bluuebunny/crossref_metadata_2025 huggingface dataset:
Flow estimation from observed water levels using differentiable modeling for low-lying rivers affected by vegetation and backwater
Authors: Aarestrup Phillip , Pedersen Jonas Wied , Butts Michael Brian , Bauer-Gottwein Peter , Löwe Roland
Published: March 2024

Simulations of river flows and water levels are crucial for flood predictions and water resources management. Water levels are easy to observe using sensors, while the mapping between water levels and flows in rivers is usually derived from rating curves. However, rating curves frequently do not include geometry, backwater effects, and/or seasonal variations, which can limit their applicability – especially in stream systems that are affected by seasonal vegetation and backwater effects. To address this, we propose a differentiable model that merges a neural network with a physically based, steady-state implementation of the Saint-Venant equations. 

In the setup, the neural network is trained to predict seasonal variations caused by vegetation growth in Manning’s roughness based on inputs of meteorological forcing and time, while the physical model is responsible for converting flow estimates into water levels along the river channel. The framework efficiently estimates model parameters by tracking gradients through both the physical model and the neural network via backpropagation. This allows us to calibrate parameters for both the runoff and the Manning’s roughness from measured water levels, thus overcoming rating curve limitations while accounting for backwater, river geometry, and seasonal variations in roughness. 

We tested the model on a 20 km stretch of the Vejle River, Denmark, which is both heavily vegetated and affected by backwater from the coast. The model was trained across five water level sensors using two years of data (2020-2022). When evaluated against 10 years of observed flow measurements (2007-2017), the model demonstrated a Mean Absolute Relative Error (MARE) of 10% compared to manually gauged discharge observations. This is comparable to the estimated uncertainty of 10% in the discharge measurements.  

The framework enables a calibration of dynamic Manning roughness within a few hours, and therefore offers a scalable solution for estimating river flows from water levels when cross-section information is available. Potential applications span across many disciplines in water resource management. 
Distribution and morphology of moulins at Isunnguata Sermia, West Greenland 
Authors: Peacey Matthew , Livingstone Stephen , Doyle Samuel , Sole Andrew , Storrar Robert , Edwards Laura , Bagshaw Elizabeth , Chudley Thomas , Ross Neil , Buzzard Sammie , Booth Adam , Bianchi Gianluca , Ing Ryan , Clason Caroline , Young Tun Jan , Thorpe Sian , Gimbert Florent , Le Bris Tifenn , Barruol Guilhem , Gilbert Adrien ,   Cryoegg
Published: March 2024

This study presents high resolution mapping of moulins located above three subglacial lakes at Isunguata Sermia. Moulins are the primary pathway for transferring supraglacial melt to englacial and subglacial environments. The formation of moulins has been explained by the flow of water into a notch, associated with glacier structures and incision of supraglacial streams, which are directly related to glacier morphology and dynamics. Meltwater input to subglacial systems, along with glacier dynamics, will in turn affect the development of subglacial meltwater networks, which control glacier morphology and dynamics. This study focusses on Isunguata Sermia, West Greenland, which has an active subglacial drainage system that includes distinct subglacial lakes. Hydrologically connected or active subglacial lakes may be directly influenced by water input from supraglacial to englacial systems via moulins during the ablation season.Moulins were mapped using a combination of high resolution orthomosaics and digital elevation models derived from uncrewed aerial vehicle flights. Moulin locations and morphologies were compared with glacier structures, ice flow velocities, and bed topography. We reveal a distinct pattern of moulin locations relative to each subglacial lake and the locations of primary and secondary glacier structures an supraglacial hydrology. Furthermore, we also outline a clear morphological pattern, wherein morphology of moulins varies distinctly at with the location of each subglacial lake between vertical shafts, crevasse associated and keyhole morphology. These observations will be used to consider the efficiency of meltwater routing from the surface to the bed, and the potential for inputs to subglacial lakes, and the wider implications for varying ice flow velocity and evolution of the subglacial drainage system.
Insights into the tectonic evolution of the northern Norwegian passive margin: Integrating field observations and plate modeling over 200 million years.
Authors: Distelbrink Amber , Shephard Grace E. , Koehl Jean-Baptiste P. , Bergh Steffen G. , Beniest Anouk
Published: March 2024

Constraining the evolution of the opening of the northernmost region of the Northeast Atlantic Ocean is of particular importance for understanding the diversity of ocean basin opening dynamics, including the development of oblique margins and shear zones. Accurately determining the timing and kinematics of the motion along the Senja Shear Zone and opening of the Fram Strait is of particular importance for climate research as this region forms the only deep-water gateway between the Northeast Atlantic Ocean and Arctic Ocean. This study combines new and legacy data and presents an analysis of the tectonic evolution of the northern Norwegian passive margin over the past 200 Ma, including integrating structural field observations and plate tectonics models.Fieldwork took place on the islands of Senja and Kvaløya in Troms County of northern Norway. The field observations reveal four dominant brittle fault groups corresponding to four normal-oblique extension directions: E-W, NNW-SSE, NW-SE, NE-SW. In the Senja Shear Zone, the strike-slip faults are predominantly oriented NNW-SSE to NW-SE. Analysis of existing plate motion models for the region for 200 Ma to present day includes three prominent extension phases in chronological order: E-W, NNW-SSE, and NW-SE.This study suggests that during the E-W oriented crustal thinning phase, normal faulting and minor strike-slip faulting dominated and gave way to basement-seated strike-slip faults during the NNW-SSE oriented extension phase. The presence of mid-upper crust faulting is argued by fault mineral striation assemblages and hydrothermal alteration. In the NW-SE oriented extensional phase, both normal faults and strike-slip faults were active. Comparisons to existing rigid plate tectonic models for the region suggest a revised deformable plate framework is required, and offers insights into the original thickness of the North-American and European plates and the role of mid-crustal tectonics in the breakup. The role of inheritance, including earlier shear zones and extensional phases will also be discussed. In addition, the present research encourages scientists to digitize analogue maps and data, preventing loss of knowledge during the analogue to digital transition.
Building an ecosystem of computational geosciences software: why Julia?
Authors: de Montserrat Navarro Albert , Räss Ludovic , Kaus Boris , Utkin Ivan , Aellig Pascal
Published: March 2024

Traditionally, the Earth science community has relied on statically compiled and explicitly typed, long-lived programming languages, namely C/C++ and Fortran, for computationally intensive production runs. In contrast, dynamic languages such as Python and MATLAB have served as alternatives for less computationally demanding tasks, prototyping, visualisation and teaching. The lower entry-level of the latter is often used as a “glue language” where the performance-critical code is written in a static language. In the recent decades other modern languages (C#, Nim, Go, Rust…) have been developed, but so far none of them have had a significant impact on the general scientific community.  Among the new modern programming languages there is Julia -with the 1.0 version being released just in 2018- which was designed with the computational scientific community as the main target user base. Julia’s main appeal for computational science are (i) performance, it produces compiled machine code with performance potentially similar to other statically compiled languages; (ii) interactivity,  it is a dynamic language, and most of the development and prototyping can be done in interactive sessions using its built-in REPL (read-eval-print loop); and (iii) readability, code is often easier to read than e.g. C++ or Rust. Julia also natively supports linear algebra operations (e.g. it ships its own wrappers for   libraries such as OpenBlas, SuiteSparse or LAPACK), multi-threading and distributed parallelism, which are crucial for a vast number of scientific applications. Additionally, Julia offers a series of features that are not intrinsic to the language itself which can ease and improve the user experience compared to traditional C/C++/Fortran: (i) Julia has a well-built package manager where one can easily add and install any version of any registered third-party package by typing two words in the REPL;  (ii) Julia itself is open source, as well as all the registered packages (hosted in Git repositories), and discourages black-box software; (iii) reproducibility is easy thanks to .toml files containing what exact version packages are needed to be installed.Here we will discuss how the combination of the previous points, along with other important features of the language (multiple dispatch, metaprogramming,…), and existing scientific libraries (GPU support, auto-differentiation,…) make Julia an excellent platform for the geoscientific community to build an ecosystem of open-source  and highly modular software, opposite to the classic lone-wolf large monolithic code. Finally, we will present an overview of the current status of the JuliaGeodynamics and related organisations, as well as the general Earth sciences ecosystem.
Using a hybrid hydrological modelling approach to simulate drying patterns in 3 non-perennial European river networks
Authors: Mimeau Louise , Künne Annika , Branger Flora , Kralisch Sven , Devers Alexandre , Vidal Jean-Philippe
Published: March 2024

Intermittent and ephemeral streams account for more than half of the world’s river channels, yet their hydrological functioning remains understudied. Modelling non-perennial river systems can help understanding the spatio-temporal patterns of drying and rewetting, but is challenging due to limited monitoring in intermittent river networks.This study is part of the EU-funded project DRYvER, which aims to understand the repercussions of drying river networks for biodiversity, functional integrity, and ecosystem services (Datry et al. 2021). Here we propose a novel hydrological modelling approach using the J2000 distributed hydrological model (Krause et al. 2006), coupled with a Random Forest classification model, to predict daily and spatially distributed flow conditions (flowing or dry). The hybrid flow intermittence model is trained using observed flow condition data from diverse sources, such as water level measurements, photo traps, remote sensing, and citizen science applications (Mimeau et al, 2023). We evaluate the model's performance in three European River Networks in Finland, France, and Spain.Results show that the hybrid flow intermittence model accurately predicts the drying events, with a probability of prediction of a drying event above 0.9 for the French and Finnish study cases. The spatio-temporal patterns of flow intermittence are contrasted among the 3 study cases: while the model simulates a few drying episodes during the summer season in the Finnish case study, mainly in the small upstream tributaries, it also simulates more complex drying patterns in the French and Spanish case studies, with drying episodes occurring throughout the year and drying events in the main river sections.Additionally, we provide insights on the role of the observed data used to train the model on the simulated flow intermittence patterns. Results indicate that the quantity of observed data, as well as their temporal distribution, their spatial location in the river network, and the representativeness of the observed flow condition can have a significant impact on the simulation performance of flow intermittence. This study shows that combining different sources of observed flow condition data can help to reduce the uncertainty in predicting flow intermittence. Datry et al. (2021) Securing Biodiversity, Functional Integrity, and Ecosystem Services in Drying River Networks (DRYvER). Research Ideas and Outcomes. https://doi.org/10.3897/rio.7.e77750.Krause et al. (2006) Multiscale investigations in a mesoscale catchment: hydrological modelling in the Gera catchment. Advances in Geosciences. https://doi.org/10.5194/adgeo-9-53-2006.Mimeau et al. (2023) Flow intermittence prediction using a hybrid hydrological modelling approach: influence of observed intermittence data on the training of a random forest model, EGUsphere [preprint], https://doi.org/10.5194/egusphere-2023-1322.
Canadian wildfires of Summer 2023:  high smoke episodes over Central Europe - observations and GEM-AQ model results.
Authors: Jefimow Maciej , Nagmarova Ainur , Struzewska Joanna , Norowski Aleksander
Published: March 2024

           In 2023, Canada faced the threat of wildfires, a recurring environmental challenge exacerbated by factors such as climate change and dry conditions. The wildfires likely posed significant challenges to various regions, leading to evacuations, property damage, and adverse effects on air quality. Government agencies and firefighting teams were likely mobilized to contain the spread of the fires and protect affected communities.      Copernicus Atmosphere Monitoring Service (CAMS) provides products related to emissions from wildfires (PMWF – particular matter from wildfires). Based on CAMS data specific periods were selected. The GEM-AQ model, which is a part of the CAMS ensemble, was run on a global grid to reproduce the hemispheric transport of smoke plum. Model results were compared against satellite measurement (TROPOMI – aerosol index and aerosol layer height) and with available in-situ observations (PolandAOD network). We will present the evolution of transport episodes over Poland as well as the analysis of the model performance in terms of timing and height of the aerosol plume observed.  
Modelling subglacial drainage with GlaDS on GPUs
Authors: Pohle Annegret , Utkin Ivan , Räss Ludovic , Werder Mauro
Published: March 2024

The Subglacial Drainage System model (GlaDS) is one of the most widely used advanced glacier drainage models, with implementations in several ice sheet models. Here we present a new version of this model capable of execution on graphics processing units (GPUs) programmed in Julia. The aim is for the model to run on meshes larger than 10,000² grid points, which would allow, for instance, to simulate Antarctica at 500m resolution. Unlike the original GlaDS implementation, this is based on a finite difference scheme on a structured grid. Together with a matrix-free solver, this allows us to leverage the full performance capabilities of GPUs. We present model runs of the SHMIP test cases, show the model's scalability and provide an outlook towards higher-resolution continental-scale applications and inversion schemes.
Exploring the Interaction between Aircraft Emissions and Cirrus Clouds: Through Simulation Techniques and Satellite retrievals
Authors: Marjani Sajedeh , Quaas Johannes
Published: March 2024

Aviation outflow is the only anthropogenic source of pollution that is directly emitted into the upper troposphere and potentially alters cloud patterns by creating linear contrails. These contrail cirrus formations can either increase high-cloud cover in supersaturated, cloud-free air or modify the microphysics of existing natural cirrus clouds. Despite the likelihood of aircraft intersecting natural cirrus, the extent of their impact remains uncertain.Our study interests using the ICON_NWP model, integrated with a two-moment cloud microphysical scheme, to simulate contrail formation and dynamics. Central to this research is examining how aviation aerosols and emitted water vapor influence contrail development within already existing cirrus clouds.The number of surviving nucleated ice crystals after the jet phase depends on engine and fuel parameters as well as on the ambient atmosphere (Kärcher et al 2015) and displays large regional variation (Bier & Burkhardt, 2019).  Bier and Burkhardt (2022) demonstrated that the concentration of ice crystals after the jet phase varies, ranging in terms of ice particle concentrations from 160 to 200 cm-3 over the North Pacific.We assume a suggestive fixed-wing span of 50 meters, typical of aircrafts such as Airbus 300 and Boeing 737, correlating to a water vapor emission rate of 10 g per meter of flight. In our simulations, contrail formation is initiated at 450 seconds, marking the end of the vortex phase. Beyond this point, the remaining ice crystals are predominantly influenced by atmospheric conditions. Within each grid box, our initial step involves assessing the critical contrail temperature according to the Schmidt-Appleman criterion. Depending on whether these criteria are met, we then proceed to either introduce ice crystals or add the corresponding amount of water vapor.Ultimately, we compare our simulation results with corresponding aircraft data, utilizing the DARDAR-NICE dataset that offers height-resolved measurements within cirrus clouds, to validate the imprints of aircraft emissions.
Greenland Tip Jet in the future: Declining Surface Heat Loss in a High-Resolution CESM Simulation (2015-2099)
Authors: Fedorov Aleksandr M. , Wieners Claudia E. , de Jong Marieke Femke , Dijkstra Henk A.
Published: March 2024

The Greenland Tip Jet is a strong westerly wind generated by the interaction between the synoptic Icelandic Low and the steep Greenland orography. Tip Jets were not extensively explored until the beginning of 2000s when gridded atmospheric products reached temporal and spatial resolution high enough to resolve such mesoscale wind events. This mesoscale wind affects surface heat and freshwater content in the area to the southeast of Greenland and then it causes intensification of deep water formation in the Irminger Sea. Through this increase in deep convection intensity, Tip Jets can potentially affect the large scale Atlantic Meridional Overturning Circulation (AMOC) transport on daily-centennial time scales. Given Tip Jets’ role in deep convection, the research question arises: Will the influence of Tip Jets on AMOC change in the future? In the current research, we aim to fill the gap on the Tip Jet variability in the 21st century using the high resolution (0.25°) CESM 1.3 future climate simulation forced with RCP 8.5 for 2015-2099. We identify Tip Jets, estimate future composite anomalies of the surface heat flux and wind stress associated with Tip Jet events, and define the leading factors of their variability in the 21st century. Our analysis reveals no significant trends in Tip Jet frequency or wind stress for 2015-2099. Although no long-term changes are modelled in Tip Jets and wind stress, upward surface heat flux decreases both during Tip Jet days and during the whole winter season (DJFM) in the area to the southeast of Greenland. We attribute this decrease in surface cooling to changes in air-sea temperature difference (Ta – SST). To the east of Cape Farewell, the atmosphere is warming faster than water, causing Ta – SST to shrink during the 21st century. The observed trend in Ta – SST subsequently appears in surface latent and sensible heat fluxes growth for 2015-2099. Therefore, the more rapid warming of the atmosphere compared to the ocean leads to an increase in background latent and sensible heat, resulting in less cold being transported to the central Irminger Sea during Tip Jets. We showed that Tip Jets will likely continue to affect heat and freshwater content in the Irminger sea, however, the character of this influence will be different with climate change during the 21st century. 
Cetacean chronicles: Exploring Ecology and Proxy Potential from whale teeth 
Authors: Rahman Shirin N. , King Helen , IJsseldijk Lonneke , Jarochowska Emilia
Published: March 2024

Marine mammals such as whales are an integral part of the oceanic ecosystems, however, they are also heavily affected by anthropogenic impact. In order to assess the long-term human impacts on modern whales, it is necessary to establish reliable baselines of their past and present populations.In this study we analyzed both modern and subfossil teeth from sperm whales (Physeter macrocephalus) and harbor porpoises (Phocoena phocoena). Growth layers of the teeth were investigated by the use of SEM-BSE, to gain insight into the growth dynamics and age of our specimens. Since the tooth enamel is an important indicator of diet, migration and habitat, weused Sr/Ca ratios to reconstruct the ecological niches of our taxa.Raman spectroscopy was implemented to investigate teeth surface structure and crystallographic structure, and EDX allowed us to study the chemical composition of the teeth.In conclusion, this study provides valuable insight into the ecology of modern and subfossil whales and an assessment of chemical and structural proxies that can be utilized.
Direct coupling of petrological and thermo-kinematic modelling: application to magmatic chambers
Authors: Riel Nicolas , Kaus Boris , Ranocha Hendrik , Aellig Pascal , Green Eleanor
Published: March 2024

Understanding how magmatic systems work is of interest to a wide range of Earth Scientists. One of the key components when studying magmatic systems is the ability to predict stable mineral assemblage. These predictions allow retrieving critical information such as mineral stability, fraction and composition of melt.However, the dynamic evolution of magmatic chambers, including the cycling between magmatic recharge and extraction in and out of the reservoir, imply that compositions of crystals and melts are constantly evolving. Hence, the use of phase equilibrium parameterization or look-up-tables of fixed bulk-rock composition is inappropriate to predict the dynamic chemical evolution of magmatic systems, and we instead need methods that can take the evolving chemistry into account.Here, we present an updated version of our in-house Gibbs energy minimization package, MAGEMin [1,2]. MAGEMin is ideally suited so simulate the chemical evolution of magmatic systems by incorporating a range of recently developed thermodynamic melting models suitable to simulate both melting of magmatic arcs and of pelitic crustal rocks. Through its Julia wrapper, MAGEMin_C, it is particularly easy to perform (parallel) pointwise computations, and couple it with other thermal or thermomechanical codes.We have made several additions to MAGEMin which include a) adding more thermodynamic databases, b) developing a new web-based graphical user interface, MAGEMin_app, which simplifies creating publishable phase diagrams and c) coupling MAGEMin with dynamic codes.The ability to couple MAGEMin with other codes is demonstrated by linking it with the MagmaThermoKinematics.jl Julia package [4,5] that simulates the thermal evolution of magmatic systems following the intrusion of dikes and sills, in 2D, 2D axisymmetric and 3D geometries. For this to be efficient, we develop a new system in which we dynamically create a database of pre-computed points as a function of pressure, temperature and chemistry that is updated on the fly. This allows simulating the evolving chemistry of a crustal-scale mush system. [1] Riel, N., Kaus, B.J.P., Green, E.C.R., Berlie, N., 2022. MAGEMin, an Efficient Gibbs Energy Minimizer: Application to Igneous Systems. Geochem Geophys Geosyst 23. https://doi.org/10.1029/2022GC010427[2] https://github.com/ComputationalThermodynamics/MAGEMin[3] https://github.com/ComputationalThermodynamics/MAGEMin_C.jl[4] Schmitt, A.K., Sliwinski, J., Caricchi, L., Bachmann, O., Riel, N., Kaus, B.J.P., de Léon, A.C., Cornet, J., Friedrichs, B., Lovera, O., Sheldrake, T., Weber, G., n.d. Zircon age spectra to quantify magma evolution. Geosphere 19. https://doi.org/10.1130/GES02563.1[5] https://github.com/boriskaus/MagmaThermoKinematics.jl
Impacts of biochar on nitrous oxide emissions and ammonia volatilisation in wheat and maize cropping systems
Authors: Hartmann Ferdinand , Spiegel Heide , Diaz-Pines Eugenio , Hood-Nowotny Rebecca
Published: March 2024

Agriculture and other land use practices are major contributors to greenhouse gas emissions. To meet the needs of an increasing global food demand while mitigating climate change, sustainable agricultural practices are necessary. Biochar seems to be a promising tool to support this transition to sustainability in agriculture. The application of nitrogen fertilizers increases N2O emissions and NH3 volatilisation. Nitrous oxide (N2O) is a highly potent greenhouse gas and ammonia (NH3) can re-react with soil and forms N2O or can lead to other environmental issues in the surrounding. Besides its carbon sequestration potential, it is known that biochar can positively influence soil properties like water holding capacity, nutrient leaching and mitigation of nitrous oxide emissions and ammonia volatilisation. However, these effects depend on pedoclimatic conditions, the properties of the applied biochar, and other agricultural practises. Therefore, it is necessary to expand the knowledge of these effects, especially under field conditions, to generate valid estimates on biochar’s mitigation potential for N2O and NH3 emissions. A good and extensive data basis is essential for recommendations and a large-scale application in agriculture. In a two-year field experiment in Grabenegg (Lower Austria) we cultivated silage maize (Zea mays) in 2022 and spring wheat (Triticum aestivum) in 2023 with different organic (external organic matter, EOM) and inorganic (NPK) fertilisers. For the biochar treatments we applied 7 t/ha hardwood biochar additionally. The original soil was loamy, low in organic carbon and slightly acidic. We found substantial reductions with 36% (NPK) and 53% (compost) for N2O and 56% (NPK) and 40% (compost) for NH3 emissions. There are several factors discussed in literature how biochar mitigates N2O and NH3 emissions. We suggest that the immobilisation effect of biochar on NH4+ and NO3- (which was observed in the soil), and possibly an increased dinitrogen monoxide reductase activity are responsible for this reduction. Our data support that biochar can be a suitable amendment for highly productive agroecosystems where high amounts of fertiliser are needed and often applied at one timepoint. Still, further investigations on the long-term effect on emission mitigation of biochar and the mechanisms behind are necessary.
Modeling the effects of forest stand characteristics on the water dynamics of mountain forests
Authors: de Bastos Franciele , Hasenauer Hubert
Published: March 2024

Mountain forests are essential for reducing runoff, sediment transport, and risk of natural hazards. In this analysis we address the protection function of mountain forests by assessing the interactions among the forest structure and the water dynamics. We are specifically interested in the forest's ability to reduce the outflow during a 10-day rainfall period according to the leaf area index (LAI) of the forested areas. The study was conducted using 31 Norway spruce (Picea abies) forest stands covering a wide range of LAI located in the Rindbach watershed in Austria. The elevation ranges from 446 m to 1379 m, and the predominant soil type is the Orthic Rendzina. From 1960 to 2022, the mean average annual precipitation was 1498 mm, and the mean average annual temperature was 6.6 °C. We use the biogeochemical ecosystem model Biome-BGC with its parameter settings for European tree species to simulate the daily carbon, nitrogen, water, and energy flux dynamics and assess the relative proportion of the daily water balance parameters during the 10-day rain period grouped according to the leaf area index (LAI). Our results for the 10-day rain period with a total accumulation of 135.3 mm (about 9.7 % of the annual rainfall in the area) suggest: (i) Norway spruce forest areas with an LAI < than 1 m²/m², outflow was evident on the first day of rainfall while Norway spruce forests with an LAI ≥ 7 m2/m-2 exhibited the first outflow on the ninth day of rainfall. (ii) This resulted in a 4 to 5 times lower outflow compared to forest stands with an LAI < 1m²/m² (e.g. 51.3 versus 11.1 mm, within 10 days). This emphasizes the importance of forest vegetation coverage in reducing runoff, avoiding flooding, mudslides, and sediment transport, and improving the protection function of mountain forests.
Geomorphological signatures of known climatic extreme events and validation of theoritical emplacement approach: Boulders on Cuban low-lying Marine Terraces 
Authors: Authemayou Christine , Dunán Avila Pedro Luis , Jaud Marion , Pedoja Kevin , Jara Muñoz Julius , Peñalver Hernández Leandro , Floc'h France , Bertin Stéphane , Nuñez Labañino Arelis , Benítez Frometa Pedro de Jesus , Ross Cabrera Hassan , Letortu pauline , Rodríguez Valdés Angel Raúl , Coutín Lobaina Noel , Chauveau Denovan
Published: March 2024

To assess coastal hazard where Coastal boulder deposits (CBDs) are found, it is crucial to constrain the forces governing their emplacement: from either storms/tropical cyclones or tsunamis. Here we focus on the CBDs on the island of Cuba and the extreme climatic events responsible for their formation. Four sites are being studied to identify the CBDs produced during known hurricanes over the last fifty years.The selected CBDs are located on a low-lying coral reef terrace on the Cuban shore, emplaced by the Cuban hurricane of 1935, Lili hurricane of 1996 and Matthew hurricane of 2016. These meteorological events associated with reported geomorphological objects are analyzed to quantify the hydrodynamic parameters of such extreme events (maximum orbital velocity). Furthermore, the quantification of CBDs volume by stereophotogrammetry (using Agisoft Metashape Professional version 1.7.2) and CBDs density by water immersion method on samples allow us to use deterministic and theoretical approaches ( hydrodynamics equations of Nandasena et al., 2013, 2022 ) to assess the assumed associated hydrodynamic parameters (minimum flow velocity) responsible for the dislocation of the coral reef terraces and transport of the resulted boulders. Finally, we compare these velocities with ones  calculated from the meteorological  events to discuss the reliability of these approaches to determine the climatic or tsunamigenic origin of the past extreme waves from geomorphological analyses of CBDs.
Identifying the drivers of sediment strength and erosion resistance in natural and restored tidal marshes
Authors: Stoorvogel Marte , Temmerman Stijn , van de Koppel Johan , de Smit Jaco , Wiesebron Lauren , Fivash Gregory , van Belzen Jim , Oosterlee Lotte , Schoutens Ken , van IJzerloo Lennart , Maris Tom , Meire Patrick , Bouma Tjeerd
Published: March 2024

Tidal marshes can contribute to nature-based coastal protection by reducing both wave loading onto the shore and erosion of the shoreline. To implement such nature-based coastal protection requires knowledge on how to restore or create tidal marshes in such a way that they quickly become highly stable and erosion resistant. Hence, we aimed to identify the drivers controlling the rate by which sediment strength and erosion resistance build up in natural and restored (managed realignment, sand suppletion, and controlled reduced tide) tidal marshes, using three different approaches. That is, we quantified sediment strength and erosion resistance (1) at natural marsh locations of different age, (2) at a restored marsh in sediment layers of different age, and (3) in a controlled experiment with pots filled with sandy or muddy sediment subjected to four different tidal regimes, with pots either left bare or planted with a sparsely or a densely growing marsh pioneer species. Sediment strength and erosion resistance were measured by a broad range of techniques, including shear vane, penetrologger, and flumes.Our results revealed several important drivers affecting the development of sediment strength and erosion resistance in tidal marshes. Firstly, a densely growing pioneer species (e.g., Spartina anglica) increased sediment strength faster than a sparsely growing pioneer species (e.g., Scirpus maritimus). Secondly, a smaller tidal inundation frequency as well as lower sediment water content  increased sediment strength and erosion resistance. Lastly, lower sedimentation rates led to stronger consolidation, and thus higher sediment strength, in deeper sediment layers. Overall, our research shows that to create erosion resistant sediment beds in future marsh restoration projects, one should ideally aim for densely vegetated tidal marshes with well-drained, cohesive sediments at relatively high intertidal elevation, where sedimentation rates are moderate. These conditions provide the highest chance of resulting in highly erosion resistant tidal marshes that can serve within a reasonable amount of time as a nature-based coastal protection strategy.
Geospatial distribution of groundwater potential zone using Remote sensing, GIS and analytic hierarchy process (AHP) approach: a case study of Raipur district, Chhattisgarh, India
Authors: Dey Mukesh Kumar , Sathawane Sanyukta
Published: March 2024

In India, groundwater is the major source of water for various activities.  Due to over-extraction, the groundwater levels are declining over the period. The Present study has an objective of investigating the groundwater potential zone (GPZ) and finding the most sensitive parameter for the study area which is Raipur district, Chhattisgarh, India. The state is located in the Mahanadi River basin with a coverage area of 2892 Km2. The following study uses the AHP (Analytical hierarchical process) technique for analysis along with geographic information system (GIS) and Remote sensing. Mapping GPZ includes various hydrogeological and topographical features. Seven different datasets namely precipitation data, drainage density, lineament density, slope data, land use land cover (LULC), soil data, and lithological conditions of the area were considered. These thematic maps were created using various raw datasets like meteorological data, digital elevation model (DEM), satellite data, soil data, and lithological data. The AHP method which is based on multi-criteria decision analysis (MCDM) assigns weights on Saaty’s scale to all layers as per their contribution to groundwater potential in the study area. After the formation of the AHP matrix, overlay analysis was performed with the normalized weights in the GIS environment. Layer-wise sensitivity analysis was performed for all the input layers. Sensitivity analysis highlights the importance of parameters by removing each parameter at a time.  The use of sensitivity analysis is to find out the relationship between the given input layers and the output layer generated. The study also cross-validated the groundwater level data of the Raipur district. This verification confirms the authenticity of the method. The study area was divided into five potentiality zones based on spatial distribution analysis. The results indicate that 22.06% and 21.34% of the study area fall under poor and good potentiality zones, respectively whereas the moderate potential zone is the most dominant one with a percentage of 37.82. The analysis also revealed that 7.87% and 10.92% of the area belong to extreme zones i.e. very poor and very good groundwater potential zones respectively. The result also shows that Raipur City and the northeastern parts of the district have a very poor groundwater potential zone. The analysis shows that the most sensitive parameter is land use land cover with a mean variation of 4.37% followed by slope, lineament density, and lithology with 4.20, 3.69, and 2.17% respectively. The least sensitive parameter for groundwater potential zone is soil type with a mean variation of 0.79% followed by drainage density and rainfall with 1.48, and 2.12% respectively. Consequently, this study can be used to locate the Groundwater Potential Zone at a lower scale for effective groundwater extraction and sustainable groundwater management.
Lithium prospectivity and capacity assessment in the North German Basin
Authors: Alms Katharina , Groeneweg Alicia , Heinelt Manfred
Published: March 2024

Lithium production has increased tenfold over the past two decades and is expected to grow steadily over the next decade, driven by the rapid development of modern technologies such as mobile electronics, electric vehicles (EVs) and grid storage applications. The European Union including Germany, however, has no conventional lithium resources and is therefore geopolitically dependent on imports. As a result, unconventional resources such as lithium recovery from geothermal brines in the Upper Rhine Graben have been explored. Elevated lithium concentrations have also been reported in other regions including the North German Basin (NGB), but no resource estimates are available. Therefore, all available data for the NGB are summarized here in order to limit potential deposits. Their potential is then assessed using a probabilistic volume-based approach.The highest concentrations are found in the Permian Rotliegend and the Zechstein Ca2 at the basin margin. Lithium concentrations can locally reach up to 600 mg/L in the Rotliegend and 300 mg/L in the Zechstein. Our resource estimates indicate that 0.08 to 5.76 Mt of lithium could be contained in the Rotliegend and an additional 0.06 to 3.06 Mt in the Zechstein. Elevated lithium concentrations have also been reported in the overlying Triassic Buntsandstein deposits that occur over much of the basin. Values of up to 200 mg/L lithium have been detected, which we estimate to be between 0.2 and 3.48 Mt of lithium.On the one hand, our study shows that there are sufficient domestic lithium resources in geothermal waters. However, it is also clear that the most promising resources are associated with deep, low-permeability Permian deposits that inhibit conventional (non-engineered) hydrothermal geothermal energy production. It is therefore unclear whether geothermal energy production and lithium exploration can co-exist and further studies are needed to analyze the local, onsite potential. Our study provides the starting point for this analysis.
Reducing the Impact of Aircraft-Induced Clouds on Climate –Development of the Contrail Avoidance Tool (CoAT)
Authors: Dedekind Zane , Korolev Alexei , Milbrandt Jason A.
Published: March 2024

Civil aviation is estimated to contribute ∼90 mW m−2 (∼ 4 %) towards the global anthropogenic radiative forcing of ∼2.38 W m−2. Compared to the radiative forcing caused by aviation CO2 emissions estimated at 35 mW m−2, aviation-induced clouds formed behind aircraft have a larger forcing and a large uncertainty. These clouds form when the emissions from the aircraft exhaust mix with the environmental air, cool rapidly and increase the humidity such that the air becomes supersaturated over water. Aviation-induced clouds are categorized as persistent contrails and contrail cirrus of which the latter spread horizontally and can be kilometers-wide and has the largest forcing. Therefore, to reduce the radiative forcing of the aviation industry, we are developing the Contrail Avoidance Tool (CoAT) to mitigate the formation of contrails.
Within the development of CoAT, we are working towards tracking the evolution of contrail cirrus using Environment and Climate Change Canada’s (ECCC) High-Resolution Deterministic Prediction System at a horizontal resolution of 1 km x 1 km. The model utilizes the Particle Properties (P3) bulk three-moment microphysics scheme with three "free" ice categories. This scheme enables the physical properties to evolve smoothly through the changes of five prognostic variables, which include total ice mass, rime ice mass, total ice number, rime ice volume and reflectivity factor (Milbrandt et al., 2021). Part of developing CoAT involves developing a contrail model. This model consists of first simulating contrail formation regions using the Schmidt-Appleman criteria (Schumann, 1996). We then simulate the contrail volume to estimate the contrail ice number concentration (Unterstrasser, 2016). We then track the evolution of ice number concentration in the control model and its radiative forcing, independent of whether contrail cirrus forms within cirrus. Next, we’ve applied our contrail model within CoAT to a case study. An important challenge in modeling contrails is the extent to which contrail cirrus and cirrus clouds may overlap and become indistinguishable. To understand the radiative forcing from contrail cirrus, we modified P3 by designating the contrail ice from the contrail model to one of the three free ice categories which does not interact with the other two ice categories.
The ultimate goal is to implement CoAT into ECCC’s Global Deterministic Prediction System (GDPS). The GDPS will cover the Canadian air space, the North Atlantic and Arctic Oceans to predict and mitigate contrail formation, thus reducing the impact of aircraft-induced clouds on climate.
Using data assimilation to improve land subsidence prediction from a data-driven and physics-based modeling approach: An application to Bangkok, Thailand
Authors: Soonthornrangsan Jenny , Bakker Mark , Vossepoel Femke C.
Published: March 2024

Accurate and precise subsidence simulation is greatly influenced by limited availability of data, specifically input forcings/drivers and calibration data. In this study, an ensemble-based data-assimilation method is used to improve the estimates of land subsidence in Bangkok, Thailand, which is simulated by a linked data-driven and physics-based modeling approach. The approach models land subsidence caused by groundwater pumping at observation well nests and deals with limited data availability. A data-driven time series analysis method is first utilized to model groundwater heads in aquifers, which then serves as boundary conditions to a one-dimensional land subsidence model.  Simulated land subsidence near an observation well nest is a compaction-based, vertical estimate that assumes elastoplasticity. The assimilation of uncertain head observation data results in an estimate of the probability distributions of various state and parameter values based on the model, data, and their uncertainties. Results consist of an improved land subsidence estimation and uncertainty quantification. In Bangkok, the approach is applied with limited groundwater and subsidence observations and only an estimate of basin-wide pumping. Prior to data assimilation, groundwater and subsidence dynamics are successfully captured at 23 well nest locations. The application of the data assimilation method provides an improved understanding of these dynamics in Bangkok through uncertainty quantification of heads and subsidence as well as related parameters. Ultimately, this study demonstrates the applicability of data assimilation to improve land subsidence estimates when dealing with data scarcity.  Risk assessments of relative sea-level rise of Bangkok and other deltaic regions depend on improving land subsidence estimates and associated uncertainty, which is essential for future flood mitigation efforts.
Modelling the sedimentation of macro-, micro- and nanoplastics in the ocean from surface to sediment
Authors: Wu Nan , Grieve Stuart , Manning Andrew , Spencer Kate
Published: March 2024

The ocean is considered a sink for plastic waste, with buoyant plastics remaining at the surface for up to 50 years. Removal of plastic waste from the ocean by manpower is not feasible, but natural-based removal strategies are promising. Among these, the biological pump stands out as a crucial process responsible for transferring materials and nutrients from the surface to the deep ocean. In this context, plastic particles can be incorporated into and transported with marine snow aggregates, providing a potential mechanism for removing plastic waste from the upper ocean (human food chain) to the deep ocean. However, the longevity of plastic debris at the ocean surface remains poorly understood. To address this gap, we developed a degradation-aggregation model to predict the longevity of different types, sizes and shapes of buoyant plastics at the ocean surface. Our results show that the longevity of plastic debris is primarily determined by the time it takes for plastic debris to degrade sufficiently and become small enough (< 100 µm) to be incorporated into marine snow aggregates. Larger plastics take decades to degrade into small microplastics that can be trapped in marine snow, prolonging their presence in surface waters. Conversely, once microplastics are small enough to be incorporated into marine snow, they can reach the seafloor sediment within two years. Interestingly, our model highlights that vertical settling of microplastics occurs through multiple incorporation and settling via vector transport of marine snow, which differs from previous studies reporting oscillations of microplastics in the ocean subsurface. This study explains the mechanisms of plastic debris removal by the biological pump and the longevity of plastic debris at the ocean surface. In addition, this theoretical model can be extended to different aquatic ecosystems to predict the fate and longevity of plastic debris in different environments.
Impact of Sudden Stratospheric Warmings on the Neutral Density, Temperature and Wind in the MLT region
Authors: Yi Wen , Zhou Baozhu , Xue Xianghui , Zeng Jie , Li Guozhu , Gulbrandsen Njal , Tsutsumi Masaki
Published: March 2024

In this study, the neutral density and horizontal wind observed by the four meteor radars, as well as the temperature measured by the Microwave Limb Sounder (MLS) onboard the Aura satellite are used to examine the response of neutral density, wind, and temperature in the MLT region to the stratospheric sudden warmings (SSWs) during 2005 to 2021 in the Northern Hemisphere. The four meteor radars include the Svalbard (78.3°N, 16°E) and Tromsø (69.6°N, 19.2°E) meteor radars at high latitudes and the Mohe (53.5°N, 122.3°E) and Beijing (40.3°N, 116.2°E) meteor radars at middle latitudes.The superposed epoch analysis results indicate that 1) the neutral density over Svalbard and Tromsø at high latitude increased at the beginning of SSWs and decreased after the zonal mean stratospheric temperature reached the maximum. However, the neutral density over Mohe at midlatitudes decreased in neutral density at the beginning of SSW and increase after the zonal mean stratospheric temperature reached the maximum. 2) The zonal wind at high latitudes show a westward enhancement at the beginning of SSWs and then shows an eastward enhancement after the stratospheric temperature reaches maximum. However, the zonal wind at midlatitudes shows an opposite variation to at high latitudes, with an eastward enhancement at the onset and changing to westward enhancements after the stratospheric temperature maximum. The meridional winds at high and midlatitudes show a southward enhancement after the onset of SSW and then show a northward enhancement after the stratospheric temperature maximum. 3) In general, the temperature in the MLT region decreased throughout SSWs. However, as the latitudes decrease, the temperature cooling appears to lag a few days to the higher latitudes, and the degree of cooling will decrease relatively.