bluuebunny/crossref_metadata_2025 huggingface dataset:
On external and internal drivers of extreme discharges in the Danube Lower Basin
Authors: Mares Constantin , Mares Ileana , Dobrica Venera , Demetrescu Crisan
Published: February 2023

The extreme discharges in the Danube Lower Basin, highlighted by the Generalized Extreme Value theory, were analyzed by their internal and external drivers. For the former, some large and regional scales climate indices, such as the North Atlantic Oscillation (NAO), the Greenland-Balkan Oscillation (GBO), and the Palmer type drought indices, respectively, were used. For the latter the sunspot number (SSN) time series was considered.Wavelet coherence for multiple variables, different types of filters and regression models were applied.The results obtained in this study depend on the season, and can be beneficial for different decision-makers for a good management of water resources in case of extreme events.
Landslide Susceptibility Mapping via binomial Generalized Additive Model
Authors: Scaringi Gianvito , Loche Marco
Published: February 2023

Developments of geostatistical models in landslide susceptibility mapping often do not consider interpretability, although this element has a reasonably fundamental importance on risk assessment. Last trends in machine learning demonstrate that enhancement of performances influences the interpretability of mechanical processes in geostatistical models, in which geomorphic causation is suddenly lost.We took the benchmark dataset in central Italy as our study case, for which a complete inventory of landslides is available. We built two landslide susceptibility models using a Generalised Additive Model (GAM) with a slope-unit partitioning of the area (~4,100 km2, comprising 7,360 slope units), and a set of 26 independent variables, with the aim of classifying the presence/absence of landslides.We tested the capability of a binomial GAM through nonparametric smoothing functions to evaluate the interpretability of the covariates. Furthermore, we obtained satisfactory results in terms of performance with a reasonable compromise in the interpretability.GAMs are very popular classifiers in landslides susceptibility and even though other methods yield better performance, we suggest that interpretability in geostatistical analyses should proceed in tandem with improving the models’ performances.
A machine learning-powered Digital Twin for extreme weather events analysis
Authors: Accarino Gabriele , Elia Donatello , Donno Davide , Immorlano Francesco , Aloisio Giovanni
Published: February 2023

In recent years, Climate Change has been leading to an exacerbation of Extreme Weather Events (EWEs), such as storms and wildfires, raising major concerns in terms of their increase of their intensity, frequency and duration. Detecting and predicting EWEs is challenging due to the rare occurrence of these events and consequently the lack of related historical data. Additionally, gathering of data when the event manifests is not a straightforward process, due to the intrinsic difficulty of positioning and using acquisition systems. Advances in Machine Learning (ML) can provide cutting-edge modeling techniques to deal with EWE detection and prediction tasks, offering cost-effective and fast-computing solutions which are strongly required by policy makers for taking timely and informed actions in the presence of EWEs.Solutions based on ML could, thus, support studies of such extreme events, providing scientists, policy makers and also the general public with powerful and innovative data-driven tools. However, from an infrastructural point of view, supporting such types of applications requires a wide set of integrated software components including data gathering and harmonisation pipelines, data pre-processing and augmentation modules, computing platforms for model training, results visualization tools, etc.A Digital Twin for the analysis of extreme weather events, focusing on storms and wildfires, is being developed in the context of the EU-funded InterTwin project. The InterTwin project aims at defining a Digital Twin Engine for supporting scientific applications from different fields. In particular, for the EWEs, neural networks are being adopted as modeling tools capable of learning the underlying mapping between drivers and outcomes from past data and generalizing it to future projection data. This contribution will present the early concept behind the design of this machine learning-powered Digital Twin for EWE studies.
Using reduced representations of atmospheric fields to quantify the causal drivers of air pollution
Authors: Hickman Sebastian , Griffiths Paul , Nowack Peer , Archibald Alex
Published: February 2023

Air pollution contributes to millions of deaths worldwide every year. The concentration of a particular air pollutant, such as ozone, is controlled by physical and chemical processes which act on varying temporal and spatial scales. Quantifying the strength of causal drivers (e.g. temperature) on air pollution from observational data, particularly at extrema, is challenging due to the difficulty of disentangling correlation and causation, as many drivers are correlated. Furthermore, because air pollution is controlled in part by large scale atmospheric phenomena, using local (e.g. individual grid cell level) covariates for analysis is insufficient to fully capture the effect of these phenomena on air pollution.  Access to large spatiotemporal datasets of air pollutant concentrations and atmospheric variables, coupled with recent advances in self-supervised learning, allow us to learn reduced representations of spatiotemporal atmospheric fields, and therefore account for non-local and non-instantaneous processes in downstream tasks. We show that these learned reduced representations can be useful for tasks such as air pollution forecasting, and crucially to quantify the causal effect of varying atmospheric fields on air pollution. We make use of recent advances in bounding causal effects in the presence of unobserved confounding to estimate, with uncertainty, the causal effect of changing atmospheric fields on air pollution. Finally, we compare our quantification of the causal drivers of air pollution to results from other approaches, and explore implications for our methods and for the wider goal of improving the process-level treatment of air pollutants in chemistry-climate models.
Vortices and Dust Devils at Jezero crater after one year of measurements with MEDA on Mars 202
Authors: Hueso Ricardo , Newman Claire , del Río-Gaztelurrutia Teresa , Aiser Munguira , Sánchez-Lavega Agustín , Toledo Daniel , Lemmon Mark , Martínez Germán , Lorenz Ralph , de la Torre-Juarez Manuel , Rodríguez-Manfredi Jose Antonio , Pla-García Jorge , Murdoch Naomi , Chide Baptiste
Published: February 2023

After one year of surface operations at Jezero, the MEDA meteorological sensors have captured the signals produced by the close approach of hundreds of vortices and dust devils over different seasons and terrains. Here we update findings on the vortex and Dust Devils published in Hueso et al. (JGR: Planets, 2023). That work analyzed MEDA data from spring to early autumn identifying vortices as pressure drops and later characterizing them from the ensemble of MEDA measurements. In this updated analysis we show that, in winter, declining surface temperatures and smaller vertical gradients result in a wane of vortex activity. This decreased activity affects more the frequency of intense vortices (Δp >1.5 Pa) without showing a stiff decay in the total number of vortices (Δp>0.5 Pa). In this contribution we concentrate on the specific aspects of the thermodynamics of the vortices from temperature measurements obtained by MEDA that characterize the vertical thermal gradient at the time of the vortex passage. In addition, when vortices approach the rover closely in a favorable geometry (coming from the front of the vortex) we measure the increased temperatures inside the vortex. We also explore the increased nighttime vortex activity found on some sols, when pressure drops equivalent to those created by daytime vortices appear in the early morning before sunrise, with clusters of nighttime activity in winter and early spring.
An integrated resistivity-density model of Southern Africa
Authors: Moorkamp Max
Published: February 2023

The tectonic history of southern Africa includes Archean craton formation, multiple episodes of subduction and rifting and some of the world's most significant magmatic events. Lithospheric models based on seismological and magnetotelluric data show highly heterogeneous crustal structure, significant anomalies in the lithospheric mantle and strong variations of the depth to the lithosphere-asthenosphere boundary. While some of the spatial patterns agree between different geophysical methods, there are also significant differences in the geometry and location of many structures. I perform a joint inversion of magnetotelluric and satellite gravity data to reconcile these apparent discrepancies. Resistivity and density are coupled through a newly developed Variation of Information constraint which strives to establish a one-to-one relationship between the two quantities. This allows the resistivity-density relationship to evolve data driven during the inversion. The final combined resistivity-density model shows detailed lithospheric and sub-lithospheric structure below the Kaapvaal Craton and adjacent mobile belts. In addition, the retrieved parameter relationship exhibits several branches indicating strong variations in composition. Compared to results from a similar inversion in the western United States, the inversion indicates significantly less fluid related low resistivity anomalies and a dominance of high-density low-resistivity structures. This corroborates earlier ideas that fluids are difficult to contain within in the Earth over long time scales. I will discuss the implications for the tectonic evolution of the region and for the interpretation of low resistivity anomalies world-wide.
An ocean surface paradox: gas equilibrium with atmosphere
Authors: Durham Brian , Pfrang Christian
Published: February 2023

Marine science tells us that the surface of Earth’s oceans is in gaseous equilibrium with its atmosphere (Yingxu Wu et al 2022). In the case of the key atmospheric trace gas CO2, the partition across the phase boundary is given by Henry constants as established by Li and Tsui 1971 and by Weiss 1974, while outside the laboratory there are extensive datasets for the atmospheric mol fraction (ppm CO2) embodied in the familiar `Keeling curves’, as measured at oceanic, polar and continental locations (Yuan et al 2019).Sea surface temperatures are widely available for Earth’s oceans (Kent and Kennedy 2021). We have therefore interpreted the Henry Constants from Li and Tsui (1971) and from Weiss (1974) as headspace mol fractions (ppm CO2) against temperature, and added representative field data from Mauna Loa (https://gml.noaa.gov/ccgg/trends/).A disparity is evident, which we address as follows: In case the well-known differential between the two 1970s laboratory curves is somehow attributable to pre-treatment including acid in both cases and a biocide in one, we speculate that the outcomes of both might be different if the seawater samples had been treated as biological fluids.Expanding therefore our studies of atmospheric gas partitioning at a growing ice surface reported to recent EGU conferences, and building on valued conversations with colleagues at EGU 2022, we will present provisional results from gas equilibration in the headspace above freshly-collected (≈`live’) seawater from UK’s Atlantic coast.  
Atmospheric water capture by desert soils: can we measure it?
Authors: Kool Dilia , Agam Nurit
Published: February 2023

Atmospheric water, or non-rainfall water inputs (NRWIs) are a critical, albeit largely overlooked, component of the global hydrological cycle. Water vapor adsorption specifically, is not only the least studied form of NRWI but likely the most common one in arid areas.Lysimeter measurements in the Negev desert during the summers of 2019-2022 indicate that water vapor adsorption in loess soil amounts to at least 33 mm when looked at cumulatively over the summer (0.3-0.5 mm night-1): about ~30% of annual rainfall (116 mm). Given the challenges using lysimeter measurements, attempts to quantify NRWI amounts and duration have generally been limited to short time periods at point or local scales. Determining the true importance of NRWIs in arid and extremely arid environments, which comprise 20% of the terrestrial surface, requires new approaches to measure water content in the 0.5-5% range.Using weighing lysimeters as a reference, we tested of-the-shelf temperature and relative humidity sensors to assess changes in water content with high temporal resolution over longer periods of time for sand and loess soils. Relative humidity was converted to water potential (Kelvin equation). The water content was then determined using a water retention curve measured with a vapor sorption analyzer. Results showed diurnal patterns in water content consistent with lysimeter measurements. Maximum increase in water content correlated well with lysimeter measured NRWIs. While not all issues are yet resolved, this direction opens possibilities to expand our measurement capacity over longer periods of time and increase the number of measurement locations at relatively low cost. This provides one step forward in trying to understand the magnitude of NRWIs in arid environments across the globe.
Waves…a tool to explore our home! A successful experience in improving risk perception
Authors: Gargiulo Maria Vittoria , Napolitano Ferdinando , Capuano Paolo
Published: February 2023

In a geologically interesting land like Italy, and in particular Campania, educating and informing about the concept of risk in general, and specifically seismic risk, is of fundamental importance.The possibilities of seismic risk mitigation, in fact, depend not only on the scientific community but also on how well prepared and informed society is about the risk itself. It is, therefore, crucial to train the local population to increase disaster risk preparedness and resilience within our region.The Science Capital framework, developed by Prof. Louise Archer er al. (https://doi.org/10.1002/tea.21227), refers to a person’s science-related resources, such as their science-related understanding, knowledge, attitudes, activities, and social contacts. It also offers a key to defining how everyone's store of scientific knowledge is enriched and influenced by their habits, family, and network of contacts. Understanding this context and its dynamics helps us to enhance the resources available for scientific culture, with a view to building a competent and inclusive educational community. With this in minds, we built a didactic protocol dedicated to seismic risk perception taking into consideration the Science Capital framework.“Waves…a tool to explore our home!” allows students to acquire both specific topics, such as the physical quantities involved in an earthquake, its generation and its dynamics, and general concepts, such as the perception of seismic risk and the impact of man in the prevention, in the possible induction and in the response to an earthquake.An evaluation phase was carried out to assess the learning experience and the effectiveness of the science communication technique.This work has been supported by CORE ("sCience and human factor for Resilient sociEty") project, funded from the European Union’s Horizon 2020 - research and innovation program under grant agreement No 101021746 . 
Multidisciplinary reconstruction of the May 1853 flood episode
Authors: Balasch Josep Carles , Izard Feliu , Calvet Jaume , Tuset Jordi , Pino David , Barriendos Mariano , Barriendos Josep
Published: February 2023

Climate variability conditioned by the effects of climate change justifies the study of historical periods in order to identify and characterise episodes of high severity and low frequency. The increase in the irregularity of the rainfall regime in some regions justifies the study of these events for a better assessment of their presence in the immediate future. In this regard, the study of extreme hydrometeorological episodes that happen in unusual seasons of the year for these extreme episodes is of particular interest.One of these unusual episodes was the torrential rainfall and floods of May 1853 in Catalonia (NE Iberian Peninsula). The whole month of May 1853 is a unique hydrometeorological anomaly, being the second most rainy month of May in the whole instrumental series of precipitation of the city of Barcelona (period 1786-2022).This work reconstructs this episode of heavy rainfall and floods using a multidisciplinary approach. Old instrumental meteorological data are used to obtain the daily pluviometric behaviour in Barcelona. Surface atmospheric pressure data from different points of Western Europe allow its synoptic description.Historical information allows the identification of the different river overflow points and the floods caused by this episode. These points are represented cartographically together with the documented impacts on infrastructures. For this episode, there are 38 cases with historical information on impacts caused by floods or overflows. These occurred in eight different river basins which are included in the hydrographic demarcations of the Ebro River and the Catalan Coastal Basins. In order to appreciate the magnitude of the event, a limnimark (or floodmark) located in Tres Ponts Canyon on the Segre River is used. This record enables us to assimilate the episode with the most severe episode measured on the Segre River, one of the main tributaries of the Ebro River, in November 1982, with 1900 m3/s. This confirms the magnitude of the event of 1853, which is one of the most severe episodes of the lower Ebro basin for the last 500 years. 
Assessment of the impact of soil hydraulic parameters based on various Microwave datasets on estimation of hydrological fluxes
Authors: Maurya Vikrant , Gupta Manika , Thomas Juby , Srivastava Prashant Kumar , Pandey Dharmendra K. , Pant Naresh Chandra , Sahai Atul Kumar
Published: February 2023

Soil Moisture (SM) is a key variable in the quantification of the water and the energy-balance fluxes occurring within the atmosphere and the surface. Recent advances in microwave remote sensing provide an unprecedented opportunity to monitor surface soil moisture globally but at a coarse (~25-40 km) spatial resolution. Although hydrological models based on water and energy fluxes are also used for estimation of the high spatial resolution soil moisture at regional scale to understand the surface hydrological processes, agricultural applications, and the water resource management remains a challenge as it depends upon hydraulic parameters. Therefore, the study focuses on the assessment of the impact of the downscaled SM derived from different microwave datasets on optimized soil hydraulic parameters and eventually its effect on discharge at the basin scale. The aim is achieved in two steps: firstly, the coarse scaled SM products from different microwave datasets (Advanced Microwave Scanning Radiometer 2 (AMSR-2) and Soil Moisture Active Passive (SMAP)) are downscaled to 1km spatial resolution using a disaggregation algorithm. Secondly, effective soil hydraulic parameters are optimized with dual input of downscaled SM and the discharge for the Kosi Basin. The results show that there is a significant impact of the optimization of soil hydraulic parameters on the hydrological fluxes and discharge. The effective soil hydraulic parameter derived from the downscaled product of SMAP L3 shows a promising result in simulation of SM from hydrological model in addition to that the optimization technique using GA in the hydrological models ensures a better process representation and spatial prediction.
Three-field finite-element modelling of coupled two-phase flow for geological problems: Towards the zero-porosity limit
Authors: Lu Gang , May Dave , Huismans Ritske
Published: February 2023

Two-phase flow, a system where Stokes flow and Darcy flow are coupled, is of great importance in the Earth's interior, such as in subduction zones, mid-ocean ridges, and hotspots. However, it remains challenging to solve the two-phase equations accurately in the zero-porosity limit, for example when melt is fully frozen below solidus temperature. Here we propose a new three-field formulation of the two-phase system and present a robust finite-element implementation, which can successfully solve for the system where zero and non-zero porosity domains are both present. The reformulated equations, with solid velocity (vs), total pressure (Pt), and fluid pressure (Pf) as unknowns, include penalty and regularization to avoid singularities, which exactly recover to the standard single-phase Stokes with penalty at zero porosity. The new formulation is implemented using a 2-D finite-element discretization with Q1P0Q1 elements. We demonstrate the correctness of our implementation based on benchmarks against analytical solutions, which gives expected convergence rates in both space and time. Example experiments, such as self-compaction, falling block, and mid-ocean ridge spreading, show that this formulation can robustly resolve zero- and non-zero-porosity domains simultaneously, and be used for a large range of applications in various geodynamic settings.
The role of strong Eastern Pacific El Nino events in ENSO-amplitude variability in Observations and Climate Models
Authors: Bayr Tobias , Lübbecke Joke F. , Latif Mojib
Published: February 2023

The amplitude of El Niño/Southern Oscillation (ENSO) varied considerably over the last 140 years, for which we have relatively reliable Sea Surface Temperature (SST) observations over the tropical Pacific. The difference between periods of high and low ENSO amplitude results mainly from the number of strong Eastern Pacific (EP) El Niños, while the amplitude of Central Pacific (CP) El Niños is comparable in both periods. Further, the asymmetry of ENSO, i.e. that the SST anomalies during El Niño are on average stronger and located further to the east than during La Niña, covaries with ENSO amplitude in observations, indicating that the number of strong EP El Niño events dominates both ENSO amplitude and asymmetry variations.
We find similar relations in the 40 historical runs of the Large Ensemble with the CESM1-CAM5-BGC model that can simulate the ENSO asymmetry quite realistically.  Further, there is a strong relation between the ENSO amplitude and the tropical Pacific mean state, indicating that a warmer eastern equatorial Pacific favors more EP El Niños due to a lower convective threshold in that area. We also analyze the spatial asymmetry and amplitude asymmetry of the atmospheric and oceanic feedbacks and show that the spatial asymmetry is more pronounced in the atmospheric feedbacks, while the amplitude asymmetry is more pronounced in the oceanic feedbacks, and that both together form the observed asymmetry of ENSO.  A comparison with 360 years-long CESM1 experiments with a -4.0 K colder and +3.7 K warmer mean state indicates that the present-day ENSO may be in a transition zone between a CP El Niño dominated ENSO state and an EP El Niño dominated ENSO state and that ENSO may lock-in into the EP El Niño dominated state under global warming.
Finally, our analysis of ENSO-amplitude variability in preindustrial control simulations of the CMIP6 database supports a strong relation of ENSO amplitude and asymmetry with the number of strong EP El Niño events.
Climate change alters the global diversity of food crops
Authors: Heikonen Sara , Heino Matias , Jalava Mika , Kummu Matti
Published: February 2023

Climate change has already impacted the productivity of important food crops. The projected increasing temperatures and changing precipitation patterns affect the climatic suitability of food production areas. Changes in climatic suitability require adaptive actions on farms and will likely alter the potential volume and diversity of food crop production globally.Existing research has mostly analysed the impacts of climate change on the four staple crops: wheat, rice, maize, and soybean. However, other food crops contribute more than 50% to the global calorie and protein supply and therefore constitute a crucial element of food security. Moreover, these crops might succeed in more diverse climate conditions than the staple crops. If climate change narrows the production potential of the staple food crops, other food crops could become even more important for global food security in the future. Therefore, to comprehensively understand the implications of climate change on food crop production, there is need for analysis on a diverse set of food crops.In this study, we delineate suitable climate conditions for 27 major food crops using historical climatic data and examine the effect of future changes in climate suitability on food crop production volume and diversity. We define the crop-specific suitable climate conditions utilizing the Safe Climatic Space concept, based on global gridded datasets on biotemperature, precipitation, and aridity in 1970–2000 as well as crop production in 2010. Then, using future climate parameter data, we project changes in global climate suitability for the 27 food crops. The analyses cover five global warming scenarios from +1.5 °C to +5 °C.The preliminary results indicate that the global food crop production potential on the current croplands will decrease for most crops in all five global warming scenarios. Furthermore, the potential diversity of food crops will decrease significantly at low latitudes but increase in other areas. In all five scenarios, areas near the equator will become unsuitable for most studied crops. On the other hand, on the current extent of cropland, the potential production area of especially oil crops and starchy roots will expand in the northern hemisphere.For many crops, there is distinct difference in the magnitude of lost production and diversity potential between global warming of +2 °C and +3 °C, highlighting that it is important to restrict global warming at the very maximum to +2 °C. The results of this study could provide insights for agricultural adaptation to climate change by illustrating opportunities for geographically shifting or expanding production in regions where climate suitability is projected to change. Further, the results could identify potential substitute crops for regions where climate conditions might become unsuitable for the currently cultivated food crops.
Fossil Onagraceae flower and insects with in situ or adhered pollen from the Eocene of Eckfeld, Germany
Authors: Geier Christian , Bouchal Johannes M. , Ulrich Silvia , Wappler Torsten , Grímsson Friðgeir
Published: February 2023

The Onagraceae or evening-primrose family has a fossil record composed mainly of dispersed pollen that has been discovered in Late Cretaceous to Holocene sediments around the globe. The pollen record suggests the family reached a cosmopolitan distribution during the Eocene. Currently, there is no reliable Onagraceae leaf record, and the meagre mesofossil record is composed of only a few fruits/seeds of Circaea and Ludwigia from the Oligocene to Pliocene of Eurasia. There is also a unique fossil Fuchsia flower that was described from the early Miocene of New Zealand, but other than that, there are no fossil Onagraceae flowers known to date. In addition, Onagraceae pollen has never been found adhering to fossil insects, and as such, there is no direct evidence of which insects visited Onagraceae flowers prior to modern times. Here we present an exceptional finding, an Onagraceae flower bud of Eocene age, from Eckfeld in Germany. Due to the flower’s bud stage the stamens were still packed with pollen. Nevertheless, the in situ pollen enabled us to assign the flower to the genus Ludwigia, based on a combination of unique morphological and ultrastructural traits observed with combined LM, SEM, and TEM, making it one of the earliest records of this genus. More importantly, we also discovered the same Ludwigia-type pollen adhering to the exterior of two different fossil beetles, a Buprestidae and Scarabaeidae, from the same locality. These provide the first-ever direct evidence for paleo-flower-insect visitation in Ludwigia and Onagraceae. Interestingly, we did not discover any Ludwigia-type pollen on the several Hymenoptera fossils investigated during this study, but Hymenoptera are the main flower visitors and pollinators of Ludwigia at present. These findings might suggest that beetles were the main flower visitors and potential pollinators of European Ludwigia during the Eocene and that there has been a shift in primary pollinators through the geological record.
Late Mesozoic rift evolution and deformation reconstruction of the Songliao Basin, northeastern China
Authors: xing hongxin
Published: February 2023

Abstract:The development of faults governs the kinematics of continental deformation. The Songliao Basin, located at the central part of late Mesozoic lithospheric thinning province in East Asian region, experienced intense rifting during Early Cretaceous epoch and formed an intricate syn-rift fault system. However, the geometric and kinematic relationships inherent in the fault system have not yet been satisfactorily explained, hampering the understanding of basin formation and related marginal plate tectonic processes. Here, theories for polymodal faulting were applied to evaluate the faulting evolution of the Songliao Basin, based on which a quantitively deformation reconstruction was developed. Our reconstruction shows that the basin formation during the syn-rifting period was subdivided into three main stages: late Valanginian–Barremian(133-118.2Ma) initiation of extension, Aptian(118.2-113.9M) extension climax, and Albian(113.9-100.5Ma) extension wanning and initiation of post-extensional subsidence. The deformation of the Songliao Basin is spatially heterogeneous. Faulting analyses revealed a three-dimensional strain filed with a dominating horizontal ESE-WNW extension, a minor horizontal near N-S extension, and a large vertical shortening in the Northern Songliao Basin (NSL). The 3-D non-plane strain with non-zero intermediated extension(ε2) magnitude controlled the synchronous displacement of a NNE–SSW-striking fault set and a NNW–SSE-striking fault set in orthorhombic pattern to create the characteristic rhomboidal fault geometry. Whereas, the Southern Songliao Basin (SSL) deformed under a 2-D plane strain filed with a horizontal ESE-WNW extension and vertical shortening. The plane strain condition is interpreted as a special case with no intermediated strain(ε2), and produces a pair of near N-S-striking fault sets in conjugate symmetry. Our results illustrate that this particular three-dimensional deformation result in the intricate fault system in the Songliao Basin and that the fault geometry is controlled by the ratios of the principal strains, especially the relative magnitude of the intermediate strain. We argue that the three-dimensional strain field in the NSL reflected the trench retreat in the Paleo-Pacific subduction zone and the gravitational collapse of the thickened lithosphere, and that the extension of the SSL is merely the consequence of the trench retreat.Keywords:Songliao Basin, three-dimensional strain, orthorhombic fault, syn-rift deformation, quantitative reconstruction
Pore-scale simulation of mucilage drainage using phase field method.
Authors: Esmaeelipoor Jahromi Omid , Patel Ravi. A , Huisman Johan Alexander , Vanderborght Jan
Published: February 2023

Rhizosphere differs from bulk soil due to the presence of root mucilage, which affects physical, chemical, and microbial processes. It is well known that the rhizosphere responds slowly to water potential changes, which buffers changes in water content and helps keep the rhizosphere wetter than bulk soil during drying. Mucilage can affect solute transport and gas diffusion by affecting the distribution of liquid and gas phases. Despite increased recognition of the importance of mucilage, there still is a lack of models that describe the connectivity between different phases in the pore space of the rhizosphere during wetting and drying. The main challenge for model development is the complex concentration-dependent behaviour of mucilage. At low concentrations, mucilage is more like a liquid, whereas at higher concentrations, dry mucilage becomes a solid. In between, a viscoelastic state is observed where mucilage can be considered as a hydrogel.In previous work, we have developed a model based on a lattice spring method (LSM). This model was able to simulate the distribution of mucilage in the dry state at the pore scale. However, for wetter states, it is necessary to consider additional physical phenomena like surface tension, contact angle and viscoelasticity. In this study, we therefore aim to develop a Lattice-Boltzmann simulation framework to simulate two phase flow involving mucilage. To capture the interface between the two phases, a phase-field method will be used for interface tracking as this approach has gained considerable attention in recent years. The simulations will proceed as follows. We first assign the properties of a Newtonian fluid to the mixture of water and mucilage and calculate the equilibrium distribution of the liquid phase (mixture of water and mucilage) and gas in a simple pore geometry. Then, the water content will be gradually decreased, which will lead to an increase of mucilage concentration. This will in turn affect the viscosity, surface tension and contact angle, which will result in the emergence of the required viscoelastic behaviour of the mixture. For each of the water contents, the distribution of liquid (or hydrogel) and gas phases will be calculated.The newly developed model will provide us with new perspectives on hydrodynamic processes within the pore space of the rhizosphere. In addition, the model will help to better understand processes that strongly depend on hydraulic dynamics in the rhizosphere, such as solute transport, root penetration resistance, rhizosheath formation, and microbial activity.
Trends in drought across Europe and their links to atmospheric circulation
Authors: Bešťáková Zuzana , Kyselý Jan , Lhotka Ondřej , Eitzinger Josef
Published: February 2023

We study trends in drought across the central latitude strip of Europe (defined as the region 47.5–52.5 °N and 2.5°W–32.5°E) during 1950–2019, and their links to atmospheric circulation. Drought characteristics are based on difference between potential evapotranspiration and precipitation in E–OBS data, and atmospheric circulation is characterized in terms of circulation types classified using daily sea level pressure patterns from the NCEP–NCAR reanalysis. Circulation types supporting drought in vegetation season (April–September) are identified, and we analyse changes in their occurrence since 1950, seasonal changes, and the connection with drought trends in individual European regions. We find that while in the early vegetation season, drought develops mainly in Central Europe, in the late vegetation season the most pronounced trends are shifted towards west. The circulation types supporting drought depend on regions and seasons, especially for directional types. The largest increase of the dry circulation types is observed in both seasons in Central Europe, and contributes to the pronounced drying.
The use of collaborative robots (cobots) in an analog modeling laboratory
Authors: Bonini Lorenzo , Bertone Nicolò
Published: February 2023

During the last decades, analog models have taken extraordinary advantage of new technologies. High-resolution cameras, analytical methods to extract quantitative data from the experiments (e.g., Digital Image Correlation), and new analog materials are only a few examples of the new improvement. The ease of extraction of quantitative data means that the modeling results can be used to provide new views on natural processes. Reducing unwanted uncertainties is crucial to propose robust new theories. One of the main difficulties for analog modelers is reducing the uncertainties related to the initial setup arrangement. Most of these uncertainties are classically referred to the handmade processes, such as handling analog materials. In the Analog Modeling laboratory of the University of Trieste, we tested the use of a cobot (a cobot is a robot for direct physical interaction with a human user within a shared workspace) to simulate pre-existing faults in wet clay boxes. We present two different sets of experiments. The first set has been designed to evaluate the kinematic efficiency of Riedel shears. The second reproduces differently oriented inherited dip-slip faults in an experimental box reproducing extension. In both cases, we reproduced the same setup more than one time. The collaborative robot reduced the variability of the results, demonstrating the effectiveness of the use of cobots in analog modeling laboratories.
Multi-stage tectonic evolution of the Tatra Mts recorded in the para- and ferromagnetic fabrics
Authors: Staneczek Dorota , Szaniawski Rafał , Marynowski Leszek
Published: February 2023

Magnetic fabrics analysis is widely applied in reconstructions of the tectonic evolution of orogenic belts. The main advantage of this method is the ability to trace even weak deformation in rocks. The main goal of this work is to shed new light on the Cretaceous-Neogene tectogenesis of the Tatra Mts by investigating the para- and ferromagnetic fabrics of nappe units and post-thrusting sequences. It is worth mentioning, that this study provides the first magnetic fabric data from the thrust nappe system of the High Tatra Mts (the most elevated part of the Tatra Mts). We focused on Cretaceous marly limestones, the youngest part of the Mesozoic nappe system in the Tatra Mts, and Oligocene post-thrusting shales/siltstones. Petromagnetic methods combined with paleotemperature estimations enabled us to identify the magnetic mineralogy and its origin. The subsequent analysis of para- and ferromagnetic fabrics supported by the previously obtained mineralogical results let us recognize and characterize different stages of the tectonic evolution of the Tatra Mts. Even though the paleotemperatures recorded for Oligocene and Cretaceous rocks are higher in the High Tatra Mts than in the Western Tatra Mts, petromagnetic features of rocks sampled in both areas remain similar. Anisotropy of Magnetic Susceptibility (AMS) fabric of post-thrusting cover is governed by phyllosilicates. A consistent, approximately NE-SW-oriented magnetic lineation of tectonic origin is present in most analyzed sites and documents weak deformation presumably related to the Miocene uplift of Tatra Mts. Mean ferromagnetic mineral in Oligocene clastic sediments is magnetite. Origin of the AARM lineation in this unit is presumably related to the crystallization of the secondary magnetite on a preexisting phyllosilicate matrix and/or the stress field present during magnetite formation. The magnetic fabric of the Cretaceous marly limestones is controlled mainly by the orientation of phyllosilicates and differs significantly among the High and Western Tatra Mts. AMS results from The Western Tatra Mts’ sites document consistently the NW direction of alpine nappe thrusting. On the contrary, the AMS fabric in the High Tatra Mts shows no clear evidence of tectonic deformation. Ferromagnetic mineralogy of the Cretaceous nappe unit is complex and combines magnetite, hematite and maghemite in various proportions, with the usual dominance of magnetite. In the High Tatra Mts, the AARM fabric carried by magnetite is characterized by sub-vertical magnetic lineation, which we interpret as the impact of local transpression-related deformation associated with the Miocene uplift.
Comparison Analysis of the Climate Extreme in 2022
Authors: Ji Chaonan , Montero David , Grupp Veronika , Mora Karin , D. Mahecha Miguel
Published: February 2023

Extreme events are on the rise. The 2022 compound heatwave and drought event caused significant vegetation mortality and serious ecosystem destruction in Europe that urgently need to be investigated. In this study, we used climate data (ERA5-Land air temperature at 2 m and precipitation) and remote sensing products (kNDVI derived from MODIS and ESA CCI Land Cover product) to investigate the dynamics of the 2022 extreme events and vegetation responses. Furthermore, we compared the effects of this year to other normal as well as abnormal years in Europe. We propose a ranking-based approach that compares cumulative sums of climate variables and kNDVI over the growing season to determine extreme areas and compound intensity over the last 23 years.
The results show that the 2022 event is a widespread compound heatwave and drought event, with a similar spatial pattern to the 2018 extreme event, but less severe. Vegetational response differed among land cover classes, grassland was more affected while deciduous trees were barely affected in the 2022 event. In general, vegetation recovered relatively quickly after the 2022 event.
Our ranking-based approach enables an effective comparison and characterization of climate extremes and their effects on vegetation over different years. A more in-depth analysis of spatial and temporal patterns can contribute to the development of targeted measures and support decision-makers in responding to climate extremes.
Development of soil research supporting climate resilience and decision-making in Finland
Authors: Pihlaja Jouni
Published: February 2023

The development of the balance of carbon stocks is at the EU level as well as nationally a key issue related to climate change and the state of the environment, and nowadays it is also strongly linked to the economic perspective through common agreements related to taxonomy. This places the need to produce new researched information as a basis for decision-making.In Finland, the lack of soil information is becoming a limitation of climate-resilient agriculture and forestry policy measures. Because of this, Geological Survey of Finland (GTK) and its partners have launched several projects to improve the situation. In the new projects, remote sensing methods, digital tools and the use of artificial intelligence have been developed in particular to expand the regional coverage of soil data and to enable the assessment of the national carbon stock. By developing the production of information and making the use of databases more efficient, land use measures can be directed and targeted in such a way that they maintain and strengthen carbon sinks and stores.GTK's partners in the projects have been the Natural Resources Institute Finland, the Universities of Helsinki and Turku, the Finnish Food Authority, the National Land Survey of Finland and RADAI, and the work would not be possible without interdisciplinary cooperation.
Validation of a High-Fidelity Monte Carlo Model for Airborne Gamma-Ray Spectrometry with Field Measurements
Authors: Breitenmoser David , Butterweck Gernot , Kasprzak Malgorzata M. , Mayer Sabine
Published: February 2023

The objective of the present study is to simulate the spectral gamma-ray response of the Swiss Airborne Gamma-Ray Spectrometry system (SAGRS) using Monte Carlo radiation transport codes. The SAGRS is mounted in the cargo bay of a AS-332M1 Super Puma helicopter from the Swiss Air Force and consists of four prismatic NaI(Tl) scintillation crystals with a total volume of 16.8 l. We developed a high-fidelity Monte Carlo model of the SAGRS including the detector system and the helicopter using the multi-purpose radiation transport code FLUKA. As part of the measurement campaign ARM22c organized by the National Emergency Operations Centre (NEOC), we performed hover and line flights in combination with ground measurements using certified 133Ba and 137Cs point sources to validate our model. The performed measurements revealed a significant impact of the helicopter fuel on the detector response for various solid angles. In general, we found an excellent agreement between the measured and simulated detector response with relative errors in the full energy peak <10%. The validated model presented herein offers a novel way to simulate the spectral detector response of the SAGRS for the generation of fundamental spectra in a full spectrum analysis framework.
Convection in Europa’s icy shell: the role of composite rheology and dynamic grain size evolution
Authors: Rolf Tobias , Manjón-Cabeza Cordoba Antonio
Published: February 2023

Europa’s outermost layer is a shell of water ice with a probable thickness of a few to a few dozens of km. It is most likely underlain by a liquid water ocean in direct contact with mantle rock, which makes Europa a prime target for understanding habitability. Europa’s surface is heavily deformed and the mean surface age is low (< ~100 Myr), implying active resurfacing, perhaps even through subduction-like processes. While this requires future confirmation, convection in Europa’s icy shell is a viable mechanism to drive such processes. However, the pattern of convection and its link to resurfacing is poorly understood. Here, we use 2D numerical simulations to shed light on these aspects and implement a composite rheology featuring the different slip mechanisms potentially relevant for ice: diffusion creep, basal slip (BSL), grain-boundary sliding (GBS), and dislocation creep. We couple this to grain-size evolution (GSE) and test in basally and mixed basally-tidally heated cases in a 20 km-thick shell the parameters governing the deformation mechanism and GSE.Without imposing a yield stress to modulate pseudo-plastic deformation, we typically observe an immobile layer at the top of the ice shell. This layer tends to deform via GBS/BSL and features very small grain-sizes (<40 µm), while grains are on the order of cm in the warmer deeper parts, due to stronger grain growth. The thickness of the immobile layer decreases with enhancing the rate of tidal heating and with the sensitivity of grain growth to temperature variations. The immobile layer is thinnest (10-20% of the total thickness), if grain growth in the interior is only moderately enhanced compared to the cold shallow parts, while a large contrast in grain growth increases the layer thickness until eventually convection in the ice shell ceases completely. The omnipresence of an immobile layer (no matter how thick) appears at odds with Europa’s strongly deformed surface and its low age, unless other processes can explain this aspect. Preliminarily, mobilization of the surface layer is possible in our models by imposing a small finite yield stress. Using a very low coefficient of friction, surface velocities can reach rates of up to tens of centimeters per year, under which the surface would be recycled efficiently.

 

 

 