bluuebunny/crossref_metadata_2025 huggingface dataset:
Analysis of oscillatory flow around a rigidly attached spherical particle to the bottom in a sloshing tank
Authors: Yagci Oral , Aksel Murat , Yorgun Fatih , Valyrakis Manousos
Published: March 2022

Oscillatory flows are commonly observed flow conditions in sloshing tanks or at the seabed/river mouths under the effect of gravity and seiche waves. In such environments, particles are exposed to bi-directional oscillation-caused forces. These particles are usually sediments in settling basins under earthquake conditions or deposits on seabed/river mouths.

Physical model tests investigated the hydrodynamic forces acting on a spherical particle. This step is followed by a computational fluid dynamic model (i.e., RANS model), which aims to resolve the pressure and force fluctuations around a rigidly attached spherical particle to the bottom.

The experiments were conducted in a sloshing tank with 28.5cm length, 14.5 cm in width, and 20 cm in depth. A step-type-computer-controlled motor triggered the body of water within the tank. The motion of the mobile component of the tank was measured using two independent devices, i.e., an accelerometer and an ultrasonic distance sensor. The utilization of these measurement devices enables verifying the records of the motion double. Six different cases were conducted to define the error band for each device. These calibration cases emerge as a combination of the “better step motor speed” and “maximum displacement”. The acceleration records constitute a basis as an input for the RANS-based numerical model. During the validation/calibration of the CFD model, video records of the water surface observed during the experiment and the CFD outputs were comparatively analyzed based on an image-processing technique.

Once it was ensured that the CFD model simulated the sloshing process within the tank with an acceptable accuracy, a spherical particle was fixed to the bottom as the second phase of this study. Various sloshing scenarios were performed better to understand the fluctuation of the pressure field around the sphere. Based on these simulations, the variation of drag coefficient around the spherical body which emerges under the oscillatory flow was calculated.
A Convolutional Neural Network approach for downscaling climate model data in Trentino-South Tyrol (Eastern Italian Alps)
Authors: Crespi Alice , Frisinghelli Daniel , Klisho Tatiana , Petitta Marcello , Jacob Alexander , Pittore Massimiliano
Published: March 2022

Statistical downscaling is a very popular technique to increase the spatial resolution of existing global and regional climate model simulations and to provide reliable climate data at local scale. The availability of tailored information is particularly crucial for conducting local climate assessments, climate change studies and for running impact models, especially in complex terrain. A crucial requirement is the ability to reliably downscale the mean, variability and extremes of climate data, while preserving their spatial and temporal correlations.

Several machine learning-based approaches have been proposed so far to perform such task by extracting non-linear relationships between local-scale variables and large-scale atmospheric predictors and they could outperform more traditional statistical methods. In recent years, deep learning has gained particular interest in geoscientific studies and climate science as a promising tool to improve climate downscaling thanks to its greater ability to extract high-level features from large datasets using complex hierarchical architectures. However, the proper network architecture is highly dependent on the target variable, time and spatial resolution, as well as application purposes and target domain.

This contribution presents a Deep Convolutional Encoder-Decoder Network (DCEDN) architecture which was implemented and evaluated for the first time over Trentino-South Tyrol in the Eastern Italian Alps to derive 1-km climate fields of daily temperature and precipitation from ERA-5 reanalysis. We will show that in-depth optimization of hyper-parameters, loss function choice and sensitivity analyses are essential preliminary steps to derive an effective architecture and enhance the interpretability of results and of their variability. The validation of downscaled fields of both temperature and precipitation confirmed the improved representation of local features for both mean and extreme values, even though lower performances were obtained for precipitation in reproducing small-scale spatial features. In all cases, DCEDN was found to outperform classical schemes based on linear regression and the bias adjustment procedures used as benchmarks. We will discuss in detail the advantages and recommendations for the integration of DCEDN as an efficient post-processing block in climate data simulations supporting local-scale studies. The model constraints in feature extraction, especially for precipitation, over the limited extent of the study domain will also be explained along with potential future developments of such type of networks for improved climate science applications.
Transformation of the shape and spectrum of femtosecond pulses during propagation in gaseous media
Authors: Cidorkina Katsiaryna , Dorozhko Natalia , Suschenko Egor , Svetashev Alexander , Turishev Leonid
Published: March 2022

Investigation and practical use of the propagation processes of ultrashort pulses of high-power optical radiation in media of various physical nature and composition is of considerable experimental and theoretical interest. However, in order to determine more accurate parameters when obtaining the optimal pulse required for conducting research, it is necessary to understand how the pulse changes as it propagates.

This paper presents the results of numerical simulation of the propagation of high-intensity ultrashort pulses with a positive and negative chirp in the atmosphere in the regime of stimulated Raman scattering (SRS) and stimulated Raman self-scattering (SRS) on the main components of air - oxygen (21%) and nitrogen (78%), and also mixtures thereof. The calculation was carried out for λ = 400, 800, nm, pulse duration 1–25 fs.

To obtain the temporal localization of the spectral components of the changes, various types of continuous wavelet transform were used.

As a result, the structure of changes in the spectrum of the pulse with time was revealed and it was shown that when such a pulse propagates, a transition of photons occurs from the beginning of the pulse to its end with practically no change in energy.
New C-CO2 scattering cross sections at eV energies and their impact on photochemical escape of Carbon from Mars
Authors: Gacesa Marko
Published: March 2022

Recent years have seen a renewed interest in the problem of “missing carbon” at Mars and missing physical mechanisms that could explain it. At present, the carbon escape rates derived from in situ observations conducted by Mars orbiters1 appear to be at least an order of magnitude lower than the observed oxygen escape rates. This would imply that majority of the oxygen escape from Mars that took place over the last epochs has been from water rather than from CO2 – in contradiction with geological evidence and atmospheric models that would require significantly higher carbon escape at higher solar inputs in its past2.

It has been widely regarded that photochemistry is the major source of hot escaping carbon in the present-day Martian atmosphere. Recently, photodissociation of CO2 by solar UV photons was identified as its leading contribution1,3. Theoretical models suggest that, regardless of the exact process, hot carbon atoms are predominantly produced at the altitudes near the exobase1, at about 200 km above the planet’s surface, and have to traverse through the exosphere without losing their kinetic energy in collisions in order to successfully escape. Thus, due to the abundance of atmospheric CO2, one of the key parameters that determine the C escape rate are the C-CO2 scattering cross sections. These cross sections are not well known at the energy range of interest.

In this work, we constructed from first principles quantum-mechanical velocity-dependent elastic, inelastic, and corresponding differential and momentum-transfer cross sections for C(3P)-CO2 scattering for collision energies up to 5 eV and estimated the impact on the C escape rate at Mars using simple column escape models.

 

1Lo et al., Carbon photochemical escape rates from the modern Mars atmosphere. Icarus 360, 114371 (2021)

2Jakosky et al., Loss of the Martian atmosphere to space: Present-day loss rates determined from MAVEN observations and integrated loss through time. Icarus 315, 146 (2018)

3Lu et al., Evidence for direct molecular oxygen production in CO2 photodissociation. Science 346, 61 (2014)
Analysis of VLF and LF signal fluctuations recorded by Graz facility prior to earthquakes occurrences
Authors: Boudjada Mohammed  Y. , Biagi Pier Francesco , Eichelberger Hans Ulrich , Galopeau Patrick H.M. , Schwingenschuh Konrad , Solovieva Maria , Lammer Helmut , Voller Wolfgang , Hayakawa Masashi
Published: March 2022

We report in our study on earthquakes that occurred in Croatia and Slovenia in the period from 1 Jan. 2020 to 31 Dec. 2021. Those seismic events happened in a localized region confined between 13.46°E and 17.46°E in longitude and 45.03°N and 49.03°N in latitude. Maximum magnitudes Mw6.4 and Mw5.4 occurred, respectively, on 29 Dec. 2020, at 11:19 UT, and 22 March 2020, at 05:24 UT. We use two-radio system, INFREP (Biagi et al., 2019) and UltraMSK (Schwingenschuh et al., 2011) to investigate the reception conditions of LF-VLF transmitter signals. The selected earthquakes occurred at distances less than 300km from the Graz station (47.03°N, 15.46°E) in Austria. First, we emphasize on the time evolutions of earthquakes that occurred along a same meridian, i.e. at a geographical longitude of 16°E. Second, we study the daily VLF-LF transmitter signals that exhibit a minimum around local sunrises and sunsets. This daily variations are specifically considered two/three weeks before the occurrence of the two intense events with magnitudes Mw6.4 and Mw5.4. We discuss the unusual terminator time motions of VLF-LF signals linked to earthquakes occurrences, and their appearances at sunrise- or sunset-times. Such observational features are interpreted as disturbances of the transmitter signal propagations in the ionospheric D- and E-layers above the earthquakes preparation zone (Hayakawa, 2015).

 

References:

Biagi et al., The INFREP Network: Present Situation and Recent Results, Open J. Earth. Research, 8, 2019.

Hayakawa, Earthquake Prediction with Radio Techniques, John Wiley and Sons, Singapore, 2015.

Schwingenschuh et al., The Graz seismo-electromagnetic VLF facility, Nat. Hazards Earth Syst. Sci., 11, 2011
On the short-scale spatial variability of electron inflows in electron-only magnetic reconnection in the turbulent magnetosheath observed by MMS
Authors: Pyakurel Prayash , Phan Tai , Shay Michael , Stawarz Julia , Øieroset Marit , Cassak Paul , Haggerty Colby , Drake James , Li Tak Chu , Burch James , Ergun Robert , Gershman Daniel , Giles Barbara , Torbert Roy , Strangeway Robert , Russell Christopher
Published: March 2022

In the Earth’s turbulent magnetosheath downstream of the quasiparallel bow shock region, magnetic reconnection without ion coupling was observed with bi-directional super-Alfvénic electron jets. The lack of ion coupling was attributed to the small-scale sizes of the current sheets. In an electron-only reconnection event that occurred on 26 December 2016, we examine the detailed properties of electron inflows observed by all 4 MMS spacecraft. Even though the farthest MMS probe in the outflow direction from the X-line was no more than 8 electron skin depth, the electron inflows have significant asymmetry and highly variable amplitudes. We compare MMS observations with 2D-kinetic PIC simulation and find that the asymmetry in the inflow stems directly from the tilt of the out-of-plane (guide) magnetic field structure in the reconnection plane, with inflow asymmetry enhanced in the downstream region.
What is driving the isotopic composition of surface snow in East Antarctica? - Insights from a multi-year time series of surface snow at Dome C
Authors: Zuhr Alexandra , Landais Amaëlle , Casado Mathieu , Minster Bénédicte , Prié Frederic , Harris-Stuart Romilly , Picard Ghislain , Arnaud Laurent , Dumont Marie , Ollivier Inès , Laepple Thomas
Published: March 2022

The isotopic composition (d18O, dD) of surface snow on an ice sheet is primarily seen as a recorder of the air temperature and is used to reconstruct past climatic conditions from ice cores. The second order parameters d-excess and 17O-excess can preserve climatic signals from the moisture origin and are indicative for kinetic fractionation processes in the water cycle between the source and the deposition site. Fractionation is especially important for the surface snow which can exposed to the atmosphere for a long time during periods without snowfall. The resulting effect of this process on the isotopic composition and the second order parameters in the interior of Antarctica is, however, unclear. In order to better understand the contribution of secondary processes on the isotopic signature and to disentangle the climate characteristics at the moisture source region and at the ice core site, we study both the isotopic composition and the second order parameters of surface and subsurface snow at Dome C on the East Antarctic Plateau. For this, we make use of an extensive data set of isotopic data (d18O, dD, dexcess and 17O-excess) from surface (0 - 1.5 cm) and subsurface snow (1.5 - 4.5 cm) covering continuously the period from 2016 to 2020. This data set is complemented with previously published isotopic data of surface snow and precipitation data back to 2011. For additional comparisons and analyses, we use data from a nearby weather station, the ERA5 reanalysis data set, a satellite-derived grain index estimate and simulations from the detailed snowpack model CROCUS.

We observe a good (weak) correlation between the ambient temperature and the surface (subsurface) layer. Most years are characterised by a strong increase in the isotopic composition towards the summer and a gentle decrease towards winter while d-excess shows a contrary behaviour. We suggest that the strength of the summer increase is related to the amount of precipitation and the magnitude of metamorphism at the surface. The degree of metamorphism can (to some degree) be approximated from observational data (e.g. the grain index) or from model output (e.g. latent heat flux from CROCUS). In addition to presenting possible mechanisms leading to strong or weak increases in the isotopic composition in summer, we developed a simple model using temperature and snowfall data from ERA5 to analyse the contribution of temperature and other parameters to the observed isotopic signals.
Assessment of the transport capacity of floating plastics through fluvial systems
Authors: Raquib Ridwan , Przyborowski Lukasz , Valyrakis Manousos
Published: March 2022

Since the early times of plastic production, the relative change increased approximately about 391,050%. It went from a cumulative production of 2 million tons in 1950 to 7.82 billion tons in 2015. Even though there are variable recycling methods at present, not all discarded plastic gets recycled. The vast majority of the waste plastic makes its way to the ocean through specific pathways, with one of the most dominant being transport via fluvial networks. Moreover, a relatively minimal amount of data is available on the transport of riverine plastic. Plastics found in rivers can accumulate, causing flow blockages and potentially affecting flow routing (intensifying flooding and other climate risks). They can also affect water quality and ecology, including biota that may ingest these through the leakage of chemicals. Out of the various types of plastic, buoyant macro plastic is a major polluter, and understanding its flow in rivers can help us reduce plastic pollution in the long run.

This study focuses on getting a better understanding of how floating plastics debris is transported in rivers with aquatic vegetation by undertaking well-controlled lab flume experiments. Specifically, the transport of floating plastic debris in a river system was studied through a series of flume experiments, using instream simulated vegetation. Vegetation patches of different densities were used to assess their effect on the flow field carrying buoyant plastics of variable sizes. The video camera is used to record the transport process of plastic along the flume until they impinge on the simulated vegetation patch. Obtained video files of the flume experiments are analyzed to assess the effect of vegetation density on the transport efficiency of the plastic. Preliminary results focus on using specific transport metrics, particle velocity before contact with the vegetated patch, focusing on the size of plastics being transported. Altered according to various flow conditions and river morphology, the results of this study will help engineers in the future to design and produce more resilient methods of vegetation patches and engineering structures in order to exploit the trapping effects of macro plastics.
Developing semantic interoperability in ecosystem studies: semantic modelling and annotation for FAIR data production
Authors: Pichot Christian , Beudez Nicolas , Callou Cécile , Chanzy André , Clavreul Alyssa , Clastre Philippe , Jaillet Benjamin , Lafolie François , Le Galliard Jean-François , Martin Chloé , Massol Florent , Maurice Damien , Moitrier Nicolas , Monet Ghislaine , Raynal Hélène , Schellenberger Antoine , Yahiaoui Rachid
Published: March 2022

The study of ecosystem characteristics and functioning requires multidisciplinary approaches and mobilises multiple research teams. Data are collected or computed in large quantity but are most often poorly standardised and therefore heterogeneous. In this context the development of semantic interoperability is a major challenge for the sharing and reuse of these data. This objective is implemented within the framework of the AnaEE (Analysis and Experimentation on Ecosystems) Research Infrastructure dedicated to experimentation on ecosystems and biodiversity. A distributed Information System (IS) is developed, based on the semantic interoperability of its components using common vocabularies (AnaeeThes thesaurus and OBOE-based ontology extended for disciplinary needs) for modelling observations and their experimental context. The modelling covers the measured variables, the different components of the experimental context, from sensor and plot to network. It consists in the atomic decomposition of the observations, identifying the observed entities, their characteristics and qualification, naming standards and measurement units. This modelling allows the semantic annotation of relational databases and flat files for the production of graph databases. A first pipeline is developed for the automation of the annotation process and the production of the semantic data, annotation that may represent a huge conceptual and practical work without such automation. A second pipeline is devoted to the exploitation of these semantic data through the generation i) of standardized GeoDCAT and ISO metadata records and ii) of data files (NetCDF format) from selected perimeters (experimental sites, years, experimental factors, measured variables...). Carried out on all the data generated by the experimental platforms, this practice will produce semantically interoperable data that meets the linked opendata standards. The work carried out contributes to the development and use of semantic vocabularies within the ecology research community. The genericity of the tools make them usable in different contexts of ontologies and databases.
Crustal and uppermost mantle structure of Cape Verde from ambient noise tomography
Authors: Carvalho Joana , Silveira Graça , Kiselev Sergey , Custódio Susana , Ramalho Ricardo , Stutzmann Eleonore , Schimmel Martin
Published: March 2022

Using seismic data from 38 broadband seismic stations deployed across the volcanic islands of Cape Verde, we construct the first 3D-model of Sv-wave velocities for the uppermost 30 km of the region. We computed phase cross-correlations for vertical component recordings for all possible inter-island stations followed by a time-frequency phase-weighted stack to obtain robust Rayleigh wave group velocity dispersion curves in the period band between 10 s and 24 s. Next, the dispersion curves were inverted, through the Fast Marching Surface Tomography package (FMST), in order to obtain the 2D group velocity-maps. We then inverted the group-velocity maps for the 3D shear-wave velocity structure of the crust and uppermost mantle beneath Cape Verde. As major features we considered the following: 1) low-velocity anomalies beneath and in the vicinities of the islands of Brava and Fogo, which we attribute to the predominance of melting pockets in these islands. Furthermore, the local seismicity also suggests the occurrence of ongoing intrusive processes beneath Fogo and Brava, which translates into a hotter, melt-rich upper crust and uppermost mantle 2) high-velocity anomalies in the northern islands, especially strong in the area surrounding the island of São Nicolau, that can reflect non-altered crust or remnants of magma chambers or solidified basaltic intrusions, which fed the ancient volcanism in these islands. The observed features are also distributed in three domains, according to the island volcanism age and latest major shield-building stages. If this is more than a coincidence, it can reflect different states of thermal maturity of the crust and uppermost mantle as a result of modification by magmatism and as a function of time. Our study, which allowed to image the crustal and uppermost mantle structure beneath Cape Verde, complements earlier deeper structure studies of the region and may also contribute to the characterization of the local seismicity by providing a new velocity model for structure.
Drivers of the natural CO2 fluxes at global scale as simulated by CMIP6 simulations
Authors: Martin-Gomez Veronica , Ruprich-Robert Yohan , Bernardello Raffaele , Samso Cabre Margarida
Published: March 2022

The implementation of the Paris Agreement should translate into a decrease of the growth rate of atmospheric CO2 in the coming decades due to the reduction in emissions by signing countries. However, the detection of this decrease and its attribution to mitigation measures will be challenging for two reasons: 1) the internal variability of the Earth system may temporarily offset this signal and 2) countries may not maintain their promises. Unless absolute transparency on emissions is adopted by all signing parties, without a robust estimate of the impact of internal variability on the atmospheric CO2 changes, there is no independent way to verify their claims. 

Historical reconstructions and future predictions of global carbon cycle dynamics with predictive systems based on state-of-the-art Earth System Models (ESMs) represent an emerging field of research. With the continuous improvement of ESMs and of these predictive systems, these tools might have the potential of becoming skillful enough in their predictions to represent a useful instrument for policy makers in their effort to monitor and verify the progress of the Paris Agreement’s implementation. 

Here we analyze the main sources of the atmospheric CO2 concentration variability at inter-annual timescale due to internal climate processes in three ESMs, which are used in carbon cycle prediction systems: EC-Earth3-CC, IPSL-CM6A-LR, and MPI-ESM1-2-LR. These results are then compared to the available CMIP6 simulations database.

Investigating the surface CO2 fluxes, we find that land flux inter-annual variations are 10 times higher than ocean flux variations. This has direct consequences in terms of predictability since the land surface processes are generally less predictable than the ocean ones. The regions contributing the most to the variations are Australia, South America and sub-Saharan Africa, suggesting that those are the most important regions to simulate correctly in order to constrain the atmospheric CO2 variations. Interestingly, all those regions are linked to tropical SST variations resembling El Niño Southern Oscillation variability.

Investigating the ocean CO2 fluxes, we find that the regions contributing the most to the global CO2 variations are the Southern Ocean followed by the tropical Pacific.

Therefore, from the analysis of the CMIP6 simulations, we conclude that the main internal driver of the global atmospheric CO2 fluctuations is the tropical Pacific. If the ratio between land and ocean CO2 variations is realistically simulated by the CMIP6 ESMs, this implies that the predictability of the atmospheric CO2 variations due to internal climate processes is tied to the predictability of the tropical Pacific.
Redox Transitions as Microbial Hotspots of Manganese-Mediated Organic MatterDegradation
Authors: Chin Nathan , Liu Xiaojun , Domeignoz-Horta Luiz , DeAngelis Kristen , Keiluweit Marco
Published: March 2022

Oxic-anoxic interfaces serve as hotspots of organic matter decomposition, regulating soil and sediment carbon storage and nutrient cycling. Oxic-anoxic interfaces present along redox gradients, which are ubiquitous in soil and sediment environments, also serve as hotspots of reactive Mn(III) formation and Mn(III)-mediated organic matter degradation. Reactive manganese represents an important control on organic matter degradation in soil and sediment environments, impacting both greenhouse gas emissions and carbon storage. Mn(III) formation at redox interfaces depend not just on soil redox conditions, but also on microbially-mediated Mn redox cycling across the redox gradient. However, the extent to which microbially-mediated Mn(III) formation and subsequently Mn(III)-driven organic matter oxidation depends on Mn availability remains largely unknown. In this study, we quantified how variations in Mn bioavailability affects the microbial pathway and rates of Mn(III)-driven organic matter degradation across redox interfaces. To achieve this, we established redox gradients within forest soils using diffusion reactors and varied Mn availability in the anoxic zone, thereby controlling Mn(II) mobilization to the oxic-anoxic interface. We quantified changes in microbial activity and function in relation to Mn(III) formation and organic matter degradation across the redox gradient over a 12-week incubation period. Metatranscriptomics revealed Mn(II)-oxidizing enzymes responded strongly to Mn bioavailability at the redox interface, while qPCR showed that shifts in microbial community composition coincided with Mn(III) formation. Wet-chemical extractions combined with Mn XANES indicated that Mn(III) formation at the redox interface peaked after 4 weeks of incubation and was most pronounced with increasing M availability. Bioassays, combined with soil respiration measurements and carbon NEXAFS indicated organic matter degradation increased with increasing Mn availability, coinciding with the formation of Mn(III) at redox interfaces. Combined, our results show that redox gradients and oxic-anoxic interfaces serve as hotspots for Mn(III) formation and subsequent organic matter degradation and are driven by enhanced Mn availability. Our work highlights the critical role of Mn redox cycling within microbial hotspots may have in regulating carbon dynamics in terrestrial environments. 
The role of stable and traveling reactive waves in mineralization
Authors: Koehn Daniel , Ulrich Kelka , Toussaint Renaud , Mullen Gary , Boyce Adrian
Published: March 2022

Fluid mixing is interpreted as one of the main drivers for the development of hydrothermal mineralization whereby the actual physical processes that lead to mineral precipitation, and thus ore localization, are poorly understood. In this contribution, we will shed light on the mechanisms that are active in a simple fluid-mixing scenario by simulating the infiltration of a metal-rich fluid into a rock saturated with seawater derived pore-fluid and study the developing mineral saturation patterns.

We combine an advection-diffusion code in the microstructural model Elle with the geochemical module iphreeqc to study the distribution of enhanced saturation indices during fluid mixing. In the simulations the hot highly saline metal rich fluid enters the small 5x5m system through two high-permeable faults from below and percolates into the pore space. For the fluid we solve transport of temperature and 12 chemical species, giving us a fluid composition at every node in the model. We then use iphreeqc to calculate the mineral saturation indices for minerals in every node and we use these values as a proxy for reaction localization. In order to better understand the effects of fluid mixing on mineralization we specifically look at the saturation index of Baryte, which is a mineral in the investigated system that only precipitates when elements of both fluids are present. Our simulations show that the saturation index of Baryte is at a maximum in a fluid comprising 90 to 80 percent of pore fluid and 10 to 20 percent of metal rich fluid. During the infiltration into the permeable faults, the metal rich fluid pushes the pore fluid away, and mixing is occurring at the interface between the two fluids and is driven mainly by diffusion. With temperature diffusion being three orders of magnitude faster than matter diffusion, the temperature is negligible for the mixing, which is only driven by matter diffusion at the model scale.

We will show that two types of reactive waves with high saturation indices of Baryte develop in the system: travelling and stable waves. Traveling waves progress during advection through the permeable faults and layers and are potentially too fast for minerals to precipitate. Therefore, these areas probably remain permeable in a natural system during advection dominated transport. In contrast, areas with low fluid velocities, and hence low advection, are diffusion dominated with reaction waves that are stable over a long time. These areas are prone for mineral reactions, because there is enough time for the reactions to take place. Stable reactive waves and thus areas of mineralization are fault walls, areas below seals, and areas between two faults where fluid velocities are diverging. We discuss the implications of our results in light of hydrothermal mineral systems.
Assessing four approximation methods to solve the Boltzmann integral for estimating the transfer of energy due to non-linear interactions in WAVEWATCH III wave model.
Authors: Fernandez Leandro , Ponce de Leon Sonia , Dias Frédéric
Published: March 2022

The analytic solution of the Boltzmann equation becomes rather difficult in most physically relevant situations due to its mathematical characteristics and it represents a challenge for scientific computing. In this regard, it is well known that some methods yield better results at the expense of longer computational time. Then, the present work, introduces a comparison between the Webb-Resio-Tracy method, the Discrete Interaction approximation, the Multiple Discrete Interaction and the Two-Scale Approximation sources to solve the Boltzmann integral for estimating the transfer of energy due to non-linear interactions implemented in WAVEWATCH III, with the ST4 parametrization.  The assessed period is during the EWANS storm, in March of 2017, on the Ireland coast. The bias, the root-mean-square, the correlation coefficient and the scatter index are used to compare the form of the different spectra obtained from in-situ measurements and numerical simulations. Previous results show that the quality of the resulting spectra does not represent significant differences when a shorter computational times method is used for simulations in the WAVEWATCH III model. 
Ice shelf stability and glacial history in coastal Dronning Maud Land, East Antarctica
Authors: Eisermann Hannes , Eagles Graeme , Ruppel Antonia , Jokat Wilfried
Published: March 2022

Topographic data sets in and around Antarctica have covered increasingly more ground over recent years and decades. While shipborne hydroacoustic data deliver seafloor information at and beyond the ice shelves’ calving fronts, ice penetrating radar data provide bedrock information beneath grounded ice sheets. The seafloor beneath the interjacent ice shelves, however, is largely unexplored and its unveiling by seismic reflection data is linked with tremendous logistical efforts. A lack of knowledge regarding topographic boundary conditions in these crucial coastal regions has not only hindered proper assessments of water mass and heat exchange between the open ocean and ice shelf cavities, but also an interpretation of glaciodynamic and geomorphological processes in their entirety.

We have modelled the subglacial bathymetry for the majority of ice shelves at the coast of Dronning Maud Land in East Antarctica from 10º W to 35º E by inverting topographic signals in airborne gravity data and tying them to existing acoustic and radar soundings. Our models cover the Ekström, Atka, Jelbart, Fimbul, Vigrid, Nivl, Borchgrevink, and Roi Baudouin ice shelves. Recurring bathymetric patterns beneath the ice shelves are linked back to their shared regional setting. Deep troughs that mimic present-day ice flow are confined landward by grounding lines and seaward by shallow bathymetric sills at or close to the continental shelf break. These sills and further minor ridges crossing the troughs and continental shelves run perpendicular to current ice flow and were likely formed at paleo-grounding lines over previous glacial cycles.

The shallow bathymetric sills along the shelf breaks are crossed by narrow gateways. Although deeper than the sill crests, the floors of these gateways mostly still lie above or at the average depth of the Warm Deep Water thermocline off coastal Dronning Maud Land. Hence, warm and deep water intrusion into the ice shelf cavities of Dronning Maud Land is currently likely to be limited and sporadic. The depths of the gateways are, however, critical for an understanding of future risk to ice shelf stability in Dronning Maud Land in response to thermocline shallowing during oceanographic change.
Climatological study of frontal precipitation over the Mediterranean
Authors: Bitsa Evangelia , Flocas Helena A. , Hatzaki Maria , Kouroutzoglou John , Rudeva Irina , Simmonds Ian
Published: March 2022

It is well known that severe weather and heavy precipitation are closely connected to the presence or passage of cold fronts over a region. In this study, the MedFTS_DT scheme, developed recently for the identification of cold fronts, is used to perform an objective climatological analysis of cold frontal activity and precipitation in the Mediterranean region. The MedFTS_DT algorithm has been developed for the automated and objective identification of cold fronts and optimized for the Mediterranean. It is based on a combination of wind-shift and thermal criteria. Wind-shift is applied in 6-hour intervals for the identification of cold fronts, whereas the thermal criteria are used to properly filter out any erroneous frontal identifications.

In this work, the spatial distribution and frequency of cold fronts are calculated over the Mediterranean for the period 2007–2016 on a monthly, seasonal and annual basis. The spatial distribution of the total precipitation (TP) and the frontal-induced precipitation (FP) are also calculated for the same region and temporal scales in order to determine the contribution of cold fronts to the total precipitation (FP/TP) It is observed that, in general, the local maxima of FP agree well with the corresponding maxima of frontal activity. It also becomes evident that, contrary to the TP regime, the maxima of FP are not found over the main mountain ranges of the Mediterranean regions, suggesting that orography does not play an important role in the formation of FP.
Findability of laboratory data in the solid Earth sciences: a portal for cross-disciplinary metadata
Authors: Samshuijzen Laurens , Lange Otto , Pijnenburg Ronald , Elger Kirsten , Wessels Richard , ter Maat Geertje , Frenzel Simone , Drury Martyn
Published: March 2022

The Thematic Core Service Multi-scale Laboratories (TCS MSL) is a community within the European Plate Observing System (EPOS) that includes a wide range of world-class laboratory infrastructures and that provides a cross-disciplinary, though coherent platform for virtual access to data and physical access to solid Earth science labs. The data produced at the participating laboratories are crucial to serving society’s need for geo-resources exploration and for protection against geo-hazards. To model resource formation and system behaviour during exploitation, researchers need an understanding from the molecular to the continental scale, based on experimental and analytical data.

Data coming from the MSL laboratories provide the backbone for scientific publications, but they are often available only as supplementary information to research articles. Moreover, the vast majority of  the collected data remain unpublished, inaccessible, and often not sustainably preserved for the long term. To allow reuse of these valuable but often neglected data, the TCS MSL developed a full publication chain to support their FAIR dissemination and sustainable accessibility. This chain consists of a community-driven metadata standard that allows multiple discipline-specific detailed descriptions, a publication tool (metadata editor), and an online community portal that gives access to DOI-referenced data publications at multiple research data repositories related to the TCS MSL context (https://epos-msl.uu.nl/). The portal is built on the CKAN repository toolkit and is driven by the richness of the TCS MSL metadata standard. Besides its importance for the TCS MSL community, it also provides a showcase of how to set up the CKAN environment as a cross-disciplinary catalogue for FAIR metadata exchange through a cascade of infrastructures.
The combined effect of electron and proton firehose instabilities for the solar wind plasma conditions
Authors: López Rodrigo A. , Micera Alfredo , Lazar Marian , Shaaban Shaaban M. , Poedts Stefaan , Lapenta Giovanni
Published: March 2022

In the absence of collision, kinetic instabilities triggered by velocity space anisotropies of plasma particles play an essential role in limiting the deviations from isotropy. For example, in the solar wind, firehose instabilities may inhibit the growth of the temperatures in the direction parallel to the background magnetic field, counterbalancing the effect of the expansion. Electron and proton firehose instabilities can be triggered depending on the plasma parameters and the different branches within (periodic and aperiodic). Despite the significant difference between electron and proton spatial and temporal scales, both modes can work together to alter the dynamic of the plasma.
We use a fully kinetic 2D semi-implicit particle-in-cell simulation, iPic3D, to study the evolution and interplay of firehose instabilities triggered by electrons and protons when both species are anisotropic. The aperiodic electron firehose instability remains largely unaffected by the proton anisotropy and saturates rapidly at low-level fluctuations. On the other hand, the presence of anisotropic electrons has a considerable impact on the proton firehose modes, especially on the aperiodic branch, shifting the onset of the instability and boosting the saturation levels of the fluctuations. Anisotropic electrons contribute to more effective regulation of the proton anisotropy.
On the seasonal prediction and predictability of winter temperature swings over North America
Authors: Yang Xiaosong , delworth Tom , Jia Liwei , Johnson Nathaniel , Lu Feiyu , MacHugh Colleen
Published: March 2022

A novel temperature swing index (TSI) is formed to measure the extreme surface temperature variations associated with the winter extratropical storms. The seasonal prediction skill of the winter TSI over North America was assessed versus ERA5 data using GFDL’s new SPEAR seasonal prediction system. The location with the skillful TSI prediction shows distinctive geographic pattern from that with skillful seasonal mean temperature prediction, thus the skillful prediction of TSI provides additive predictable climate information beyond the traditional seasonal mean temperature prediction. The source of the seasonal TSI prediction can be attributed to year-to-year variations of ENSO, North Pacific Oscillation and NAO. These results point towards providing skillful prediction of higher-order statistical information related to winter temperature extremes, thus enriching the seasonal forecast products for the research community and decision makers beyond the seasonal mean.
Monitoring mining-induced ground deformation in Karagandy mining basin using InSAR
Authors: Meldebekova Gauhar , Yu Chen , Mills Jon , Li Zhenhong
Published: March 2022

Strata deformation associated with underground longwall coal mining can induce large magnitudes of ground surface subsidence. The Karagandy basin, one of the largest coal mining regions in Kazakhstan, is located in close proximity to urban areas and critical infrastructure, necessitating detailed investigation into the spatial distribution and temporal dynamics of subsidence. Synthetic aperture radar interferometry (InSAR) is recognised as a powerful tool to detect, map and quantify ground deformation. In this research, C-band Sentinel-1 products were used to implement interferometric and time-series analysis using the Small BAseline Subset (SBAS) algorithm. Subsidence bowls were detected over eight mining sites. The maximum annual velocity along line-of-sight, some ‑82 mm/year,  was detected at the Kostenko mine, whilst cumulative subsidence reached a maximum of 350 mm in five years.  Wavelet transform analysis was used to inspect the non-linear nature of the signal and confirmed the annual periodicity of ground deformation. Spatio-temporal analysis of subsidence patterns revealed the different drivers of deformation, with sites clustered accordingly. Results from the research offer considerable insight for facilitating decision-making in forward sustainable mining operations, both in Kazakhstan and further afield.
Public Drinking Water Access in Texas (United States) Communities During The Winter Storm 2021
Authors: Tomko Brianna , Sawyer Audrey H. , Sánchez-Vila Xavier , Nittrouer Christine
Published: March 2022

The Winter Storm of February 2021 left millions of Americans in Gulf Coast states without access to reliable, clean domestic water during the COVID19 pandemic. In the state of Texas, over 17 million people served by public drinking water systems were placed under boil water advisories for periods ranging from one day to more than one month. We combine public boil water advisory data with demographic information from the 2010 United States Census to understand the affected populations. Additionally, we are conducting a survey of over 350 households in Texas to portray the impact of demographics and family considerations on Texans personal experiences with water access during the Winter Storm of 2021. Statistical analysis shows that the duration of boil water advisories depended partly on the size of the public water system. Large, predominantly urban systems (serving more than 10,000 individuals) tended to issue shorter advisories (median of 6 days and a maximum of 12 days). Smaller systems (serving less than 10,000 individuals) experienced a wide range of advisory lengths with a median of 8 days and a maximum of 36 days. Principal component analysis shows two main dimensions of variability among public water systems based on weather and demographics. Some of the longest boil water advisories exhibit clustering consistent with smaller, more rural systems (which also tend to serve predominantly white communities). Though these communities' benefit from public water service, the systems that serve them may have fewer resources to address problems that arise in extreme weather events. Small, rural or ex-urban communities with a greater portion of non-white residents have historically been excluded from public water service in the US (a problem known as underbounding). Some of these communities lack access to clean drinking water year-round and are more likely to experience more significant barriers to access in extreme weather events such as the Winter Storm of 2021. More studies are needed to understand and address disparities in clean water access throughout the US.  
Using public cloud computing infrastructure for rapid simulations of large-scale global reservoirs
Authors: Hazenberg Pieter , Weerts Albrecht , van Osnabrugge Bart , Miltenburg Ivo , van Verseveld Willem
Published: March 2022

Water reservoirs play an important role in relation to water security, flood risk, agriculture production, hydropower, hydropower potential, and environmental flows. However, long-term daily information on reservoir volume, inflow and outflow dynamics are not publicly available. To enable deriving long-term reservoir dynamics for many reservoirs across the globe using a distributed hydrological model, large amounts of computer power are needed. Therefore, these types of simulations are generally performed on super computers. Nowadays, public cloud computing infrastructure offers interesting alternative and allows one to quickly access hundreds to thousands of computer nodes.

The current work presents an example of making use of the public cloud offers by simulating the dynamics of 3236 headwater reservoirs on a Kubernetes Cluster on Microsoft Azure. Within the cloud, distributed model forcing and hydrological parameters at a 1-km grid resolution were derived using HydroMT, which subsequently were used by wflow_sbm to perform long-term hydrological simulation over the period 1970-2020. To enable operation in the cloud, usage is made of the Argo workflow engine, that is effective able to schedule the sequential execution of the HydroMT and wflow_sbm containers. Using this setup, all model simulation results were obtained in less than a week. We will present the executed modeling setup within the public cloud as well as present some of the results derived in this manner by comparing observations with in situ and satellite observations.