bluuebunny/crossref_metadata_2025 huggingface dataset:
Properties of cosmic ray test particles in global MHD simulation of the heliosphere
Authors: Matsukiyo Shuichi , Yoshida Kotaro , Washimi Haruichi , Hada Tohru
Published: March 2022

Heliosphere is a bubble occupied by the solar wind plasma and magnetic field in the local interstellar space. The motion of galactic cosmic rays (GCRs) invading into the heliosphere are strongly affected by the electromagnetic structures of the heliosphere. The statistical behavior of the GCRs near and inside the heliosphere have been conventionally studied by many authors using the diffusion convection model [e.g., Moraal (2013)].

  In this study we investigate the behavior of GCRs invading into the heliosphere in the level of particle trajectory. We conduct test particle simulations of GCRs by using the electromagnetic fields obtained from a global MHD simulation of the heliosphere. The MHD simulation assumes steady solar wind and interstellar wind. GCR protons are initially distributed outside the heliosphere and their motions in the steady virtual heliosphere are calculated by using the Buneman-Boris method. Depending on their initial energy, various types of particle motions, current sheet drift, polar drift, spiral motion, shock drift, Fermi-like acceleration, linear motion, resonantly scattered motion, mirror reflection by bottleneck interstellar field, are observed. We further discuss some statistics of the particles reached at the inner boundary (=50AU from the sun) of the simulation domain.
Ecotiles designed to mimic natural rocky shore biogeomorphic interactions: evidence of colonisation patterns after 12 and 18 months 
Authors: Naylor Larissa A. , Kosova Eliska , Vovides Alejandra , James Kelly
Published: March 2022

Natural rocky shore landforms show high habitat heterogeneity, as they have pools, crevices, groves and holes, which accommodate large variety of intertidal species. Urban coasts are often armed with smooth hard flood defences that lack the geomorphological features of natural rocky shores where biodiversity thrives. Hard coastal infrastructure can be ‘greened’ by improving habitats using ecotiles inspired by the natural coastal biogeomorphology to mimic geodiversity of rocky shores and support key species. The tiles for ecological enhancement were designed based on scientific evidence (ecology and biogeomorphology science) to support species richness, abundance and diversity. The highly and less textured tiles were deployed on City of Edinburgh’s coastal protection assets, rock armour and seawalls, in 3 sites in 2020, enabling comparision between two tile types in two locations, as well as comparison to the rock armour and walls. Tiles on rock armour showed higher settlement than tiles on seawalls, which were positioned high in the intertidal zone but are expected to colonise with time, and will be especially important to prevent coastal squeeze with sea level rise. Our data suggest that there was no difference in settlement patterns based on time of deployment (March vs May) suggesting that timing in the settlement season has little ecological impact. The results show that highly textured tiles enhanced habitat on rock armour for seaweed species, notably fucoids, which showed limited presence on rock armour prior to installation. The finer grooves and crevices and biomimicry features on the textured ecotile provided sites for sessile and mobile species, such as barnacles and littorinids, showing statistical differences between the two tile types tested. The less textured tiles on rock armour had colonised by seaweed species contrary to the hypothesis. This finding suggests that the selection of biogeomorphologically informed engineering materials is important for biodiversity enhancement. Active grazing of limpets was observed, which shows that the ecotiles provide foraging habitat for intertidal species that serve as food source for seabirds. The ecotile project represents a pioneer example of greening the grey to support biodiversity on urban coasts in Scotland; and one of the first known to be funded by nature conservation initiatives. This project shows that our understanding of the abiotic-biotic interactions can benefit in designing nature-based solutions to increase resilience and adapt to climate change-related coastal impacts.
Modelling of sediment transport pattern in the estuary of the Piave River
Authors: Menzione Antonia , Mancini Marco
Published: March 2022

Over the last decades numerous models for sediment transport prediction have been proposed with application to fluvial transport or littoral transport. However, the morpho-dynamic interactions that occur at the river mouth are still largely unexplored given different concurring phenomena, deriving from both river hydraulics and marine hydrodynamics. Knowing the magnitude of these phenomena is important to analyse and predict sediment discharge and deposition, erosion and potential effects on biological processes. The paper investigates the possibility to assess the behaviour of suspended sediment pattern at river mouth using numerical models and satellite images, providing a platform for the prediction of the effect of climate change in estuarine morpho-dynamic.

For this purpose, the hydrodynamic model (TELEMAC-2D) and the sediment transport model (SISYPHE) are coupled and their simulated suspended sediment maps are compared with the satellite Sentinel 2 images of SSC (suspended solid concentration) supporting the advection diffusion model coefficients calibration. 

TELEMAC-2D, a module of TELEMAC, solves the Saint-Venant equations and allows to evaluate the depth of the water, the depth-averaged tidal currents and the velocity components. Based on the outputs of the hydrodynamic simulation, the SISYPHE module simulates the transport of the fine sediments by calculating the erosion / sedimentation fluxes, concentration in the water column and layer thickness of deposited fine sediments using the Krone and Partheniades formulation, as well as the bedload flux calculated as a function of the friction and the bed shear stress.The estimate of suspended solids from remote sensing data is performed based on the relationship between SSC and spectral reflectance.

The case study in consideration is the estuary of the River Piave (3000 sq km), which flows from the eastern Italian Alps to the North Adriatic Sea. The impacts and influence of the different drivers (fluvial current, tidal currents, etc.) on the concentration, dispersion pattern and deposition of sediment are discussed.
Quantification of submarine groundwater discharge towards coral reefs around Curaçao, a semi-arid island in the Caribbean.
Authors: Kruijssen Titus , Wit Mike , van der Ploeg Martine , van Breukelen Boris , Vermeij Mark , Bense Victor
Published: March 2022

Recent studies show that submarine groundwater discharge (SGD) often equals or exceeds riverine inputs into marine environments. Pollution or extraction of groundwater may affect submarine groundwater discharge quality and quantity, impacting marine ecosystems. Most research focuses on relatively humid environments where large amounts of SGD can be expected and detected.

However, SGD has been poorly studied on smaller (semi-)arid islands, where SGD is relatively hard to detect and quantify. We aim to shine a light on the hydrogeological link between terrestrial processes and coral reef health in the semi-arid Caribbean island Curaçao.

It is hypothesized that the coral reef around the island is impacted by pollutants from tourism and agriculture. Previous hydrogeological measurements suggest the presence of groundwater fluxes towards the ocean through the karstic geology. However, quantitative data are lacking.

Groundwater level and quality measurements were conducted at study locations in the various geological settings of the island. Soil infiltration measurements were performed to assess the infiltration capacity of different soil types across the island. Rainfall and groundwater level fluctuations were monitored and used to determine the hydrogeological response after rainfall events. Geophysical ERT surveys have been conducted on different geomorphological settings to assess the hydrogeology and detect preferential flow paths in the karstic geology.

The field measurements will serve as input for a coupled groundwater-surface hydrology model of Curaçao in MODFLOW. The model outcomes will be used to guide field measurements in the future. These will include tracer tests, surface runoff measurements, marine Radon measurements and offshore geophysics.

This study is part of the interdisciplinary SEALINK research project, comprising nine PhD projects at different Dutch universities and research institutes.
Merging multiple observational data streams to constrain carbon uptake and water loss in the Amazon basin
Authors: Levine Paul , Bloom Anthony , Konings Alexandra , Worden Matthew , Parazoo Nicholas , Braghiere Renato , Norton Alexander , Ma Shuang , Worden John , Reager John
Published: March 2022

The Amazon River basin contains a substantial amount of carbon stored within terrestrial ecosystems. The unknown fate of this this carbon remains a substantial source of uncertainty in projections of the Earth system. While increasing atmospheric carbon dioxide concentrations could potentially enhance photosynthetic carbon uptake and/or reduce transpiration, increasing vapor pressure deficits have the potential to act with the opposite sign on both of these fluxes. Here, we investigate these competing factors at a process level, using a data assimilation system in which we constrain a parsimonious ecosystem model with observations from river runoff gauging stations, gravimetric water storage anomalies, and solar-induced chlorophyll fluorescence. Our model-data fusion provides us with an observationally consistent reanalysis of 21st-century ecohydrology across 14 Amazon watersheds along side the posterior distribution of key process parameters and emergent ecosystem properties such as water use efficiency (WUE). We find that the response to trends in atmospheric carbon dioxide concentrations and meteorological drivers varies across a hydroclimatic gradient within the Amazon, with implications for how carbon and water cycling could be expected to change subject to future biogeochemical and climatic trends.
Drought impacts on forest carbon sequestration and water use – evidence emerging from quantification of tree-ring formation
Authors: Fonti Patrick , Treydte Kerstin , Lehmann Marco , Rigling Andreas , Martínez-Sancho Elisabet
Published: March 2022

The impacts of climate extremes on forest ecosystems are still poorly understood but important for predicting carbon and water cycle feedbacks to climate. Despite evidences of the different climatic thresholds of tree carbon source and sink activities, implementations of mechanistic growth components into dynamic global vegetation models (DGVM) remain challenged by lacking observational data into the most important terrestrial biological sink, i.e.; into the cambial zone of tree stems.

In this study, we aim to provide a framework for mechanistic understanding of drought impacts on carbon and water dynamics based on accurate analyses of the physiological processes that indirectly regulate these budgets. We quantified the drought impact and resilience of intra-annual carbon sequestration and water use in four mature Norway spruces from a Swiss subalpine site by comparing high-resolution growth (i.e., xylogenesis and wood anatomy) and physiological (i.e., stable carbon isotope ratios) data from an exceptional dry summer (year 2015) with those from a regular growing season (year 2014).

Our observations described the cascade of impacts from leaf physiology to cambial activity during and after a 41-day period of physiological water deficit. During water deficit, all wood formation processes were strongly reduced diminishing carbon sequestration by 67% despite a 11% increased water-use efficiency. However, with the recovery of the positive hydric state in the stem, we observed a fast recovery of the rates of the different cell formation phases at the expenses of the accumulated assimilates produced during the drought event.

Our results clarify how the interaction between source and sink is modulated via external environmental factors and provide evidence that, under specific circumstances, tree growth can be extremely resilient. These novel findings should provide a framework to improve sink model components in DGVMs and consequently help to bridge understanding of carbon and water fluxes between atmosphere and forest ecosystems. 
Geophysical Investigations of Celestial Bodies through the Combination of Radio Science and Altimetric Crossover Data
Authors: Del Vecchio Edoardo , Petricca Flavio , Genova Antonio , Mazarico Erwan
Published: March 2022

The challenging science objectives of future planetary missions will require highly accurate trajectory reconstruction of deep space probes. Novel techniques that improve the navigation capabilities are developed with the purpose to expand the scientific return of geophysical investigations across the Solar System. Science instruments that provide geodetic data from the spacecraft orbit may support the orbit determination process in combination with deep space radio tracking measurements. Altimetric data that measure the relative distance of the spacecraft with respect to the celestial body’s surface yield key constraints on the orbit evolution. Differential measurements, from observations that are repeated over the same location (crossover), are less prone to errors associated with surface mismodeling, leading to significant improvements in the estimation of the spacecraft position.

In this work, we present a method based on the combination of ground-based radio science and altimetric crossover measurements to enhance the estimation of the spacecraft orbit and geodetic parameters. The methodology is developed to carry out thorough numerical simulations of mission scenarios, including the generation of synthetic observables. We show the results of our covariance analysis of the NASA mission Europa Clipper by simulating and processing measurements of the Radar for Europa Assessment and Sounding: Ocean to Near-surface (REASON) and the Gravity and Radio science (G/RS) investigations.
The Kuroshio Current at the Last Glacial Maximum and implications for coral palaeobiogeography
Authors: Vogt-Vincent Noam , Mitarai Satoshi
Published: March 2022

The Kuroshio Current is the western boundary current of the North Pacific Subtropical Gyre and flows through the East China Sea, entering through a relatively narrow, 800m-deep sill (the Yonaguni Depression). The warm surface waters associated with the Kuroshio support habitable conditions in the East China Sea for some of the world’s most northerly warm-water coral reefs. However, it has been suggested that sea-level fall at the LGM, with a possible further contribution from tectonics, obstructed the glacial Yonaguni Depression and diverted the Kuroshio to the east of the Ryukyu Arc.

Using a set of 2km-resolution dynamically downscaled ocean simulations with LGM boundary conditions from four PMIP3 contributions, we present regional state estimates for the glacial East China Sea which are both physically consistent, and compatible with sea-surface temperature proxy compilations. We find that, whilst the Kuroshio Current transport in the East China Sea is slightly reduced at the LGM, its path is relatively unchanged, with limited sensitivity to glacioeustatic sea-level change, glacial-interglacial changes in climate, and tectonic shoaling of the Yonaguni Depression. Simulations with the best model-proxy agreement predict only minor changes in the zone of habitability for warm-water coral reefs in the glacial East China Sea. Strong surface currents associated with the glacial Kuroshio may have maintained or even improved long-distance coral larval dispersal along the Ryukyu Arc, suggesting that conditions may have enabled coral reefs in this region to remain widespread throughout the last glacial. These findings are supported by seismic evidence for glacial coral reefs in the northern East China Sea. Further field studies are needed to investigate whether this is genuinely the case, and to provide additional constraints on how the coral reef front responds to long-term environmental change.
A new approach toward integrated inversion of reflection seismic and gravity datasets using deep learning
Authors: Rashidifard Mahtab , Giraud Jeremie , Jessell Mark , Lindsay Mark
Published: March 2022

Reflection seismic data, although sparsely distributed due to the high cost of acquisition, is the only type of data that can provide high-resolution images of the crust to reveal deep subsurface structures and the architectural complexity that may vector attention to minerally prospective regions. However, these datasets are not commonly considered in integrated geophysical inversion approaches due to computationally expensive forward modeling and inversion. Common inversion techniques on reflection seismic images are mostly utilized and developed for basin studies and have very limited application for hard-rock studies. Post-stack acoustic impedance inversions, for example, rely a lot on extracted petrophysical information along drilling borehole for depth correction purposes which are not necessarily available. Furthermore, the available techniques do not allow simple, automatic integration of seismic inversion with other geophysical datasets. 

 

 We introduce a new methodology that allows the utilization of the seismic images within the gravity inversion technique with the purpose of 3D boundary parametrization of the subsurface. The proposed workflow is a novel approach for incorporating seismic images into the integrated inversion techniques which relies on the image-ray method for depth-to-time domain conversion of seismic datasets. This algorithm uses a convolutional neural network to iterate over seismic images in time and depth domains. This iterative process is functional to compensate for the low depth resolution of the gravity datasets. We use a generalized level-set technique for gravity inversion to link the interfaces of the units with the depth-converted seismic images. The algorithm has been tested on realistic synthetic datasets generated from scenarios corresponding to different deformation histories. The preliminary results of this study suggest that post-stack seismic images can be utilized in integrated geophysical inversion algorithms without the need to run computationally expensive full wave-form inversions.  
Ensembles of Euro-CORDEX RCMs for assessment of specialized climate indices in Ukraine
Authors: Krakovska Svitlana , Shpytal Tetiana , Chyhareva Anastasiia , Pysarenko Larysa , Trofimova Iryna , Kryshtop Lidiia
Published: March 2022

Regular update of climate projections is a crucial task in all countries since such data should be a basis for development further adaptation measures on all levels from national down to local. And the more detailed data is available the more reliable and focused measures to combat climate change could be developed. At the moment data of EuroCORDEX initiative with 0.1o spacing is the most suitable, detailed and freely available dataset for Ukraine. We used bias-adjusted daily and monthly air temperature and precipitation datasets projected by 34 regional climate models (RCMs) for RCP4.5 and RCP8.5 scenarios for 3 future periods: near-term 2021-2040, mid-term 2041-2060 and far-term 2081-2100. Further bias-adjustment by the delta-method has been applied for the RCMs ensemble means when differences in temperatures (or ratio in case of estimations for precipitation) in future periods were added to (or for precipitation - multiplied by) values in the base period 1991-2010, obtained from the E-OBS v20.0e data. The Delta method applied provides more reliable results and allows to effectively exclude systematic biases in RCMs.

At the same time, in response to practical needs not only main climate parameters such as air temperature and precipitation should be projected under different scenarios but specialized climate indices that are different for different sectors. We’ll present as an example a set of indices relevant to forestry which is among the most vulnerable sectors to climate change in Ukraine. They are as follows: daily and annual temperature ranges, continentality, the coldest month temperature, heat and moisture supply during warm season with t>0o, and types of climates by Worobjov index. All climate indices for the base period 1991-2010 and past WMO period 1961-1990 are estimated from the E-OBS data. To visualize the above indicators Ukraine atlas has been developed in QGIS application which represents 2 past and 3 future periods for 2 scenarios.
Disco Gravel: Image-based bedload tracking in shallow water flume experiments
Authors: Montakhab Fatemeh Asal , Iun Megan , MacVicar Bruce
Published: March 2022

Previous experiments on the restoration of sediment cover in semi-alluvial channels with irregular boundaries have shown that coarse size fractions of the bedload are dispersed faster over a bare bed than the finer fractions, and that the coarse fraction helps to build a set of skeleton bars that are later covered by finer sediment. Unsteady flow experiments in the same channel confirmed these trends over a bed of mobile sediment and further indicate strong spatial gradients in bedload transport and deposition. Despite these advances, a methodological gap remains in the tracking of bedload sediment during the experiments. In this study we advance a tracking technique for obtaining vectors of particle displacements during unsteady flow experiments. Methods involve painting the coarsest three sediment fractions with different colours of fluorescent paint and illuminating a region of interest within the flume with ultraviolet lights (wavelength 400-410 nm) during the experiment, which results in the painted gravel appearing in bright neon colors while the water remains transparent and dark (i.e. the ‘Disco’). We use a Panasonic BGH1 camera recording at 60 fps and a resolution of 1080 x 1920 pixels to film a region of interest in the channel roughly 0.25 m wide 1.0 m long.  With this technique we are able to identify the displacements of the two coarsest size fractions. For the third size fraction the tracers were too numerous and too small to be tracked with confidence. Analysis of the videos occurred in three steps: 1) color segmentation to isolate the size class of interest, 2) application of TracTrac algorithm (Heyman, 2019) to identify particle paths, and 3) post-processing to reduce two types of error.  The errors are likely related to the irregular water surface, which can result in particles appearing to ‘vibrate’ in place when they are not moving, and also result in a continuous tracer path being broken into a series of shorter discontinuous paths.  Overall the technique appears to be useful for characterizing spatial variability at the threshold of motion and delimiting preferential transport pathways. Future improvements in resolution and tracer concentration should help to reduce the minimum size of tracer that can be tracked with confidence.
Ionospheric Measurement Using a Linearly Polarized Tri-Band Small Satellite Beacon
Authors: Lanter Ferry Pascal , Sutinjo Adrian , Morgan John
Published: March 2022

Radio waves propagating the ionosphere are subject to a number of unpredictable and corrupting effects, the most significant of which are phase path reduction, Faraday rotation, and scintillation. A method of measuring these effects is therefore necessary in order to study, understand and anticipate their impact. The rise in popularity of small satellites presents a new cost-effective opportunity to study the ionosphere in detail, however the challenge of realizing a beacon within the constraints of a CubeSat system must be overcome. First we introduce a measurement technique that builds on past multi-frequency beacons, incorporating the well established differential phase technique, as well as introducing a new differential polarization technique. We achieve this by employing linearly polarized beacon signals, which enables us to separate phase path reduction and Faraday rotation into a phase and polarization change respectively. The introduction of linear polarization overcomes some of the key limitations in current ionospheric measurement techniques: eliminating errors associated with indirect Faraday rotation measurement, and enabling absolute unambiguous parameter measurement. To validate the capability of measuring the ionosphere within the constraints of a small satellite package, we establish the influence of system noise, weak scattering, clock errors and antenna characteristics on the measurement technique. We then use this to inform a practicable CubeSat beacon design solution which achieves absolute and high resolution measurement of ionospheric parameters within the constraints of the system.
3D Reconstruction of the ancient church Santiago the Apostle, Morelos, Mexico as a follow up to the damage caused by the 2017 earthquake
Authors: Méndez Serrano Jesús Eduardo , Ruiz Sánchez Jesús Octavio , Ramírez Serrato Nelly Lucero , López Valdés Nestor , Jácome Paz Mariana Patricia
Published: March 2022

On September 19, 2017, Mexico was rocked by a 7.1 earthquake, causing an immense amount of damage in the states near the epicenter. This earthquake caused hundreds of damages in historical heritage, mainly in the states of Puebla, Oaxaca and Morelos. The patrimonial damages occurred were so extensive that they are prolonged till this day. Nepopualco Morelos was one of the towns that suffered great destruction by this shaking event. Their historical and main church, “Santiago the Apostle”, was  shattered in the shake, and the cleanup is still ongoing. The objective of this project was to create a 3D model of the Santiago the Apostle Church to view the process of restoration done by the National Institute of Anthropology and History (INAH). The 3D model obtained was the result of 478 images, which were captured by three different drone flights and a set of images shot on terrestrial. These flights were done by an Anafi Parrot drone, two circular flights and a double grid flight (180 and 256 images, respectively). For the purpose of obtaining a georeferenced accurate model, twelve ground control points were acquired in the field using a Emlid Reach RS+. The 3D model  presented in this project is a high-resolution model that allows the spatial analysis of the cabinet structure and represents a low-cost methodology. This model presents a centimeter resolution, while the error corresponds to 1.56%. The main contribution of this work is the obtainment of a 3D model of  Nepopualco´s historical church in which the final product shows the present stage of reconstruction done on the structural damages caused by the earthquake. The 3D reconstruction model will be delivered to the corresponding authorities of the National Institute of Anthropology and History. There is a possible consideration in creating other models that may help the INAH in the recovery process of cultural heritage affected by natural phenomena, as well as its structural mitigation. This project is the first effort on creating a digital catalog of these types of structures that make up Morelos’ historical heritage.
Acknowledgments:
Thanks to Arq. Antonio Mondragón from INAH,  Arq. Aimeé Mancilla and Arq.  Fabián Bernal Orozco for their facilities and support. We also want to thank Mr. Félix García Reyes and Gilberto García Peña, the community representatives, for their assistance in opening the entrance to the church.
Combined measurement of snow depth and sea ice thickness by helicopter EM bird in McMurdo Sound, Antarctica
Authors: Rack Wolfgang , Tan Adrian , Haas Christian , Farooq Usama , Taylor Aston , Kind Adriel , Barnsdale Kelvin , Leonard Greg
Published: March 2022

Snow on sea ice is a controlling factor for ocean-atmosphere heat flux and thus ice thickness growth, and surface albedo. Active and passive microwave remote sensing is the most promising way to estimate snow depths over large sea ice areas although improved validation is understood as a missing information to support further progress. However, severe limitations in the representative measurement of snow depth over sea ice persist, which exacerbates sea ice mass balance assessments as well as the indirect estimation of consolidated ice thickness from remotely sensed freeboard.

We have designed and flown a snow radar in combination with an electromagnetic induction device for sea ice thickness. The goal was the simultaneous measurement of both the consolidated sea ice thickness and the snow depth on top as a tool to derive snow and ice statistics for satellite validation. The snow radar was integrated into an EM-bird and flown about 15 m above the surface by suspending the instrument from a helicopter. The combination of the applied technologies hasn’t been deployed in this configuration before. The helicopter flight speed was around 70 knots, resulting in a snow measurement about every four meters. The EM instrument can detect ice thickness at 0.1m accuracy, whereas the snow radar is designed to measure snow depth at 0.05m accuracy.

Our field area was the land-fast sea ice and adjacent ice shelf in McMurdo Sound (Antarctica) in November 2021. During this time we found a relatively shallow but variable snow cover (up to about 0.3m) above sea ice of about 2m thickness. Deeper snow was only measured at the transition from the sea ice to the ice shelf, and on the ice shelf itself, where the maximum radar penetration in snow in ideal conditions is estimated to be around 2-3 meters.

We present first results of snow cover statistics in comparison to ground validation and observed snow characteristics, and we compare these results to airphotos and optical satellite imagery. We show that the measurement set-up meets the requirements for level ice and rough fast ice with patchy but dry snow cover. The system still needs to be tested over pack ice with potentially more complex snow morphology.
Integrated Approach to Identify Variables for the Prediction of Metallic Content in a Slag Heap using Time-Domain ERT and SIP Laboratory Measurements
Authors: Isunza Manrique Itzel , Caterina David , Dumont Marc , Nguyen Frederic
Published: March 2022

There are two main drivers to integrate former metallurgical residues or mine waste into the circular economy through an efficient resource recovery. First, the economic driver, which considers land and resource recovery of high value elements such as critical raw materials. Secondly, the environmental and human health driver, as these types of residues might be a potential source of pollution. In both scenarios, there is a need to improve the characterization of past metallurgical sites and to locate and quantify materials of interest. To this aim, mostly geoelectric methods applied in the laboratory and/or in the field have been used and they are often complemented with geochemical or mineralogical studies. In this contribution, we present an approach that integrates a 3D Electrical Resistivity Tomography (ERT) and Induced Polarization (IP) acquisition in the field, lab measurements of ERT, IP and Spectral Induced Polarization (SIP) in several samples together with chemical analysis, to predict the metallic content in a slag heap from a former iron and steel factory located in Belgium. The samples were collected at locations targeting the observed geophysical anomalies. We first look for correlations between geophysical lab measurements and the chemical analysis to identify the variables which could potentially have a larger impact or control in the metallic content. Second, we use the geophysical lab measurements to improve the deterministic constrained inversion carried out for the 3D field data. Third, we use a supervised learning algorithm - Gaussian Process Classification (GPC)- to predict the metallic content of the slag heap from the 3D inverted resistivity/chargeability model. Overall, we found that variations in the chargeability are correlated with changes in iron, calcium and silicon content. Additionally, the GPC represents a suitable algorithm to integrate the uncertainty in the prediction results as well as the uncertainty that arises from the direct comparison of field and lab data. Finally, this methodology which integrates geophysical field data, targeted sampling, lab measurements and supervised learning can be applied in broader contexts where such data are available.
Water and conflict on internal displacement: network analysis of Somalia case
Authors: Oh Woi Sok , Muneepeerakul Rachata , Rubenstein Daniel , Homayounfar Mehran , Levin Simon
Published: March 2022

Recent decades have witnessed an increasing trend of displacement—forced movements of people, e.g., refugee, internal displacement, asylum. The greatest portion of global displaced populations are internally displaced persons (IDP) who travel within a country's boundary. IDPs are relocated due to varying reasons such as conflict, drought, flood, etc. Somalia is particularly renowned for protracted internal displacement due to long-lasting conflicts, extreme droughts, and flooding events. Despite the severity and continuity of the problem, we still lack an understanding of how water (here, droughts and floods) and conflict build IDP networks respectively. This research answers the following questions to solve the gap: (1) What are the underlying push and pull mechanisms in water-induced and conflict-induced IDP networks?; (2) How are water-induced and conflict-induced IDP networks structured and characterized?; (3) How do geographical locations cluster differently in two IDP networks? The analysis was conducted on the yearly IDP flow data at the district level in Somalia. We compared water-induced and conflict-induced IDP networks in Somalia using multiple network metrics, motif analysis, and community detection algorithms. From the analysis, conflict-induced IDP networks followed a power law for both indegree and outdegree. Though the in-degree networks of water-induced IDPs were weakly scale-free, the out-degree case was a random network. Both water-induced and conflict-induced IDP networks shared a similar mesoscopic network structure through the motif analysis. Closed triads were more frequently observed, supporting the importance of social linkages such as social homophily or information/knowledge sharing. Through the community detection, we found that water drove IDPs to move to nearby locations and led neighboring locations to clustered. Conflict, however, facilitated IDP flows between remote locations, building geographically-dispersed clusters. These findings offer an in-depth insight into commonalities and differences between water-induced and conflict-induced IDP networks in Somalia.
One Saddle Point and Two Types of Sensitivities Within the Lorenz 1963 and 1969 Models
Authors: Shen Bo-Wen , Pielke, Sr. Roger , Zeng Xubin
Published: March 2022

The fact that both the Lorenz 1963 and 1969 models suggest finite predictability is well-known. However, it is less known that mechanisms (i.e., sensitivities) within both models that lead to finite predictability are different. Additionally, the mathematical and physical relationship between these two models has not been fully documented. New analyses along with literature review are performed here to provide insights on the similarities and differences for these two models. The models represent different physical systems, one for convection and the other for barotropic vorticity. From theperspective of mathematical complexities, the Lorenz 1963 (L63) model is limited-scale and nonlinear; and the Lorenz 1969 (L69) model is closure-based, physically multiscale, mathematically linear, and numerically ill-conditioned. The former possesses a sensitive dependence of solutions on initial conditions, known as the butterfly effect, and the latter contains numerical sensitivities due to an ill-conditioned matrix with a large condition number (i.e., a large variance of growth rates).

Here, we illustrate that the existence of a saddle point at the origin is a common feature that produces instability in both systems. Within the chaotic regime of the L63 nonlinear model, unstable growth is constrained by nonlinearity, as well as dissipation, yielding time varying growth rates along an orbit, and, thus, a dependence of (finite) predictability on initial conditions. Within the L69 linear model, multiple unstable modes at various growth rates appear, and the growth of a specific unstable mode (i.e., the most unstable mode during a finite time interval) is constrained by imposing a saturation assumption, thereby yielding a time varying system growth rate. Both models have been interchangeably applied for qualitatively revealing the nature of finite predictability in weather and climate. However, only single type solutions were examined (i.e., chaotic and linearly unstable solutions for the L63 and L69 models, respectively), and the L69 system is ill-conditioned and easily captures numerical instability. Thus, an estimate of the predictability limit using either of the above models, with or without additional assumptions (e.g., saturation), should be interpreted with caution and should not be generalized as an upper limit for predictability of the atmosphere.
An Improved Micro Scale Average Annual Flood Loss Implementation Approach  
Authors: Rahim Md Adilur , Gnan Ehab S , Friedland Carol J , Mostafiz Rubayet Bin , Rohli Robert V
Published: March 2022

Average annual loss (AAL) is used as the basis for the evaluation of risk mitigation measures.  However, the current AAL implementations in flood risk assessment have several shortcomings. For instance, results generated using Riemann trapezoids for the available return periods of a site are typically gross approximations, especially when damage changes rapidly with depth. Monte Carlo simulations offer improvements in precision but at the expense of being computationally intensive. The log-linear method that extrapolates losses to higher return periods and performs piece-wise Riemann sum with these limited return periods can fail to capture the non-linear flood behavior. This paper presents an improved implementation that quantifies AAL at the micro-scale level including the full range of loss‐exceedance probabilities. To demonstrate the methodology, the financial benefit of increasing the lowest floor elevation for a one-story single-family residence is assessed. Several depth-damage functions (DDFs) are selected and compared to examine the variability in AAL results related to the DDF choice. Results demonstrate the need for an AAL estimate that includes the full loss‐exceedance probabilities. Results also highlight the need to assess flood risk at the micro-scale level for a more localized and accurate assessment, whereupon the estimate can be expanded to broader-scale risk estimations with a higher degree of accuracy. The more realistic AAL estimates results could encourage homeowners and communities to take action and support government decision-makers by investing in flood mitigation and considering building code changes.
Active time-reverse imaging: Defect detection by coda waves in digital concrete physics
Authors: Balcewicz Martin , Finger Claudia , Saenger Erik H.
Published: March 2022

The localization of defects (i.e., fractures or damages) is essential in evaluating and assessing concrete in, for example, bridges. For this reason, this study presents a non-destructive testing method used primarily in passive seismology applied to active ultrasonic waveforms. Changes in the coda wave can provide information about the defect location by comparing two measurements with and without a defect.

The signal comparison of active transducer signals recorded with several receivers for material before and after an applied load is the basis of Active Time-Reverse Imaging (A-TRI). This study applies the TRI technique to the signal-based analysis of reinforced concrete specimens' acoustic emission (AE). Classical time-reverse modeling uses recorded passive signals, recorded laboratory, or field experiments as input. The recorded wavefield is reversed in time and backpropagated numerically through an adequate medium representation. The wavefield will then ideally focus on the original source location. In contrast to the standard passive TRI method, an active ultrasound method using the generated wavefield from an active source is used in A-TRI. The general workflow is divided into two basic steps: (1) Ultrasonic waves are emitted from single or multiple transducers on the surface and propagate through the original medium. Several receivers record the signals. (2) The experiment is repeated with precisely the same setting after a specific loading scenario. However, the potential damage is to be detected in this case. The difference of both signals is reversed in time and used as the input signal for a time-reverse simulation to locate the defect.

We see the A-TRI method as a complementary method to typically used coda-wave interferometry (CWI) to detect velocity changes in the medium. On the other hand, A-TRI can precisely determine the location of the defect. In the following, a feasibility study is presented in which the A-TRI method is applied to a synthetic data set to localize the defect.
First detailed polarimetric study of type III solar radio bursts with the Murchison Widefield Array
Authors: Dey Soham , Kansabanik Devojyoti , Oberoi Divya
Published: March 2022

Type III solar radio bursts form a well known class of active solar emissions and are associated with energetic electron beams propagation outwards through the coronal plasma, and in the process giving rise to their characteristic rapid spectral drifts. Though they have been the subject of a large number of studies since their discovery in the 1950s, the high fidelity and dynamic range spectroscopic snapshot images from the new technology instruments, like the Murchison Widefield Array (MWA) are enabling the exploration of a previously inaccessible part of phase space and leading to the discovery of previously unknown aspects of these well known bursts even in recent times (e.g. Mohan et al., 2019, ApJ, 875). We have now developed a robust and general full Stokes polarization calibration and imaging algorithm optimized for MWA solar observations.. Referred to as “Polarimetry using Automated Imaging Routine for Compact Arrays for the Radio Sun'' (P-AIRCARS; Kansabanik et al., 2022, in prep.), it can deliver full Stokes solar images with leakages on par with usual astronomical radio maps. Here we use this novel capability to carry out a detailed polarimetric study of a type III solar radio burst observed with the MWA. This is, once again, enabling an exploration of new phase space with an exciting discovery potential. Preliminary results show that these type III bursts show presence of linearly polarized emission. While conventional wisdom says that all traces of linear polarization should get washed out due to differential Faraday rotation in the corona, we have convincing reasons to believe that this emission is solar in origin. Here we present the current status of our first detailed polarimetric imaging study oa this  type III radio source. 
Preliminary Analysis on Multi-Devices Monitoring of Potential Deep-Seated Landslide in Xinzhuang, Southern Taiwan
Authors: Wang Ji-Shang , Lai Tung-Yang , Hsu Yu-Chao , Fu Guei-Lin , Tsai Cheng Hsiu , Huang Ting-Yin
Published: March 2022

In-situ monitoring of slope is crucial for recognizing and recording the occurrence of landslide. Figuring out the correlation between monitoring data and hillslope displacement would help early warning for landslide-induced disasters. Xinzhuang potential deep-seated landslide area has been identified by Taiwan executive authority where is located in Kaohsiung City, southern Taiwan, it covers a 10.3 hectares’ area and 20 buildings with an average slope of 22.8 degrees. The lithology of the upper slope is sand-shale interbedded with highly sand contented, which differs from lower slope in shale with mud contented.

For conducting early warning and comprehending displacement of landslide in this study, the monitoring of ground displacement was carried out using the tiltmeter and the GNSS RTK (Real Time Kinematic), and the hydrology data (rainfall and ground water level) were recorded every 10 minutes by automatic gauges. Furthermore, we executed manual borehole inclinometer measurement to obtain the possible sliding position of subsurface.

This study has been conducted for two years, the results shows that (1) The local shallow creep (4-5 meters underground) in the central deep-seated landslide area was recorded by the tiltmeter, GNSS and borehole inclinometer measurement. (2) The groundwater level is the significant factor for displacements of creep in this site. (3) The velocity of the displacement would be accelerated when the groundwater level was higher than 2.1 meters. (4) The 6-hours displacement has a highly correlation with accumulative rainfall and ground water level. Moreover, the results have been applied to the landslide early-warning system of Taiwan authority.
Evolution and behaviour of hydromulches in organic woody crops under open field and container conditions.
Authors: Moreno Marta M. , Villena Jaime , González Mora Sara , Morales Pablo A. , Atance Concepción , Ortega Carlos , Ruiz-Orejón Antonio , Campos Juan A. , Moreno Carmen
Published: March 2022

The use of hydromulches in agriculture is being investigated nowdays by different research groups in their search for harmless materials which mainly exert a reasonable weed control and allow saving crop water consumption by reducing soil evaporation, both in open field as in container nurseries. To achieve these goals, these materials would avoid, or at least reduce, the use of chemical herbicides or plastic mulches derived of non-renewable sources, with the environmental, economy and energy effect it implies, aspects clearly appreciated in organic farming. However, one of the most important problems associated to the hydromulches is their degradation process and their useful life, because, due to their organic origin, may disappear early and therefore not fulfil their function.

For this reason, in both an intensive almond crop planted in the open field and in young olive trees grown in big containers, we evaluated the evolution and disintegration process of different mixtures based on by-products derived from the agricultural sector (barley straw, rice husk, rests from mushroom production, pruning wood chips), mixed with a binder and recycled paper paste and applied in liquid form on the ground with subsequent solidification (hydromulch). For that, we focused on the evolution of the continuous formation of cracks (shape and size), thickness, puncture resistance and ground cover by the material.

In summary, and a basis for future tests, the main conclusion derived from the results is the importance of keeping the hydromulch materials as dry as possible. We have been able to verify that, when the material gets wet (either by irrigation water, or by rain or fog), it softens, thus losing its puncture resistance and disappearing early. In addition, when the material becomes wet, the attack of the fauna (rabbits, wild boars, birds, etc.) intensifies, accelerating the process of deterioration of the hydromulch installed on the field. In relation to the materials tested, the hydromulches based on rests from mushroom production undergoes strong and early disintegration, integrating completely into the soil, especially in field conditions. The best results in terms of permanence and stability throughout the trials were obtained in rice husk and pruning wood chips, which would position these mixtures as interesting alternatives especially in container crops, important for nursery crops.

Keywords: hydromulches, deterioration, puncture resistance, organic farming.

Acknowledgements: Project RTA2015-00047-C05-03 - INIA (Spanish Ministry of Economy and Competitiveness).