bluuebunny/crossref_metadata_2025 huggingface dataset:
Addressing uncertainty in models for improved decision making
Authors: Straub Daniel , Betz Wolfgang , Ruf Mara , Hoffmann Amelie , Koutas Daniel , Papaioannou Iason
Published: February 2023

In science and engineering, models are used for making predictions. These predictions are associated with uncertainties, mainly due to limitations in the models and data availability. While these uncertainties might be reduced with further analysis and data collection, that is often not an option because of constrained resources. Whenever the resulting predictions serve as a basis for decision making, it is important to appraise the uncertainty, so that decision makers can understand how much weight to give to the predictions. In addition, performing uncertainty and sensitivity analysis at intermediate stages of a study can help to better focus the model building process on those elements that contribute most to the uncertainty. Decision sensitivity metrics, which are based on the concept of value of information, enable to identify which uncertainties most affect the conclusions drawn from the model outcomes. We have found that such decision sensitivity metrics can be a powerful tool to understand and communicate an acceptable level of uncertainty associated with model predictions.In this contribution, we will discuss the general principles of decision-oriented sensitivity measures for dealing with uncertainty and will demonstrate them on two real-life cases: (1) the use of geological models for the choice of the nuclear waste deposit site in Switzerland, and (2) the use of flood risk models for decisions on flood protection along the Danube river. 
Thermal conductivity of deep earth minerals using high pressure-temperature time-resolved powder X-ray diffraction at European XFEL
Authors: Younes Zena , Massai Bernhard , Liermann Hanns , Konopkova Zuzana , Husband Rachel , Prescher Clemens , Sanchez Carmen , Jaisle Nicolas , McWilliams Stewart
Published: February 2023

Large scale dynamics within the Earth are the result of cooling. Heat is transported towards the surface by large scale convection in the mantle and in the core, and by conduction across the thermal boundary layers at the core–mantle boundary and the lithosphere. There is a range of estimates for the thermal transport properties, e.g. thermal conductivity (k) in the lower mantle ranges between 4 and 16 W/m K, [i] resulting from a lack of consensus on how to represent the pressure (and temperature) dependence of k; different models yield very different extrapolations.[ii]A three-pronged approach is here established to study thermal conductivity of deep earth minerals at CMB conditions.(i) Generating high-pressure and high-temperature states of matter in a diamond anvil cell (DAC) and resolving crystallographic changes in the sample via powder XRD. HED at European XFEL is the only facility at present that has sufficiently high X-ray energy coupled with MHz pulse trains to perform time resolved measurements of heat flow in high pressure samples heated by XFEL pulse trains. The femtosecond FEL pulses generate a unique thermal disturbance in bulk matter at a definitive time point, providing an idealized starting point for thermal relaxation. The AGIPD detector at HED allows for easier determination of relaxation dynamics and heat flow. (ii) Powder XRD analysis can be carried out by utilising the different timescales of XRD and X-ray absorption, whereby XRD is immediate and occurs before any subsequent unit-cell expansion due to X-ray absorption. The first X-ray pulse is used to collect a diffraction image of the unexcited state of the sample. The next X-ray pulse probes the heated state of the sample 222 ns after first excitation (at 4.5 MHz), before heating the sample again and the step is sequentially repeated.(iii) Finite element modelling studies allow the determination of thermal parameters such as thermal conductivity and expansivity. Utilising volume change with temperature in a sample, which can be extracted from the diffraction data, a primary model can be made. Temperature dependent thermal conductivity is fitted to the data. Beam energetic data is integrated into the Finite element modelling to dynamically model the fluctuations in the intensity of energy pulses.
[i] (Goncharov et al., 2009, Lay et al., 2008, Hofmeister, 2007, Hofmeister, 1999, Brown, 1986, Kieffer, 1976)

[ii] Goncharov et al., 2009, Hofmeister, 2007, Brown, 1986).
Resolving river planform and width effects on flow in meandering rivers for optimal placing of ADCP cross sections
Authors: Langendoen Eddy , Shoemaker Dylan , Ursic Mick , Konsoer Kory
Published: February 2023

Acoustic instruments such as multibeam echosounders (MBES) and acoustic Doppler current profilers (ADCPs) can collect flow and bathymetric data at high spatial and temporal resolutions. Researchers are widely using MBES and ADCP instruments to advance our understanding of meandering river morphodynamics. Whereas MBES instrumentation produces a continuous bathymetric surface, ADCP usage acquires the three-dimensional flow field at a series of cross sections. The spacing of ADCP cross sections has generally been based on a rule of thumb (for example, a multiple of the channel width), but is constrained by the available survey time. Theoretical advances regarding the morphologic adjustment of meandering rivers over the past 50 years have identified two important parameters: channel width-to-depth ratio (W/H) and channel radius of curvature-to-width ratio (R/W). Though, width is a controlling factor, it is its ratios with respect to channel depth and radius of curvature, that are important. In addition, channel curvature and width may vary considerably along the river. Hence, determining ADCP cross section locations based on a multiplication factor of channel width is challenging. We used a suite of wavelet analysis methods to determine the effects of channel curvature and width on flow measured using ADCPs along the Pearl River, LA/MS, Little Tallahatchie River, MS, and Wabash River, IL/IN. For example, for six bends on the Pearl River, curvature varied between 0.01 and -0.01 and top width varied between 80 and 180 m. The analysis showed that the streamwise velocity along the channel centerline was controlled by variations in channel width for most of the study reach. The primary extremes in near-bank streamwise velocity were controlled by channel curvature, but secondary peaks at some compound bends were controlled by changes in channel top width rather than local increases in curvature.  These findings are used to develop a tool combining a constant-width linear model of meandering-river flow with streamwise channel width profiles to determine the optimal placing of ADCP cross sections. Such information is specifically useful for rivers, such as the Little Tallahatchie River, that have a small width-to-depth ratio and a large channel radius of curvature-to-width ratio. To collect ADCP data using spacing equal to channel width for such rivers would lead to unrealistic survey duration.
Assessment of of high-resolution L-band radiometry application in precision irrigation
Authors: Daccache Andre , Houtz Derek , Emani Mohammad , Ahmadi Armand
Published: February 2023

Spaceborne microwave radiometers are historically used to estimate and analyze global soil moisture and ocean salinity. Despite providing valuable inputs to global hydrological models, the use of satellite-based L-band radiometry in agriculture was limited by the coarse spatial resolution not pertinent to field level observations or by the cost and size of the ground-based system.  TerraRad has recently developed a portable dual polarization passive L-band radiometer (PoLRa) for meter-scale retrievals of soil moisture (SM) and vegetation optical depth (VOD) suitable for field level application. PoLRa is designed to be mounted on UAV, fitted on ATV’s, or fixed on a tripod for continuous measurement. To examine the potential of L-band microwave radiometry in precision irrigation, the retrieved VOD and SM from PoLRa were compared against high resolution vegetation indices (i.e NDVI), plant parameters (i.e. LAI), surface soil moisture and  soil apparent electrical conductivity (ECa) from multi-frequency EMI soil scanner. We will summarize the findings from measurements conducted over bare soil, alfalfa, tomatoes, almonds and olive fields in California. We will also discuss the performance of the L-band radiometer in detecting spatial soil variability, surface soil moisture content, plant water status and vigor. We will also identify research gaps and limitations for L-band use for precision irrigation.
Sensitivity analysis for the optimization of hydraulic properties using transient pressure and flow data
Authors: Song Insun
Published: February 2023

Analysis of the sensitivity of measurable physical variables (i.e., pressure and flow) to material properties is very useful to reduce uncertainty in estimation of the properties. The subsurface fluid flow through a porous rock is characterized by two hydraulic properties, hydraulic permeability k and specific storage Ss. The pore pressure diffusion is controlled by the hydraulic diffusivity implicating the ratio of the transmitting ability to the storage capacity. Both values of k and Ss can be determined only from a transient pore pressure curve. However, the hydraulic properties (k and Ss) are defined in the relation between pressure (gradient) and flow (rate). The permeability is a proportional parameter between volumetric flux of fluid and pressure gradient. The specific storage denotes the proportionality constant between the increment of fluid content and the pore pressure. Thus, the flow (rate) measurement is also beneficial to obtain the hydraulic properties. This paper presents the sensitivity analysis of pressure and flow data to the properties. One-dimensional pressure diffusion test was conducted on a cylindrical sample of shale subjected to a triaxial confining stress. No flow was allowed at the downstream for the boundary condition. A sudden increase in the upstream pressure followed by a constant pressure leads to the downstream pressure rising transiently until it reached an equilibration to the constant upstream pressure. During the transient period, the upstream fluid flows into the sample because of the time-dependent pressure gradient. Both the downstream pressure and the upstream flow were measured to estimate the hydraulic parameters using curve fittings. The downstream pressure curve fitting yields 4.1×10-20 m2 for the permeability and 1.2×10-11 Pa-1 for the specific storage. However, these values for the best fit of the pressure data yield a completely different flow curve from the flow measurements. The permeability and the specific storage obtained from the best fit of the flow curve are 2.6×10-19 m2 and 2.1×10-10 Pa-1, respectively. The theoretical pressure curve using these values fits well (not the best) the measured data. Conclusively, the flow data is more sensitive to the hydraulic properties than the pressure data. The flow analysis yields less uncertainty in the optimization of hydraulic properties than the pressure analysis.
Monitoring airborne pathogens by nanopore sequencing
Authors: Pozdniakova Sofya , Reska Tim , Cañas Lídia , Borràs Sílvia , Rodó Xavier , Urban Lara
Published: February 2023

Next generation sequencing technologies have revolutionized the field of environmental science. Widely used short-read sequencing enables accurate microbial identification but is often slow, requires large centralised equipment, and does not allow to distinguish highly homologous genomic regions, making the taxonomic classification and genome assembly of closely-related species complicated. Those challenges may be resolved by the implementation of real-time long-read sequencing technologies such as Nanopore sequencing. Nanopore sequencing is a rapid technology that can be employed in situ through portable devices. The long sequencing reads can further improve precision of species identification in mixed microbial communities, and can provide more detailed characterisations of individual microorganisms. Despite its promising application to other environmental samples, nanopore sequencing has not yet been implemented to study bioaerosols and detect pathogens in air samples.Here, we used nanopore sequencing to analyse the environmental DNA extracted from air samples collected in Barcelona, Spain, as an example of a highly urbanised area. As the total amount of DNA found in the air is significantly lower compared to other typical environmental material such as soil or water, we first optimised DNA extraction in combination with the newest nanopore rapid sequencing protocols to achieve a highly accurate genome assembly-based description of the air microbiome. We identified the presence of potentially pathogenic organisms, and annotated the genome assemblies with respect to phenotypic read-outs such as increased virulence and antimicrobial resistance.  We hereby compared the air microbiome assessed through a variety of air sampling methods, including high-volume air samplers, liquid impingers, and standard air filtering approaches. We further assessed if our optimized DNA extraction methods introduced a bias into the described microbiome composition by including positive controls. We were able to demonstrate that it is possible to identify airborne pathogens even when the amount of DNA is low, by leveraging cutting-edge nanopore sequencing technology without requiring cultivation or amplification. This method has the potential to enhance and speed up the surveillance of airborne diseases such as pneumonia, measles, and COVID-19. In upcoming research, we plan to utilise this framework to study the microorganisms present in the air in different settings in order to detect the potential emergence of antimicrobial resistance or highly virulent pathogens in real-time.
Strategies for crisis organisations and management of torrential floods and important urban runoffs
Authors: Chave Sylvain
Published: February 2023

Flash floods have often very high societal impact because of their rapidity and surprise effect for flood crisis organisations, essentially because of complex forecast and anticipation. Deployed organisations must be as responsive as possible to face these events and to have reflex to put people in safety.This paper aims to present methods and reflections implemented to let organisations face to these situations that will becoming more frequent with climate change in the next decades, particularly in the mediterranean zone that is considered as a hot spot of the climate change and the increasing of these events in the future.Many recent examples of flash flood occured in the south of France let us to rest on concrete examples : in october 2021 near Nimes and in Ajaccio (Corse) in june of 2019. In international activities, Predict has developed method to inform territories exposed to these events, in crossing meteorological situation and exposed stakes presents in these areas.In these two cases, methodologies and supports of crisis management must integrate progressive and reactive organisation able to adapt its mobilisation in real time according to the context and the stakes threatened.
Chandra Long-Exposure Observations of Jupiter’s X-ray Auroral Emissions Near Juno Apojove 202
Authors: McEntee Seán , Jackman Caitríona , Weigt Dale , Louis Corentin , Dunn William , Boudouma Adam , Connerney Jack , Kurth William , Kraft Ralph , Branduardi-Raymont Graziella , Gladstone Randy
Published: February 2023

In this study we analyse a 40 hour (~ 4 jovian rotation) Chandra X-ray observation beginning on 15 September 2021 in order to study the morphology and time variability of the auroral X-ray emissions at Jupiter. At the time of this observation, Juno's orbit had taken the spacecraft into the dusk magnetosphere of Jupiter, thought to be the most likely source region for driving of jovian auroral X-rays. One leading theory for the driver of these emissions is Ultra Low Frequency (ULF) waves propagating along jovian magnetic field lines which can be initiated by processes on the dusk flank of the magnetosphere. This was the first time that this region had been observed by an orbiter since Galileo > 20 years ago, and never before has there been contemporaneous in situ and X-ray observations here. The long exposure time of this observation enables monitoring of the auroral regions over multiple jovian rotations, which is key to understand how variable the X-ray emissions can be. This allows for the identification of short timescale changes in the magnetospheric dynamics. Wavelet transforms and Rayleigh testing are used to search for statistically significant quasi-periodic pulsations of the X-ray emissions in the dataset. We combine the remote X-ray analysis with examination of data from the Juno Waves instrument, which has already shown that quasi-periodic emissions in the radio waveband can change on timescales of a few hours. Furthermore, we incorporate data from the Juno MAG instrument to provide magnetospheric context over the duration of the Chandra X-ray observation, and identify a possible compression event in the second half of the 40 hour time window. The Tao et al. (2005) solar wind propagation model also suggests a disturbed/compressed magnetosphere at this time, which is further supported by comparing the measured magnetic field against the baseline Kivelson and Khurana (2002) lobe magnetic field model.
Josef Underground Research Laboratory
Authors: Šťástka Jiří
Published: February 2023

The Centre of Experimental Geotechnics (CEG) is an experimental department of the Faculty of Civil Engineering of the Czech Technical University (CTU) in Prague. The CEG operates the Josef Underground Laboratory (the Josef UL) situated in a former exploration mine (the Josef Gallery) that was excavated in connection with potential gold mining. This facility provides practical courses for students and also provides a unique location for the conducting of experimental and research projects. The Josef Gallery was substantially reconstructed to form the Josef Underground Laboratory in 2007. The most important role of this underground research facility is to provide practical in-situ training in the fields of geotechnical engineering, geology, geochemistry, radiochemistry, radioecology etc. The training of future experts in this authentic underground setting involves the participation of several other Czech universities and numerous experienced specialists from outside the academic sphere. The IAEA (International Atomic Energy Agency) has added the Josef UL to its prestigious list of international training centres and the Josef Underground Laboratory is a member of the Underground Research Facilities network.The Josef underground complex provides excellent opportunities for both the conducting of in-situ research and teaching. The advantages of the facility include its varied geological conditions (tuffs, tuffites and granitic rocks) and excellent infrastructure which, together, form a modern and unique research and teaching facility. The total length of the reconstructed and ready-for-use galleries is currently over 5 km and the rock cover varies from 0m to 170m. Support for the experimental research conducted in the underground complex is provided by an experimental hall, laboratories and administration facilities that are housed in a specially-reconstructed surface building located near to the entrance to the Josef Gallery.The Josef complex has been designed as a multi-disciplinary rather than a single topic-oriented facility. The size of the Josef underground gallery and its unique geological diversity make it ideal for the conducting of experimental research across a wide spectrum of scientific disciplines.The research projects in which CEG staff participate and which are conducted or partially conducted at the Josef Underground Laboratory fall under the areas of underground and surface structures, modern tunnelling technologies, crash testing, ecology, waste storage and disposal, gas and heat storage, underground architecture and robotics.
Attributing Extreme Weather Events and Mean Climate Change using Dynamical and Event Storylines
Authors: van Garderen Linda , Feser Frauke , Mindlin Julia , Shepherd Ted
Published: February 2023

The impact of extreme weather events on society, as well as natural systems, have been increasingly damaging. Climate change has altered the frequency and intensity of these extremes. The question remains how quantifiable that influence is, so that society can prepare itself for the future, and reduce possible negative impacts.
Storylines are a conditional attribution method, that aids the understanding of climate change influence on extreme weather events, as well as mean climate change, by quantifying the climate signal. Instead of trying to estimate if or when a certain level of warming would happen, storylines show the effect such a climate change level would produce if it occurs. Conditioning on the dynamical part of the climate change signal strongly reduces uncertainties and makes the attribution quantifiable.
Generally speaking, there are two types of meteorological storylines, what IPCC AR6 refers to as dynamical and event storylines. Dynamical storylines can be evaluated through statistical analysis based on an ensemble of model simulations and used to characterize physically self-consistent mean climate change. Examples of climate change effect on southern-hemisphere precipitation will show how dynamic storylines can be applied. Event storylines recreate the dynamics of an extreme event in worlds with different plausible climate change backgrounds that are also physically self-consistent. The thermodynamic signal of climate change is quantified for the Russian heatwave of 2010. Overall, the storyline method is an important tool to be added to the standard climate change attribution toolbox.
Participation of off-equatorial wave energy for the Atlantic Niño events identified by wave energy flux in case studies
Authors: Song Qingyang , Tang Youmin , Aiki Hidenori
Published: February 2023

In the tropical Atlantic Ocean, extreme climate events with anomalous sea surface temperature, current, and precipitations are often referred to as the Atlantic Niño. It has many similarities with the EI Niño including the analogous mechanism that winds above the western equatorial ocean will excite oceanic waves to amply the temperature anomaly in the east. However, the Atlantic Niño presents more diversity in its intensity and occurrence time, especially in recent years, eg. 2019 and 2021, in which the classic theory becomes insufficient to explain. This study focuses on ocean responses to atmospheric forcing, manipulating the wind forcing in both equatorial and off-equatorial regions to excite linear ocean models for three types of events that occurred in 1999, 2019, and 2021 respectively. This study has found those extraordinary Atlantic Niños may owe to the wind in the off-equatorial region, where the winds can also excite oceanic waves that transfer energy to the western boundary and reflect back to the equatorial Atlantic. The interaction between the energy from the equatorial and the off-equatorial region makes the event less predictable. The participation of off-equatorial wave energy leads to the diversity of the Atlantic Niños. Hence, for the Atlantic Niño forecast,  more concerns about ocean dynamics to cover a wider latitude range should be required.
Relationships between radiation quality and ecosystem carbon and water fluxes
Authors: Wang Bin , Yue Xu
Published: February 2023

Both the quantity and quality of radiation could be altered by aerosols and cloud, and thus changing ecosystem carbon and water fluxes, as well as their coupling relationship. Although the importance of radiation quantity to ecosystems has been well studied, how radiation quality (characterized by diffuse radiation fraction, the proportion of diffuse to total radiation, Kd) affects ecosystem carbon and water cycles remains unclear due to the lack of diffuse radiation observations. In this work, taking advantage of a newly derived Kd dataset, we comprehensively explored the impact of Kd on ecosystem carbon uptake (net ecosystem exchange, NEE), carbon flux (gross primary production, GPP), water flux (evapotranspiration, ET), and water-use efficiency (GPP/ET, WUE) based on measurements at 201 global FLUXNET sites. We found that diffuse radiation is more efficient to improve NEE, GPP and ET than direct radiation at the same radiation level for all vegetation types, leading to increased ecosystem carbon uptake and water loss with Kd at the low and middle Kd levels. Furthermore, the enhancement of GPP is stronger than ET, leading to improved ecosystem WUE by diffuse radiation. By separating radiation into diffuse and direct components, we found that diffuse radiation is the most important factor for GPP, while ET is more dominated by direct radiation, indicating the complex process underlying the response of WUE to changes in Kd. This research helps improve our understandings of the responses of ecosystem carbon and water cycle to aerosol/cloud changes.
Progressive Excavation Disturbance Zone Evolution during and Post Mine-by Tunneling (PRECODE) – Insight into New Underground Research Laboratory
Authors: Hamdi Pooya , Achtziger Peter , Moulaeifard Seyyedmohammad , Rinaldi Antonio , Durand Virginie , Villiger Linus , Amann Florian , Wiemer Stefan
Published: February 2023

Development of brittle damage around nuclear waste repository tunnels is a common phenomenon in massive rocks in highly-stressed conditions. The time-dependent brittle fracturing may lead to an interconnected fracture network (i.e. excavation damage zone; EDZ) and induced seismicity. Within the excavation damage zone (EDZ), the permeability is often enhanced and – in the framework of nuclear waste disposal – may provide preferential pathways for radionuclide migration. Therefore, a comprehensive understanding of the brittle fracturing requires multi- multidisciplinary monitoring systems to allow for spatial and temporal characterization of the EDZ. Recently, the Swiss Federal Institute of Technology (ETH) Zurich established a new Underground Research Laboratory (URL) in Southern Switzerland in the old Bedretto Gallery. Within the PRECODE experiment, we will establish a new, experimental tunnel as a branch from the existing tunnel, which will be densely instrumented with strain, pore pressure and acoustic emission sensors prior to the excavation. The main objectives of the PRECODE experiment are to understand: (1) short-term rock mass behavior and EDZ formation during tunneling; (2) long-term fracture propagation within the EDZ associated with environmental conditions (fluctuations in humidity and temperature); (3) permeability changes with time around an open excavation and (4) the impact of tunneling on the nearby fault zones. This study outlines an overview of the project objectives, details of the planned monitoring systems, and some preliminary results obtained from a baseline study of characterization of the +40-year EDZ from the existing Bedretto Tunnel.Bedretto Team: The team involves more than 30 people from ETHZ and 10 research institutes and companies involved in the Bedretto Laboratory (see http://www.bedrettolab.ethz.ch/en/home/ for more details)
Thermal penetration evidence recorded since 1999 in the deep Tyrrhenian Sea (Mediterranean Sea)
Authors: Artale Vincenzo , Ciuffardi Tiziana , LoBue Nadia , Raiteri Giancarlo , Reseghetti Franco
Published: February 2023

The warming trend is already well known for the Mediterranean region, which is considered a climate hotspot warming 20 % faster than the global average. Every year, the Mediterranean Sea reaches new records for seawater warming, and year after year, this heat is penetrating deeper and deeper into the sea. New temporal and spatial evidence of this thermal penetration were depicted in the Tyrrhenian Sea thanks to a twenty-year continuous XBT monitoring. This work aims at dealing with the Tyrrhenian Sea sub-basin dynamics and processes. In particular, the mechanisms responsible for penetration of warming signal down to the deep layers (1800 m). What can hinder or exacerbate this spread and what areas are mostly affected by mechanisms of propagation and why?It’s well known that the seafloor's uneven topography and bottom roughness influences ocean circulation in two basic ways: first, it steers local vorticity flows; second, it provides barriers that prevent deep waters from mixing, except within deep passageways and straits that connect ocean basins or in hydraulically controlled overflow regions. The ways in which the warm signal entering from the south spreads rapidly northward affecting the entire Tyrrhenian Sea basin will be depicted, also considering its sub-basin peculiarities, such as features of the wind-driven surface circulation, strong stratification, and related mixing processes along the entire water column as well as its variability.
Tectono-magmatic evolution of Central Afar since 5 Ma: late syn-rift and break-up processes
Authors: gommery sarah , Bellahsen nicolas , Pik Raphael , Rabaute Alain , Nomade Sebastien
Published: February 2023

Central Afar (Ethiopia) is an active example of the final stages of continental rifting. The Stratoid magmatic series (ages between 5 and 1 Ma) were emplaced in a large fissural volcanic province, following an episode of thinning by normal faulting and detachment at 5-6 Ma (Stab et al., 2016). The Gulf Basalt series (0.9-0.4 Ma) later emplaced in more restricted areas attesting for the localisation of the deformation. Current active magmatic axes are even more localized and the most recent lava geochemistry attests for very little crustal contamination (Ayalew et al., 2018) along with recent dyking episodes. This suggests that Central Afar is currently in a late syn-rift stage, possibly close to continental break-up with divergence accommodated by magmatic accretion. The detailed study of the tectono-magmatic evolution of the region will allow us to better constrain the break-up processes active during volcanic margin formation.Our new mapping of Central Afar has consisted in defining Stratoid sub-series to better follow the interplay between magmatism and deformation during continent-ocean transition. This map is supported by field data, new mapping using satellite multispectral images, and new Ar/Ar dating. We defined three new units: the old Stratoid (5-3 Ma), the intermediate (3-2 Ma) and the young Stratoid (2-1 Ma). This mapping shows that the localisation processes started during the old Stratoid emplacement, which we interpret as an equivalent of Seaward Dipping Reflectors described in magma-rich margins. The detailed mapping of the normal faults in Central Afar is used to quantify the amount of deformation through space and time and discuss the mechanism of divergence accommodation (dyke vs normal faults) in order to track the timing and controlling parameters of the eventual switch from rifting to break-up processes. In the next future, we will study the chemical signature of each series to determine the evolution of magma sources and conditions of melting during the Stratoid phases we defined. Moreover, new dates will provide much needed data on this volcanic series's continuous vs discrete (with pulses) nature.
Capability of selected indicators for soil organic carbon stability to predict soil functions
Authors: Koorneef Guusje , de Goede Ron , van Rijssel Sophie , Pulleman Mirjam , Comans Rob
Published: February 2023

Soil organic carbon (OC) is pivotal for soil functioning, especially in the domains of elemental cycling, disease control and the regulation of soil structure and water. High OC contents are generally associated with improved soil functioning, and therefore OC content is widely used as a soil health indicator. The stability of OC influences all functions that depend on microbial decomposition (e.g. nutrient provisioning) or carbon retention (e.g. C sequestration). Yet, a standardized indicator for OC stability that can be used in soil health assessments is still in development. Here, we investigate to what extent selected OC stability indicators can predict soil functioning, and which type of OC stability indicator improves predictions most as an additional measurement besides OC content.We collected soil samples from arable fields in the Netherlands on marine clay (n=144) and sand (n=81) soils. For each soil sample, 18 different soil function measurements were performed and grouped into 3 function domains (i.e. elemental cycling, disease control, and the regulation of soil structure and water). In addition, 21 OC stability indicators were analyzed and grouped into 4 types of OC stability indicators (i.e. carbon pools; carbon fractions, thermal stability indicators, and indicators based on elemental ratio). Multiple linear regression was used to determine how much of the variation in each soil function measurement could be predicted by the OC stability indicators and other measured intrinsic soil properties (e.g. texture and pH).We found that OC stability and intrinsic soil properties could significantly predict soil functions better in the domain of regulation of soil structure and water (R2adj=40±18%) than in the other 2 function domains (elemental cycling: R2adj =32±31%; disease control: R2adj =22±11%). OC stability indicators could predict 80±26% of this maximum explainable variation, averaged over all soil functions (clay: 82±18%; sand: 77±32%). This percentage did not differ significantly between the function domains. A regression model with only total OC content explained 18±21% of the maximum explainable variation (clay:23±26%; sand:14±14%). The addition of 1 OC stability indicator increased this percentage to 49±23% (clay: 58±20%; sand: 39±22%). Predictions of soil functioning were most strongly improved by including a thermal stability indicator in addition to total OC content.We conclude that OC stability indicators can predict soil functioning adequately and that thermal stability indicators show particular potential as OC stability indicator in soil health assessments.
Identifying the dominant hydrochemical processes post wetland restoration along stream valleys, Denmark
Authors: Fredriksson Filippa , Baumane Marta , Båstrup-Spohr Lars , Bruun Hans Henrik , Martinsen Kenneth Thorø , Aagaard Sofie , Michelson Bjørg Friis , Sand-Jensen Kaj , Jessen Søren
Published: February 2023

Restoration and rewetting of wetlands previously drained for agriculture, is currently used to decrease net greenhouse gas (GHG) emissions, while improving biodiversity. Wetland hydro(geo)logy is known to exert a key control on GHG-retention and on conditions facilitating improved biodiversity. Yet knowledge of the major hydrochemical processes that occur in wetlands prior to drainage and after restoration is limited, although links between wetland hydrochemistry, GHG-retention and biodiversity might well exist. To reduce the knowledge gap, we sample surface waters, precipitation, and shallow (<1 m) groundwater from 61 wells. The sampling sites are either near-natural or restored wetlands of the riparian zone, and are distributed along three separate stream valleys, with subsurface geologies consisting of carbonate rock, glacial till or sand from glacial outwash. Furthermore, the wetlands are categorized based on management (grazed or unmanaged). Surface and groundwater samples are analyzed for dissolved major ions, methane (CH4), organic carbon (DOC), fluorescence, and all samples are analyzed for stable water isotopes (δ18O, δD) and electrical conductivity (EC). EC, pH, dissolved oxygen (O2) and temperature are measured in the field using a flow cell. Initial results from the groundwater wells in the wetlands indicate EC values between 101-5300 μS/cm (the high end due to marine influence), O2 between 0.1-6.7 mg/L, and that the pH varies from acidic (min. 5.0) to alkaline (max. 7.7). The groundwater’s Fe(II) concentration appears to be significantly elevated in restored stream valley sites versus the near-natural sites. The results suggest differences in redox conditions that in turn may control production of GHGs, such as CH4. In addition, the hydrochemistry and subsurface geology seem to be a key factor in the development of the present vegetation in the various field sites. With shifting climate, terrestrial wetness will change too, under influence of hydrogeochemical-vegetation interactions. To understand the associated climate feedbacks, a detailed understanding of wetland hydrology and ecology is needed. Through a method-independent approach, this study helps clarify the response related to hydrochemistry, geology, and time. The increased understanding could also contribute to fine-tuning of current and future restoration programs, thus increasing their success.
Micro-Continuum Modelling of Coupled Hydro-Bio-Chemical MICP Processes in Fractured Rock
Authors: Sang Guijie , Lunn Rebecca , El Mountassir Grainne , Minto James
Published: February 2023

Subsurface storage of CO2 and retrievable green energy (i.e. compressed air and hydrogen) in depleted gas reservoirs, deep saline aquifers and salt caverns, are considered as key transitions within the energy sector to enable many countries to meet their net zero carbon emissions targets. One of the main challenges in underground storage is the presence of potential leakage pathways (such as caprock fractures/faults) which pose a threat to economic feasibility and to the environment. Seeking an efficient technique to remediate leakage pathways is crucial to guarantee sealing efficacy. Microbially induced carbonate precipitation (MICP) is regarded as a promising bio-grouting technique for leakage remediation due to its advantages such as the low water-like viscosity and micron-size microbes, which enables permeation far from the injection point and excellent penetration into fine aperture fractures.MICP utilizes ureolytic bacteria, commonly Sporosarcina pasteurii (S. pasteurii) to produce highly active urease enzyme, which can catalyze urea hydrolysis and result in the production of carbonate ions. Carbonate precipitation occurs if a calcium source is supplied, which can effectively remediate leakage by filling void space and improve strength by bonding solid grains.We propose a micro-continuum model which accounts for the coupled hydro-bio-chemical MICP processes in fractured porous rock. In this micro-continuum model, the flow is controlled by the Darcy-Brinkman-Stokes equation over a number of control volumes (i.e. voxels based on X-ray CT scan). The kinetic parameters of urea hydrolysis and calcium carbonate precipitation are calibrated based on batch experiments. The bacteria deposition parameters, which feature the bacteria deposition in fractured rock, are calibrated based on experimentally measured bacteria breakthrough curves in a 1-dimensional column filled with fracture gouge materials. The proposed micro-continuum model can well represent the decreases in porosity and permeability of an artificially-cut anhydrite fracture filled with anhydrite gouges under MICP treatment cycles. Our modelling results also suggest that when the CaCl2 concentration is equal to or higher than the urea concentration in the injected cementing solution, the rate of microbially induced carbonate precipitation is predominantly limited by the kinetics of urea hydrolysis rather than the kinetics of calcium carbonate precipitation. The proposed micro-continuum model serves as a useful tool for evaluating MICP treatment strategies and may be upscaled to predict and optimise field-scale leakage remediation.
Visualising high-resolution global land use change of six decades
Authors: Winkler Karina , Fuchs Richard , Rounsewell Mark , Herold Martin
Published: February 2023

People have shaped the land surface for many centuries. However, the global expansion of land use is fuelling climate change and threatening biodiversity. At the same time, there is an ever-increasing need to supply our growing world population with food, energy and materials. Despite the crucial role of land use for solving global sustainability challenges, existing data on long-term land use change lacks the spatial, temporal and thematic detail to comprehensively capture the changes in its full dynamics.We synergistically combined multiple open data streams (remote sensing-based land cover maps, land use reconstructions and statistics) to examine the spatio-temporal patterns of global land use change of global land use change. For this, we developed the HIstoric Land Dynamics Assessment+ (HILDA+), a modelling framework providing data-derived, annual gross changes between six land use/cover categories (urban, cropland, pasture/rangeland, forest, unmanaged grass/shrubland, sparse/no vegetation) at a spatial resolution of 1km and for a reference period of 1960-2020. Derived land use/cover maps are published as Open Data.In this live demo, we present our findings through an interactive map viewer - a visualisation of global land use change of the past six decades. The data visualisation builds on the open-source server GeoServer. We will interactively explore the extent of land use change and its diverging patterns across the globe.
Effect of increased sulfate reduction on the stability of authigenic vivianite in lake sediment
Authors: van Kuppevelt Harm , Hupfer Michael
Published: February 2023

The presence of high levels of phosphorus (P) in surface waters can negatively impact the functioning of ecosystems and water quality. Despite efforts to decrease P concentrations, the accumulation of P reservoirs in sediment from past high external inputs still poses a problem. This legacy P can contribute to internal P loading, which has been shown to extent eutrophication in many freshwater systems. To effectively restore these systems, it is important to understand the geochemical processes that control the fixation and release of P in the sediment. While it is known that under anoxic conditions, P can be stored in the form of the mineral vivianite, it is not well understood if the vivianite reservoir can also act as a source of P. In a field study, mixed sediment from Lake Arendsee, Germany that naturally contained vivianite was placed in the sediment floor of the same lake, in both sulfate reduction depths and below (0-45cm). After three months, the sediment was retrieved and analyzed to investigate the effect of sulfide production on the vivianite pool. Sequential extraction and XRD analysis of the sediment solid phase showed that at shallower depths where sulfide concentrations were higher, there was a significant reduction of the vivianite reservoir and a decrease of P bound to Fe relative to S bound Fe forms. This suggests that P bound in vivianite can act as a P source in sulfidic sediment. Further research is needed to determine the extent of this phenomenon in lakes with increased sulfide production.
New pathways for EMIC wave propagation within the ionosphere: SWARM observations and modelling
Authors: Rankin Robert , Sydorenko Dmytro , Mann Ian R
Published: February 2023

Electromagnetic ion cyclotron (EMIC) waves are important because of their essential role in reducing the amount of radiation in the Earth's radiation belts under geomagnetic storm conditions. In this presentation, we show results from a new simulation model of EMIC waves and compare them with SWARM satellite data and ground-based observations [I. P. Pakhotin et al., Geophys. Res. Lett., 2022, doi:10.1029/2022GL098249]. The EMIC wave model is a first-of-a-kind in accounting for wave propagation in the magnetosphere and a realistic ionosphere specified using the IRI and MSIS empirical models. The inclusion of a realistic ionosphere in the model enables new pathways to the upper atmosphere to be identified, which is crucial for understanding the waves detected on the ground. We show using a model-data comparison that EMIC wave energy is reflected at different locations in the ionosphere toward the equator to form standing waves. This is a new resonance phenomenoncreated by interference of waves that produces an amplitude peak in the upper atmosphere at lower latitudes, far from the location of the initial source. Understanding such pathways is crucial for correctly diagnosing the location of EMIC wave populations in space, and assessing their role in radiation belt loss.
DOH! – The interface of isotope hydrology, ecology, and organic geochemistry
Authors: Meador Travis Blake , Jabinski Stanislav , Mičanová Anna , Zehetner Niclas , Umbria-Salinas Karelys , Pilecky Matthias , Wassenaar Leonard
Published: February 2023

Dissolved organic matter (DOM) cycling is essential to understanding energy flow in aquatic ecosystems and their role as a source or sink of CO2 in the global carbon cycle. Quantifying DOM turnover and reactivity have been confounded by the barely detectable changes in the molecular composition and 13C & 15N stable-isotope compositions. We hypothesized that significant seasonal isotopic changes in environmental waters and primary biological productivity might be reflected in the H & O stable-isotope composition of DOM, providing an alternative way to assess the accumulation, turnover, and transport of DOM in aquatic environments. H & O stable-isotope analyses of DOM from lakes showed temporal coupling of water isotopes with organic molecules that accumulate in natural aquatic environments, which varied between catchments and by molecular size components of DOM. An in-situ stable-isotope labelling (HDO) experiment revealed (microbial) turnover of DOM occurred on a weekly timescale. Further development of δ2H- and δ18O-DOM analyses may improve our understanding of the provenance and processing of DOM and help better constrain unknowns in the metabolic balance of inland waters.
An assessment of the most suitable DEM for tectonogeomorphic analysis in tectonic basins
Authors: Viveen Willem , del Rosario González-Moradas Maria , Vidal-Villalobos Raúl Andrés , Villegas-Lanza Juan Carlos
Published: February 2023

Digital Elevation Models (DEMs) are a fundamental data source for the calculation of tectonogeomorphic indices in areas with active tectonic deformation. There are, however, hardly any studies available that compared the strength and weaknesses of the various, freely available medium-resolution DEMs for these kinds of applications. As such, it is difficult for researchers to make a well-informed choice regarding the most suitable DEM for their specific study. We have therefore carried out an exhaustive analysis of the five, most commonly used medium-resolution DEMs. These are the 30-m SRTM v.3.0, AW3D30, ASTER GDEM3, Copernicus and the 12-m TanDEM-X. We have analysed the performance of these DEMs by calculating the most commonly used tectonogeomorphic indices for 22 river basins in two geographically contrasting tectonic basins in the Peruvian Andes. Calculated metrics included drainage basin areas, fluvial network length and position, longitudinal profile and knickpoint representation, concavity indices θ and m/n, the normalised steepness index ksn and the Hypsometric integral. We also performed a mapping exercise of fluvio-tectonic landforms such as fluvial terraces, folds and fault traces. Statistical analysis were carried out to highlight similarities and differences in performance between the five DEMs. Copernicus and TanDEM-X were the best performing DEMs across the whole range of analysed metrics, closely followed by AW3D30. SRTM3 v. 3.0 and ASTER GDEM3 performed well in some of the tests, but lacked in other areas and are therefore not recommended. 