bluuebunny/crossref_metadata_2025 huggingface dataset:
Projecting the Surface UV Radiation from CMIP6 Models and how Factors Influencing it are Changing
Authors: Chatzopoulou Anthi , Tourpali Kleareti , Bais Alkiviadis F. , Karagkiozidis Dimitris , Braesicke Peter
Published: March 2024

Links between stratospheric ozone depletion, climate change and UV variability reaching the ground have been established already in a number of studies. Apart from ozone variability and among other factors, aerosol properties, surface reflectivity and clouds are critical for the modulation of the surface UV radiation levels.In the first part of the study, we examine the evolution of these variables through the years, as derived from simulations by models participating in the 6th Phase of the Coupled Model Intercomparison Project (CMIP6). The period of interest extends from the years before the peak of the ozone depletion (here we selected as reference period the years 1950-1960), up to the end of the 21st century. For a better understanding of future UV radiation levels, we selected three of the IPCC Shared Socioeconomic Pathways (SSPs); SSP1–2.6 as the most sustainable, SSP3–7.0 with high amounts of GHGs and SSP5–8.5 as the most extreme.In the second part of the study, we provide an overview of the surface UV changes around the globe, with radiative transfer model (RTM) simulations of solar irradiance using libRadtran version 2.0.3. Monthly mean data of ozone, aerosol optical depth (AOD) at 550 nm and surface reflectivity from CMIP6 models are used as input data for the RTM simulations. Here we present changes of the local noon UV-Index (UVI), after weighting the simulations with the Commission Internationale de l'Éclairage (CIE) erythemal action spectra.Some key changes in drivers and UVI will be discussed. After the middle of the 21st century there is an increasing trend of total ozone column, and more specifically over the Antarctic region, where the depletion is more pronounced, we find that ozone recovery is projected under SSP3–7.0 and SSP5–8.5, while this never fully occurs under SSP1–2.6. According to RTM simulations, reduction of UVI is expected due to the recovery of the ozone layer after the middle of the 21st century. AOD increases over the areas with strong emissions under the three SSPs, which leads to more scatter of irradiance and consequently to lower surface UVI. Finally, surface reflectivity simulations for the end of the 21st century show reductions under all SSPs, mostly over the high latitudes, mainly attributed to ice melt, resulting in decreases of surface UVI.
Physics-informed neural networks for 3D seismic travel time tomography
Authors: Yang Shaobo , Zhang Haijiang
Published: March 2024

Seismic travel time tomography is a widely used technique to image the Earth’s interior. Recently, there have been growing interests in employing deep learning for seismic tomography, and physics-informed neural networks (PINNs) are attractive for their integration of physical information into the networks and their greater stability compared to conventional neural networks. PINNs have been successfully used in 2D tomography, including cross-hole tomography (Waheed et al., 2021) and surface wave phase velocity tomography (Chen et al., 2022). However, 3D seismic tomography based on PINNs has not been developed. Here we propose a novel method for 3D travel time tomography based on PINNs and show its effectiveness using both synthetic and real data. The network consists of two branches, one taking in the 3D coordinates of a pair of source and receiver for fitting observed travel times and another taking in the receiver location for predicting velocities. The loss function also consists of two terms, the data fitting residual term and the Eikonal equation residual term. In this way, the two branches are connected using the Eikonal equation loss function term. After training, the network can simultaneously reconstruct the travel time fields and estimate the subsurface velocities. Our method is tested using synthetic and real travel time data for seismic network in Parkfield, California. Compared to traditional travel time tomography methods, this approach offers many advantages, including meshless modeling, no need for regularization and independent on the initial velocity models.
Progressive assessment of multivariate parameter estimation in distributed hydrological modelling using spatial patterns of remote sensing data
Authors: Moreira Vinicius , Silva Francisco , Welerson Camila
Published: March 2024

Hydrological models are traditionally calibrated using observed flow records. This challenge is magnified in distributed modeling due to the increased dimensionality of the problem, where parameters must be estimated for hydrologically homogeneous subareas (HRUs). Regardless, the estimated flows can present significant inconsistencies, even though the modeled flows are quite similar to those observed. Products derived from remote sensing techniques have been employed to circumvent this problem. In summary, spatial patterns of hydroclimatological variables are used to assess the consistency of the modeled flows. In this study, the mesoscale hydrologic model (mHM) was used to simulate a mesoscale basin in Brazil, located in the savanna biome. In addition to the flows monitored at different fluvial stations, estimates of actual evapotranspiration (AET) and total water stored in the basin (TWS) obtained from remote sensing were used for parameter calibration. Comparison occurred from scenarios where these variables were considered independently, in pairs, and together. The similarity between monitored and modeled flows was assessed using KGE metric, while spatial similarity was characterized through the SPAEF. In the multi-objective scenarios, these indices were aggregated using weightings to compose a single objective function. The results obtained demonstrated that similar degrees of agreement between flows can be obtained for completely disparate spatial flows. Furthermore, the spatial consistency of these flows generally implies a reduction in the similarity between flows. Lastly, the weightings proved to be an interesting alternative, meriting further analysis, as they facilitate the definition of priorities in the search for optimal solutions.
A novel view of gamma-ray glows from the ALOFT 2023 flight campaign
Authors: Marisaldi Martino , Østgaard Nikolai , Lang Timothy J. , Grove J. Eric , Quick Mason , Christian Hugh , Schultz Christopher J. , Blakeslee Richard , Adams Ian S. , Kroodsma Rachael A. , Heymsfield Gerald M. , Mezentsev Andrey , Sarria David , Bjørge-Engeland Ingrid , Fuglestad Anders , Lehtinen Nikolai , Ullaland Kjetil , Yang Shiming , Qureshi Bilal Hasan , Søndergaard Jens ,   ALOFT team
Published: March 2024

The Airborne Lightning Observatory for FEGS and TGFs (ALOFT) was a field campaign targeted at Terrestrial Gamma-ray Flashes (TGFs) and gamma-ray glows from thunderclouds. The campaign was successfully carried out during July 2023, for a total of 60 flight hours in the Gulf of Mexico and the Caribbean. The scientific payload was flown on a NASA ER-2 research aircraft, capable to fly at 20 km altitude above thunderclouds. The payload included a suite of gamma-ray detectors spanning four orders of magnitude dynamic range in flux, and a complete suite of instruments for the characterisation of the electrical and optical activity, and the thundercloud environment. A key asset of the mission was the real-time downlink of gamma-ray count rates, which enabled the immediate identification of gamma-ray glowing regions. The pilot was then instructed to turn and pass over the same glowing region to explore its spatial extension and duration.ALOFT resulted in the detection of hundreds of gamma-ray glows, anticipating a revolution in our understanding of the phenomenon. Thunderclouds were observed to glow for hours and over several thousands of square kilometers, making glows a much more pervasive phenomenon than previously reported. Glows show significant time variability from seconds down to millisecond time scale, suggesting a relation to short transients such as TGFs more complex than previously thought. Glows are observed in association with the overpass of active convective cores, 20-25 km in size, yet their time variability and intensity modulation suggest a more complex spatial structure.These observations challenge the current view of glows as quasi-stationary phenomena related to relatively stable electrification conditions. The observed glows show highly dynamic temporal and spatial structures and are closely related to the development phases of active thunderclouds. These observations call for a rethinking of the assumptions at the basis of current modeling efforts.
Characterization of shallow fault parameters from the near-field ground motion data and non-planar dynamic rupture simulations for the Mw7.8 February 6th Pazarcık, Turkey, earthquake
Authors: Aochi Hideo , Cruz-Atienza Victor
Published: March 2024

We focus on the main rupture process of the Mw7.8 Februrary 6th 2023 01:17 UTC Pazarcık, Turkey, propagating to the south-west direction where more than ten acceleration stations recorded the ground motions within a distance of a few kilometers from the fault. On one hand, we estimate the frictional parameters directly from the waveforms of the acceleration records. Several stations are sufficiently close enough to characterize the cohesive zone length, and the estimated critical displacement (Dc) ranges from 90 cm to 150 cm. On the other hand, we carry out the dynamic rupture simulations along the constructed non-planar fault and also simulate the ground motions in the surrounding, using boundary integral equation and finite difference methods.  Upon the constructed standard model, we prepare different models of Dc distribution both along dip and strike. Our numerical simulations show that a longer Dc is necessary in the shallowest depth (2-3 km depth) than in the deep seismogenic zone. The observed ground motion pattern in terms of PGV (Peak Ground Velocity) shows a strong correlation with the estimated strike-variated Dc and the rupture process controlled by the fault geometry.
Assessment of Wind Energy Potential and Future Deployment in the Arabian Peninsula
Authors: Yousef Latifa
Published: March 2024

Recent years have seen an increased push towards the utilization of renewable energy, due to it being inexhaustible and providing greatly reduced emissions in comparison to fossil fuels, which are the origin of greenhouse gasses that cause global warming. Wind energy is the second biggest contributor to the renewable energy mix in the world, due to benefits such as low operating costs and efficient land space use. The Arabian Peninsula has vast areas which are greatly suited to utilizing solar energy, yet wind energy is also being explored for both onshore and offshore projects to compliment the solar resources. This study uses vertical and horizonal wind components from the ECMWF ERA5 dataset. Monthly averages are downloaded from January 1940 to December 2022, at a spatial resolution of 0.25 x 0.25. The goal of the study is to conduct a long-term assessment of wind variability over space and time, to determine the most optimal conditions for wind farm operations. Initial results show that the summer season has the highest wind speeds due to the Shamal summer winds. Further examination reveals individual months and possible linkages to climate oscillations impacting the region’s wind potential. Recommendations are provided for optimal times and locations to operate wind farms.
Anticipating the unseen: a community review on how to better prepare for exceptional weather events
Authors: Kelder Timo , Klok Lisette , Slater Louise , Thompson Vikki , Goulart Henrique M. D. , Suarez-Gutierrez Laura , Wilby Rob , Heinrich Dorothy , Coughlan de Perez Erin , Stephens Liz , Hawkins Ed , Burt Stephen , van den Hurk Bart , de Vries Hylke , van der Wiel Karin , Fischer Erich
Published: March 2024

Extreme weather events of unprecedented intensity in historical records can have major impacts on society and ecosystems. While adaptation plans often consider past trends in extreme weather events, few consider the possibility of exceptional extremes. This oversight leaves society underprepared and ill-equipped to handle ‘surprising’ events. There is a long history of science inquiry into the question of what low likelihood weather events are possible. Here, we present an overview of the methods used to identify exceptional weather events. We discuss tools for scientists, practitioners and policy-makers to ‘see the unseen’ and evaluate unexpected yet plausible disruptive events. We first discuss existing approaches for estimating rare extremes; then give an example for exceptional heat in The Netherlands; and finally outline how this knowledge can be leveraged to strengthen resilience and adaptation efforts.
Trade-offs between growth, carbon use efficiency, and the production of extracellular polymeric substance and soil enzymes of soil microbes under long-term warming with different resource complexities
Authors: Li Yuhua , Li Tao , A. Eichorst Stephanie , A. Anthony Mark , Wanek Wolfgang
Published: March 2024

A large amount of research has demonstrated that global warming leads to changes in the structure and function of soil microbial communities. Despite the large number of studies which have identified soil microbes as key drivers of biogeochemical processes, little is known about the trade-offs between soil microbial activities under environmental change and how this will affect soil biogeochemistry.To this end, we currently develop high throughput methodology to measure growth, respiration, extracellular polymeric substance (EPS), extracellular enzyme activity (EEA) and carbon use efficiency (CUE) in pure cultures of a wide range of bacterial isolates. In response to resource quality (concentration, lability, stoichiometry), temperature and oxygen stress, we will assess trade-offs between key microbial catabolic and anabolic processes. The methodology will finally be applied to soils collected from the Achenkirch forest warming experiment in Austria to examine how complex communities and isolates from long-term warming and control soils express trait trade-offs. Isolates will be selected and checked to cover the most actively growing microbes in control and warmed soils using the qSIP method. The purpose of this study is to gain a deeper understanding of the anabolic and catabolic transitions of soil microbes under the influence of warming and, consequently, to predict the potential biogeochemical impacts of long-term warming on forest soils.
The role of ammonia in the primordial distribution of volatiles in the hydrosphere of Europa
Authors: Amsler Moulanier Alizée , Mousis Olivier , Bouquet Alexis
Published: March 2024

The presence of hydrospheres within the Galilean moons raises the question of whether or not they could provide habitable environments. The study of nowadays’ volatiles inventory on those moons is indicative of their formation processes and their effects on this inventory. However, for the ability to disentangle between the possible scenarios, it is necessary to examine the post-accretion processes that could impact the volatile inventory of the hydrospheres. Especially, an “open-ocean” phase which took place shortly after accretion, before the icy crust formation, must be considered, in view of its influence on the volatile inventory. More specifically, the abundance of ammonia in Europa’s building blocks is a key constrain, both on the habitability conditions of the ocean and the volatile distribution in the primordial thick atmosphere of the moon.Our work focuses on modelling the ocean-atmosphere equilibrium which took place over this period, based on different formation scenarios of Europa. To do so, we compute the vapor-liquid equilibrium between water and volatiles, as well as the chemical equilibria happening within the ocean to investigate the primitive hydrosphere of Europa. Our model allows for an assessment of the impact of the initial distribution of volatiles resulting from the thermodynamic equilibrium between Europa’s primordial atmosphere and ocean. In particular, we show the correlation between the ratio of dissolved CO2 and NH3 and the distribution of partial pressures in the primordial atmosphere of Europa.Navigating between two endmembers for the composition of the building blocks (nitrogen delivered by hydrated rocks or cometary ices), and varying the proportion of ammonia incorporated into the ocean after accretion, we obtain a range of primordial volatile distributions, to be linked to nowadays inventory. We also find ammonia abundance thresholds above which CO2 content is significantly depleted by NH2COO-  formation.
Assessing meteorological fire danger over Europe based on a statistical model of satellite-derived fire radiative power
Authors: Ponte Oliveira Mariana , A. Nunes Sílvia , C. DaCamara Carlos , M. Trigo Ricardo , F. Trigo Isabel
Published: March 2024

The Satellite Application Facility for Land Surface Analysis (LSA SAF), that is part of EUMETSAT’s ground segment, operationally disseminates daily forecasts of meteorological fire danger over Mediterranean Europe. The so-called Fire Risk Map (FRM) product relies on estimates of the probability of exceedance of predefined thresholds of daily released energy by active fires as derived from a Generalized Pareto model that uses FWI as covariate for the scale parameter; FWI, the Fire Weather Index (FWI), is part of the Canadian Fire Weather Index System and has proven to be very suitable to rate fire danger over Europe.The aim of this study is to extend the procedure to Northern and Central Europe making use of a statistical model of Fire Radiative Power (FRP) as derived from MODIS observations over Europe covering the period 2000-2022. Following the approach developed by DaCamara et al. (2023), the statistical model consists of an 8 parameter, doubly truncated lognormal body distribution with generalized Pareto tails, using FWI as a covariate of its parameters.First, Europe is divided into eight regions according to the recorded number of hotspots and to the averaged FRP over the study period. Each one of those regions is then stratified into three subregions according to the dominant land cover type, i.e., forest, shrub, or agriculture. For each of the subregions, a statistical model is fitted to the sample of historical records of FRP together with the associated sample of FWI values obtained from the Copernicus Emergency Management Service.The fitted models are then applied to Europe to generate monthly climatological values of probability of exceedance of prescribed thresholds of FRP. This information is used to define appropriate limits for classes of fire danger (i.e. low, moderate, high, very high and extreme) for each subregion of Europe. Finally, these classes are validated by analyzing the distribution of recorded FRP among the classes and by examining maps for extreme fire events. This work was supported by EUMETSAT Satellite Application Facility on Land Surface Analysis (LSA SAF) and by Instituto Dom Luiz (IDL), a research unit financed with national funds (PIDDAC) by FCT (UIDB/50019/2020). References:DaCamara, C. C., Libonati, R., Nunes, S. A., de Zea Bermudez, P., & Pereira, J. M. C. (2023). Global-scale statistical modelling of the radiative power released by vegetation fires using a doubly truncated lognormal body distribution with generalized Pareto tails. Physica A: Statistical Mechanics and Its Applications, 625. https://doi.org/10.1016/j.physa.2023.129049
Soil health increases primary productivity across Europe
Authors: Romero Ferran , Labouyrie Maëva , Orgiazzi Alberto , Ballabio Cristiano , Panagos Panos , Jones Arwyn , Tedersoo Leho , Bahram Mohammad , Guerra Carlos , Eisenhauer Nico , Tao Dongxue , Delgado-Baquerizo Manuel , García-Palacios Pablo , van der Heijden Marcel
Published: March 2024

The role of soil health in regulating primary productivity at large scale across different land-use types remains poorly understood. This hinders our ability to predict the impact of soil degradation on essential ecosystem services such as food provision and climate regulation. To address this gap, we conducted a pan-European observational field study using data from 588 sites and 27 countries to investigate the link between soil health (a composite index based on soil properties, biodiversity, and plant disease control) and primary productivity across three major land-use types: woodlands, grasslands, and croplands. We found that soil health in woodlands was 31.4% higher than in grasslands, and 76.1% higher than in croplands. We further observed that soil health was positively linked to cropland and grassland productivity at the continental scale. Woodland productivity was linked to climate conditions rather than to soil health status. We observed that soil organic carbon and the richness of Acidobacteria, Firmicutes, and Proteobacteria had a positive effect on primary productivity. Among microbial functional groups, we found that nitrogen-fixing bacteria and mycorrhizal fungi positively related to primary productivity in croplands and grasslands, while plant pathogens showed a negative relationship. Together, our results point to the importance of soil biodiversity and soil health for maintaining primary productivity across contrasting land-use types.
Zonal Wave Three: Trends and links to extreme events
Authors: Renwick James Arthur
Published: March 2024

In the Southern Hemisphere atmospheric circulation, one of the most prominent wave patterns is zonal wave three (ZW3), which exhibits three positive and three negative anomalies in the zonal eddy field around the Southern Hemisphere, with maximum amplitude over the Southern Oceans. Using ERA5 data, this presentation will describe the form of ZW3 and trends in its behaviour. Over the past 60 years, the amplitude of ZW3 exhibits significant upward trends throughout the year but most prominently in summer (Dec-Feb). Such trends are related to increasing meridional temperature gradients and to trends in eddy activity in general and to trends in poleward energy fluxes. Implications for surface climate temperature and precipitation extremes will be outlined.
Sensing Cr(VI) retention with spectral induced polarization (SIP) in a magnetite-coated sand pack
Authors: Rahmani Ali , Franz Marc , Bär Frederik , Backes Claudia , M. Byrne James , Mellage Adrian
Published: March 2024

Removing Cr from contaminated (ground)water is often attempted via active remediation using easily deployable permeable reactive (barrier) materials, such as iron oxide mineral coatings. In particular, magnetite has been shown to be a highly effective and low-cost option for removing redox-active Cr from solution. Magnetite not only binds Cr, but it also reduces Cr(VI) to the less toxic and immobile Cr(III). Monitoring the extent of Cr retention in remediation schemes, however, relies on down-flow concentration sampling. Consequently, detectable levels of Cr must exit remediation barriers in order to detect the decreasing remediation efficiency of reactive materials with the progression of immobilization. Spectral induced polarization (SIP), a non-invasive geophysical technique sensitive to sorption-induced changes in the surface charging properties of mineral surfaces in porous media, offers a potentially powerful monitoring alternative to detect changes in remediation efficiency in situ without the need for down-flow monitoring and contamination hazard. Here, we apply SIP, as a proxy to monitor the extent of Cr retention in a flow-through column experiment, packed with magnetite-coated sand. We observed a rapid increase in polarization upon Cr(VI) adsorption on magnetite coated sand, followed by a strong continuous decrease. Our joint reactive transport modeling and post-column geochemical measurements highlighted a drop in the remaining sorption capacity of the coated sand, thereby linking the reduced sorption capacity to the drop in SIP signal. The excellent agreement between concentration breakthrough curves, our model and SIP measurements suggests that SIP signals can be used as an early warning tool to detect the approaching saturation of reactive materials deployed in remediation schemes.
Exploration of a Time-dependent Forecast for Tsunami in New Zealand
Authors: Wavelet Emeline , Fry Bill , Gorman Andrew , McCurrach Sarah-Jayne
Published: March 2024

New Zealand’s (NZ) entire coastline is at risk of tsunami from local, regional, and distant sources. With more than 75% of New Zealanders living or working within 10 km of the coast, the tsunami risk is significant.The Rapid Characterization of Earthquakes and Tsunamis (RCET) research programme is being undertaken to better understand, mitigate and respond to tsunami events in NZ. Within this project, my PhD focuses on improving the communication of tsunami threats to local stakeholders and the emergency response sector by creating a new concept: a time-dependent forecast for tsunami.I have been using the software ComMIT (a tsunami model developed by the NOAA Center for Tsunami Research) to create a catalogue of synthetic tsunamis focusing on the cities of Tauranga and Whangarei, situated on the northeast coast of the North Island. These two cities have been selected due to their exposure to tsunamis: flat topography, densely populated, infrastructure-rich harbour, exposed coastline, proximity to the Kermadec-Tonga trench. Using Python, I have generated a diverse assembly of forecasts where the tsunami waves amplitude  measured on the coastline are linked to threat levels, resulting in the creation of the final product: a time-dependent forecast. I have also been engaging with stakeholders and various end user communities with the aim of adapting these models to their needs. We anticipate that this new tool will help them to respond to these threats more efficiently.
Evolution of root hydraulic properties of wheat with breeding and its influence on root water uptake: insights from a field experiment and modelling
Authors: Baca Cabrera Juan C. , Vanderborght Jan , Behrend Dominik , Gaiser Thomas , Nguyen Thuy Huu , Boursiac Yann , Lobet Guillaume
Published: March 2024

Root water uptake is a pivotal process in the regulation of water movement within the soil-plant-atmosphere continuum. At a specific atmospheric demand, root water uptake is determined by the architecture of the root system and the hydraulic properties of individual roots and root segments. In agricultural settings, root traits are affected by management practices, including breeding. Specifically for wheat, the most important European crop, a decrease in root system size has been observed in modern varieties compared to historical ones1, and differences in root hydraulic properties between cultivated and wild species have been documented2. However, an assessment on the long-term evolution of root hydraulic properties with breeding is still absent.  Here, we investigated the effect of breeding on root hydraulic properties of wheat and its implications for root water uptake at the plant scale. For this, an experiment encompassing six wheat cultivars spanning over a century of breeding history was conducted. We measured the number of root axes (crown roots and seminal roots) of plants grown in the field during the tillering phase (BBCH
Investigating the divide and measure nonconformity 
Authors: Klotz Daniel , Gauch Martin , Kratzert Frederik , Nearing Grey , Zscheischler Jakob
Published: March 2024

This contribution presents a diagnostic approach to investigate unexpected side effects that can occur during the evaluation of rainfall--runoff models.The diagnostic technique that we use is based on the idea that one can use gradient descent to modify the runoff observations/simulations to obtain warranted observations/simulations. Specifically, we show how to use this concept to manipulate any hydrograph (e.g., a copy of the observations) so that it approximates specific NSE values for individual parts of the data. In short, we follow the following recipe to generate the synthetic simulations: (1) copy the observations, (2) add noise, (3) clip the modified discharge to zero, and (4) optimise the obtained simulation values by using gradient descent until a desired NSE value is reached.To show how this diagnostic technique can be used we demonstrate a behaviour of Nash--Sutcliffe Efficiency (NSE) that appears when evaluating a model over subsets of the data: If models perform poorly for certain situations, this lack of performance is not necessarily reflected in the NSE (of the overall data). This behaviour follows from the definition of NSE and is therefore 100% explainable. However, from our experience it can be unexpected for many modellers. Our results also show that subdividing the data and evaluating over the resulting partitions yields different information regarding model deficiencies than an overall evaluation. We call this phenomenon the Divide And Measure Nonconformity or DAMN.
Seismicity near Mayotte explained by interacting magma bodies: Insights from numerical modeling
Authors: de Sagazan Clement , Retailleau Lise , Gerbault Muriel , Peltier Aline , Feuillet Nathalie , Fontaine Fabrice J. , Crawford Wayne C.
Published: March 2024

Mayotte island experienced a large volcanic eruption 50 km offshore in 2018-2021, creating the submarine volcano “Fani Maoré”. The eruption was accompanied by intense seismicity at mantle depths (20-45 km), divided into a “proximal” and a “distal” cluster centered 10 and 30 km east from the island, respectively. Previous studies suggest that two separate magma reservoirs may lie at the top and bottom of the proximal cluster. Here, we assess whether two reservoirs are a mechanically viable explanation for the proximal cluster’s truncated conical shape.We developed finite-element models of pressurized magma reservoirs in a 2D axisymmetric domain, modeling the reservoirs as compliant elastic ellipsoids embedded in an elastoplastic host rock. We find that, at these depths, extremely low friction is required to generate failure at realistically low reservoir pressures. This implies in turn that mechanical weakening must occur at these depths. The weakening could be induced by fractures or pore fluid overpressure in the volcanic system. We find that two superimposed reservoirs can generate a plastic domain between them, if they are spatially close enough. Several reservoir geometries (from spherical to sill-like) are plausible.A conical fracture domain is more likely to appear for reservoirs with opposite pressure loads (i.e. one inflating, one deflating). Given the geometrical match with the proximal seismicity cluster at Mayotte, we suggest that the shallower (Moho-depth) reservoir is inflating, creating a potential hazard for Mayotte island. 
The effects of environmental factors on stability of forest carbon sink exceeded biotic factors
Authors: Wu Xiaoyun , Xu Hang , Pang Jianzhuang , Zhang Zhiqiang
Published: March 2024

The stability of forest carbon sinks is pivotal for mitigating carbon-climate feedbacks and achieving climate objectives. Emerging evidence suggested that this stability was diminished by climate change and extreme weather events, thus jeopardizing the carbon sequestration capacity and enhancing forest vulnerability. Yet, how biotic factors react to the effects of environmental change on it remains unknown. Here, we integrate long-term (7-29 years) flux and micrometeorological observations of 48 forest sites from ecosystem observation networks (FLUXNET2015, AmeriFlux and ICOS) with interpretable machine learning algorithm (SHAP values) to show how biotic factors and environmental factors impacts stability of forest carbon sink, quantified by critical slowing down indicators (i.e., temporal autocorrelation, TAC), and comparatively analyzed the differences between high- and low-stability forests. Our analysis revealed that environmental factors (i.e., mean annual temperature MAT; mean annual temperature, MAP; carbon dioxide concentration, Ca; incoming shortwave radiation, SW; vapor Pressure Deficit, VPD; soil water availability, the Priestley-Taylor coefficient, α) held a substantially greater impact (the cumulative mean SHAP values) on TAC than biotic factors (i.e., marginal water cost of carbon gain, G1; canopy photosynthetic capacity, Amax; reference canopy conductance, Gcref; carbon sink capacity, NEP), with most of this influence ascribed to MAT, MAP, Ca, G1, and NEP. High-stability forests more intensively presented in conditions with relatively warm and humid long-term climate, coupled with moderately conservative water-use strategies and carbon sink capacity. Although CO2 fertilization effects increased the positive effects of moderate G1 to carbon sink stability, however, higher Ca markedly diminished its stability. Our findings underscore the necessity for caution regarding the detrimental impacts of sustained rise in Ca, gradual warming and drying of the long-term climate, and extreme atmospheric and soil drought events on the stability of forest carbon sinks, given the current limitations of vegetation's biotic factors to adapt to these changes.
Carbon recalcitrance and stabilization processes vary across mangrove eco-geomorphologies
Authors: Maceiras Marion , Arnaud Marie , Lovelock Catherine , Pearse Alex , Dang Huyen , Robin Sarah , Marchand Cyril , Felbacq Axel , Abiven Samuel , Lebrun Thauront Johanne , Bottinelli Nicolas , Mishra Amrit kumar , Hilal Farooq Syed , Bhadra Tuhin , Rumpel Cornelia
Published: March 2024

Mangrove ecosystems are one of the most carbon dense ecosystems worldwide. Yet, the stabilization and recalcitrance of carbon (C) and organic matter (OM) are little understood in mangroves, especially across eco-geomorphological settings and depths. Here, we characterized the sediment C and OM of Indo-Pacific mangroves, located in four distinct eco-geomorphological settings (i.e., delta, estuary, non-carbonated open coast, carbonated open coast) and at two different depths (i.e., 0-20 cm and 80-100 cm). We quantified the fraction of C within (i) mineralized associated organic matter (MAOM), and (ii) within particulate organic matter (POM). We coupled these analyses with lignin quantity and composition, as well as stable C isotopes analysis in mangrove sediments.We found significant variation in the quantity of MAOM and POM across mangrove eco-geomorphological settings, but not across mangrove sediment depths. The terrigenous deltaic mangrove exhibited up to three times more MAOM than the carbonate open coast mangrove, which was dominated by POM. Mangroves of the carbonate coast type had higher C content than other eco-geomorphic types. The  was not different across mangrove eco-geomorphologies, but was different across mangrove sediment depths. Regarding OM recalcitrance, the lignin content displayed strong variations across the different eco-geomorphologies, however, there was no clear pattern of lignin degradation stage across depths. Finally, an inverse correlation between sediment C recalcitrance (i.e., lignin content) and stabilization (MAOM) processes were determined across mangroves.Our findings suggest that the processes leading to OM preservation differ among mangroves in various eco-geomorphological settings. Those results have important implications to guide mangrove restoration for carbon persistence and to model carbon pools across mangrove areas.
Revealing Diurnal Variations of Air Quality Observations in Asia from Geostationary Environment Monitoring Spectrometer (GEMS)
Authors: Kim Jhoon ,   GEMS Science Team
Published: March 2024

A new era of air quality observations from geostationary Earth orbit(GEO) has begun with the launch of Geostationary Environment Monitoring Spectrometer (GEMS) over Asia and Tropospheric Emission of Pollutants (TEMPO) over North America as the two components of geostationary air quality (AQ) constellation. GEMS has provided hourly observations of AQ over Asia from a GEO since November 2020. Column amounts of atmospheric pollutants (O3, NO2, SO2, HCHO, CHOCHO, and aerosols) have been provided to capture their diurnal variations with the UV–visible spectrometer at 0.6 nm spectral resolution and sophisticated retrieval algorithms. Details of the latest GEMS version 3 products are presented, including validations, calibration, and case studies of volcanic eruption, dusts, and urban pollution. In version 3, there are noticeable improvements in trace gases from updated AMF, the separation of stratospheric/tropospheric components, fitting window, spectroscopy etc. Calibration/validation activities including the ASIA-AQ, Pandora Asia network (PAN), PEGASOS, GMAP/SIJAQ, ACCLIP, and international CAL/VAL team works are critical to evaluate and improve the overall data quality. The GEMS retrievals indicate good agreements from the campaigns, but still require further improvements in L1 processing as well. We are improving L1 processor including BTDF correction. Faster sampling rates at higher spatial resolution increase the probability of finding cloud-free pixels, leading to more observations of aerosols and trace gases than have been possible from LEO. Planned ESA’s Sentinel-4 in 2025 will complete the GEO AQ satellite constellation with GEMS and TEMPO, as recognized by the Committee on Earth Observation Satellites (CEOS).
Evaluation of the mine thermal energy storage potential with a stochastic discrete fracture matrix model
Authors: Chen Chaofan , Binder Martin , Oppelt Lukas , Hu Yingtao , Engelmann Christian , Arab Alireza , Xu Wenjie , Scheytt Traugott , Nagel Thomas
Published: March 2024

Decarbonizing the industrial and building heating and cooling sectors is a crucial step toward achieving carbon neutrality, necessitating innovative and sustainable solutions for the over-seasonal storage of excess heat energy. With Germany alone having more than 10,000 old mines, repurposing these sites to implement a controlled thermal energy storage strategy, known as mine-based thermal energy storage (TES), has emerged as a potential solution. To effectively utilize such partially flooded artificial cavities, it is crucial to fully understand the heat transport and storage behavior in these systems.In this work, a three-dimensional hydro-thermo-component (HTC) model was developed using the open-source simulation code OpenGeoSys (OGS). The model was initially verified against analytical solutions for the single fracture flow of heat and solute transport, respectively. Subsequently, stochastic discrete fracture matrix (DFM) geometries and meshes were generated using the computational suite Frackit, based on data from a pilot heat storage site in a water-filled mining cavity in Freiberg, Germany. This test site is geologically characterized as the Freiberg gneiss, a metamorphic fractured rock formation.The developed setup allows for investigating the thermal energy storage capacity and the energy recovery efficiency based on process simulations in OGS. The study evaluated the thermally affected zone in the fractured formation and quantified the amount of heat stored and recovered during cyclic operation. In addition, the solute transport distance within the surrounding rock can be evaluated under different hydraulic conditions. The general modeling workflow provides a basis for conducting techno-economic feasibility analysis of mine-based TES systems.
Sedimentary systems archive the chronology of landscape evolution in the developing Okavango Rift Zone in southern Africa 
Authors: Vainer Shlomy , Schmidt Christoph , Garzanti Eduardo , Ben Dor Yoav , Pastore Guido , Mokatse Thuto , Prud'homme Charlotte , Léanni Laëtitia , King Georgina , Verrecchia Eric
Published: March 2024

The Kalahari Basin in southern Africa, shaped by subsidence and epeirogeny, features the Okavango Rift Zone (ORZ) as a significant structural element characterized by diffused extensional deformation forming a prominent depocenter. This study elucidates the Pleistocene landscape evolution of the ORZ by examining the chronology of sediment formation and filling this incipient rift and its surroundings.Modeling cosmogenic nuclide concentrations in surficial aeolian sand from distinct structural blocks around the ORZ provides insights into sand’s residence time on the surface. Sand formation occurred from ~2.2 to 1.1 Ma, coinciding with regional tectonic events. Notably, provenance analyses of sand within ORZ's lowermost block where large alluvial fans are found indicate different source rocks and depositional environments than those of the more elevated aeolian sand. This suggests that the major phase of rift subsidence and the following incision of alluvial systems into the rift occurred after aeolian dune formation. Luminescence dating reveals that deposition in alluvial fan settings in the incised landscape began not later than ~250 ka, and that a lacustrine environment existed since at least ~140 ka.The established chronological framework constrains the geomorphological effects of the different tectono-climatic forces that shaped this nascent rifting area. It highlights two pronounced stages of landscape development, with the most recent major deformation event in the evolving rift probably occurring during the middle Pleistocene transition (1.2-0.75 Ma). This event is reflected as a striking change in the depositional environments due to the configurational changes accompanying rift progression.
Beyond ESGF – Bringing regional climate model datasets to the cloud on AWS S3 using the Pangeo Forge ETL framework
Authors: Buntemeyer Lars
Published: March 2024

The Earth System Grid Federation (ESGF) data nodes are usually the first address for accessing climate model datasets from WCRP-CMIP activities. It is currently hosting different datasets in several projects, e.g., CMIP6, CORDEX, Input4MIPs or Obs4MIPs. Datasets are usually hosted on different data nodes all over the world while data access is managed by any of the ESGF web portals through a web-based GUI or the ESGF Search RESTful API. The ESGF data nodes provide different access methods, e.g., https, OPeNDAP or Globus. 

Beyond ESGF, there has been the Pangeo / ESGF Cloud Data Working Group that coordinates efforts related to storing and cataloging CMIP data in the cloud, e.g., in the Google cloud and in the Amazon Web Services Simple Storage Service (S3) where a large part of the WCRP-CMIP6 ensemble of global climate simulations is now available in analysis-ready cloud-optimized (ARCO) zarr format. The availibility in the cloud has significantly lowered the barrier for users with limited resources and no access to an HPC environment to work with CMIP6 datasets and at the same time increases the chance for reproducibility and reusability of scientific results. 

Following the Pangeo strategy, we have adapted parts of the Pangeo Forge software stack for publishing our regional climate model datasets from the EURO-CORDEX initiative on AWS S3 cloud storage. The main tools involved are Xarray, Dask, Zarr, Intake and the ETL tools of pangeo-forge-recipes. Thanks to similar meta data conventions in comparison to the global CMIP6 datasets, the workflows require only minor adaptations. In this talk, we will show the strategy and workflow implemented and orchestrated in GitHub Actions workflows as well as a demonstration of how to access EURO-CORDEX datasets in the cloud.
One dimensional models of frictional plastic strain localisation
Authors: Duretz Thibault , Le Pourhiet Laetitia
Published: March 2024

Frictional plasticity governs the state of stress and the deformation style of the Earth’s upper crust. Frictional models depend on both deviatoric stress and pressure and include coupling between shear and volumetric stress via dilatancy and compaction. Elastic-plastic strains can takes the form of shear bands that can further be compared to geological observations. The study of frictional shear banding is non trivial because (1) this process is highly non-linear and (2) the models may require enrichment/regularisation to yield successful integration. 2D or 3D models may be used to model shear banding, they are however computationally expensive, which hinders systematic exploration of shear banding processes. We here present a 1D dimensional model of frictional plastic strain deformation. These models allow for exploring the process of strain localisation and the coupled effects of fluid flow and material microstructure.  
Introducing the BULL Database – Spanish Basin attributes for Unraveling Learning in Large-sample hydrology
Authors: Senent-Aparicio Javier , Castellanos-Osorio Gerardo , Segura-Méndez Francisco , López-Ballesteros Adrián , Jimeno-Sáez Patricia , Pérez-Sánchez Julio
Published: March 2024

Large-Sample Hydrology (LSH) plays a crucial role in understanding different hydrological processes, using large basin datasets as fundamental resources that allow researchers to explore multiple facets of hydrology (Addor et al. 2020). In recent years, multiple LSH datasets adapted to the national scale have been developed. We present BULL, a novel basin dataset for large-sample hydrological studies in Spain. BULL includes data from 503 watersheds, providing daily hydrometeorological time series (streamflow and climatic variables) and attributes related to basin characteristics. To collect these attributes, the recommendations included in the CARAVAN (Kratzert et al. 2023) initiative for the generation of a truly open global hydrological dataset have been followed. BULL covers the entire territory of Peninsular Spain, which is characterized by its wide climatic and hydrological variability, including catchments ranging from 100 km2 to 2000 km2. One of the main novelties of BULL to other national-scale datasets is the analysis of the hydrological alteration of the basins included in this dataset. The hydrological alteration is calculated by statistical comparison of the monthly flow values measured in the gauges and the flow values obtained from the Integrated System for Rainfall-Runoff Model (SIMPA) (Estrela and Quintas, 1996) developed by the Center for Hydrographic Studies (CEDEX), for the entire Spanish territory. This aspect is especially important in countries such as Spain, which is characterized as one of the countries in the world where rivers suffer from the highest levels of anthropization. The BULL dataset is made freely available to scientific users via the open-access repository Zenodo.                           References: Addor, N., Do, H.X., Alvarez-Garreton, C. et al. Large-sample hydrology: recent progress, guidelines for new datasets and grand challenges. Hydrological Sciences Journal 65, 712–725 (2020). https://doi.org/10.1080/02626667.2019.1683182Estrela, T., Quintas, L., 1996. A distributed hydrological model for water resources assessment in large basins. Proceedings of 1st International Conference on Rivertech. Vol. 96, pp. 861–868.Kratzert, F., Nearing, G., Addor, N. et al. Caravan - A global community dataset for large-sample hydrology. Sci Data 10, 61 (2023). https://doi.org/10.1038/s41597-023-01975-w