the HILDCAA and chorus last, the higher the maximum energy of the accelerated relativistic electrons. The acceleration to higher and higher energies is by a bootstrap mechanism. Due to the unusually long process associated with the electron acceleration to ~7 MeV, spacecraft controllers can be given proper advance warning to shift to other modes of operation for the protection of spacecraft electronics.
Radiative Effects on Kinetic and Potential Energy Budgets Associated with Rapid Intensification of Typhoon Mujigae in 2015
Authors: Zhang Chi , Li Xiaofan
Published: March 2024

This study investigated radiative effects on kinetic and potential energy budgets associated with rapid intensification of Typhoon Mujigae in 2015 by conducting sensitivity experiments with Weather Research and Forecasting (WRF) model simulation. We found that the inclusion of radiative effects mainly increases the symmetric rotational kinetic energy, while the radiative effects are from infrared longwave radiative effects. The comparison in symmetric potential energy and symmetric rotational kinetic energy budget between the sensitivity experiments excluding the radiative effects and solar shortwave radiative effects only reveals that the inclusion of infrared longwave radiative effects destabilizes the moist atmosphere and increases the conversion from symmetric potential energy to symmetric divergent kinetic energy , which reduces symmetric potential energy and enhances symmetric rotational kinetic energy through the strengthened conversion from symmetric divergent kinetic energy to symmetric rotational kinetic energy.
Short-term submesoscale eddy variations observed in SWOT KaRIn SLA fields
Authors: Chen Xiaoyan , Quartly Graham , Chen Ge
Published: March 2024

In this study, we present a series of typical submesoscale eddy short-term variations revealed by one-day repeat SWOT KaRIn sea level anomaly (SLA) fields. First, several representative cases demonstrate SWOT’s capacity to continuously track submesoscale signals (