bluuebunny/crossref_metadata_2025 huggingface dataset:
Strain relaxation around stressed quartz inclusions in garnet
Authors: van Schrojenstein Lantman Hugo , Wallis David , Bonazzi Mattia , Thomas Jay , Hamers Maartje , Drury Martyn , Alvaro Matteo
Published: March 2022

The measurement of residual stresses in exhumed rocks yields valuable information about metamorphic temperature and pressure, deformation and rheology, and stress state. However, the state of elastic strain and stress at the surface of a sample does not necessarily correspond to the state well below the surface. When a sample under elastic strain is cut, polished, or otherwise prepared for analysis, a part of the constraining rock is removed, allowing for the partial relaxation of the elastic strain. To be able to work with residual elastic strain and stress with analytical methods that probe the upper few microns of a sample, the process of strain relaxation must be well understood.

For this work we used high-angular resolution EBSD to analyse stressed quartz inclusions in natural garnet from a range of settings, and in several samples grown in piston-cylinder experiments that were previously analysed with Raman spectroscopy for inclusion pressures. The experimental samples are not expected to have undergone plastic deformation in the garnet during cooling, as the majority of the pressure within the inclusion built up during decompression at room temperature. Additionally, the inclusion pressures in buried inclusions matches what is expected for the experimental conditions, suggesting no plastic yielding. Thus, in these samples we can isolate elastic strain from potential plastic deformation. One of the experimental samples was analysed with TEM to test this expectation.

Forescatter images reveal topographical effects resembling quartz and adjacent garnet “extruding” out of the sample. Furthermore, rotations of the quartz lattice and the garnet lattice immediately around the quartz inclusion are observed. The rotation axis of the misorientation generally lies in the plane of the sample surface. TEM analysis revealed a number of dislocations in experimental garnet where these were not expected. However, a significant degree of bending of a wedge of garnet between the original sample surface and a quartz inclusion is also observed.

The dislocations observed with TEM do not fit with the model of the experiments. Also, the formation of dislocations before sample preparation does not explain the dependence of the rotation axis on the surface orientation. A likely scenario for the deformation measured with EBSD is that the partial relaxation of elastic strains in stressed quartz inclusions in garnet as result of sample preparation induced local distortion of the inclusion and host. Additionally, the persistence of topographical features related to this relaxation despite several steps of polishing suggests that relaxation is not instantaneous but occurs over time.
Is snow more distructive agent than rain from the perspetive of land degradation?
Authors: Antic Nevena , Stefanovic Milica , Mijatovic Nevenka , Tosti Tomislav , Xie Chunxia , Kašanin-Grubin Milica
Published: March 2022

Badlands, between researcher also known as natural field laboratories, present areas formed in a wide range of lithologies and different climate conditions. Complex mineralogical and physico-chemical sediment composition make them suitable for numerous laboratory experiments that can replicate changes that occur in the field.

As climate is one of the most significant factors in badlands forming and since climate changes are one of the biggest environmental concerns nowadays in this research badlands material was exposed to different conditions with the aim to monitor changes caused by extreme climate.

Three samples of badlands from China were organized in twelve sets and treated with rain, acid rain, ice (presenting snow) and acid ice (frozen acid rain). Six sets were treated with rain and acid rain of different intensity and under high and low temperatures during fifteen cycles, while the other six were treated with ice and acid ice during fifteen cycles, dried at 50°C for three cycles and then treated with ice and acid ice for additional five cycles. All of the samples were photographed after each cycle to follow physical change occurring on the sample surface Leachate was collected and volume, electrical conductivity, pH and ion concentration were measured.

Generally parameters did not oscillate much neither between samples, nor between treatments except electrical conductivity that was higher in the samples treated with ice and acid ice. Physical changes that occurred during the experiment present the main difference. In all of the samples high temperature caused the most noticeable decay, in samples treated with rain, sediment decay was minimal, while in samples treated with ice a noticeable decay occurred.

This experiment confirmed that high temperature/drought has great impact on land degradation, but interestingly pointed out that ice/snow and its thawing have greater impact on degradation then rain and its intensity. These kind of result opens up a new perspective on climate impact on forming and badlands evolution that should be further examined.
Soil pipe collapses in Europe: towards a continent-wide assessment
Authors: Bernatek-Jakiel Anita , Vanmaercke Matthias , Poesen Jean , Biernacka Anna , Derii Anastasiia , Hałys Joanna , Nadal-Romero Estela , Panagos Panos , Piątek Dawid , Regensburg Taco H. , Rodzik Jan , Stolarczyk Mateusz , Verachtert Els , Wacławczyk Patryk , Zgłobicki Wojciech
Published: March 2022

Piping erosion leads to land degradation and causes several environmental and societal problems, although this process is rarely considered in soil erosion studies. So far, there are no systematic studies at regional to global scales aiming to understand the patterns and controlling factors of soil piping. This is mainly due to the methodological challenges related to detecting soil pipes. With this project, we aim to address this gap by identifying piping-affected areas in Europe. For this, we are constructing a database on surface evidences of soil piping, i.e. pipe roof collapses (PCs) for the European Union and the UK. Locations and other details of PCs in this database are collected based on an in-depth literature review in combination with detailed mapping based on Google Earth imagery, ortophotos and LiDAR data (if available). While the work is still ongoing, we have already compiled information on >2000 PCs in 10 different countries. In a next phase, we will use this PC database to construct the very first data-driven piping erosion susceptibility map of Europe.

This research is part of the Twinning project “Building excellence in research of human-environmental systems with geospatial and Earth observation technologies” that has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No 952327.
A Geochemical perspective on A-type granites of Nilgiri area, Southeastern Singhbhum Craton, Odisha India: Implication for petrogenesis
Authors: Sahoo Manoj Kumar , Dey Sukanta
Published: March 2022

Singhbhum Craton is one of the oldest cratonic nuclei of Indian shield that represents a complex evolutionary history that includes granite emplacement at different episodes, episodic sedimentation and polyphase magmatism. A wide variety of granitoids are exposed in the south-eastern part of Singhbhum Craton, in and around the Nilgiri area, Odisha, India. However, their petrogenesis is poorly understood due to the lack of high precision geochemical, geochronological and isotope data.

Nilgiri granite are characterised by their ferron nature and high K2O concentration along with high TiO2/MgO and 1000*Ga/Al ratio. Nilgiri granite also show enriched HFSE and total REE and marked depletion in Ni, Cr, V and MgO. Nilgiri granite samples fall within the “within plate granite” field in the Nb Vs Y tectonic discrimination diagram. In the 1000*Ga/Al vs Zr bivariate diagram these granite plot as A type granite. Thus from the salient geochemical characteristics and discrimination diagrams the Nilgiri granite suite appear as A-type granite. In the Y-Nb-Ce ternary space these granites are classified as the A2 type suggesting the probable origin through partial melting of the prexisting  continental crust in an extensional rifting system.

 Well fractionated LREE/REE, flat HREE along with strongly negative anomaly in Eu indicate a shallow depth of source rock melting for the formation of these granitoids. The depletion in (HFSE) Nb, Ta and Ti in the primitive mantle normalized multi-element variation diagrams is probably inherited from the source rocks. The negative anomaly in Sr is in agreement with the negative Eu-anomaly and corresponds to its low pressure origin.
Privacy in space
Authors: Mackay Murray
Published: March 2022

Author: M.Mackay

Co – authors : S. Gervasoni, E. Kaiser, A.M. Kolodziejczyk, A. Miccoli, S. Pukinskis, P. Rudzinski,  in collaboration with the Analog Astronaut Training Center, Poland

Astronaut missions require crew members, who come from various educational and social backgrounds, to co-exist and work with one another for a prolonged period of time in an extremely confined and isolated environment. Additionally, whilst working within the space environment, astronauts are subjected to continuous monitoring of their daily living activities and previous research suggests that decreased access to privacy can induce increased levels of psychological and physiological stress, thus producing risk factors which may hinder cohesion within the crew. For this reason, the present study evaluates how the implementation of a privacy shelter within the sleeping environment during an Analog Astronaut Mission may affect the sleep quality, physiological and psychological stress parameters of crew members during their period of isolation. The aim of this study is to gain a better insight into how potential mitigators to stress, such as privacy shelters within the bedroom module, may be introduced to further facilitate effective crew dynamics, and improve the overall likelihood of a space mission’s success. Materials and Methods: 4 male and 2 female Analog Astronauts underwent mental state and cognitive function testing, sleep cycle recordings and physiological parameter analysis before, during and after sleeping within the shared bedroom module without a privacy shelter for the first three nights of their mission. Following this, 2 control subjects then continued the rest of their mission sleeping within the previous conditions and the 4 other test subjects were provided with a privacy shelter. Test parameters, along with crew mission reports were then analysed to assess whether increased access to privacy during their sleeping hours would result in any significant effect on their psychological and physiological well-being as well as overall crew dynamics.
Influence of the ocean initial state on the weather anomalies simulation for 2019/2020 winter in the INMCM5 seasonal hindcasts
Authors: Tarasevich Maria , Vorobyeva Vasilisa , Chernenkov Alexey , Gasanov Mikhail , Bardashov Danila , Volodin Evgeny
Published: March 2022

During the 2019/2020 winter season the extremely high air temperature and precipitation were recorded over northern Eurasia, eastern Asia and eastern North America. Over the UK this winter was stormy and one of the wettest for the entire observational period. Moreover, it was the only winter without stable snow cover in the central East European Plain. The reason of such exceptional weather is the domination of a North Atlantic Oscillation (NAO) positive phase during the whole season.
Since the NAO effect on winter weather is strong, prediction of its phase is a challenge for all national meteorological services. Several of them predicted the positive sign of North Atlantic Oscillation phase for 2019/2020 winter season, but underestimated the magnitude and duration. Forecasts obtained from INM RAS climate model (INMCM5) demonstrated consistent results for the considered season.
In this work we use the INMCM5 to study the sources of the predictability of both the extremely positive NAO phase and the weather fields anomalies in the 2019/2020 winter season. In particular we consider whether the INM RAS climate model simulates the positive Indian Ocean dipole — positive North Atlantic Oscillation phase teleconnection.
The research was carried out during the student educational program "Computational Technologies, Higher Order Data Analysis and Modelling" at the Sirius University and partially supported by the Russian Science Foundation (project 20‑17‑00190).
Lower Danube Floodplain: Middle to Late Holocene sedimentation rates and organic matter sink (processes and patterns)
Authors: Laureţiu-Florin Ţuţuianu , Alfred Vespremeanu-Stroe , Ionel Stan , Mihaela Dobre , Luminita Preoteasa , Tiberiu Sava , Cristian Panaiotu
Published: March 2022

The stratigraphy of the lower reaches and floodplains store both mineral sediments and organic matter which are very important for understanding the environmental evolution and organic carbon storage over time. By deciphering the sedimentation patterns of floodplains is important for understanding how they adapt to Holocene sea level and climate changes.

The present study is based on 10 cores from the Lower Danube floodplain between Braila and Tulcea, 50 14C ages and over 1000 samples which were sedimentologically and geochemically analyzed. These data allowed us to reconstruct sedimentation and environmental evolution patterns of the floodplain during the Middle and Late Holocene. Two major phases have been desciphered: I) between 8000 and 5500 years BP - a floodplain with a dynamic (rapid-changing) landscape characterized by interchangeable wet and dry areas), developed in a period with a decelerated sea level rise. In that time we find a decrease in the sedimentation rate (from 6.7 to 1.2 mm / year) and the grain mean-size (from ~ 4.75phi to ~ 6.5phi) and an increase of the organic matter content by about four times (from 2.5 to 10%) and II) between 5500 BP and the middle of the 20th century - a relatively-stable and wet floodplain (with large lakes and wetlands) which was partially silted by small channels). This latter phase was developed in a time with a quasi-stable sea level and it can be subdivided into two sub-phases: IIa) (5,500 - 2,200 BP) and IIb (2,200 - XX century). In the first, the sedimentation rate decreases slightly (up to 0.7 mm / year) while the organic matter content becomes almost double (~ 19%, 2200 years ago) and in the second, once with the rise of the Roman Empire, the sediments become finer with a much lower content of organic matter (~ 12%) and the sedimentation rate become doubles (~1.7 mm / year in the last millennium), all due to increased anthropogenic influence in the Danube river basin.
Dŵr Uisce Climate Action Hackathon – A cool connection
Authors: Bellini Roberta , Bello-Dambatta Aisha , Coughlan Paul , Mc Nabola Aonghus , Dreyer-Gibney Katrin , Murali Madhu
Published: March 2022

Climate literacy and awareness have greatly deepened over the past few years but how strongly they shape our values and therefore inform our decisions is still a weak link. Inaction today will result in an even heavier burden on today’s youth. How does it feel to be 15 years old in 2021?

As a team of researchers involved in a water-energy nexus project, we felt a compelling responsibility to work with young people to build their knowledge, awareness and skills to tackle climate change through water efficiency. We therefore decided to reach out to young people aged 15-17 to explore the climate action potential of saving water resources in a way that is meaningful and relevant to their circumstances. Looking beyond lecture-style activities but rather focusing on a dialogue that could support their efforts to tackle the climate crisis, we considered the following questions: How can we make our research agenda informative and relevant to young people? What kind of engagement activity can foster youth-centred learning, skills development and innovation processes to take climate action within the water-energy nexus?

A recent global trend of organising hackathons to find solutions to societal issues offered the perfect answer to our needs. In our submission we describe how the rationale behind the choice of a hackathon-style event was informed by pedagogy, social science and management theory. We illustrate the details of the 2-day Climate Action Hackathon we planned, organised and facilitated to a group of 15-17 years old students, members of Irish NGO ECO-UNESCO. Then, we present the outcomes of the hackathon and how we assessed the impacts. To conclude, we describe how the lessons learnt have been incorporated into three further future engagement projects at larger scale in Ireland, Wales and at European Union level.
Restoring the liver of the river: Instream wood as a nature-based solution to nutrient pollution in agricultural watercourses
Authors: Howard Ben , Baker Ian , Kettridge Nick , Ullah Sami , Krause Stefan
Published: March 2022

The hyporheic zone, the regions in the river sediment where surface water and groundwater interact, acts as the liver of the river that often can attenuate nutrients and other pollutants from mixing groundwater and river water. Nutrients can be retained and transformed by sediments to environmentally benign products (e.g. N2) by microbially mediated reactions. However, in most watercourses the capacity for this filtering function has been reduced by centuries of mismanagement such as channel straightening and the removal of instream wood and riparian buffers. The addition of instream wood, directly in restoration or indirectly by rewooding riparian zones, could restore the functioning of hyporheic zones and provide nature-based solutions to persistent water quality challenges.

Nutrient transformation in the river corridor is limited by two primary mechanisms which could be abated by wood introductions. Firstly, reaction kinetics, including the availability and quality of organic matter. Here, the decomposition of wood could provide a local and sustained source of labile organic matter. Secondly, transport, namely the total flux of water into the hyporheic zone and its residence time therein. Instream wood causes an obstacle for river flow which can induce hyporheic exchange of suitable properties to allow favourable nutrient transformations.

Here we present the results of two linked experiments which have been designed to investigate the effect of wood introductions at different scales: the microbial, restoration feature and reach scales. An incubation experiment focuses on the microbial scale, which allowed us to demonstrate that additions of wood to river sediments increases concentrations of dissolved organic carbon, leading to increased rates of nutrient transformation and increased microbial metabolic activity and production of greenhouse gases. The restoration feature and reach scale impacts are investigated using a before-after-control-intervention field experiment – including a series of smart tracer injections to estimate (metabolically active) transient storage. Preliminary results from this study suggest that wood introductions in river restoration increased reach-scale residence time and ecosystem metabolism, which are good indicators for reach scale nutrient turnover. 

Our results could provide evidence that supports the use of wood in river restoration and of nature-based solutions to water quality challenges.
Impact of a new sediment parameterization method in VFSMOD on PECsw/sed in FOCUS step4
Authors: Reichenberger Stefan , Sur Robin , Sittig Stephan , Multsch Sebastian , Carmona-Cabrero Álvaro , Muñoz-Carpena Rafael
Published: March 2022

The most widely implemented mitigation measure to reduce transfer of pesticides and other pollutants to surface water bodies via surface runoff are vegetative filter strips (VFS). The most commonly used model for assessing the reduction of surface runoff, eroded sediment and pesticide inputs into surface water by VFS is VFSMOD, which simulates reduction of total inflow (∆Q) and reduction of incoming eroded sediment load (∆E) mechanistically. These variables are subsequently used to calculate the reduction of pesticide load by the VFS (∆P). Since errors in ∆Q and ∆E will propagate to ∆P, for strongly sorbing compounds, an accurate prediction of ∆E is crucial for a reliable prediction of ∆P. The most important parameter characterizing the incoming sediment in VFSMOD is the median particle diameter d50, which is currently fixed to 20 µm in the regulatory tool SWAN 5.01. The objective of this study was to derive an improved, generic d50 parameterization methodology that can be readily used for regulatory VFS scenarios.

A test dataset of d50 values and explanatory variables has been compiled from heterogeneous data sources. The established test dataset (n = 93) was analysed using Machine Learning techniques (Random Forest, Gradient Boosting) and multiple regression analysis (MLR). With the help of the knowledge gained with Machine Learning, a MLR equation with six predictor variables was established and thoroughly tested. Since three of the predictors are event-specific (eroded sediment yield, rainfall intensity and peak runoff rate), the predicted d50 values vary between runoff events according to their magnitude and intensity.

A modified version of SWAN-VFSMOD containing the improved d50 parameterization method was run for a number of contrasting compounds and application scenarios. The obtained ∆E and ∆P values as well as the resulting pesticide concentrations in surface water and sediment (PECsw/sed) were compared with the current FOCUS step4 approach.
Prediction of Adverse effects of Geomagnetic storms and Energetic Radiation (PAGER)
Authors: Shprits Yuri Y. ,   Horizon 2020 PAGER team
Published: March 2022

This project aims to provide space weather predictions that will be initiated from observations on the Sun and to predict radiation in space and its effects on satellite infrastructure. Real-time predictions and a historical record of the dynamics of the cold plasma density and ring current allow for evaluation of surface charging, and predictions of the relativistic electron fluxes will allow for the evaluation of deep dielectric charging. The project aims to provide a 1-2 day probabilistic forecast of ring current and radiation belt environments, which will allow satellite operators to respond to predictions that present a significant threat. As a backbone of the project, we use the most advanced codes that currently exist and adapt existing codes to perform ensemble simulations and uncertainty quantifications. This project includes a number of innovative tools including data assimilation and uncertainty quantification, new models of near-Earth electromagnetic wave environment, ensemble predictions of solar wind parameters at L 1, and data-driven forecast of the geomangetic Kp index and plasma density. The developed codes may be used in the future for realistic modelling of extreme space weather events. The PAGER consortium is made up of leading academic and industry experts in space weather research, space physics, empirical data modelling, and space environment effects on spacecraft from Europe and the US.
Mechanistic differences of leaf and ecosystem-scale water use efficiencies on the Qinghai-Tibet Plateau
Authors: Wang Xiang , Chen Guo , Wu Mingquan , Li Xiaozhen , Wu Qi , Wang Peng , Zeng Hui , Yang Rui , Tang Xiaolu
Published: March 2022

Water use efficiency (WUE) is an important indicator of carbon and water cycles in terrestrial ecosystems. However, little is known about differences in water use efficiency at the leaf scale (WUELeaf) and ecosystem-scale (WUEECO) and response to environmental variables, particularly in plateau ecosystems with gradient effects. We obtained leaf carbon isotope data and calculated leaf-scale water use efficiency on the Qinghai-Tibet Plateau through field surveys and literature collection and calculated ecosystem-scale water use efficiency based on remote sensing data (MODIS). The study analyzed the differences between leaf-scale WUE and ecosystem-scale WUE in terms of vegetation type and spatial distribution and explored the response of water use efficiency to changes in environmental factors at both scales. The results found that the two water use efficiency scales showed different vegetation type trends and spatial distribution. At the leaf scale, WUELeaf showed grasses (10.91 mmol/mol) > trees (9.55 mmol/mol) > shrubs (8.34 mmol/mol), and spatially as a whole showed higher in the western high altitudes (Grasses) than in the low eastern altitudes (Trees). In contrast, at the ecosystem scale, WUEEco shows trees (1.17 g C/kg H2O) > shrubs (1.05 g C/kg H2O) > grasses (0.53 g C/kg H2O), while at the spatial scale, the eastern low elevation region (Forests) is greater than the western high elevation region (Grasslands). Climate (MAT) and vegetation (EVI) factors are the most important environmental variables affecting the variation of WUE at leaf and ecosystem scales, respectively, on the Tibetan plateau. The effect of altitude on water use efficiency is not caused by the vegetation type, although the WUE varies among vegetation types. Conversely, the effect of elevation is influenced by the interaction between environmental conditions and vegetation. These results suggest that the appropriate water use efficiency scale should be selected for specific purposes in carbon and water cycle studies. When the focus is on the influence of climate on the carbon-water cycle, leaf-scale water use efficiency is more appropriate, while if the effect of vegetation, ecosystem-scale water use efficiency would be more appropriate.
Formation model of silica sinter deposits: an example from Western Turkey
Authors: Ercan Hatice , Ece Ömer Işık , Schroeder Paul A. , Gülmez Fatma
Published: March 2022

Silica sinter systems occur in regions of magmatic intrusion, where silica-rich alkali chloride fluids rise to the Earth's surface. The Oligo-Miocene Etili silica deposits are one of the most well-known geothermal systems in Turkey, which occur mainly on E-W and NE-SW trending extensional faults with past associated magmatic activity. The mineralogical assemblage of the Etili epithermal system consists of kaolinite, halloysite, alunite +/- jarosite, and quartz. The most common silica polymorph detected in the sinters is -quartz. No other silica polymorphs were observed and proximal apron lithofacies were the only facies preserved in the region. Other lithofacies were not preserved due to erosion and tectonism. The lithofacies observed in the Etili epithermal systems include; silica infiltrates, spring conduits, nodular and finely laminated geyserite, sinter clast breccia, silicified volcanic rocks, and epithermal veins.
Hydrothermal alteration assemblages aged using the 40Ar/39Ar dating method indicate three distinct periods of hydrothermal activities that took place in different vacinities of the Etili Fossil Silica Sinter Region. These include: a) Early stage in the western part of the Etili ( 32.4 ± 1.2 to 22.6 ± 0.22 Ma), b) Intermediate stage in the eastern part of the Etili (12.3 ± 0.3 to 15.2 ± 0.3 Ma ) in the north of the Hamamtepe, and c) Late-stage to the south of the Etili (5± 0.18 to 7 ± 0.3 Ma). These chronological data indicate that the hydrothermal activity in the region started earliest in the west and shifted through to the east and/or south over time.
Keywords: epithermal system; hot spring; silica sinter; 40Ar/39Ar dating; hydrothermal alteration
DeepStor-1 exploration well at KIT Campus North (Upper Rhine Graben, Germany)
Authors: Eva Schill , Bauer Florian , Steiner Ulrich , Frieg Bernd , Kohl Thomas
Published: March 2022

DeepStor-1 is the exploration well to the Helmholtz research infrastructure "DeepStor". DeepStor focuses on the investigation of high-temperature heat storage at the rim of the fromer oil-field „Leopoldshafen“. It is located about 10 km north of the city of Karlsruhe (Germany). The DeepStor-1 well is planned to reach the Pechelbronn group at 1‘460 m, i.e. it includes nearly the entire Oligocene sediments at the site. Seismic investigation reveal a structurally undisturbed section that below 200 m depth covers the Landau, Bruchsal, Niederrödern and Froidefontaine Formations. Cores will be taken from the entire section below 820 m. In addition to coring, the logging program is planned to include besides technical logging, a caliper-, self-potential-, temperature-, dual latero-, natural gamma spectrometry-, neutron-gamma porosity-, sonic-, elemental capture spectroscopy-, as well as image-logs in the sections 215-820 m as well as 820-1460 m. Drilling of DeepStor-1 is planned between 2022 and 2023.
Simultaneous estimation of soil hydraulic properties and surface evaporation using inverse modeling for a large field-lysimeter
Authors: Joshi Deep Chandra , Peters Andre , Iden Sascha C. , Zimmermann Beate , Durner Wolfgang
Published: March 2022

A sound prediction of water and energy fluxes at the soil-atmosphere interface is important for many practical questions regarding e.g. irrigation and salinity management. Precise knowledge of soil hydraulic properties (SHP) is mandatory for such predictions. The SHP can be measured either in the laboratory within a wide moisture range or at the field scale, e.g. by inverse simulation techniques based on in situ matric potential and water content measurements. Depending on the installation depth of the sensors, soil texture, and boundary conditions, field-determined SHP are often limited to a quite narrow range of moisture conditions. Prediction of actual surface fluxes on basis of this limited information is highly uncertain. With well-instrumented large weighable lysimeters, systems are now available that allow to measure very precisely surface (and bottom) water fluxes under natural atmospheric conditions. In particular, they can be used to quantify the difference between potential evaporation, Ep, and observed actual evaporation, Ea. The difference (Ep-Ea) increases during the drying process when the soil hydraulic conductivity becomes limiting for the evaporation process. Thus, our hypothesis was that this information can be used to improve the identification of SHP of soils.

Accordingly, the aim of this study was to see whether the information on (Ep-Ea), measured during a calibration period and supplemented by water content and matric potential data measured inside of a lysimeter, is sufficient to inversely estimate the SHP. Furthermore, we were interested to see if the prediction of Ea was possible and reliable also for time periods beyond the calibration period.  For a proof-of-concept study, we conducted forward simulations with Hydrus-1D where we generated synthetic data of actual surface fluxes and soil hydraulic internal state variables. The atmospheric boundary was given by natural precipitation and potential evaporation rates in a semi-arid climate. The study showed that it was possible to identify SHP by inverse modeling, and prediction of the cumulative actual evaporation after the calibration period was successful. In a second step, the methodology was applied to data of a real large bare-soil field-lysimeter. Our simulation results showed also here a good match between observed and predicted cumulative evaporation.
High Spatiotemporal Resolution Planetary Boundary Layer Dynamics Across the Israeli Coast—Mountain—Valley Terrain Unraveled by WRF Simulations
Authors: Avisar David , Berkovic Sigalit
Published: March 2022

Jerusalem (Jer, Israel) is located on a mountain (~800m above sea-level), between the Eastern Mediterranean coast, to the west, and the Jordan valley (~400m below sea-level), to the east. This coast—mountain—valley (iCMV) complex terrain structure has a relatively smooth contour line. Nevertheless, the corresponding boundary layer dynamics (BLD) has not yet been fully unraveled for the summer season, which is characterized by a persistent synoptic regime. In this work we use the Weather Research and Forecasting (WRF) model, together with ceilometer measurements, to decipher the detailed mesoscale evolution of the iCMV BL during the late summer period of Sep. 5-15, 2017, where the maximal BL depth in Jer vary in the range 500-1500m. We first validate the BL height (BLH) simulated by 4 WRF BL parameterizations. Accordingly, the MAE is around 120m and 180m for the coastal and Jer areas, respectively. An analysis of the modeled daytime iCMV BL evolution shows that the topography, sea-breeze, and the synoptic regime conspire to produce the following pattern: In the morning, the topography and the radiation forcing induce a surface-flow-convergence (SurFCon), above which the BLH is locally elevated. The initial SurFCon position, relative to Jer, depends on the synoptic flow. Afterwards, as the sea-breeze propagates inland, it advects the SurFCon eastward. The locally-elevated BLH collapses in the late afternoons when it reaches the valley. Generally, the weaker, or easterly, the synoptic flow is, the more likely the initial location of the elevated BLH (SurFCon) will be west to Jer, and during noontime it will pass through Jer, which probably experiences a higher daily maximum BLH. On the other hand, during a westerly synoptic flow the SurFCon is located east to Jer at all times. Thus, the city experiences relatively lower daily maximum BLH, in contrast to the coastal plains.  Furthermore, we conclude that the surface synoptic classification cannot serve as a BLH predictor for Jer. This conclusion should be validated for BLD throughout the year.
In situ stress state and earthquake hazard assessment in Dayi seismic gap of the Longmenshan thrust belt
Authors: li bing , Huang Jinshui , Xie Furen
Published: March 2022

The Dayi seismic gap of the Longmenshan thrust belt is located between the ruptures of the 2008 Wenchuan Earthquake and the 2013 Lushan Earthquake, with a length of about 40 ~ 60 km. So far, it has been still a heated debate on whether the Dayi seismic gap has the hazard of strong earthquakes in the near future. The occurrence of a strong earthquake in the seismic gap is closely related to the existence of high stress accumulation and the most direct method is to measure the borehole stress in the field. In order to find out the present stress state, in-situ stress measurements were carried out at the hanging wall and footwall of Dachuan-Shuangshi fault zone in Dachuan Town. The results showed that the hanging wall and footwall of Dachuan-Shuangshi fault zone in Dayi seismic gap are in a high-stress state. Based on seismicity parameter b-value, crustal velocity structure, GPS deformation monitoring data and temperature data, etc., it can be learned that there is a positive correlation coupling relationship between near surface shallow stress and deep stress. In this paper, a response model of shallow stress to deep locking was established. It was speculated that Dayi seismic gap has the potential hazard of strong earthquakes. This research result not only deepens the understanding of the relationship between stress and earthquake preparation, but also provides an effective scientific method for identifying seismic hazards in other active fault seismic gaps.
Quantifying the spatial representativeness of ice core surface mass balance records using ground-penetrating radar data in Antarctica
Authors: Cavitte Marie G. P. , Goosse Hugues , Wauthy Sarah , Medley Brooke , Kausch Thore , Tison Jean-Louis , Van Liefferinge Brice , Lenaerts Jan T.M. , Pattyn Frank
Published: March 2022

The future contributions of the Antarctic Ice Sheet to sea level rise will be highly dependent on the evolution of its surface mass balance (SMB), which can offset increased ice discharge at the grounding line. In-situ SMB constraints over annual to multi-decadal timescales come mostly from firn and ice cores. However, although they have a high temporal resolution, ice cores are local measurements of SMB with a surface footprint on the order of cm2. Post depositional processes (e.g. wind driven redistribution) can change the initial snowfall record locally and therefore affect our interpretation of the SMB signal recovered. On the other hand, regional climate models have a high temporal resolution but may miss some of the processes at work as a result of their large spatial footprint, on the order of km2. Comparisons of ice core and model SMB records often show large discrepancies in terms of trends and variability.

We investigate the representativeness of a single shallow core record of SMB of the area surrounding it. For this, we use ice-penetrating radar data, co-located with the ice core records examined, to obtain a multi-annual to decadal radar-derived SMB record. We then compare the radar-derived SMB records to the ice core SMB records to determine the surface area that the ice core record is representative of, in terms of mean SMB as well as SMB temporal variability on historical timescales. We examine ice core records situated over the coastal ice rises of East Antarctica, where SMB is high and spatially heterogeneous, as well as over the interior of the West Antarctic Ice Sheet, where SMB is more uniform spatially. By comparing these two contrasting regions in terms of SMB, we will determine whether a general rule of thumb can be obtained to determine the spatial representativeness of an ice core SMB record.
Investigation of different geoid computation techniques in the frame of the ModernGravNet project
Authors: Grigoriadis Vassilios , Andritsanos Vassilios , Natsiopoulos Dimitrios , Vergos Georgios
Published: March 2022

In the frame of the “Modernization of the Hellenic Gravity Network” project, we aim at computing a high resolution and accuracy geoid for Greece. For this reason, we selected initially two test areas in northern and southern Greece covering an area of about 100 km2 each, where gravity and GNSS/leveling measurements were carried out. Based on these recent, well documented and reliable measurements, we investigate the use of different techniques for the determination of the geoid, including Least-Squares Collocation, FFT and Input-Output Systems, following the Remove-Compute-Restore approach. For the remove/restore part, we examine different Residual Terrain Modeling schemes along with the use of older and recent Global Geopotential Models. Moreover, we compute the geoid-quasigeoid separation term using different approaches. We then validate the results obtained against the new GNSS/leveling measurements across the test areas and draw conclusions towards the determination of a regional geoid for Greece.
Exploring the contribution of free-living nematodes in soil to plant health
Authors: Topalović Olivera , Geisen Stefan
Published: March 2022

Soil is a reservoir of a myriad of plant-beneficial to plant-hostile (micro)organisms. Plant-parasitic nematodes (PPN), which contribute to around 15% of annual global yield losses, are particularly important soil-borne pests. Several bio-products based on specific microbial strains with PPN-antagonistic properties have appeared on the market as an alternative to the environmentally harmful chemical pesticides, but the efficiency of these bio-products is usually low in the field. By contrast, we know nothing about the potential and antagonistic mechanisms of complex assemblages of soil microorganisms and of free-living nematodes as the most abundant animals on Earth in regulating PPN damage on plants. Here we present how the microbiome associates with PPN in soil and explore the potential of free-living nematodes to boost the antagonistic effects of these microbiomes. We show that the soil-borne stages of PPN acquire specific microbiomes on their surface and that different factors including the soil type, nematode designation, microbial density and competition affect the outcome of microbial attachment to nematodes. We also show that some of these microbiomes suppress PPN and reduce their root-invasion rate. In addition to a direct antagonism, we demonstrate that some PPN-attached microorganisms are able to trigger pathogen-associated pattern-triggered immunity in plants upon nematode penetration into the roots. We are currently expanding these results by elucidating how the biological action of nematode-antagonistic microbes can be increased in a native soil system that is dominated by free-living nematodes. Together we show the importance of the complexity of soil biodiversity as a potent player in the suppression of PPN and therefore as a potential measure to increase sustainability in agriculture.
On the derivation of data-driven models for partially observed systems
Authors: Ouala Said , Chapron Bertrand , Collard Fabrice , Gaultier Lucile , Fablet Ronan
Published: March 2022

When considering the modeling of dynamical systems, the increasing interest in machine learning, artificial intelligence and more generally, data-driven representations, as well as the increasing availability of data, motivated the exploration and definition of new identification techniques. These new data-driven representations aim at solving modern questions regarding the modeling, the prediction and ultimately, the understanding of complex systems such as the ocean, the atmosphere and the climate. 

In this work, we focus on one question regarding the ability to define a (deterministic) dynamical model from a sequence of observations. We focus on sea surface observations and show that these observations typically relate to some, but not all, components of the underlying state space, making the derivation of a deterministic model in the observation space impossible. In this context, we formulate the identification problem as the definition, from data, of an embedding of the observations, parameterized by a differential equation. When compared to state-of-the-art techniques based on delay embedding and linear decomposition of the underlying operators, the proposed approach benefits from all the advances in machine learning and dynamical systems theory in order to define, constrain and tune the reconstructed sate space and the approximate differential equation. Furthermore, the proposed embedding methodology naturally extends to cases in which a dynamical prior (derived for example using physical principals) is known, leading to relevant physics informed data-driven models. 
Multidimensional forward modelling of EM induction data within a salinization context – is it worth the extra cost?
Authors: Deleersnyder Wouter , Hermans Thomas , Dudal David
Published: March 2022

In (time-domain) Electromagnetic Induction (EMI) surveys, an image of the electrical conductivity of the subsurface is obtained non-invasively. The electrical conductivity serves as a proxy for salinity via petrophysical laws. The advantage of geophysical EMI surveys is their cost-effectiveness because it is a non-contacting method, one can easily walk with the device or mount it on a vehicle or a helicopter (AEM).

An accurate interpretation of the data is computationally expensive as it requires a full 3D simulation of the induced electric currents embedded within an iterative and ill-posed inverse problem. Therefore, this forward model is usually approximated with an 1D forward model which only considers horizontal layers, for which fast analytical forward models exist. Quasi-2/3D inversion allows for lateral variation in the subsurface models, but uses those 1D forward models to generate the data. The final inversion model usually fits the (potentially intrinsic 2/3D) data well up to noise level. But what with the discrepancy between the 1D and 2D data? The biased modelling error, introduced by using a 1D forward model in a 3D problem, is difficult to estimate. Does the inversion model that fits the data via 1D model also fit the data via a 3D model? This question has already been addressed in the literature about fault detection, but in a saltwater intrusion context, the lateral variation is expected to be much smoother. And the question remains to what extent multidimensional modelling is crucial.

The time-domain AEM field data from the salinization map of the region of Flanders, Belgium is used as the case study (Flanders environment agency published the map in 2019). A specific flight line is selected for which validation data is available that shows a 2D (lateral) variation. Both results from the quasi-2D and stitched inversion with a traditional smoothing regularization is presented. An accurate 3D forward modelling is performed on both inversion models via the SimPEG package. The results of the simulations are compared with the actual field data and help us to answer the question of whether multidimensional modelling is crucial in geophysical inversion at the AEM scales and a saltwater intrusion context.
Towards interior-atmosphere coupling on Venus: CO2 and H2O
Authors: van Zelst Iris , Plesa Ana-Catalina , Brachmann Caroline , Breuer Doris
Published: March 2022

Here, we show the first results of coupling a grey atmosphere model (i.e., we assume that the absorption coefficients are constant and hence independent of frequency) considering only CO2 and H2O as greenhouse gases to the geodynamic code Gaia (Hüttig et al., 2013). The evolution of the atmospheric composition of a planet is largely determined by the partial melting and volcanic outgassing of the interior. In turn, the composition of the atmosphere dictates the surface temperature of the planet (due to processes like the greenhouse effect), which is an important boundary condition for crustal and mantle processes in the interior of a planet. Venus in particular has a thick atmosphere at present with an abundance of the greenhouse gas CO2 and a small amount of water vapour. However, the surface conditions may have been much milder up to recent times (e.g., Way et al., 2016). Volcanic outgassing during the thermal history of Venus is thought to have significantly affected the planet's surface temperature and hence its global mantle evolution. Here, we calculate the outgassing of CO2 and H2O from the melt and then use the resulting partial pressures to calculate the surface temperature, which we then use as our boundary condition for the mantle convection. We compare our results to previous studies who employed similar coupled models to address the interaction between the interior and atmosphere of Venus (e.g., Noack et al., 2012; Gillmann & Tackley, 2014; Höning et al., 2021). Ultimately, we aim to consider more chemical species than CO2 and H2O to shed light on the Venus’ interior and atmosphere evolution. Therefore, we also show preliminary results of outgassing models that consider chemical speciation of the entire C-O-H system, i.e., CO2, H2O, H2, O2, CO, and CH4. 