bluuebunny/crossref_metadata_2025 huggingface dataset:
Recent progress in nesting a DEM- based regional sea ice model within a continuum model
Authors: Lu Wenjun , Tsarau Andrei , Zhang Yuan , Lubbad Raed , Løset Sveinung
Published: March 2024

Understanding sea-ice dynamics at the floe scale is crucial to improve regional ice forecast and comprehend the polar climate systems. Continuum models are commonly used to simulate large-scale sea-ice dynamics. However, they have both theoretical and computational limitations in accurately representing sea-ice behaviour at small scales. Discrete Element Models (DEMs), on the other hand, are well-suited for modelling the behaviour of individual ice floes but face limitations due to computational constraints. To address the limitations of both approaches while combining their strengths, we explored the feasibility of nesting a DEM within a continuum model. This paper reports recent progresses in addressing two challenges associated with this method: 1) how to couple a discrete element method (DEM) – based model (a Lagrangian model explicitly tracking each element in space) into a continuum model (a Eulerian model with fixed spatial mesh transferring state variables within); 2) how to explicitly model fracture of sea ice at large scales. Based on our assessment, integrating DEM and continuum model simulations showed potential for offering accurate, high-resolution predictions of sea ice, particularly in coastal areas and near islands. Simulating fracture of sea ice still poses great computational challenges. However, we see a potential in a data-driven approach to accelerate the computational efficiency in resolving floe-scale ice fractures.  
Improving 2D resistivity model obtained from DC Resistivity Data Inversion by using Convolutional Neural Network Algorithm to Find Buried Archaeological Remains
Authors: Över Demet , Candansayar Mehmet Emin
Published: March 2024

The Direct Current Resistivity (DCR) method is one of the well-known geophysical methods used for a wide range of areas such as mining geophysics, hydrogeophysics, and archaeogeophysics investigations. DCR data is generally collected along profile using multi-electrode and multi-channel measurement systems and interpreted using ‘two-dimensional (2D) or three-dimensional (3D) inversion algorithms. The inverse problem of DCR data is ill-posed (nonlinear, nonunique, and unstable). Therefore, the generally smoothing regularization inversion method is used for DCR data inversion. Additionally, a homogenous resistivity model is used as the initial model in regularized inversion. Hence, we generally obtain a smooth resistivity model after 2D/3D inversion. However, some structures such as buried archaeological targets, cavities, and fault structures have sharp boundaries with their neighboring medium. In this research, we propose enhancing 2D DCR data inversion results using a convolutional neural network (CNN), aiming for sharp boundaries. We developed a U-net-based CNN algorithm, named DCR2D_Net_Archeo. This method utilizes 2D inversion results as the input, with the real resistivity model serving as the output, streamlining geophysical data interpretation for archeological applications.  We tested the DCR2D_Net_Archeo algorithm by using synthetic and real data.  We showed that the developed resistivity model enhancement algorithm, DCR2D_Net_Archeo, improves smooth inversion results and buried archeological remains' size and position can be delineated from those enhanced models.  KEYWORDS: DC Resistivity, 2D, Inversion, Deep Learning, archaeo-geophysics. ACKNOWLEDGEMENT: This study is part of the Ph.D. thesis of the first author and the manuscript about this study has been submitted to Pure and Applied Geophysics. This study is also made under the Ankara University Technopolis R&D projects (STBP code: 084286).  
Monitoring high resolution variations in proglacial lake area using an Uncrewed Aerial Vehicle (UAV) at Fjallsjökull, Iceland
Authors: Andrews Ameila , Baurley Nathaniel , Dash Jadu , Hart Jane
Published: March 2024

The subglacial hydrological system is a key component in understanding the response of glaciers to climate change. However, due to its inaccessibility, the subglacial system is logistically difficult to investigate. Here we use an Uncrewed Aerial Vehicle (UAV) to monitor variations in the lake area of Fjallsárlón, a large proglacial lake in SE Iceland, at high spatial and temporal resolutions to better understand the hydrology of the adjacent soft-bedded outlet glacier Fjallsjökull. Surveys were undertaken over 10 days in July and 7 days in September 2023, with the acquired imagery used to generate high-resolution orthomosaics and DEMs (0.01 m and 0.03 m, respectively). We then developed and applied a novel method to the resultant 3D models to measure variations in proglacial lake area on a diurnal scale, bridging the gap between ground and satellite-based observations. We were able to measure a minimum diurnal variation of ~9,800 m2 and a maximum diurnal variation of ~56,000 m2 in lake area during the study period. As such, our results indicate the potential of UAVs to monitor changes in proglacial lake area at high resolutions. We suggest that the novel method applied here can successfully be used to measure variations in the lake area of Fjallsárlón, which can be used alone or alongside satellite records of lake area change. From these data, insights into the outputs of the hydrological system can be obtained, which can be used alongside meteorological data to better understand the subglacial system of Fjallsjökull.
How beech trees use isotopically heavier precipitation because of seasonality
Authors: Bernhard Fabian , Lehmann Marco M. , Gessler Arthur , Meusburger Katrin
Published: March 2024

Soil-vegetation systems partition incoming precipitation into either the freshwater system ("blue water") or back to the atmosphere as evapotranspiration ("green water"). The isotope signatures of these fluxes are observed to be distinct. We investigate the partitioning of precipitation and illustrate one potential mechanism for this "apparent" isotopic fractionation of root water uptake by means of an isotope-enabled mechanistic water balance model [1].Stable water isotope signatures were collected at a Swiss forest site dominated by beech trees (>60 cm DBH, 37m stand height) with a mean annual precipitation of ~1050 mm/year, at 800 m.a.s.l throughout two vegetation seasons. Up to bi-weekly samples of xylem and mobile soil water and six bulk soil water campaigns (down to 150 cm) were combined with continuous hydrometric measurements (down to 200 cm) to constrain modelled water fluxes such as preferential infiltration patterns and seasonal patterns of root water uptake.During the model validation period in 2022, the model faithfully reproduced seasonal and vertical patterns in isotope signatures. The goodness of fits of time series showed δ18O RMSE smaller than 0.4‰ for mobile soil water at 50cm or 80cm or smaller than 1.0‰ for stem xylem water at breast height, while the goodness of fits of vertical profiles had δ18O RMSE smaller than 1.7‰ for bulk soil water profiles down to 150cm. Reduced soil water availability in the topsoil during the summer of 2021 led to a downward shift of the flux-weighted average water uptake depths of beech trees. However, while the relative contribution to water uptake of soil layers below 80 cm increased during the summer of 2021, their absolute contribution did not increase sufficiently to compensate the water missing in the topsoil layers where most roots are located. Modelled infiltration pathways and root water uptake illustrate how seasonal and vertical selectivity of root water uptake leads to distinct isotope signatures in the modelled green and blue water fluxes. This behaviour is obtained at this site without a two-domain representation of the soil domain nor preferential flow to deeper layers. Further, simulations with synthetic seasonal isotope patterns in precipitation demonstrate how this "apparent" fractionation factor depends on the timing of transpiration together with the seasonality of the precipitation isotope signature. In conclusion, this study highlights that the soil-vegetation system may fractionate heavier precipitation for the green water fluxes mainly because of the seasonal patterns in precipitation isotope signatures and transpiration rates. [1] Fabian Bernhard. (2024). fabern/LWFBrook90.jl: v0.9.8 (v0.9.8). Zenodo. https://doi.org/10.5281/zenodo.10463109
The Planetary Boundaries Framework: Status (“PB3.0”)
Authors: Richardson Katherine , Steffen Will , Lucht Wolfgang ,   PB3.0-Team
Published: March 2024

The planetary boundaries framework emerges from Earth system science and was developed to help guide the global community in its efforts to manage Anthroposphere interactions with the Earth’s bio-physical components. In the third iteration of the framework, PB3.0 (September 2023), six of the nine boundaries are found to be transgressed and anthropogenic pressure is increasing on all the boundaries earlier found to be exceeded. Metrics are, for the first time, proposed for all boundaries. Human Appropriation of Net Primary Production is proposed as the control variable for the function of the biosphere as photosynthesis represents the energy input supporting almost all life. The probability of achieving global climate goals is argued to be closely linked to the fate of global forests. Thus, the climate and biodiversity crises must be addressed together. Directions for the framework’s further development are discussed.
Demethylation of Naproxen and Caffeine by Marine Sedimentary communities
Authors: Gilevska Tetyana , Rotaru Amelia , Fonseca Alexis , Kümmel Steffen , Krauss Martin , Inostroza Pedro Inostroza , Bonaglia Stefano
Published: March 2024

Naproxen and caffeine may enter marine environments through discharge of wastewater, subsequently accumulating in marine sediments at nanogram per gram (ng/g) levels. These compounds, containing methyl groups linked to heteroatoms, may serve as potential substrates for microbial communities, including methanogens.  Methanogens could utilize these methyl groups directly for methylotrophic methanogenesis, or indirectly for hydrogenotrophic or acetoclastic methanogenesis. Alternatively, some other microorganisms are capable solely of demethylation. Our study investigates the capacity of marine sedimentary communities to demethylate naproxen and caffeine, potentially leading to methane production in marine sediments.To elucidate the biotransformation pathways and potential methane production from these compounds, we employed a multiple line of evidence approach, including microbial incubation with surface marine sediments, stable isotope analysis, concentration analysis, and 16S rRNA amplicon sequencing. Sediments were collected from Hakefjorden, near the town of Stenungsund on the Swedish west coast, adjacent to the Strävliden WWTP's discharge outflow. Sediments were characterized to contain 4 and 7 ng/g of caffeine and naproxen, respectively. The top sediment layer (2-10 cm) was used for microbial incubation experiments with 13C-labeled methyl group substrates, including naproxen, caffeine, and standard methanogenesis substrates such as acetate, methylamine, and carbonate. This enabled tracing of the microbial transformation of the methyl groups within these compounds. Results indicate that both naproxen and caffeine act as precursors to 13C-methane production, with naproxen additionally leading to 13C-carbon dioxide formation. The presence of these compounds enriched specific microbial populations, including methanogens (Methanomicrobiaceae), other Archaeal groups (Lokiarchaeia), various fermentative bacteria, and sulfate-reducing bacteria.The transformation of naproxen and caffeine stemming from wastewater into methane and carbon dioxide highlights alternative substrates for greenhouse gas production in marine sediments, an area of concern considering these and other anthropogenic compounds' presence in the sediment. This underscores the need for detailed research into the interactions between marine microbes and methylated pharmaceuticals, given their potential impact on greenhouse gas emissions.
From high-T Hydrothermal Alteration To Near-Surface Weathering – The Alteration History of the Rolvsnes Granodiorite, W Norway
Authors: Drivenes Kristian , Knies Jochen , Kurz Tobias , Margreth Annina , Schonenberg Jasmin
Published: March 2024

The Rolvsnes Granodiorite, comprising the major extent of the northern part of Bømlo Island, Western Norway, has been proposed to be an onshore analogue to the weathered basement rocks at Utsira High hosting significant petroleum resources. A total of 205 meters of core in three boreholes was collected crosscutting both fault zones and apparently tectonically undisturbed rocks. Four distinct lithologies were identified in the drillholes: A medium-grained (grano-)diorite, a range of biotite granites, a porphyritic granite, and aplites/pegmatites. All rock types display evidence of hydrothermal alteration as either pervasive discoloration or more localized veining. Early propylitic alteration of the granodiorite is easily observed macroscopically as distinct greening, caused by primary amphibole being replaced by epidote, and calcic plagioclase cores being altered to epidote+muscovite+quartz. The extent and transition of the alteration steps can be observed in the hyperspectral logs. A second generation of epidote can be observed as 1-2 mm veins crosscutting all lithologies. With decreasing temperature and/or higher fluid/rock ratio, biotite is altered to chlorite. Late infiltration of carbonic fluids is evident from calcite veins cutting former alteration types, and ankerite/Fe-rich dolomite + Fe-oxide veins associated with open fractures. The clay mineralogy is dominated by smectite and kaolinite, and several meter long sections of the drill cores are near or completely disintegrated from drilling and core handling due to the high smectite content. Kaolinite and smectite may occur together as alteration products, but in open fractures kaolinite is found as infilling in vugs and fractures lined with quartz or associated with the Fe-carbonates, with little or no smectite. This indicates that during late fluid circulation in the faults, kaolinite was precipitated directly from the fluid, and that smectite in the smectite-rich zones was a part of a low temperature pervasive alteration event.K-Ar dating of the clay-rich alteration zones from this and former studies show a large range of ages, with the ages of the finest (
Soil loss due to sugar beet harvesting is an underestimated but significant soil erosion process in mechanized agricultural systems.
Authors: Saggau Philipp , Busch Fritjof , Brunotte Joachim , Duttmann Rainer , Kuhwald Michael
Published: March 2024

Soil loss due to crop harvesting (SLCH) is a globally occurring, but underestimated process that contributes to soil degradation, adversely affecting soil functionality and fertility. In northern Europe, sugar beets play a crucial role for SLCH due to their high production rates, yet there is a lack of research in commercial mechanized farming of sugar beets. The aim of this study is to measure SLCH for sugar beets using typical commercial harvesters and identify relationships to crop and soil variables. Therefore, sugar beets and soil samples were collected for 14 sampling sites between 2018 and 2020 in Northern Germany.The results show that SLCH is in average 0.064 kg per kg sugar beet (SLCHspec), which corresponds to a loss of 5.7 Mg ha-1 harvest-1 (SLCHcrop). These numbers are higher than former comparable studies and 83.9 % higher than SLCH estimates by sugar beet factories. In addition, we found that i) SLCH considerably varies among years, fields, but also within fields, ii) the most influential drivers for SLCH are soil water content and clay content, iii) soil properties impact SLCH differently in dependence to soil water content, iv) SLCH of sugar beets can lead to significant nutrient and soil organic carbon losses. Thus, the results underline that SLCH is an important and underestimated determinant of soil erosion processes, which urgently needs to be considered in models and estimates additionally to concurrent processes like water, wind and tillage erosion. This is important for the adaptation of soil conservation measures in order to reduce ongoing soil degradation, especially in highly mechanized agriculture.
Detecting the magnetic characteristics of submarine volcanic area off the coast of northern Taiwan
Authors: Lo Chung-Liang , Hsu Shu-Kun , Lin Shiao-Shan , Tsai Ching-Hui , Chen Song-Chun , Su Pin-Ju
Published: March 2024

Taiwan Island, the product of an active mountain building, is deduced from the oblique collision between the Eurasian and the Philippine Sea plate, and its northern part and offshore region are under post-collision collapse. We have collected the magnetic data to combine and compile a map of regional magnetic anomalies for investigation of the volcanic and igneous arrangement over this area off the coast of northern Taiwan, where a series of submarine volcanoes and igneous rock isles are rooted. Generally, a magnetic high largely dominates the area of most submarine volcanoes and extends eastward, while the adjacent area to the north is lower. To better understand the magnetic features for the submarine volcanic area, several magnetic methods are used, such as the inversion with an equivalent magnetic layer thickness for the magnetization distribution; the enhanced analytic signal technique for evaluating the magnetic source strength distribution; using the tilt angle of the total horizontal gradient and the tilt angle of the analytic signal amplitude for detecting the source edges. Amongst the area, a small part segment with dense survey line that may provide a more detailed resolution result.
U-Net Deep Learning for Geospatial Landslide Inventory Mapping in Genting Highlands, Malaysia
Authors: Sappe Siti Nuha Amisyah , Abu Bakar Rabieahtul , Razak Khamarrul Azahari , Mohamad Zakaria , Ab Rahman Abdul Aziz , Abd Manap Mohamad , Jamaluddin Tajul Anuar
Published: March 2024

Genting Highland is predominantly the mode of landslides, especially prevalent during and post monsoon seasons. Globally, landslides encapsulates the widespread hydro-geological disaster elucidating their causes, risks, and impacts on infrastructure and human life. Attributed  from Malaysia natural undulated terrain, torrential rainfall, expanding urbanization contributed to the increasing landslide occurrences. Laying the groundwork for a more efficient landslide mapping over a vast area underscores the imperative need of Artificial Intelligence (AI). Landslide mapping to-date transitions from conventional delineation to employing U-Net, a deep learning architecture, to automate and expedite the process of identifying landslides from remote sensing data towards the emphasizes on rapid landslide mapping. This study is to create detailed landslide inventory maps by mapping new and old landslide footprint for Genting Highlands, with U-Net Deep Learning as a pivotal tool. Entail a systematic process, to identify landslide structures according to predefined categories, using high-resolution satellite imagery to train the U-Net model, and ultimately producing validated landslide maps for the region. The stages for integrating U-Net Deep Learning with geospatial analysis include data acquisition, pre-processing, DL training, analysis, and the final output of landslide mapping. Spot-7 imagery as input to the U-Net and  landslide semantic shapes that consist of crown, transportation body and foot, whereby pixel by pixel are classified when introduced. The anticipated results, showcasing the validity and precision of the model's landslide automated delineation on other imageries. Verification involves the comparison between U-Net's projected landslides to a manually delineated landslide inventory for Genting Highlands. Hence, this research provide precise and efficient tools for identifying and forecasting landslides in landslide-prone areas. 
Tektonika: one more year of open science 
Authors: Eagles Graeme , Pérez Díaz Lucía , Gouiza Mohamed , Bond Clare , Fernández-Blanco David , McCarthy Dave , Doré Tony , Kavanagh Janine , Lacassin Robin , Magee Craig , Peron-Pinvidic Gwenn , Schmitt Renata , Welford Kim
Published: March 2024

Science, without effective dissemination, has a very short life and little impact. Yet, most scientific research is hidden away behind exclusive and expensive paywalls imposed by traditional publishers. Tektonika is an Earth Science community-led diamond open-access journal (DOAJ: free for authors, free for readers) publishing peer reviewed research in tectonics and structural geology. It is a grass-roots initiative driven by the enthusiasm and devotion of a wide and diverse spectrum of Earth Scientists from around the globe, intended to help shape a new landscape for publishing in the geosciences. Since its launch at EGU2022, Tektonika has been growing steadily thanks to a constant stream of new manuscript submissions, many of which have already been published as part of the journal’s first two issues (the first compiled in July 2023, and the second in January 2024). In order to meet the increasing demands of running a growing journal, the original team of editors was expanded in 2023 (from 6 to 8 Executive editors, and from 13 to 21 Associate Editors). Despite initial external skepticism, our experience over the last few years mirrors those of our sister journals, proving that community-driven DOAJs can not only succeed but thrive. The community support has been palpable throughout - from those submitting their work for publication, to others helping us reach a wider audience through social media, to the many that volunteer their time to support the editorial work, the review process, and the typesetting and pagination of the accepted research papers.
The conceptual model of the formation of Earth’s habitability
Authors: Liu Yun
Published: March 2024

The difficulty in direct differentiation of the felsic crustal components from Earth’s mantle peridotite leads to a requirement for the presence of a large amount of hydrated mafic precursor of TTG in Earth’s proto-crust, the origin of which, however, remains elusive. The mafic proto-crust may have formed as early as  4.4 Ga ago as reflected by the Hf and Nd isotopic signals from Earth’s oldest geological records, i.e., zircons. The Archean continents, primarily composed of the felsic tonalite–trondhjemite–granodiorite (TTG) suite, were formed or conserved since  3.8 Ga, with significant growth of the continental crust since  2.7 Ga. Such a significant time lag between the formation of the mafic proto-crust and the occurrence of felsic continental crust is not easily reconciled with a single-stage scenario of Earth’s early differentiation. Here, inspired by the volcanism-dominated heat-pipe tectonics witnessed on Jupiter’s moon Io and the resemblances of the intensive internal heating and active magmatism between the early Earth and the present-day Io, we present a conceptual model of Earth’s early crust-mantle differentiation and the formation of habitability, which involves the tremendous heat obtained by the Moon-forming giant impact. It  forces Earth to choose an Io-like tectonics, which can efficiently dissipate heat and extract a mafic proto-crust from the early mantle, then followed by an intrusion-dominating regime that could account for the subsequent formation of the felsic continents as Earth cools. The episodic heat-pipe tectonics destroy most of rocks formed during Hadean era. The cool and hard rock layer formed due to the heat-pipe tectonics is essential for the formation of habitability of the earth. By this way, the required conditions by a habitable Earth, e.g., adequate surface temperature, aqueous sphere, and towering mountains, etc., would be appeared within a surprisingly short time. Therefore, the Moon-forming giant impact is the most important reason to make a habitable Earth. It not only brought tremendous heat into Earth and forced Earth to choose the volcanism-dominated heat-pipe tectonics but also completely destroyed the proto-atmosphere to avoid over-heated situations occurred like that of Venus at present. 
Modeling the impact of stone content on the shape of water retention curve
Authors: Doat Anne , Vincke Caroline , Javaux Mathieu
Published: March 2024

Heterogeneous soils with stone fractions are very common in non-agricultural areas. The characterization of their hydraulic properties is important but face technical challenges. Therefore, the retention of the stony fraction (larger than 2 mm) is often considered as null. However, when soil stone content is large (>15%), even a slight change of water with suction in the stone fraction will affect the shape of the bulk soil retention curve.In this study, we analyzed the retention data, between pF 0 and pF 4.2, of more than 2400 aggregates extracted from 48 soil horizons in forests down to 2-m depth. For each horizon, at each suction level, we characterized water content and stone content of at least 8 replicates of aggregates. We propose a novel methodology to extract and separate the hydraulic properties of the stony and of the fine fractions from these data. It proved to be efficient beyond 15% of stone content.In general, the change of volumetric water content between pF 2 and pF 4.2 was below 5% for stones but for some of them, it could reach up to 15%.  In addition, we could propose a general expression of the bulk retention curve that explicitly contains the fraction of stones. It is observed that the shape of the bulk retention curve (mono or bimodal) evolves with stone content for a given horizon.
Spatial and Temporal Dynamics of Agricultural Water Footprint in a Changing Climate: A CORDEX-SPARE:WATER Analysis.
Authors: Correa Alicia , Frank Natascha , Muzammil Muhammad , Weeser Bjoern , Breuer Lutz
Published: March 2024

The far-reaching impact of climate change on water resources, particularly its intensification of scarcity, poses a substantial threat to the sustainable management of water in agriculture. To enhance cross-sectoral decision-making at various scales, it is vital to quantify both current and future water consumption, employing methodologies that assess the agricultural water footprint (WF).This study employs the Site-sPecific Agricultural water Requirement and footprint Estimator (SPARE:WATER) to evaluate the susceptibility of green and blue agricultural WF at various scales across Colombia. The assessment is conducted under two CORDEX (Coordinated Regional Climate Downscaling Experiment)-driven climate scenarios, RCP2.6 and RCP8.5. High-resolution (0.22°) CORDEX climate model projections are used to drive the SPARE:WATER model, while historical weather data from fifteen stations (1977-2005) are employed to bias-correct the model's gridded data using the Equal Quantile Matching (EQM) method. This corrected data was spatialized using IDW interpolation. Ten major crops are selected based on their national production significance, based on the National Agricultural Survey. Crop characteristics such as harvested area, yield, and crop coefficients are obtained from local and FAO sources. The analysis focuses on both green and blue WF for the near future (2060) and far future (2099), compared to the present (2020).Preliminary findings underscore a national WF of 45 km3/yr, with important variations at the departmental level. The spatial variability of WF is influenced by both wet and dry years.  Cocoa, coffee, and palm oil emerge as crops with the most substantial WF, showcasing respective water requirements of 30 k m3/t, 18 k m3/t, and 8 k m3/t nationally. Regional variations reveal the significance of crops such as plantain and banana in the agricultural WF landscape. Under the RCP2.6 scenario, the green and blue WF projections for 2060 and 2099 exhibit marginal changes relative to 2020. Conversely, under the RCP8.5 scenario, a discernible increase, particularly in blue WF, is evident, with a surge of 96% by 2099. This trajectory underscores the heightened water requirements anticipated for pivotal crops like cocoa and coffee in the future agricultural landscape.These findings underscore the urgent need for informed water management strategies in the future of Colombian agriculture, particularly in the face of a high-emission scenario. The results of this study can inform policy and decision-making aimed at ensuring sustainable water resources management and food security under the evolving climate landscape.
Soil carbon storage in response to forest disturbance 
Authors: Mayer Mathias , Hechenblaikner Florian , Baltensweiler Andri , James Jason , Rusch Silvan , Didion Markus , Walthert Lorenz , Zimmermann Stephan , Rigling Andreas , Hagedorn Frank
Published: March 2024

Forest soils have significant potential to mitigate climate change through their ability to store large amounts of organic carbon. However, forests are increasingly subject to natural disturbances such as windthrow, wildfire or disease outbreaks, which threaten the permanence of this large carbon stock. In response to increasing disturbances and ongoing climate change, forests are expected to lose their ability to return to pre-disturbance conditions involving a reorganization of tree species composition and stand structure. If tipping points are crossed, even a complete vegetation shift and conversion to non-forest ecosystems is possible. Here we aimed to assess the sensitivity of forest soil carbon to disturbance and its recovery with contrasting successional trajectories by combining two field studies on soil carbon stocks in windthrown forest stands and a global meta-analysis on the effects of different disturbance agents. Our results along an altitudinal gradient in Switzerland show that mountain forests with high carbon stocks in thick organic layers were particularly sensitive to disturbance by windthrow, losing up to 90% of their carbon stored belowground. In contrast, low-elevation forest soils with thin organic layers and smaller carbon stocks were barely affected. These results are consistent with our meta-analysis, which shows that disturbance-induced carbon losses increase with the size of initial carbon stocks. Boreal and high-elevation forests with large soil carbon stocks are highly sensitive to severe and long-lasting carbon losses due to damage from storms, wildfire, insects, and harvesting, while in most temperate and tropical forests soil carbon stocks recover more rapidly and losses are smaller. Results from a disturbance chronosequence in Austria also suggest that vegetation shifts following forest damage can strongly influence the recovery of soil carbon stocks after disturbance. Disturbed sites that remained in a non-forest, grass-dominated state for three decades accumulated about a third more soil carbon than sites that regenerated with trees. In addition to high litter inputs from herbaceous fine roots at grass-dominated sites, we relate this difference to changes in microbial community structure and function. In conclusion, our results underline that the magnitude and duration of soil carbon losses after disturbance depend on the forest type and site specific soil properties. Moreover, vegetation shifts during succession significantly modify the re-accumulation of soil carbon after disturbance.
A large sample harmonized database of daily streamflow, meteorological data, and catchment attributes for over 28,000 global catchments
Authors: Abbas Ather , Beck Hylke
Published: March 2024

High-quality observational data is critical for driving, evaluating, and calibrating geo-environmental models, particularly data-driven models. The quality and availability of such data greatly influence the output of these models. Over recent decades, numerous national, regional, and global observational datasets have been developed for catchment-scale hydrological modeling. However, the regional and national datasets often differ widely in data sources, formats, and variables, making their use challenging and time-consuming. Furthermore, existing global datasets do not include all available data sources and thus have limited coverage. In this presentation, we introduce a harmonized, comprehensive database that amalgamates existing national, regional, and global datasets into a unified, user-friendly resource. Our database consists of daily streamflow observations, daily time series of 10 meteorological variables, climatic and physiographic attributes, and catchment boundaries for over 28,000 catchments worldwide. These catchments range in size from 2~km$^2 to 1300~km$^2 (mean 150~km$^2$) and the number of daily streamflow observations per catchment ranges from 200 to 18,000 (mean 400). The meteorological data covers precipitation, temperature, humidity, radiation, and wind speed for each catchment. We included precipitation estimates from 17 state-of-the-art products such as CHIRPS, ERA5, GSMaP, IMERG, MSWEP, and SM2RAIN. To explore the database and retrieve data, we have developed a straightforward Python-based Application Programming Interface (API). All related code will be open sourced and accompanied by extensive documentation and usage examples. We anticipate this database will be an invaluable resource for various hydrological studies, including model calibration, evaluation, inter-model comparisons, and the assessment of different forcing datasets.
Realistic storm surge scenarios for UK (re)insurers
Authors: Scudeler Carlotta , Willis Iain
Published: March 2024

The UK has experienced several coastal floods over the last century, which have threatened the society and the (re)insurance industry. The Winter of 2013/2014 was especially notable, in that several events have largely affected many different areas in England as 50 defence breaches occurred. Thus, simulating credible scenarios, capable of capturing the likelihood of coastal flood events arising at different locations during the same storm and modelling the impact of breaching of defence, is crucial to both disaster management planning as well as the insurance industry. In this study, which was carried out jointly by the Gallagher Research Centre and the research partner HR Wallingford (HRW), two extreme but realistic UK storm surge scenarios were developed separately for the East and West coasts of UK. The scenarios explore simultaneous flooding along extended coastline and the impact of realistic defence breaching, both in the present day and in 2050. A high-resolution footprint for each scenario run (present day non-breach, present day breach, future non-breach, and future breach) was generated by means of a 2D hydrodynamic model run on a 5m LiDAR Digital Elevation Model. Flood breaching was based on a national set of fragility curves created by HRW’s defence model. To account for climate change, the UKCP6 (UK climate projections) were used to assign the projected RCP 4.5 surge estimates for 2050. Finally, the loss potential for each simulated footprint was estimated for Gallagher Re’s insured market portfolio. Among the major findings of the analysis, it is shown how defence breaching has a significant impact on the potential loss, particularly for the East coast scenario, for which it results in a 10x increase in the number of properties affected. Climate change has also two impacts, on the number of properties flooded, but also on the depth of flooding experienced by properties already at risk, further exacerbating the potential loss. Finally, it is shown how these Realistic Disaster Scenarios are supporting UK (re)insurers in helping stress test their exposure to storm surge, while helping build a robust view of risk.
4C Bomb Spike Signal Constrains Microbial Mat Growth Rates
Authors: Blattmann Franziska R. , Bontognali Tomaso R.R. , Haghipour Negar , Rouwendaal Simon E. , Eglinton Timothy
Published: March 2024

Microbial mats are considered among the earliest forms of life to have inhabited our planet and occur in early Archean sedimentary sequences. Living mats consist of a coherent network of metabolically diverse microorganisms that produce extracellular polymeric substances, which allows them to thrive in harsh environments. Despite their importance for the study of early life on Earth and their relevance in the search for life on Mars, growth rates as well as carbon cycling of microbial mats remain unclear. Past radiocarbon (14C) studies of microbial mats show the presence of allochthonous organic particles trapped within the autochthonous biomass which complicate reconstruction of the mat growth rates (Bahniuk Rumbelsperger, 2013). In this study, millimeter-scale sampling and radiocarbon analysis was conducted on vertical profiles of microbial mats and lagoon water samples from two modern coastal sabkhas located on the Northwest and South coast of Qatar, respectively. The 14C measurements of mats from both studied sabkhas show increasing Δ14C values from the surface downwards, from an average of -25 ‰ up to a maximum 180 ‰. At the base of the mat there is an abrupt ~150 ‰ decrease in Δ14C values. This clear and shared trend between different sites and profiles shows that in both sites organic matter is predominantly being produced in situ via photosynthesis. Moreover, this 14C trend correlates with the global bomb spike carbon signal (Graven, 2015) and implies that these 45-55 mm thick mats are relatively modern structures and cannot be more than 60 - 70 years old. Therefore, the microbial mat growth rate is higher than previously estimated, suggesting that stromatolites, possibly those from earlier in Earth history, may have formed in a relatively short time. The trend also shows that most organic bound carbon is not extensively recycled within the mat. Instead, the primary source of in-situ produced organic carbon is the dissolved inorganic carbon of the lagoon water. These findings shed new light on the development of one of the earliest life forms on our planet.REFERENCESBahniuk Rumbelsperger A.M., 2013. Coupling organic and inorganic methods to study growth and diagenesis of modern microbial carbonates, Rio de Janeiro State, Brazil: Implications for interpreting ancient microbialite facies development, PhD Thesis ETH Zurich, ETH No. 20984.Graven, H.D., 2015. Impact of fossil fuel emissions on atmospheric radiocarbon and various applications of radiocarbon over this century. Proceedings of the National Academy of Sciences, 112(31): 9542-9545.
Shallow landslide early warning in typhoon rainstorm area based on Slope Warning Model
Authors: Yan Liangxuan , Yin Kunlong , Chen Lixia
Published: March 2024

To carry out refined early warning for shallow landslides in typhoon rainstorm area, it is necessary to propose hourly precipitation warning criteria. The Slope Warning Model (SWM) of analyzing the correlation between landslides and rainfall process proposes short-term early warning criteria and rainfall duration. Individual slope warning framework is established based on regional average rainfall threshold and adjustment rainfall concerning specific geotechnical factors. The regional landslide rainfall threshold, counted by I-D model, is proposed as the regional average threshold. The geological environment of individual slope is investigated as geographical figures, geological structure, composition of soils, hydrological conditions and slope cutting. In terms of the simulation of infinite slope model, slope stability varies as geological factors changes due to rainfall infiltration, which may determine threshold adjustment values. Wenzhou City, Zhejiang Province of China, located in eastern coast area where is frequently impacted by typhoon, was taken as a study area. Quantitative threshold calculation formula has been proposed. Early warning criteria of different duration is proposed according to the geological factors of individual slope. This study proposed a short-term quantitative landslide meteorological warning model for individual slope. It may provide new ideas and references for "each-slope, each-threshold" of landslide early warning and risk management. Keywords: shallow landslide, early warning, typhoon rainstorm, individual slope, “each-slope. each-threshold”
A fully automated reproducible self-documenting workflow implemented in our inverse regional carbon model
Authors: Meier Arndt , Monteil Guillaume , Karstens Ute , Scholze Marko , Vermeulen Alex
Published: March 2024

The Integrated Carbon Observation System (ICOS) and the Lund University department of Physical Geography and Ecosystem Science have developed the Lund University Modular Inversion Algorithm (LUMIA) that is being used for the inverse modelling of carbon and isotope resolved methane. The work is linked with past and present Horizon 2020 projects like DICE and AVENGERS with the overarching goal of supporting the Paris agreement goals.The ICOS Carbon Portal (https://data.icos-cp.eu/portal) collects, maintains and supports a large range of greenhouse gas observations as well as some inventory and model data all of which have a unique persistent identifier each, which is a key pre-requisite for achieving a reproducible work-flow.Here we present a self-documenting fully reproducible work-flow for our inverse carbon model LUMIA, that is based on frameworks discussed in EU initiatives like Copernicus CAMS and CoCO2 as well as our own experiences from actual work-flows routinely used in Australian court cases against illegal land use changes. We will show a live demonstration of the system including its graphical user interfaces and the created provenance and reproducibility meta-data.
Application of Spectral Decomposition approach to examine the attenuation, source parameters, and site effects in Madagascar
Authors: Ravoson Manitriniaina , Razafindrakoto Hoby N. T.
Published: March 2024

A spectral decomposition approach is applied to separate the site amplification, path attenuation, and source parameters of earthquakes that occurred in Madagascar between 2011 and 2013. Concerning source parameters, the stress drop is derived from the source spectra, fitting the Brune model. Our findings indicate an increase in stress drop with magnitude, ranging from 0.001 to 0.1 MPa. Additionally, the results unveil a consistent attenuation curve diminishing with distance, characterized by a swift decay at higher frequencies below the 1/R^2 decay function. The frequency-dependent behavior of the estimated quality factor for S waves suggests rapid damping and slow dissipation.Regarding site amplification, a robust agreement is noted between resonance frequency obtained through GIT and the H/V spectral ratio. Furthermore, we explore the correlation between site amplification and geological characteristics such as sediment depth and lithology.
Temporal variability in Earth's length of day and its connection with the geomagnetic field energy over the last 3,000 years
Authors: Puente-Borque Marina , Pavón-Carrasco F. Javier , Campuzano Saioa A. , Osete María Luisa , González-López Alicia , Folgueira Marta
Published: March 2024

Historical records of lunisolar eclipses and star occultations provide us useful information on the variation of the length of day (LOD) over the last 3,000 years. Besides a steadily increasing trend caused by tidal friction effects, there is evidence for a 1300-year oscillation in the LOD. An adequate explanation for this phenomenon requires considering an interaction between the Earth's mantle and core. Several mechanisms in which the geomagnetic field is directly or indirectly involved have been suggested, including electromagnetic coupling or angular momentum exchange. This study explores the potential connection between fluctuations in the length of day and the energy of the Earth's magnetic field. Through a frequency domain analysis and correlation tests, we examined non-tidal observations in LOD and geomagnetic field energy, using the latest archaeoreconstructions of the global magnetic field spanning the last 3,000 years. As a result, we have found a shared 1,300-year period in the LOD and energy of the non-axial terms of the Earth's magnetic field. These findings are interesting and open a possibility for further research in this field to validate and enhance our understanding of the nature and underlying causes of this potential connection between the Earth's magnetic field and the temporal variability in the LOD
WOLFHydro: a modular framework for multi-model hydrological simulations
Authors: Dessers Christophe , Archambeau Pierre , Dewals Benjamin , Erpicum Sébastien , Pirotton Michel
Published: March 2024

In hydrology, a plethora of modelling approaches exist. They differ in several aspects, including the underlying hypotheses (empirical, conceptual vs. physically based) and the spatial discretisation (lumped, semi-distributed, gridded). The advent of machine learning or AI techniques further expands the spectrum of available modelling options. In this context, there is a growing scientific interest in systematically comparing existing models, understanding the reasons behind their relative performance, and applying multi-model approaches to increase the reliability of the outcomes. However, few research has been carried out so far to compare all these types of models in the same framework, namely using similar input data, pre-processing procedures, parameter optimisation algorithms and strategy, objective function, etc. WOLFHydro, developed by the HECE group at the University of Liège, offers such a framework. It addresses a flexible simulation tool organised in ‘modules’ and capable of representing any catchment, thus keeping a tuneable level of complexity and details in the description of all the physical processes at work, while remaining in the same modelling environment and starting from exactly the same input data. The software parcels out a catchment into sub-catchments or evaluation points, which are arranged in a topology network. Each module can contain a chosen type of model (physically based, conceptual, empirical) with the desired spatial representation (lumped, gridded, semi-distributed) to be assembled and facilitate the creation of hybrid models. The software also accommodates anthropogenic structures, such as dams, storage basins, or any other hydraulic structure defined by a set of operation rules customable by the user. The software currently contains a number of models developed in-house, as well as widely accepted ones (GR4H, VHM, etc). They have been validated and tested on several Belgian catchments, in particular for the 2021 extreme floods in the Vesdre and Amblève valleys. The software also features post-processing tools and a GUI interface to facilitate inspection of the results. Thanks to its versatility, WOLFHydro aims at reducing biases in model comparisons conducted in separated frameworks, improving our understanding of dominant hydrological processes, improving the evaluation of the influence model structure complexity, and carry out ensemble modelling.