bluuebunny/crossref_metadata_2025 huggingface dataset:
Sealing impacts soil properties and the soil microbial community in urban areas
Authors: Stevens Carly , Correa Pereira Marlon , Whitlock Raj , O’Riordan Roisin , Israel da Silva Leandro , Kourmouli Angeliki
Published: March 2024

Urbanisation inevitably alters the chemical, physical and biological soil properties. Consequently, it modifies environmental soil services. The sealing of soil – covering the soil surface with non-biological structures - has gained attention in urban area in relation to flooding, loss of soil carbon, loss of soil function and other problems, which can be mitigated introducing greenspaces in urban areas. To understand the impact of sealing and greenspaces on the urban soil properties, soil beneath three pavement types (concrete, slab and tarmac) and from paired unsealed areas (representing four cover types – bare soil, grass, shrub and tree) were sampled in forty sites in Lancaster, UK to access chemical [pH, total carbon (C), total nitrogen (N), C/N ratio], physical [moisture] and microbiological [microbial biomass (MB), 16S rDNA metabarcoding data metrics] parameters. Sealed soils had lower moisture, C, N and MB, and higher pH than unsealed soils. C/N ratio had no significative difference. Changes in chemical and physical soil parameter affected the bacterial diversity indexes (richness, Shannon, Simpson and α parameter of Fisher’s log series), which were significantly lower in sealed areas as well. NMDS analysis showed high variability in the bacterial community of sealed soil, but lower variability in unsealed soil. The sum of sequences of gram positive, gram negative, oligotrophic and copiotrophic bacteria, as well gram positive:gram negative  ratio (GP:GN), were lower in sealed soil. The reduced GP:GN ratio on sealed soil suggests low-quality organic matter and the impact of low moisture and N on bacterial community. Pavement type had no effect on sealed soil parameters. However, the cover type significantly changed GP:GN and copiotrophic:oligotrophic ratio on unsealed soil, indicating that soil in grassland may have higher resource availability (C and N) and microbial growth rates than shrub and trees. Our results reinforce that the sealing, unrelated to pavement type, has a negative impact on soil properties and deplete microbial diversity. Cover type may affect resources availability on unsealed soil. These changes can affect microbial processes related to biogeochemical cycles, impacting the carbon store and the potential for nutrient cycling in urban soils.
Endorheic Lake Storage Changes in Water-Stressed Regions: Anthropogenic and Climate Impacts
Authors: Nevermann Hannes , Aminzadeh Milad , Shokri Nima
Published: March 2024

Endorheic lakes are at the core of terrestrial hydrological processes and ecosystem functioning in closed drainage basins. The storage capacity of these vital water bodies has been influenced by the climate variability and human activities (Hassani et al., 2020). We aim to investigate the role of these factors on the storage capacity of endorheic lakes in water-stressed regions worldwide. We integrate satellite remote sensing and historical data to quantify the extent of endorheic lakes and explore the relationship between the changes in their storage capacity and atmospheric parameters such as air temperature, precipitation, and wind. To examine the role of anthropogenic activities, we assess changes in the land cover and the extent of man-made water storage infrastructures (dams and water reservoirs) in the respective water basins and their correlations with storage variations of endorheic lakes situated in the water-stressed regions. Our preliminary findings highlight the complex interplay between socio-economic and environmental factors influencing the fate of endorheic lakes. This study contributes to our understanding of the broader implications of global environmental changes and offers valuable insights for policymakers, researchers, and stakeholders engaged in the sustainable management of endorheic lake ecosystems. ReferenceHassani, A., Azapagic, A., D'Odorico, P., Keshmiri, A., Shokri, N. (2020). Desiccation crisis of saline lakes: A new decision-support framework for building resilience to climate change. Science of the Total Environment, 703, 134718.
Economic impact of a drought through the integration of hydro-economic and macroeconomic models
Authors: Valle-García Ángela , Montilla-López Nazaret M. , Gutiérrez-Martín Carlos
Published: March 2024

The global demand for freshwater has been steadily increasing, aligning with the growth of the world population, the rise in new demands in other economic sectors, and the supply decrease as a consequence of climate change. This trend has resulted in elevated consumption rates. The closure of river basins further intensifies water shortages, necessitating effective demand-side policies, particularly in agriculture. The allocation of water rights is crucial in managing limited water resources. The integration of hydro-economic modeling, a tool combining biophysical and socioeconomic factors, aids in water resource planning and policy formulation.The primary objective is to analyze the effects of linking a hydro-micro-economic model with a macro-economic model. The study focuses on the Guadalquivir River Basin (GRB) in southern Spain, using a hydro-economic model and a Computable General Equilibrium (CGE) model for the Andalusian economy. The models are interconnected, providing insights into the feedback between the agroeconomic sector and the regional economy.The hydro-economic model comprises nodes representing the hydrological system and economic agents with agricultural and urban water demands. Agricultural demands are calibrated using Positive Mathematical Programming to simulate farmers adapting to water scarcity. The CGE model, calibrated at a regional level, addresses macroeconomic aspects. The models exchange information on commodity prices and land use changes.The study applies the Drought Management Protocol of the GRB, reducing water inflow in the basin by 25%. In this way, results indicate that the macroeconomic model mitigates the economic impact of reduced crop area due to drought by increasing prices. Thus, it is demonstrated that from the producer's perspective, more is gained due to this price effect, resulting in an increase of up to 4.5% in the producer's gross margin. The coupling of models enables a comprehensive understanding of the economic effects of drought, taking into account both micro and macroeconomic perspectives. This effect cannot be observed without the linkage to the macro model when considering only the hydro-economic model.In conclusion, the coupling of a hydro-economic model and a macro-economic model proves effective in addressing changes in commodity prices resulting from drought-induced reductions in crop areas. This integration attenuates the economic impacts of drought by accounting for the price effect.
Thermal remote sensing of lava lakes: a comparison of approaches
Authors: Rolain Sofie , Peumans Dries , Smets Benoît
Published: March 2024

Satellite-based thermal remote sensing is a useful tool for monitoring volcanoes. It involves detecting thermal anomalies, called 'hotspots,' and calculating the radiative energy emitted by volcanic activity. Various volcanic hot spot detection algorithms already exist in the literature. However, every algorithm has its advantages and disadvantages, as they are limited depending on the tradeoffs made during algorithm development, the sensor used for aquisition, and  the geometry of acquisition. Depending on the algorithm used, different results are obtained from the same data and, hence, different interpretations can be made in terms of, e.g., energy emitted, effusion rates, and eruption duration. In the present work, we aim at creating a new hotspot detection algorithm using MODIS and VIIRS imagery, which allows us to efficiently look at the dynamics of thermal emissions coming from persistent lava lakes, i.e., bassins of lava maintained molten through thermal convection and outgassing. We investigate the applicability of sensor fusion ideas, using multiple bands, and incorporating cloud cover information. We expect that by combining all available data the robustness of the detection process will increase.
Galactic cosmic ray cutoff rigidity and solar cycle variation at Neptune
Authors: Enghoff Martin Bødker , Romani Paul N. , Connerney John E.P. , Jørgensen John L.
Published: March 2024

Albedo changes of Neptune related to the 11-year solar cycle have been reported since the 1970s (Lockwood and Thompson, Nature 280, 1979). For nearly two decades a clear anti-correlation between solar activity and Neptune’s brightness was observed but the relationship appeared to break down between the late 1980s (Lockwood and Thompson, Nature 349, 1991) and mid 1990s (Lockwood and Jerzykieicz, Icarus 180(2), 2006) where signs of a direct correlation instead appeared. Recent results indicate a direct correlation sustained over two solar cycles (Chavez et al, Icarus 404, 2023) prompting renewed interest in attempting an explanation.Several parameters vary with the solar cycle, one being UV light which has a much higher variation than that of visible light. This could affect the photochemistry of Neptune’s atmosphere which is rich in methane that photolyzes at wavelengths below 200 nm and can produce haze (Romani and Atreya, Icarus 74(3), 1988). Another parameter that varies is the flux of galactic cosmic rays (GCRs) which is modulated by the solar wind. GCRs can ionize molecules leading to ion-induced nucleation (Moses et al, GRL 16(12), 1989) but only for the energies of particles which are allowed entry to the planetary atmosphere by the magnetic field. Solar activity modulates GCRs of energies up to about 20 GeV so a solar variation due to GCRs is only possible if particles of those energies can enter the atmosphere. The parameter used to describe GCR entry is the cutoff rigidity (in GV).In this work we have used the magnetic field model of Neptune (Connerney et al, ASR 12(8), 1992) and a particle trajectory program (the Geomagnetic Cutoff Rigidity Computer Program by Smart and Shea, 2001, Tech. Rep. No. 20010071975) to calculate a cutoff rigidity map for Neptune for vertical GCR entry. Since the magnetic field is very tilted compared to the rotational axis (by about 45 degrees) the cutoff rigidity map has interesting features as the GCRs are guided by the magnetic field lines. Thus, lower energies and therefore a higher GCR flux more susceptible to solar cycle changes are allowed to enter the atmosphere at mid latitudes, as opposed to most planets where this happens as the poles since their magnetic field is more closely aligned with the rotational axis.Furthermore, we have used fitted GCR energy spectra in combination with the cutoff rigidity map to produce a map of solar cycle variations in GCR flux at a height of 49 km, which is at the pressure level where cosmic ray showers are initiated at Earth and also close to where Neptunian clouds are found. Where the cutoff rigidity is lowest the solar cycle variations of GCR are several tens of percents which could affect cloud formation significantly.
Introducing a fully differentiable, fully distributed Rainfall-Runoff Model
Authors: Scholz Fedor , Traub Manuel , Scholten Thomas , Zarfl Christiane , Butz Martin
Published: March 2024

Traditional hydrology simulates rainfall-runoff dynamics by means of process-based models (PBMs), which are derived from physical laws. The models exhibitrealistic behavior. Their internal states can by directly interpreted, because theyreflect the modeled current state of the hydrological dynamics. Natural processesin general are very complex, though, such that is is simply impossible to modelevery aspect in detail. In the case of hydrology, for example, anthropological in-fluences, such as the exact influence of the sewer system, as well as natural factors,such as soil and rock types and structures, are extremely hard to model in all theirdetails. As a result, high uncertainty remains about the models’ necessary compo-nents and their parameterizations, leaving room for improvement Sit et al. [2020],Nearing et al. [2021]. Data-driven approaches, like deep neural networks (DNNs),offer an alternative. They are trained on large amounts of data by gradient descentvia automatic differentiation. This enables them to automatically discover rela-tionships in the training data, which often leads to superior performance Kratzertet al. [2018], Shen [2018]. Due to the DNNs’ complexity, however, these rela-tionships are hard to investigate and often fail to respect physical laws. Hybridmodeling combines both approaches in order to benefit from their respective ad-vantages. In this work, we present a physics-inspired, fully differentiable and fullydistributed rainfall-runoff model to predict river discharge from precipitation. OurDNN architecture consists of a land module and a river module. The land mod-ule receives RADOLAN-based precipitation data and propagates runoff laterallyover a regular grid (1km2 grid size) taking land surface structure information intoaccount. Runoff is then captured as input to the river module, which mimics theactual river network by means of a graph neural network. Due to the involved,physically motivated inductive biases, our model can be trained end-to-end fromthe RADOLAN data as the main input and sparse discharge data as output. Weshowcase our model on the Neckar river catchment in South Germany, achiev-ing NSE values of 0.88 and 0.84 when we predict 1 and 10 days into the future,respectively. In contrast, persistence yields NSE values of 0.5 and 0.06 for the cor-responding forecast horizons. Due to our model’s differentiability we expect to beable to infer the origin of measured discharge or turbidity—and thus erosion—inthe near future. We thus hope that this information could be used to create policiesthat mitigate both the danger of floods and extreme erosion.
Towards a direct simulation of a full cycle of the quasi-biennial oscillation in a global storm-resolving model
Authors: Franke Henning , Giorgetta Marco
Published: March 2024

This study presents the very first attempt to directly simulate a full cycle of the quasi-biennial oscillation (QBO) in a global storm-resolving model (GSRM) that explicitly resolves deep convection and gravity waves instead of parameterizing them. Using the ICOsahedral Nonhydrostatic (ICON) model with a horizontal and vertical resolution of about 5 km and 400 m, respectively, we show that a GSRM in the convective gray zone is in principle capable of simulating the basic dynamics that lead to a QBO-like oscillation of the zonal wind in the tropical stratosphere. ICON shows overall good fidelity in simulating the downward propagation of QBO jets in the upper tropical stratosphere, which happens also for the right reasons. In the lower stratosphere, however, ICON does not simulate the downward propagation of the QBO jets to the tropopause, predominantly due to a pronounced lack of planetary-scale wave forcing. As a consequence, the QBO jets degrade with increasing simulation time and lose strength substantially. We show that the lack of planetary-scale wave forcing in the lower stratosphere is caused by a lack of planetary-scale wave momentum fluxes entering the stratosphere, which are about 20%–40% too weak. We attribute this lack of planetary-scale wave momentum flux to a substantial underestimation of the spatio-temporal variability of tropical deep convection in general and convectively coupled equatorial waves in the tropical troposphere in particular. While conventional general circulation models can compensate for a lack in resolved wave forcing by tuning the parameterized gravity wave forcing, GSRMs no longer have this tuning screw, making their QBO more susceptible to being influenced by tropospheric mean state biases. We thus conclude that simulating a realistic spatio-temporal variability of tropical convection is currently the main roadblock towards simulating a reasonable QBO in GSRMs.
Airborne Gravimetry with Quantum Technology
Authors: Jensen Tim , Forsberg René , Stokholm Andreas , Dale Bjørnar , Bidel Yannick , Zahzam Nassim , Bresson Alexandre , Bonnin Alexis
Published: March 2024

In summer 2023 an airborne gravity survey was carried out utilizing the GIRAFE quantum gravimeter from ONERA and the iMAR classical strapdown gravimeter from DTU. The survey consisted of two parts: (1) In Iceland targeting the Vatnajökull ice cap and some active volcanoes, all expected to have some source of mass variation; (2) A regular survey grid around the Nuuk fjord system as input for Geoid computation, along with a strapdown test of the cold-atom sensor, which is currently operated on a stabilized platform.Results from both instruments will be presented and compared with external information. An intercomparison of the two instruments will be presented along with plans for a new cold-atom sensor designed for airborne applications.
Carbon storage in coastal reed (Phragmites australis) ecosystems
Authors: Williamson Margaret , Jilbert Tom , Norkko Alf , Gustafsson Camilla
Published: March 2024

Distribution of the common reed (Phragmites australis) has increased in coastal ecosystems across the globe. Currently, there appears to be a gap in knowledge about carbon (C) cycling and sequestration in reed beds though preliminary findings indicate these systems are unique, show great potential for C storage, and, therefore, should be taken into consideration while developing blue carbon (BC) budgets. The aim of my study is to quantify how much C is stored in reed bed biomass and sediment along the brackish Pojo Bay system in coastal Finland. We selected 6 reed beds to sample along Pojo Bay covering a range of salinities and wave exposure from the northern-most part of the Bay to the southern-most part opening into the Baltic Sea. Within each reed bed, samples were taken from randomly selected sites within each of the 3 reed bed zones (terrestrial, intermittent, and littoral) and replicate samples were taken within each zone along a transect. Plant and sediment samples were collected and taken back to the lab to run for C content.  

My results from sediment LOI (loss of ignition) show higher organic matter content in the upper segments of sediment profiles and a general trend towards higher organic matter content in terrestrial and intermittent zones than littoral zones of reed beds. Preliminary results for C content within sediment and biomass samples show similar trends. These findings are significant as they help rectify a gap in knowledge and provide us with an estimate of how much C is stored in reed bed biomass and sediment. Information on how much C is stored within this rapidly expanding coastal ecosystem type is important for the management of reed beds and greatly impacts calculations for coastal carbon budgets to combat climate change. Further information will be gathered from these field sites every 3 months for 2 years to show seasonal variability in the C storage, C isotope analysis, and methane emissions to get a more comprehensive picture of C cycling in these important coastal ecosystems reed bed systems.
Fossil Coleoptera with in situ and adhered pollen from the Eocene of Eckfeld, Germany
Authors: Bouchal Johannes Martin , Geier Christian , Ulrich Silvia , Uhl Dieter , Wedmann Sonja , Wappler Torsten , Grímsson Friðgeir
Published: March 2024

The middle Eocene Eckfeld maar (c. 44 Ma) deposits in Germany are known for numerous well-preserved fossils they have yielded until today. Among these records, thousands of insects have been recorded that potentially provide direct evidence for flower visitations and entomophilic pollination processes. In order to obtain data on flower visits and possible pollinator roles, we extracted pollen from selected groups of fossil Coleoptera from Eckfeld and studied them with light microscopy (LM) and scanning electron microscopy (SEM). In total, we screened 332 Coleoptera: 51 Buprestidae (six with pollen), 21 Cerambycidae (two with pollen), 87 Chrysomelidae (four with pollen), 80 Elateridae (three with pollen), ten Eucnemidae (one with pollen), 78 Scarabaeidae (three with pollen), and five Throscidae (no pollen). The beetles were screened for both in situ pollen occurring in their digestive system and adhering pollen occurring on various parts of their exoskeleton (head, thorax, abdomen, leg etc.). The pollen was most frequently associated with members of Sagrinae, a subfamily of leaf beetles (Chrysomelidae), and Agrilinae, a subfamily of jewel beetles (Buprestidae). The adhering or in situ pollen can be assigned to at least 15 different taxa. While some are unique and only associated with one beetle specimen (e.g., Malvaceae, Moraceae), other pollen types were found associated with two or more beetle specimens, namely, Castaneoidea, Euphorbiaceae, Oleaceae, Onagraceae (Ludwigia), Sapotaceae, and Vitaceae (Parthenocissus).
Earthquake nucleation and slip behavior altered by stochastic normal stress heterogeneity
Authors: Li Meng , Niemeijer Andre , van Dinther Ylona
Published: March 2024

Recent laboratory experiments exhibit varying nucleation locations with changing nucleation lengths. This could be caused by spatial variations in effective normal stress, due to its controlling influence on fault strength and fracture energy. We use an earthquake sequence model with stochastically variable, spatially heterogeneous normal stress, analogous to a 2-m scale laboratory experiment, to quantitatively understand its impact on earthquake nucleation and the following earthquake sequences. We identify five regimes of earthquake nucleation and slip behaviors, controlled by the ratio of the heterogeneity wavelength (λ) over the nucleation length (Lc). When λ is much smaller than Lc, full ruptures are observed. Magnitudes and recurrence intervals are similar to those on homogeneous faults with comparable averaged normal stress. When λ is much larger than Lc, slow slip events and partial ruptures occur frequently and the nucleation length of each earthquake depends on the local stress level. We find that the nucleation location becomes migratory when λ and Lc are of the same magnitude. When λ is larger than Lc, earthquakes nucleate in low normal stress regions (LSRs), and high normal stress regions (HSRs) function as barriers. However, HSRs and LSRs exchange their roles when λ is smaller than Lc. Interestingly, we observe that nucleation locations migrate from an LSR to an HSR in one earthquake, when λ is between the minimum and maximum nucleation length on a heterogeneous fault. This means that nucleation can change its preferred location from weak to strong regions. In this case, we observe a large amount of aseismic slip and associated stress drop in the initial LSR, which might be linked to the migration of foreshocks as documented in natural and laboratory observations. We summarize this in a conceptual model, where these five regimes are linked to the wavelength of the heterogeneity. This improved understanding of earthquake nucleation is important in estimating the seismic potential of natural faults, if the local stress field is well understood, but becomes especially relevant in induced seismicity settings where the effective normal stress is affected by human activities.
Contribution of glacier melt to runoff under climate change using a conceptual hydrological model in selected high alpine regions in Austria
Authors: Ehrendorfer Caroline , Koch Franziska , Lücking Sophie , Pulka Thomas , Holzmann Hubert , Maier Philipp , Lehner Fabian , Formayer Herbert , Herrnegger Mathew
Published: March 2024

The timing and quantity of snow and ice melt in high-alpine regions is of great importance, especially for time-sensitive processes such as hydropower production. In most conceptual hydrological models, the simulations of these components are frequently only based on simple temperature index methods, and the question arises whether these are sufficient to derive useful information on changing runoff seasonality and quantities for hydropower producers.This study examines the quantitative and seasonal changes in glacier melt contribution to total runoff under climate change in several Austrian high-alpine catchments with hydropower production (Stubaital, Stubachtal, Kölnbrein/Maltatal, Schlegeis/Zillertal). As the estimation of precipitation model inputs for areas with complex terrain is characterised by a high degree of uncertainty, an undercatch-correction adapted for high-alpine areas was applied, integrating information from local weather stations, topography and iterative feedback from the modelled water balance. The conceptual, semi-distributed rainfall-runoff model COSERO was set up for the case study regions.  To cover long-term changes, the model was run for Stubai- and Stubachtal for the reference period (1990-2020) and future scenarios (2021-2100) with daily timesteps. In addition to the daily timesteps, COSERO was also coupled with the physically-based snowpack model Alpine3D for simulations in the Kölnbrein and Schlegeis catchments for recent decades to implement the simulation of relevant components of the water balance including snow and ice processes at an hourly timestep based on more complex energy-balance modelling. Besides air temperature and precipitation, the coupling requires additional hourly meteorological input such as radiation, relative humidity and wind information.The combination of COSERO with Alpine3D improves results at the hourly timestep, but the conceptual model delivers satisfying results on its own as well. Moreover, the results are in line with literature and show the expected decrease of ice volume and ice melt in coming years. By 2050, the ice melt contribution to total runoff is significantly reduced in all case study areas and seasonality shifts due to less ice melt and earlier snowmelt in the form of more winter and spring runoff and less flow in summer are prevalent. In addition, we show that the modelling of the water balance components in the past can be greatly improved by using the undercatch-corrected precipitation data. Acknowledgements: We thank the VERBUND Energy4Business GmbH, the Austrian Climate Research Programme (ACRP), the Austrian Research Promotion Agency (FFG), and the ÖBB for funding, fruitful discussions and providing us with data.
Reconciling ice core CO2 and land-use change following New World-Old World contact
Authors: King Amy , Bauska Thomas , Brook Edward , Kalk Michael , Wolff Eric , Strawson Ivo , Rhodes Rachael , Nehrbass-Ahles Christoph , Osman Matthew
Published: March 2024

Ice core records of carbon dioxide (CO2) over the last 2000 years are critical to our understanding of global carbon cycle dynamics on centennial and multidecadal timescales. They also provide context for the unprecedented anthropogenic rise in atmospheric CO2. Yet for some time intervals throughout the period, the true atmospheric history of CO2 remains uncertain. One such example is the decrease in atmospheric CO2 after 1550 CE, for which the timing and magnitude is debated. To resolve this case, we measure CO2 and methane (CH4) in the new Skytrain Ice Rise ice core from 1450 to 1700 CE, presented alongside firn smoothing analysis and land carbon modelling. Our results suggest that a sudden decrease in ice core CO2 around 1610 CE in one widely used record is most likely an artefact of a small number of anomalously low values. Instead, we observe a more gradual decrease in CO2, with our analysis suggesting 0.5 ppm per decade between 1516 and 1670 CE. The resulting inferred land carbon sink of 2.6 PgC per decade agrees with modelled scenarios of large-scale reorganization of land use in the Americas following New World-Old World contact, for which a larger and more rapid CO2 decrease is incompatible.
NDT methods (GPR and UPV) for steel rebar corrosion monitoring
Authors: Rizzo Enzo , Fornasari Giacomo , Polastri Nicola , Mariacci Tommaso
Published: March 2024

Rebar corrosion is one of the main causes of deterioration of engineering reinforced structures and this degradation phenomena reduces their service life and durability. Non-destructive testing and evaluation of the rebar corrosion is a major issue for predicting the service life of reinforced concrete structures. The research work of the Geophysical Laboratory of University of Ferrara is committed to the study of RC corrosion. Several laboratory tests (Fornasari et al., 2022; Fornasari et al., 2023; Fornasari et al., 2024) were performed on a reinforced concrete beam where a corrosion was induced. In detail, this paper describes the results coming from Ground Penetrating Radar (GPR) and Ultrasonic Pulse Velocity (UPV) methods on induced corrosion experiment. A reinforced concrete sample of about 50 cm x 30 cm was used in this experiment. The concrete beam has a central ribbed steel rebar of 10 mm diameter and partially covered with epoxy resin, in order to focalize the corrosion only along the exposed part of the rebar (8cm). The same waterproof epoxy resin was applied on part of the concrete sample, in order to have a specific chlorides diffusion across a freeway zone of about 10cm x 8cm defined below the exposed rebar. The concrete sample was partially exposed (1cm) to a salty water with different NaCl concentrations. An initial NaCl concentration of 0.1 % was adopted for 7 days, then the concentration was increased to 1% and finally to 3.5% for further 7 days. The used instruments were GPR Proceq GP8000 with 2GhZ antenna and UPV Cronosonic MAE with Tx-Rx at 55KhZ. The NDT acquisitions were carried out along the same line across the central part of the buried rebar during the accelerated corrosion test. The GPR elaboration (Hilbert function) highlighted an increase of the envelope factor values with time corrosion of the rebar. In contrast, ultrasound data obtained from the rebar revealed a decrease in velocity as corrosion increased. Over the past few years, numerous experiments have been conducted using various NDT methods, each capable of illustrating signal variations during the corrosion phenomena. These results emphasize the sensitivity of NDT methods in detecting rebar corrosion. The use of multi-sensor tools serves as the starting point for integrated observation, facilitating the transition from qualitative assessments to monitoring the evolving corrosion phenomenon on reinforced steel rebars. This approach aims to establish a quantitative analysis of the observed phenomena.
Wetlands in monoculture forests – how fire activity and different forest management strategies impact Sphagnum-dominated peatlands
Authors: Marcisz Katarzyna , Bąk Mariusz , Lamentowicz Mariusz , Kołaczek Piotr , Theurer Thomas , Matulewski Paweł , Mauquoy Dmitri
Published: March 2024

Monoculture forests are now a dominant forest type in Europe. Created for easier management and increased timber production, they are now witnessing many disturbances due to climate change, such as more frequent windthrows, droughts, fires or insect outbreaks. The functioning of forests impacts other elements of the landscape, including peatlands, which also have been affected by various natural and anthropogenic disturbances (e.g., drainage) that make them more vulnerable to drying and burning. We aim to recognize how peatland functioning has changed along with changing forest management strategies. For this we studied a Sphagnum-dominated peatland located in the Tuchola Pinewoods – one of the largest Scots pine (Pinus sylvestris) monoculture forest in Poland. We used high-resolution multi-proxy palaeoecology including pollen, plant macrofossils and testate amoebae, additionally focusing on a wide range of charcoal analyses: charcoal counts, charcoal morphological types, and Raman spectroscopy. Our results show that the studied peatland experienced several critical transitions in vegetation composition and hydrology over the last 600 years when new forest management techniques were introduced. A reduction in fire activity led to a dominance of Sphagnum and increased peat accumulation rates. Establishment of a monoculture forest further impacted the site and stabilized Sphagnum growth and acidity levels. We believe that these results can be helpful for the improvement of conservation planning for peatlands located in forested areas, especially in monoculture forests. The study is funded by the National Science Centre, Poland (2020/39/D/ST10/00641).
Quantifying global water cycle—CO2 feedbacks from Earth system models
Authors: Zhang Xuanze , Zhang Yongqiang
Published: March 2024

Large uncertainty in predicting surface water availability (precipitation minus evaporation) in a CO2-enriched climate is associated to rising CO2-related hydrological feedbacks to the global water cycle, primarily including hydrological sensitivity to CO2-physiological and -radiative effects. Using the 1pctCO2 experiments of twelve CMIP6 models, we first decoupled and quantified the magnitudes of these sensitivities at global and regional scales. Results show that under a 140-year transient 4×CO2 scenario, the global hydrological sensitivity (precipitation or evaporation) for CO2-physiological effect feedback is -0.09 ±0.07 % (100 ppm) ‒1 and for CO2 radiative effect feedback is 1.54 ±0.24 % K‒1. The latter is about 10% larger than the global apparent hydrological sensitivity ( = 1.39 ±0.22 % K‒1), as estimated from the fully coupled simulations. These hydrological sensitivities are relatively stable over transient 2× to 4×CO2 scenarios. The CMIP6 models project that global precipitation or evaporation increases at 4×CO2 are dominated by the CO2 radiative effect feedback (79 ±12%) and positively contributed by the interaction between the two feedbacks (6 ±12%) but are reduced by the CO2 physiological effect feedback (-10 ±8%). This underlines the importance of CO2 vegetation physiology in global water cycle projections under a CO2-enriched and warming climate.
Implications of biosphere variability for future emission budgets and carbon dioxide removal
Authors: Schürmann Tom , Adam Moritz , Rehfeld Kira
Published: March 2024

The biosphere’s first-order response to changing Earth system conditions shifts under future emission pathways. One can anticipate such low-order responses, like rebounding carbon stocks once emissions diminish when forecasting emission budgets. However, the impact of changes in second- and higher-order biosphere variability on emission pathways and the prospective large-scale artificial carbon dioxide removal (CDR) remains unclear. An example of such higher-order responses is the vulnerability of land carbon uptake to more extreme climate forcing. In addition, implementing CDR has notable implications for land use, exerting an influence on spatial and temporal biosphere variability. Thus, constraining the interplay between the biosphere’s variability and the emission pathway could inform future emission accounting.Here, we leverage state-of-the-art Earth system model simulations to investigate the magnitude and pathway-dependency of interactions between the terrestrial biosphere’s variability and the emission pathway. We characterize biosphere variability under different emission scenarios and with varying degrees of representing CO2 removal. The emission- and concentration-driven simulations cover pathways that reach Paris targets without and with temperature overshoot. CDR is either implicitly represented in emission and land use scenarios or explicitly simulated in the model’s land component to match the respective socio-economic pathway.To understand the structure of modeled biosphere variability under the different pathways and test the consistency of the joint model system, we investigate regional events like a vegetation expansion event in the Northern Sahara. Here, the objective is to examine the interplay between terrestrial carbon fluxes and CDR utilization in detail on a smaller scale, later expanding to the global level. The following research focuses on identifying and quantifying shifts in biosphere variability over time, their interplay with CDR measures, and their effects on global carbon stocks. We test the model’s sensitivity to design choices (how and where CDR is represented) and pathway (emission target, timing, and duration of temperature overshoot). To this end, we aim to infer the margin of error biosphere variability could cause in emission accounting. Our results will help to evaluate the significance of varying biospheric carbon fluxes for future emission stock-taking in the context of CDR.
Contribution of SLR to satellite-only global gravity field model
Authors: Suesser- Rechberger Barbara , Mayer-Guerr Torsten , Krauss Sandro , Dumitraschkewitz Patrick , Oehlinger Felix , Tieber-Hubmann Cornelia
Published: March 2024

Combined satellite-only global gravity field models represent a combined solution of gravity field observations from multiple geodetic measurement principles and satellite missions. The advantage of such a combination is that it compensates for the weaknesses of individual observing techniques. However, when combining solutions estimated by different institutions, inconsistencies may arise due to the different algorithms and models used in the actually available software, leading to a deterioration in performance. To mitigate such performance degradation, it is advantageous to perform all evaluations with a uniform software package. Since our in-house Gravity Recovery Object Oriented Programming System (GROOPS) software tool has become a widely accepted tool in the scientific community, we have now also incorporated the Satellite Laser Ranging (SLR) functionality to ensure the continued development of the software. On this basis, the opportunity arises to uniformly determine all the contributions to the combined gravity field using a single software package. This contribution is intended as a preliminary study for the next Gravity Observation Combination (GOCO) model. In this regard, we present low-degree solutions based on SLR observations using GROOPS and compare them with findings from other research groups (e.g., Cheng et al. 2013, Krauss et al. 2019) as well as solutions based on the satellite mission GRACE and GRACE-FO.
Convective environments in AI-models - What have AI-models learned about atmospheric profiles?
Authors: Feldmann Monika , Poulain-Auzeau Louis , Gomez Milton , Beucler Tom , Martius Olivia
Published: March 2024

The recently released suite of AI-based medium-range forecast models can produce multi-day forecasts within seconds, with a skill on par with the IFS model of ECMWF. Traditional model evaluation predominantly targets global scores on single levels. Specific prediction tasks, such as severe convective environments, require much more precision on a local scale and with the correct vertical gradients in between levels. With a focus on the North American and European convective season of 2020, we assess the performance of Panguweather, Graphcast and Fourcastnet for convective available potential energy (CAPE) and storm relative helicity (SRH) at lead times of up to 7 days.Looking at the example of a US tornado outbreak on April 12 and 13, 2020, all models predict elevated CAPE and SRH values multiple days in advance. The spatial structures in the AI-models are smoothed in comparison to IFS and the reanalysis ERA5. The models show differing biases in the prediction of CAPE values, with Graphcast capturing the value distribution the most accurately and Fourcastnet showing a consistent underestimation.By advancing the assessment of large AI-models towards process-based evaluations we lay the foundation for hazard-driven applications of AI-weather-forecasts.
MAVEN Observations of the Interloop Magnetic Reconnections at Mars
Authors: Chen Guo , Huang Can , Zhang Ying , Ge Yasong , Du Aimin , Wang Rongsheng , Wang Lei , Shan Lican , Mazelle Christian , Luo Hao
Published: March 2024

Magnetic reconnection between neighboring magnetic field loops, so-called inter-loop reconnection, is a common process to drive flares in the solar atmosphere. However, there is no direct evidence that a similar but less explosive process can take place on planets. The strong crustal fields on Mars are capable of generating plenty of magnetic loops in the near Mars regions, which provides a unique environment to research the inter-loop reconnection on a planet. Here, we report magnetic reconnection events between crustal field loops in the Martian ionosphere observed by MAVEN for the first time. During the current layer crossing, signatures including Hall magnetic field, Alfvénic outflow, and electron energization were recorded, and the energized electrons exhibited auroral-like peaked electron distributions. This finding implies that the inter-loop reconnection in the Martian ionosphere could contribute to the localized energy deposition and particle energization, which provides the seed source for aurora in the Martian atmosphere.
How is climate change affecting hydro-meteorological triggering for debris flows? An assessment based on convection-permitting models and a bias-neutral procedure
Authors: Menapace Andrea , Dallan Eleonora , Marra Francesco , Marchi Lorenzo , Larcher Michele , Borga Marco
Published: March 2024

Debris-flow activity is expected to change in the future following the expected changes in sub-daily rainfall rates. In this study, we connect high-resolution climate simulations from an ensemble of recently developed convection-permitting models (CPM) and a threshold-based precipitation model for debris-flows triggering. We are considering CPM runs over historical (1996-2005), near future (2041-2050) and far future (2090-2099) decade-long periods. Given the biases affecting the CPM simulations and the desire to avoid bias-correction procedures, which may introduce distortions into the precipitation simulations, we propose a methodology to map the debris-flow threshold into the simulated climates. This is obtained by evaluating the return levels of the threshold precipitation rates at different durations, and mapping these in the climate simulations using the same return levels. The Simplified Metastatistical Extreme Value (SMEV) methodology is exploited for the precipitation statistical analysis. The suitability of the proposed framework is tested on the Moscardo catchment, a small study basin located in the eastern Italian Alps, where the debris flow activity is mainly transport-limited. This case study is particularly remarkable due to the high frequency of debris flows and a monitoring system working since 1990, which has permitted establishing reliable rainfall . The debris-flow triggering precipitation events are assessed by considering changes in their frequency, depth and seasonality. The promising preliminary results support the use of this approach to assess debris flow hazards in a changing climate.
High-resolution Downscaling of Disposable Income in Europe using Open-source Data
Authors: Mikou Mehdi , Vallet Améline , Guivarch Céline , Makowski David
Published: March 2024

Poverty maps have been extensively used for identifying populations vulnerable to global changes. The frequency and intensity of extreme events are likely to increase in coming years as a result of climate change. In this context, several studies have hypothesized that the economic and social impact of extreme events depends on income. However, to rigorously test this hypothesis, it is necessary to have income data on a fine spatial scale, compatible with the analysis of extreme climatic events. In order to produce reliable high-resolution income data, we have developed an innovative machine learning framework, based on random forests, that we applied to produce a 1 km-gridded dataset of disposable income for 2015 in Europe. This dataset was generated by downscaling disposable income data available for more than 120,000 administrative units. Our learning framework showed high accuracy levels, and outperformed other existing approaches used in the literature for downscaling income. Using SHAP values, we explored the contribution of the model input factors to income predictions and found that, in addition to geographic inputs (country, latitude, longitude), distance to public transport or nighttime light intensity were key drivers of income predictions. Finally, we illustrated how this new dataset can help identifying poverty areas in Europe. More broadly, this dataset offers an opportunity to explore the relationships between economic inequality and environmental degradation in health, adaptation or urban planning sectors. It can also facilitate the development of future income maps that align with the Shared Socioeconomic Pathways, and ultimately enable the assessment of future climate risks.
Quantifying the uncertainty associated with solar energetic particle transport models
Authors: Strauss Du Toit , Lang Jaclyn , Engelbrecht Eugene , van den Berg Jabus
Published: March 2024

Using magnetically well-connected solar energetic particle (SEP) observations, we derive the electron and proton parallel mean-free-paths (MFPs) by comparing in-situ observations to one-dimensional simulation results. These inferred MFPs are compared to theoretical estimates which have been constrained by solar wind turbulence observations. We show that these derived and theoretical values are mostly consistent for both protons and electrons, but do show significant inter-event variations which can be explained by changing solar wind turbulence conditions. To illustrate the influence of these changing scattering conditions on particle transport, we simulate SEP time profiles for magnetically connected and unconnected observers for different transport and/or acceleration parameters. We show that this can explain the observer inter-event variations observed for SEP events. Additionally, we show that such an ensemble modeling approach can be used to quantify the uncertainty in the underlying model assumptions and can, in principle, be used in physics-based SEP predictive models to produce SEP predictions that include an uncertainty band.