bluuebunny/crossref_metadata_2025 huggingface dataset:
Thermo-hydro-mechanical modeling of clayey geological medium: Theoretical framework and numerical study
Authors: Tourchi Saeed , Gens Antonio , Vaunat Jean , Scaringi Gianvito
Published: March 2022

In recent years, interest in argillaceous rocks has increased because they are being considered as potential host geological media for underground repositories of high-level radioactive waste (HLW). The host rock around the repository cells, containing the exothermic waste canisters, will be submitted to various coupled mechanical, hydraulic, and thermal phenomena. For a proper understanding and appropriate modelling of the excavation damaged zone around repository cells at elevated temperatures, the combined effects of those phenomena should be considered in an advanced constitutive model. The thermo-hydro-mechanical (THM) model presented herein is dedicated to non-isothermal unsaturated porous media. The model is developed within the framework of elastoplasticity, which includes features that are relevant for the satisfactory prediction of THM behaviour in argillaceous rocks: anisotropy of strength and stiffness, behaviour nonlinearity and occurrence of plastic strains prior to peak strength, significant softening after peak, time-dependent creep deformations, permeability increase due to damage, and shrinking of the elastic domain and the degradation of stiffness and strength parameters with temperature.

The model was applied to the numerical simulation of a full-scale in situ heating test conducted on Callovo-Oxfordian (COx) claystone, in the Meuse / Haute-Marne Underground Research Laboratory, simulating a heat-emitting, high-level radioactive waste disposal concept. The interpretation of the test was assisted by the performance of a numerical analysis based on a coupled formulation incorporating the relevant THM phenomena. Initial and boundary conditions for analysis, as well as material parameters, were determined from a comprehensive field and laboratory experimental programme. Thermal, hydraulic, and mechanical observations in COx claystone were discussed. The numerical analysis was able to accurately reproduce the behaviour of the experiment.

The performance and analysis of the in situ test have significantly enhanced the understanding of a complex THM problem, and have proved the ability of the theoretical formulation to provide adequate modelling capacities.
Future trends and uncertainties in the Biological Carbon Pump predicted by CMIP6 models
Authors: Wilson Jamie , Andrews Oliver , Katavouta Anna
Published: March 2022

A fraction of the carbon fixed in the surface ocean by phytoplankton is isolated away from the atmosphere in the ocean interior with the respiration of sinking detritus (Particles of Organic Carbon: POC) - a process known as the "Biological Carbon Pump'' (BCP). The BCP sequesters ~1700 Pg of dissolved inorganic carbon (DIC) in the ocean beyond the concentration expected solely with physio-chemical drivers, effectively lowering the base-line atmospheric CO2 concentration by ~150-250 ppm. The components that make up the BCP (export production, sinking and remineralisation of POC, ocean ventilation timescales) are all expected to change in response to a changing climate but there is currently low confidence in how these changes will influence the magnitude and direction of the ocean carbon feedback.

Here we quantify the predicted historical and future changes in the Biological Carbon Pump in the latest CMIP6 projections as fully as possible. We find that all models consistently predict that the BCP will accumulate carbon in the ocean interior by 2100, i.e., acting as a sink for atmospheric CO2, albeit contributing only a small fraction (~10%) of the net carbon sink. The accumulation of carbon along with a concurrent decrease in globally integrated export production at 100m is associated with warming-driven stratification. In contrast there is significant disagreement in both the magnitude and direction of global mean trends and spatial patterns of transfer efficiency of POC at 1000m. This uncertainty arises because of the range of processes resolved across the biogeochemical models that influence the sinking and remineralisation rate of POC such as: temperature and oxygen-dependent remineralisation, ballasting, and dependence of sinking velocities on cell size. We demonstrate that these changes in transfer efficiency could likely determine the larger long-term impact of the BCP on atmospheric CO2 beyond 2100. Our results have wider implications for the biogeochemical cycling of nutrients and oxygen as well as implications for future impacts on twilight zone ecology.
Atmospheric transport of microplastic particles as a function of their size and shape
Authors: Tatsii Daria , Bucci Silvia , Bagheri Gholamhossein , Stohl Andreas , Bakels Lucie
Published: March 2022

Investigation of the transport and distribution of atmospheric concentrations of microplastic (MP) particles is an important challenge, since MP may have a negative impact on human health and ecosystems. When considering particle shape, most of the atmospheric transport models assume only spherical particles, whereas MP particles cover a wide range of observed shapes. Non-spherical particles experience a larger drag in the atmosphere, which leads to a reduction of their settling velocity, hence longer atmospheric residence times. Here we study gravitational settling of one of the dominant microplastic shapes – fibers. To reduce the difference between model output and ground-based measurements, we have implemented a parameterization of the shape correction in the gravitational settling scheme of the Lagrangian transport model FLEXPART.

We have determined model sensitivity to the shape correction to explore its impact on particles transport for a range of scenarios.  This was done with a statistical comparison of 3D fields of mass concentration and deposition patterns of shape-corrected and non-corrected parameterization schemes. Using the model output, we quantified average horizontal transport distances and atmospheric residence times for spheres and fibers of different sizes and aspect ratios in different climatic regions and for different release heights of the MP particles.
Statistical methods for middle-term forecast of earthquake occurrences
Authors: Rotondi Renata
Published: March 2022

Investigation into possible precursors of strong earthquakes constitutes a challenging research topic which is carried out mainly in two directions: the one based on the analysis of physical parameters and the one based on statistical methodologies. In the first, recent studies have shown significant correlation between major earthquakes and anomalies of different physical parameters measured in the atmosphere/ionosphere which cover time intervals of months.

On the contrary in this presentation we focus on the statistical modelling of the parameters that constitute an earthquake record in a catalog (location, time, magnitude) and we show that significant variations are observed in the months/years preceding a strong earthquake. In particular we consider the spatial distribution of a set of earthquakes and its temporal variations by modelling the area of Voronoi cells generated by the epicenters through a generalized Pareto (GP) distribution. Following the Bayesian paradigm we analyze the recent seismicity of the central Italy and we compare the posterior marginal likelihood of the most promising distributions in shifting time windows. We point out that the best fitting distribution varies over time and the trend of the GP distribution and of other distributions among the most studied in the literature converges to that of the exponential distribution a few months before the start of the preparatory phase to the main shock.
Experiences and lessons learned in the construction of a new paradigm of integrated fire management in Venezuela. 
Authors: Alejdanra Bilbao Bibiana
Published: March 2022

Under the current changing climate and social governance conditions, wildfires occurrence in Latin America has become a critical issue, trespassing academic and technical disputes, and reaching sensible socio-political arenas. Developing a new vision and capacities for the integral and intersectoral management of wildfires instead of only fighting them requires the inclusion of multiple perspectives, actors and the rescue of the adaptive knowledge and practices of local communities that inhabit natural spaces. This paper summarizes the main results and advances achieved during more than 20 years of learning and working with the Pemón Indigenous peoples in northern Amazonia and the escalation towards new fire management policies in Venezuela. Our results reveal a sophisticated Indigenous knowledge system on using fire in the main subsistence activities, especially shifting cultivation and collaborative burning practices at the savanna-forests transition to protect forests from catastrophic wildfires. In addition, long-term fire experiments demonstrated that fire exclusion practices promote more severe wildfires by fuel accumulation, enhanced by the drier and warmer weather conditions. Through the inclusion of Indigenous peoples, firefighters, public officials and academics in field research and joint experimentation, as well as in debates and dialogues on socio-ecological aspects, a paradigm shift was successfully negotiated of fire that values the relevance of the ancient Pemón culture in Venezuela in the sustainable management of resources, as well as adaptation and mitigation capacity to climate change. Currently, these experiences are being capitalized to create a national integrated fire management policy preserving the same participatory, intercultural and intersectoral principles. 
Coupling between Southern Ocean Heat and Carbon: The role of atmospheric boundary conditions
Authors: Hague Mark , Münnich Matthias , Gruber Nicolas
Published: March 2022

The Southern Ocean is well recognised as globally the most important region for the uptake and storage of excess heat (Q`) and carbon (C`) resulting from anthropogenic CO2 emissions. Although the processes governing the transport and storage of Q` and C` are tightly connected, the near surface boundary conditions of the two perturbation tracers are very different. That is, the spatial distribution of C` in the atmosphere is rather homogenous, while the uptake of Q` is characterised by strong horizontal gradients and temporal variability ranging from seasonal to interannual and decadal. The effect this difference has on the uptake and storage patterns of Q` and C` has received relatively little attention, especially when compared to the role of ocean circulation changes. In order to address this, we utilise a regional ocean biogeochemical model (ROMS-BEC) forced with an atmospheric reanalysis (ERA5) and perform a suite of model experiments. A first set of experiments quantifies changes in C` and Q` over the period 1979 -2019, comparing the model results with observation-based estimates. Here we find that the model is able to reproduce the main features of the observed Q` and C` storage patters: a region of enhanced heat storage at ~40oS and down to 1200m, with carbon storage peaking in the surface layer (~200m) north of 40oS and decreasing poleward and with depth. A second set of experiments aims to isolate the role of spatial and temporal variability of net surface heat flux (SHF) in driving changes in Q`, with the resulting storage patterns then compared to those derived for C`. We find that for C` the storage pattern is driven largely by the uptake of anthropogenic CO2 , with a small contribution from circulation changes. In contrast, the storage pattern of Q` appears not to be strongly related to trends in SHF, suggesting that the mean SHF spatial distribution, as well as circulation changes may play a more prominent role. The SHF trends themselves are highly spatially heterogenous, and act to reduce the magnitude of the zonally integrated heat storage over the simulated period. However, we find that there are significant regional differences, with a modest increase in storage in the Pacific and Atlantic sectors being offset by a much stronger reduction in the Indian sector. Overall, we develop a conceptual framework for understanding the potential (de)coupling between oceanic uptake and storage of heat and carbon within the unique context of the Southern Ocean. 
Use of Remote Sensed Products for Large-scale SWAT+ Model Calibration
Authors: Thiery Wim , Chawanda Celray James , Arnold Jeffrey , van Griensven Ann
Published: March 2022

Calibration of large-scale models comes with several challenges. Among these challenges are the availability of observation data and the computational cost of running the calibration. As such, some large-scale models are not calibrated. Yet calibration of impact models is crucial, as Krysanova et al. (2018) concluded. A calibration strategy focusing on hydrological mass balance can reduce calibration computational costs and improve the model application while global remote sensed products provide data for large-scale applications. This study presents the Hydrological Mass Balance Calibration (HMBC) methodology for SWAT+. We test the method using a remotely sensed ET product (WaPOR). We also use flow data from the Global Runoff Data Centre (GRDC) and compare projections made by the HMBC model and those without. We then apply the HMBC to a SWAT+ model for Africa. Results show that HMBC leads to improved simulation of discharge and evapotranspiration with fewer iterations than a full parameter calibration. Substantial spatial differences are also observed in projections made by the HMBC model compared to the uncalibrated model. Thus, it makes a difference if we apply HMBC. In addition, HMBC used with remotely sensed data can remedy some barriers to the calibration of hydrological models applied at large scales, as demonstrated by application to the Africa SWAT+ model.
Effect of Holocene sediment redistributions on the relative sea level at present in the Ayeyarwady delta (aka Irrawaddy delta, Myanmar)
Authors: Grall Céline , Henry Adrien , Karpytchev Mikhail , Becker Melanie
Published: March 2022

Under high seasonal monsoon rainfall and active tectonics, the Ayeyarwady delta is a large delta plain characterized by a high sediment supply. Also, the Ayeyarwady river, together with the Sittaung, and the Salween Rivers are bringing ~600 Mt/yr of sediments to the Andaman Sea through the Gulf of Martaban. A recent research effort have allowed characterizing the sedimentation at present and since the mid-Holocene. We here propose to integrate these published observations in a stratigraphic reconstruction and to determine by numerical modelling how much these Holocene massive sediment transfers play on coastal subsidence and relative sea level at present.

The present average sedimentation rate at the front of Ayeyarwady delta is ~10 cm/yr and the delta may be divided in two sectors: an eastern embayed sector and a western open coast sector. During the mid-Holocene, the aerial part of the delta have experimented fast progradation rate, reaching prograding rate of ~ 30 m/yr. When applying this sedimentation pattern on a preliminary (radial) viscoelastic Earth model, we show that sediment isostasy plays on the regional coastal dynamics and subsidence at present. In addition, the Ayeyarwady delta lies in a complex tectonic setting, bounded to the west by the Indo-Burman collision zone, and to the east by the sub-vertical dextral Sagaing Fault. We are integrating this tectonic setting in an earth model that allows lateral vertical discontinuity for exploring how much this significantly changes the modelling results.
Numerical Analysis of Multispecies Solute Transport through Heterogeneous Porous Media
Authors: Gupta Kumar Rishabh , Kumar Sharma Pramod
Published: March 2022

A numerical approach to the decomposition method for the study of multispecies solute transport through heterogeneous porous media has been proposed. Governing equations of multispecies solute transport have been solved numerically using the implicit finite difference technique. The effect of time-dependent dispersion has been analyzed using exponential time-dependent dispersivity function and the same has been validated with the analytical solution. The study illustrates the solute movement involving sequential first-order decay reactions and the analysis has been carried out in three species nitrification chain and migration of radionuclides as four species. The numerical model is used to simulate the breakthrough curves and the analysis has been done using different decay rate constants. Also, this study has been carried out on the behavior of solute concentration using an increasing macrodispersivity function which accounts for the spatial heterogeneity of porous media. Further, spatial moment analysis has been performed on the concentration of all species and a comparison has been drawn using constant and exponential time-dependent dispersivity function using various breakthrough curves. This analysis revealed that the mean travel distance and variance are sensitive with the change in the dispersivity function and concludes that the solute and its transformed species may not have the same transport pattern.
Ferromagnetism of magnetite-bearing plagioclase from oceanic gabbro
Authors: Ageeva Olga , Gilder Stuart , Habler Gerlinde , Abart Rainer
Published: March 2022

Oriented needle shaped magnetite inclusions in plagioclase may give rise to magnetic anisotropy of individual plagioclase grains and, in case of preferred orientation of the plagioclase grains, contribute to magnetic anisotropy of the bulk-rock. Understanding how oriented magnetite inclusions generate magnetic fabrics in single grains of plagioclase is important for interpreting rock magnetic fabrics and for correcting paleomagnetic data. Plagioclase grains from oceanic gabbro dredged at the Mid Atlantic Ridge (11-17°N) were analyzed using optical microscopy, electron backscatter diffraction (EBSD), as well as alternating field demagnetization and anisotropy of magnetic remanence (AMR) measurements to investigate the influence of the shape orientation distribution of acicular magnetite inclusions on the magnetic properties of magnetite bearing plagioclase grains.

In pristine magmatic plagioclase, the needle elongation directions form a 30° wide girdle distribution parallel to the pl(010) plane. This girdle distribution is insensitive to twinning after the Albite, Pericline, Carlsbad and Manebach laws. The statistical maximum in the inclusion orientation lays in the pl(010) plane, closely parallel to the pl[001] direction. The overall shape orientation distribution of the magnetite inclusions produces a triaxial magnetic anisotropy ellipsoid with the minimum axis direction sub-perpendicular to the pl(010) plane and the maximum axis sub-parallel to the pl[001] direction.

The vector of natural remanent magnetization parallels the maximum AMR axis direction indicating that the magnetic anisotropy caused by the magnetite inclusion fabric controls the paleomagnetic signature. In hydrothermally modified plagioclase, most or all magnetite needles are oriented parallel to the pl[001] direction and a prolate rotational ellipsoid of remanent magnetization with the maximum remanent magnetization parallel to pl[001] should occur.

Plagioclase-hosted magnetite inclusions are particularly stable recorders of the paleomagnetic filed. The magnetic anisotropy arising from the anisotropic shape orientation distribution of the magnetite inclusions may, however, bias the magnetic record, an effect that needs to be accounted for in paleomagnetic reconstructions or for absolute paleointensity experiments.

This work was supported by the Austrian Science Fund (FWF): I 3998-N29, and by the Russian Foundation for Basic Research, Grant no. 18-55-14003.
Aerosol properties crucial to reconciling supervolcanic cooling estimates
Authors: McGraw Zachary , Dallasanta Kevin , Polvani Lorenzo , Tsigaridis Kostas , Orbe Clara , Bauer Susanne
Published: March 2022

Abstract: Volcanic aerosols can cool Earth’s surface on a global scale, with the largest eruptions (eg Toba 74kya) linked to especially severe impacts on ecosystems and human survival. However, global climate simulations of super-eruption impacts have disagreed widely on post-eruption temperatures. As no super-eruption has occurred in ~26,000 years, little is known of their aerosol byproducts other than mass estimates from ice cores. Here we use GISS ModelE climate simulations to demonstrate that unconstrained aerosol properties cause substantial radiative forcing uncertainty. By comparing ModelE sensitivity tests to previous modeling studies, we suggest that a lack of consensus on super-eruption aerosol properties is a major reason for the disagreement in post-eruption cooling.
An unconsidered source of earthquakes and tsunamis from the Kanto region of Japan
Authors: Pilarczyk Jessica , Sawai Yuki , Namegaya Yuichi , Tamura Toru , Tanigawa Koichiro , Matsumoto Dan , Shinozaki Tetsuya , Fujiwara Osamu , Shishikura Masanobu , Shimada Yumi , Dura Tina , Horton Ben , Parnell Andrew , Vane Christopher
Published: March 2022

The assessment of seismic hazards along subduction zone coastlines provides important information regarding the frequency and magnitude of earthquakes and tsunamis that can be expected in the future.  Unlike many subduction zone coastlines that involve one tectonic plate subducting under another, seismic hazard assessments for the Kanto region of Japan are complicated by the presence of a nearby triple junction; where one continental (CON) and two oceanic plates (PHS, PAC) collide.   The CON/PHS (Sagami Trough) and CON/PAC (Japan Trench) boundaries are recognized earthquake sources.  However, historical and geological evidence of a large PHS/PAC (Izu-Bonin Trench) earthquake has been lacking and decades worth of instrumental data point to low seismicity along this boundary.  Here we show that two unusually large tsunamis are evidenced by sandy deposits preserved along 50 km of coastline in the Kanto region.  The oldest of them, deposited about 1,000 years ago, contains evidence consistent with tsunami deposits reported elsewhere (e.g., marine foraminifera, rip-up clasts, pebbles, erosional base) and represents a previously unknown prehistoric earthquake.  In computer simulations, this earthquake deposited sand that extended too far inland to represent any known historical earthquake originating from the CON/PHS and CON/PAC boundaries alone.  Rather, the greater inland inundation points to significantly greater displacement on the CON/PHS and CON/PAC boundaries, which may be unrealistic, or much smaller displacement along the previously unconsidered PHS/PAC megathrust.  This plate-boundary fault adds another source for earthquakes in Tokyo and tsunamis in the Pacific Ocean.
Marine controlled source electromagnetic inversion data from a field at Campos basin SE-Brazil, post-salt reservoirs constrained by seismic and well log
Authors: Benevides Artur , Meqbel Naser , Fontes Sergio , Lima Williams , Egbert Gary , Werdt Paulo , La Terra Emanuele
Published: March 2022

This work presents results from a controlled source electromagnetic (CSEM) set of inversion runs of real data in the Campos basin, Southeast Brazil. The Campos basin is in the Brazilian east margin, with origin in the Neocomian stage of the Cretaceous period 145–130 million years ago during the breakup of the supercontinent Gondwana (South America and Africa split). The clastic reservoirs in this basin have been the largest oil producer in Brazil for the past three decades. The present challenge in exploring clastic reservoirs has moved to deeper waters, enforced by the complex geology posed by the tectonics associated with giant salt domes. Electromagnetic (EM) methods are sensitive to subsurface resistive variations and have been frequently used in exploration programs for fresh water, mining and for hydrocarbon (HC), mainly in joint approaches with seismic to minimize ambiguity in the interpretations. Reservoirs filled with HC are generally more resistive than the host rocks which is an advantage for the EM method. Combining resistive models with seismic results considerably improves the resolution of the subsurface structures and the geometry of the HC reservoirs. A set of 40 Controlled Source EM (CSEM) receivers were deployed at the seafloor (water thickness is around 1.7 km) in a grid-shape array with varying spacing between 5 km to 10 km. The electric field components have been recorded from an active electromagnetic source towed 50 m above the seafloor. The processed data consist of inline components of the horizontal electric field (Ex and Ey) for four main frequencies (0.125 Hz, 0.25 Hz, 0.5 Hz and 1.25Hz). The CSEM 3D inversion models have been obtained using the modified version of Modular System for EM inversion (ModEM code) which is under development within a research project at Observatório Nacional – Brazil. Preliminary 3D CSEM inversion results yielded a good agreement with resistivity values observed in the well logs. In the second step of this work, information from seismic and well logs are being introduced as a priori information to improve resolution of the CSEM inversion in different scenarios involving hydrocarbon accumulations in thin post-salt reservoirs in Campos basin. 
TimePicker 2017 – a fully automatic tool to extract P-wave arrivals for high-resolution unravelling structure and fabric of the lithosphere-asthenosphere system
Authors: Vecsey Luděk , Plomerová Jaroslava
Published: March 2022

Teleseismic body-wave tomography represents a powerful tool to study regional velocity structure of the upper mantle. Particularly, a need of retrieving anisotropic signal calls for processing of a huge amount of P-wave travel times (Munzarová et al., GJI 2018).  Therefore, automatic picking procedures are needed to supply tomography codes with a large amount of highly accurate absolute arrival times and/or travel-time residuals of body-wave propagation. We present and test a fully automated tool - TimePicker 2017 (Vecsey et al., 2021) for measuring P-wave arrival times on array recordings of passive experiments. The TimePicker 2017 is developed in the ObsPy/Python platform (Krischer et al., 2015) which combines picking, waveform cross-correlation and beamforming. The picker is based on two-step signal cross-correlations and allows us to measure absolute arrival times. Instead of a subjective selection of a reference trace, it cross-correlates all pairs of traces and forms a reference low-noise beam trace as a stack of the shifted traces at all stations. The picker cross-correlates all signals to the reference beam, automatically identifies outliers, and complements all picked absolute arrival times by their error estimates.

We applied the TimePicker 2017 on a set of seismograms from 1920 earthquakes from epicentral distances greater than 30° recorded at 240 temporary and permanent stations involved in the AlpArray experiments. We show uncertainties of measured P-wave arrivals, means and medians of uncertainties for both the complete dataset as well as for subset selected for tomography, and test effects of the standard selection of a reference trace vs. the low-noise beam trace as the reference trace in the TimePicker 2017.
Assessment of hydraulic conductivity from the hydrographic network in shallow crystalline aquifers
Authors: Abhervé Ronan , Gauvain Alexandre , Roques Clément , Longuevergne Laurent , Aquilina Luc , de Dreuzy Jean-Raynald
Published: March 2022

Hydrological predictions for ungauged basins at catchment and regional scales still faces the challenge of lack of available data. To meet this challenge, we propose a new method relying on the structure of the stream network. Under the assumption that the perennial stream network is mostly fed by groundwaters, its structure derives from the underlying aquifer properties. It is especially the case for shallow crystalline aquifers under temperate climates where the surface and subsurface hydrological systems are directly connected. The groundwater table remains close to the topography and the spatial extent of the stream network is then controlled by the magnitude of the subsurface hydraulic conductivity (K) with respect to the actual recharge rates (R).

 

Using a parsimonious 3D groundwater flow model, we propose a novel performance criterion to assess the similarity between the modelled seepage areas and the observed stream network. We investigate the sensitivity of our methodology to different digital elevation models (DEM) and stream network products from different databases that may impact the estimates through their different spatial resolutions. We use this method to determine the equivalent hydraulic conductivity for 25 crystalline catchments in western France.

 

The results show that our methodology allows predicting the spatial patterns of the stream network with a high sensitivity to the hydraulic conductivity. We found that estimated hydraulic conductivities vary over two orders of magnitude [10-5 to 10-4 m/s] across the 25 investigated catchments and are well correlated to the lithology. While the DEM resolution has no major effect on the results, we found that the proportion of described low-order streams significantly controls the estimations.

 

The proposed approach constitutes a paradigm shift in current methodologies designed to assess catchment-scale hydraulic properties with great perspectives regarding the emergence of remote sensing techniques for the mapping of wetlands and soil moisture. Our method might bring up new opportunities to provide predictions for ungauged basins such as the hydrographic network dynamics in a changing climate.
Tremolite and actinolite asbestos as micro-reservoirs for Potentially Toxic Elements (PTEs) : implications for human health
Authors: Punturo Rosalda , Ricchiuti Claudia , Bloise Andrea , Pinizzotto Maria Rita , Cantara Carmelo
Published: March 2022

Nowadays, the toxicity of asbestos mineral fibres is undeniable and well known. It is worthnoting that the mechanism by which these fibers induce adverse effects on human health is not completely understood yet. Major difficulties are related to the wide variability in size, bio durability, molecular arrangement, surface reactivity and chemistry of asbestos fibers. Moreover, the toxicity degree of these hazardous minerals can be further increased by the presence of potential toxic elements (PTEs), especially heavy metals hosted in the fiber lattice.

The present contribution deals with determination of PTEs amount in some tremolite asbestos and actinolite asbestos samples from Episcopia and San Severino Lucano villages (Basilicata region, Southern Italy), in order to assess their potential toxicity.

Micro X-Ray Fluorescence (µ-XRF) and Inductively Coupled Plasma spectroscopy with Optical Emission Spectrometry (ICP-OES) techniques have been used to quantify the concentration of major, minor (Si, Mg, Ca, Al, Fe, Mn) and trace elements (Ag, As, Ba, Be, Cd, Co, Cr, Cu, Li, Mo, Ni, Pb, Sb, Sn Sr, Ti, Te, V, W, Zn, Zr), with the aim of providing a contribution related to the asbestos toxicity knowledge up to now. Specifically, among minor elements, high amounts of Fe and Mn were found in the studied samples. As far as trace elements are concerned, results revealed high concentrations of Cr and Ni in both the studied samples, thus suggesting high toxicity character of the fibers.

Depending on the pseudo-total PTEs concentrations in either tremolite and asbestos samples, it is possible to speculate that some fiber samples are  more toxic than the other one, inducing adverse effects on human health and environment at various extents. Indeed, PTEs transported through asbestos in the air, water and soils come in contact with the human body and therefore can represent a source of risk to human health.
Synthesizing water-related time series for simulation studies while maintaining the original signal’s statistical moments
Authors: Perelman Gal , Fishbain Barak
Published: March 2022

In many studies arises the need to generate synthetic data sets. Such data can answer different needs as data imputation, non-stationary systems analysis, Monte Carlo simulations, training of data-driven models, uncertainty analysis and more. Previous efforts to generate synthetic data focused mostly on statistical methods which did not maintain the statistical moments of the original dataset, while producing a large number of random different time series. Here, a novel method is developed, based on signal processing and discrete Fourier transform (DFT) theory. The method allows to generate synthetic time series signals with similar statistical moments of any given signal. Moreover, the method allows control on the correlation level between the original and the synthesized signals. We also provide mathematical proofs that our method maintains the first two statistical moments. The method is illustrated on two different datasets showing that also the third and fourth moments are kept. Figure 1 shows, in blue, a true water demand time-series taken from a real-life system. For this signal, 50 synthesized signals are generated with increasing correlation levels - from top, with the lowest correlation, to bottom, presenting the highest correlations between the original and synthesized signals.

                                                                                                                    

                                                                Figure 1 – Domestic water demand signal with different correlation level
Analysis of the impacts of small-scale orography on the atmospheric boundary layer.Developing ICON-LES for the Perdigão field experiment.
Authors: Quimbayo-Duarte Julian , Schmidli Juerg , Köhler Martin , Schlemmer Linda
Published: March 2022

The response of the boundary layer flow to resolved versus parametrized orographic drag over moderately complex terrain is investigated. The larger terrain scales may trigger propagating gravity waves and generate flow blocking, while the smaller scales (smaller than 5 km) may modify the turbulent boundary layer leading to turbulent orographic form drag (TOFD). We perform high-resolution numerical simulations to evaluate the ability of a TOFD parametrization to reproduce the impact of small-scale orographic features on the flow over complex terrain. The tool selected to perform the simulations is the Icosahedral Nonhydrostatic (ICON) numerical model, a unified modelling system for global numerical weather prediction (NWP) and climate studies. In the present study, the model is used in its limited-area mode. In the TOFD parametrization used for the present simulations, the surface stress and its vertical distribution are formulated in terms of the spectrum of the orography, meaning that it only depends on the orography characteristics in the domain. As a first step simulations using different grid spacings, from the km scale to the 100 m scale, are carried out to reproduce the intensive observational period (IOP) of the Perdigão field experiment. The km-scale simulations in NWP mode are run continuously for the complete 49-day IOP using ERA5 data for initial and boundary conditions. The large-eddy simulations, at O(100 m) grid spacing, are run for selected periods nested into the NWP runs. The initial results of the NWP control simulation show good performance when compared to the tower wind observations for selected periods, but not for the entire IOP. The reasons for the variable performance is investigated.
Relativistic electron scattering by electromagnetic ion cyclotron waves: the hot plasma Model
Authors: Bashir Muhammad Fraz , Artemyev Anton , Zhang Xiaojia , Angelopoulos Vassilis
Published: March 2022

Resonant scattering by electromagnetic ion cyclotron (EMIC) waves is one of the most effective mechanisms of relativistic electron losses in the inner magnetosphere. For the majority of observed waves, such scattering is well described by the quasi-linear diffusion theory. Low-altitude spacecraft measurements, however, often show that the energy range of precipitating electrons is wider than theoretical predictions based on the cold plasma dispersion of EMIC waves. We develop a hot plasma model based on the observed ion distribution functions and investigate the hot plasma effects on EMIC wave dispersion for a wide frequency range. The results obtained from the analytical hot plasma model agree very well with the numerical solution of the exact dispersion relation of EMIC waves for a wide range of plasma parameters. We also show the implementation of this model for diffusion rate evaluation. Combining near-equatorial spacecraft measurements and wave dispersion model, we show that hot ion effects tend to increase the minimum resonant energy for the frequency range around wave intensity maxima, but can decrease the minimum resonant energy for the higher-frequency part of wave spectra.

This study highlights the importance of hot plasma effects on the relativistic electron scattering and provides a hot plasma model applicable to a wide range of plasma parameters for realistic quasi-linear diffusion rate calculations.
Rock instability hazard in high mountain area: the example of the Brenva spur (Mont Blanc massif)
Authors: Vicari Joëlle Hélène , Fei Li , Bertolo Davide , Choanji Tiggi , Derron Marc-Henri , Ferretti Gabriele , Jaboyedoff Michel , Thuegaz Patrick , Troilo Fabrizio , Uhlmann Daniel , Wolff Charlotte
Published: March 2022

Large rock-ice avalanches have been observed in the past in the Mont Blanc Massif area, notably from the Grand Pilier d’Angle in 1920 and from the Brenva spur in 1997, which involved millions of cubic meters of material. More recently, a rockslide detached from the Brenva spur in 2016, involving 35000 m3 of material. In the context of monitoring, in the fall of 2020 and 2021, two Lidar campaigns were performed to obtain 3D models of the rock face and monitor future rockfall activity. Moreover, point clouds were obtained from the Structure from Motion technique, using aerial photos from helicopter. Comparing the point clouds of 2020 and 2021 in CloudCompare software, only a few small rockfalls of 10-30 m3 were observed. The three-dimensional model of the rock wall was used as an input for the structural analysis of the Brenva Spur and Grand Pilier d'Angle, using Coltop3D software. The analysis showed that the same families of discontinuities characterizing the Brenva Spur are also found in the Grand Pilier d’Angle and other granitic crops at lower altitudes, indicating that they all belong to the same regional set of discontinuities. To monitor the collapses of the Brenva spur, an accelerometer was installed in 2017 on the wall and a high-resolution camera was placed at a distance of about 6 km. In June and July 2018, two rockfalls and one rockslide were detected, by both the accelerometric signal and the visual inspection of the photos. A spectrogram was therefore created, which showed that both high and low-frequency contents are present. Low frequencies may correspond to the sliding and high frequencies may correspond to rock bounces.

 
Using Satellite Observations to Support Water Management in South India
Authors: Vanthof Victoria , Kelly Richard
Published: March 2022

Small reservoir tank structures across South India form part of a complex ancient traditional water distribution system that has historically supplied irrigation to cropped fields during the dry-season. Despite their historical significance and the critical need for water storage in an agrarian dominated country with unpredictable rainfall, thousands of tanks have fallen into a state of disrepair. Our current understanding of these systems lacks knowledge about the functional state of these water systems. To understand tank functionality, spatially explicit and temporally dynamic frequent high-resolution surface water (SW) estimates developed in a synoptic and detailed way are needed. Building from an existing surface water monitoring approach (Vanthof and Kelly, 2019), we assess basin-scale dynamics of tank water storage state by segmenting water in multi-date and multi-sensor satellite images (Landsat-8, Sentinel-1, Sentinel-2, PlanetScope) for several years. These SW observations are converted to volumes using empirical rating curves developed for the region from Vanthof and Kelly (2019). Annually tanks were categorized by ‘tanks with water’ or ‘tanks without water’. For the ‘tanks with water’ category, an analysis was performed annually to identify spatial and temporal patterns in two indicators: temporal period of water storage and the rate of storage loss. Results show that hundreds of tanks are not able to store water despite precipitation inputs to the system. For tanks with water, further analysis reveals great variability among tanks for both indicators. As shown, this decade of Earth observation offers exciting opportunities to apply data-driven approaches to complement more traditional physically-based hydrological understanding and the ability to elucidate the role of reservoir filling strategies.

Vanthof, V., & Kelly, R. (2019). Water storage estimation in ungauged small reservoirs with the TanDEM-X DEM and multi-source satellite observations. Remote Sens. of Environ., 235, 111437.
Downscaling global wildfire model output to a relevant scale for probabilistic wildfire risk assessment of economic impacts
Authors: Steinmann Carmen B. , Lüthi Samuel , Gübeli Samuel , Guillod Benoît P. , Bresch David N.
Published: March 2022

Accurately estimating wildfire risk is essential for many use cases, such as prioritizing adaptation resources or offering insurance coverage for these devastating events. In collaboration with the Zurich-based InsurTech company CelsiusPro we present a globally consistent, open-source wildfire hazard, based on state-of-the-art fire models and providing high-resolution, probabilistic fire seasons suitable for risk analysis and insurance coverage pricing.

For the probabilistic part, we build upon the existing wildfire hazard model available on the open-source climate risk modelling platform CLIMADA (CLIMate ADAptation). This model creates stochastic wildfire events at 1 km resolution using a random walk generator that assigns a grid-point specific fire ignition and propagation probability based on Fire Information for Resource Management System (FIRMS) satellite data and physical constraints such as population density and land cover. However, this model does not account for key physical drivers, such as wind.

On the other hand, data from state-of-the-art fire models are available through the Fire Model Intercomparison Project (FireMIP), which coordinates the evaluation and comparison of these models. While most available models account for the complexity of fire ignition and propagation including relevant physical drivers, their resolution (ranging from 0.5° to 2.8°) is too coarse for the assessment of economic impacts as needed for insurance coverage pricing. In addition, most models are not fully probabilistic, but provide their outputs for present and future climate conditions.

In this work, we combine the annual fraction of burnt area provided as FireMIP output with CLIMADA’s stochastic model, resulting in a probabilistic, high-resolution wildfire hazard model that is based on state-of-the-art fire modelling. This allows us to compute a globally consistent economic risk of wildfires to physical assets by combining the newly developed hazard with an exposure and vulnerability.
Global implications of lignocellulosic crop-based BECCS for terrestrial vertebrate biodiversity
Authors: Hanssen Steef , Steinmann Zoran , Daioglou Vassilis , Cengic Mirza , van Vuuren Detlef , Huijbregts Mark
Published: March 2022

Bioenergy with carbon capture and storage (BECCS) based on purpose-grown lignocellulosic crops can provide negative CO2 emissions to mitigate climate change, but its land requirements present a threat to biodiversity. Here, we analyse the implications of crop-based BECCS for global terrestrial vertebrate species richness, considering both the land-use change (LUC) required for BECCS and the climate change prevented by BECCS. LUC impacts are determined using global-equivalent, species-area relationship-based loss factors. We find that sequestering 0.5–5 Gtonne of CO2 per year with lignocellulosic crop-based BECCS would require hundreds of Mha of land, and commit tens of terrestrial vertebrate species to extinction. Species loss per unit of negative emissions decreases with: i) longer lifetimes of BECCS systems, ii) less overall deployment of crop-based BECCS, and iii) optimal land allocation, i.e., prioritising locations with lowest species loss per negative emission potential, rather than minimising overall land use or prioritising locations with lowest biodiversity. The consequences of prevented climate change for biodiversity are based on existing climate response relationships. Our tentative comparison shows that for crop-based BECCS considered over 30 years, LUC impacts on vertebrate species richness may outweigh the positive effects of prevented climate change. Conversely, for BECCS considered over 80 years, the positive effects of climate change mitigation on biodiversity may outweigh the negative effects of LUC. However, both effects and their interaction are highly uncertain and require further understanding, along with analysis of additional species groups and biodiversity metrics. We conclude that factoring in biodiversity means lignocellulosic crop-based BECCS should be used early to achieve the required mitigation over longer time periods, on optimal biomass cultivation locations, and most importantly, as little as possible where conversion of natural land is involved, looking instead to sustainably grown or residual biomass-based feedstocks and alternative strategies for carbon dioxide removal.
Artificial intelligence reconstructs global temperature from scarce local data
Authors: Wegmann Martin , Jaume Santero Fernando
Published: March 2022

Climate variability on a monthly to annual scale is the foundation for high-impact climate anomalies and extreme weather that pose a threat to a range of sectors in our society. With anthropogenic global warming, climate variability is projected to change non-linearly. The consequences and impacts of those changes already stretch around the globe. Unfortunately, current generation coupled-climate models still lack skill in representing variability in crucial parts of the climate system. Gaining more insights about a realistic range of climate variability is therefore of utmost importance. Recently, rapid progress was made in the implementation of artificial intelligence tools for climate science. Especially deep learning tools show promise in extracting features of interest out of gridded data, forecasting time series and representing physical systems.

Here we present a basic neural network approach that reconstructs global fields from sparse local data. Rather meant as a proof-of-concept than the best possible climate reconstruction, we stay extremely conservative in both the spatial and temporal availability of data, and as such operate on very small sample sizes for a deep learning approach. Although our goal is to reconstruct temperature anomalies, our approach is flexible concerning the variable reconstructed, local data coordinates and input data type. In support of the United Nations Sustainability Goals, training and generating of our final, 4800 month temperature anomalies reconstruction cost around 30 minutes on a middle-class, GPU-supported laptop.

We focus here on a grid reconstruction problem, a typical issue in the (paleo-) climate community. By using a very conservative approach with small sample sizes (especially for a deep learning approach), we could produce a realistic, performant global temperature anomaly reconstruction. Compared to previous gridded climate reconstruction approaches, we use very scarce point data to reconstruct four orders of magnitude more data.