bluuebunny/crossref_metadata_2025 huggingface dataset:
Thermal inheritance in continental rifting.
Authors: Le Pourhiet Laetitia , Francois Thomas , Jourdon Anthony , Larvet Tiphaine
Published: February 2023

While a lot of literature exist modelling the effect of former tectonic structure faults, stacking of different lithologies with a dip or former lacolithes, little has been done in modelling the effect of heterogeneous thermal properties in the lithosphere and particularly in the crust and these contributions are old enough that some of their main results need to be reminded and extended using current modelling tools.  I will first recall how much periodic variations in heat production rate in the crust may affect the temperature at the Moho and the thickness of the lithosphere using analytical solution, I will then use thermo-mechanical simulation to demonstrate how important are these effects in 2 and 3D at tectonic timescale especially while reactivating former post orogenic collapse structures such as metamorphic core complexes and migmatite domes. I will illustrate how the simulation might apply to the West European rift, the Menderes massif or the South China Sea.I will finally show using 2D numerical simulations how much the repartition of heat production in the crust influences the long-term survival of mobile belts and can explain partly why the European lithosphere keeps large heat flow despites its thermos-tectonic age.
A Measurement Node for the continuous gravity and tilt observations in an activegeodynamic area of southern Italy: the Calabrian Arc system
Authors: Albano Anna , Carbone Vincenzo , Lamonaca Francesco
Published: February 2023

A Measurement Node for the continuous gravity and tilt observations in an activegeodynamic area of southern Italy: the Calabrian Arc systemAnna Albano1, Vincenzo Carbone1, Francesco Lamonaca21Dipartimento di Fisica, Università della Calabria, Arcavacata di Rende (CS), Italy2Dipartimento di Ingegneria Informatica, Modellistica, Elettronica e Sistemistica, Università della Calabria, Arcavacata di Rende (CS), Italy Calabria (southern Italy) is a site of considerable seismic activity related to the ongoing evolution of the Calabrian Arc system, where a complex lithospheric structure is present. For over a century the Calabrian region has been going through a period of relative seismic quietness, yet its seismic hazard is at the highest levels in the Mediterranean basin due to several catastrophic earthquakes present in the historical records. In order to strengthen the geophysical monitoring of this region, a gravity and tilt recording station was set up in the premises of the University of Calabria. The measurement node is composed by the gravimeter G-1089 from LaCoste & Romberg; the tilt-meter Model 714 from Applied Geomechanics; a 6 and ½ digits multimeter Agilent 34970A data acquisition and switching unit used to converts the analog signals of the gravimeter and tilt-meter in the corresponding digital ones; a computer used to store, elaborate and present the signals. The delay among the input channels of the multimeter is evaluated and the optimal configuration is achieved in order to make such a delay negligible for the time correlation of the input signals. The measurement node is positioned on the ground of the cube 41C. Finally, the information about the temperature and the atmospheric pressure is obtained by the nearby environmental station positioned on the roog of cube 41B. The recorded signals should allow to estimate a tidal anomaly, possibly correlated with the difference between some local feature of the lithosphere or geodynamic activity and the corresponding characteristics of the model used to calculate the reference gravity tide. A reliable model of the gravity tide is necessary for accurate processing of discrete absolute and relative gravimetric measurements and to detect in the gravity signals possible components correlated to major seismic activity. The Ocean Tide Load (OTL) effect was accounted for in the determination of the tidal field spectral parameters. The most widespread DDW99/ NH Earth’s model, adopted here as reference, fits the obtained results well enough.
A full-field approach to simulate microstructure evolution during high-temperature deformation of polycrystalline aggregates including dislocation (glide and climb) and diffusion creep mechanisms.
Authors: Griera Albert , Lebensohn Ricardo
Published: February 2023

The VPFFT-ELLE numerical scheme is a micro-dynamic approach able to simulate the microstructure evolution of polycrystalline and polyphase aggregates during deformation and recrystallisation (www.elle.ws). The approach has been widely used to simulate the dynamic recrystallisation of ice, halite and olivine aggregates, among others. A limitation of this numerical scheme is that is limited to viscoplastic deformation by dislocation glide. However, at homologous high temperatures and low stresses, point-defect mediated mechanisms such as dislocation climb and diffusion creep are important in order to accommodate plastic deformation in polycrystalline aggregates.We present an update of the approach by incorporating a new scheme able to simulate dislocation climb and diffusion creep in an elasto-viscoplastic regime. The approach is based on a previously small-strain version of a formulation based on the fast Fourier transforms (FFT) for the prediction of micromechanical fields in polycrystals (Lebensohn et al., 2012). The new approach integrates a rate-sensitivity, crystallographically-based constitutive model of a single crystal deforming by climb and glide, combined with an isotropic, linear model for the parametric simulation of active diffusion within grains and at grain boundaries.  An overview of the theoretical basis of the approach is presented with some benchmarks and applications to the prediction of the effective behaviour and evolution of crystallographic-preferred orientation of highly anisotropic minerals. As expected, the incorporation of both new mechanisms produces a relaxation of differential stresses and the integration of additional scale lengths in the models. However, challenging features are remaining, such as an efficient integration with the recrystallisation processes (grain boundary migration and nucleation of new grains), or appropriate incorporation of transient creep processes. Lebensohn et al (2012) An elasto-viscoplastic formulation based on fast Fourier transforms for the prediction of micromechanical fields in polycrystalline materials, International Journal of Plasticity, 32–33, 59–69. 
UAV-based atmospheric methane detection system
Authors: Butkus Laurynas , Ežerinskis Žilvinas , Vaitekonis Šarūnas , Plotnikov Artur , Pabedinskas Algirdas , Plukis Artūras , Remeikis Vidmantas
Published: February 2023

The intensive development of industry, agriculture, and transportation cause many issues related to the negative impact on the environment and human health. Due to increasing concentrations of greenhouse gases (CH4, CO2, etc.), the effects of global warming are already being observed. Research that addresses the challenges of climate change mitigation and creates science-based assumptions for new environmental monitoring systems and technologies is becoming more and more relevant.A new DronLab system for measuring methane and other greenhouse gases is currently in development. The system consists of a high-lifting power drone designed to carry the quantum cascade laser (QCL), parabolic mirror, and detector and a smaller quadcopter drone designed to lift the retroreflector to reflect the mid-IR laser pulse back towards the first drone. DronLab system will allow simultaneous measurement and visualization of methane dispersion and emission from a point source.Methane concentration would be measured at 3.37 µm using a quantum cascade laser. This system will provide the ability to measure the pollutants using variable optical path lengths. A changeable optical path would result in a higher dynamic range of the methane detection system.
Understanding the role of structural inheritance and flat slab geometry in Central Andes
Authors: Pons Michael , Rodriguez Piceda Constanza , Sobolev Stephan V. , Scheck-Wenderoth Magdalena , Strecker Manfred R.
Published: February 2023

The Sierras Pampeanas (29 - 35°S) located south of the Altiplano-Puna plateau above the Chilean subduction zone, consist of uplifted foreland basement blocks that are an expression of the eastward propagation of compresive deformation. Their presence is one of the most enigmatic features of the Andes. The formation of these ranges is considered an end member of the thick-skinned foreland deformation style, which involves the deformation of the sedimentary cover and the crystalline basement. At 33°S, the onset of compression occurs at 22Ma, and the change between thin and thick skinned deformation style at 16Ma. However, the mechanism responsible for this evolution remains controversial. Two main hypotheses have been proposed to explain this evolution. The first one atributes the change in foreland deformation style to the setting of the Pampean flat slab at 12 Ma, which is contemporanous to the southward migration and subduction of the Juan Fernandez hotspot ridge at 33S. Alternatively, it has been proposed that the reactivation of pre-existing structures inherited from pre-Neogen tectonic events could better explain the onset of deformation about 10 Ma before the arrival of the flat-slab. To resolve this controversial debate, we have developed a data-driven 3D geodynamic model using the FEM geodynamic code ASPECT. We incorporated the present-day geometrical and thermal configuration of the southern central Andes and the flat-slab from previous models. This approach allowed us to study the structural and thermomechanical factors responsible for the location of deformation in the Sierras Pampeanas (e.g., topography, temperature and composition, strength of the lithosphere and velocity of the plates).  Moreover,  we investigated the role of the geometry of the Nazca plate on the foreland deformation, and proposed a new mechanism ("flat slab conveyor)" that reconciles the timing of the main geological events (onset of shortening, change in tectonics style of deformation of the foreland, growth of the topography, cessation of volcanic activity, uplift of the basement, and propagation of the deformation). This work expands our understanding of how plates interact at convergent boundaries, in particular at the subduction zones, and how and where deformation is expressed at the surface of the the upper continental plate.
Identification of an elevational breakpoint where climatic signal changes for the growth of Larix decidua tree rings in a glacier-fed river basin in the Swiss Alps
Authors: Islam Nazimul , Lane Stuart , Vennemann Torsten , Meko David
Published: February 2023

Tree-rings are a valuable proxy for reconstructing past environmental conditions such as climate at annual or intra-annual resolutions. Tree-ring dating has an enormous potential for better understanding climate dynamics under a changing climate. In Alpine regions, changes in climate may well lead to switches between temperature-limitation and precipitation-limitation. However, such changes cannot be separated from local environmental influences such as altitude and aspect. In this study, we applied the standard statistical approaches of dendrochronology to understand climate-growth relationships as a function of elevational gradients to understand how altitude conditions the impacts of climate change impacts on tree growth. For the growth of European Larch (Larix decidua) trees in the Turtmann river basin (2000 m a.m.s.l.), a glacier-fed river basin in the Swiss Alps, located in south-western Switzerland, we find that climate warming is leading to some switching from temperature limitation to precipitation limitation and vice-versa according to altitude. The climate-growth relationship further reveals that the growth of Larix decidua in this river basin is positively correlated with the October and November temperature of the previous year (r= 0.46, α=0.01). Comparing these changes with other tree-ring chronologies from the international tree-ring data bank (ITRDB) for the same species at much lower elevation transects  (e.g. 1500 m and 900 m a.m.s.l) show that the tree growth switches from temperature limitation to precipitation limitation. The growth of Larix decidua for these lower elevation trees correlates positively with the current year June-July precipitation (r= 0.40, α=0.01). A number of factors including differences in micro-climate and the effects of aspect (i.e. north versus south facing) across the elevational gradient are most likely to be responsible for these differences. Therefore, in the context of Swiss Alps where the temperature is rising at more than twice the global average, there is likely a breakpoint where the signal changes from temperature-limitation to precipitation-limitation across the elevational gradient and that climate change is causing this breakpoint to rise with altitude through time.Keywords: Tree-rings, Larix decidua, Climate change, Turtmann river, Swiss Alps 
Influence of radiative forcing on Titan’s lake energy balance and sea breeze circulation
Authors: Rafkin Scot , Chatain Audrey , Soto Alejandro
Published: February 2023

Solar and infrared radiative transfer, including the effects of scattering, have been included in the mesoscale Titan WRF (mtWRF) model of Titan’s atmosphere.  A previous study with this model in the absence of radiative forcing indicated that atmosphere-lake sensible and latent heat fluxes could diminish to magnitudes comparable to radiative fluxes due to the development of a cold and stable marine boundary layer.  Consequently, it was hypothesized that radiative forcing could be important, contrary to prior expectations, and should be included in future studies. With these results we confirm the radiative hypothesis and demonstrate that radiative forcing must be included in order to more accurately simulate the energy and mass exchange between Titan’s lakes and atmosphere. Solar heating of the lake mixed layer partially offsets the latent flux cooling during the daytime, and downwelling atmospheric IR flux provides heat to the cold lake.  Due to changes in thermal contrast between the air over the lake and the land compared to non-radiative solutions, the sea breeze atmospheric structure is altered, including the development of a pronounced diurnal circulation cycle.  All of these effects perturb the energy and mass exchange, which has local meteorological implications and exerts a control on the global methane cycle.
The effects of warm air intrusions in the high arctic on cirrus clouds
Authors: Dekoutsidis Georgios , Groß Silke , Wirth Martin
Published: February 2023

In the last decades scientist have noticed that the average global temperature of the Earth has been increasing. Moreover, the arctic is warming significantly faster than the global average, a phenomenon labeled Arctic Amplification. Two atmospheric components contributing to the warming of the atmosphere in the arctic are water vapor and cirrus clouds. Both have an effect on the radiation budget of the atmosphere and more specifically the longwave radiation. A Warm Air Intrusion (WAI) event is defined as the meridional transport of warm, water-vapor-rich airmasses into the arctic. During such events large amounts of water vapor can be transported into the arctic, which also leads to high supersaturations aiding the formation and longevity of cirrus clouds. There is a strong hypothesis that WAI events in the high arctic are becoming more frequent, so it is important to study the effects these events have on the macrophysical and optical properties of cirrus clouds in the arctic.The HALO-(AC)3 flight campaign was conducted in March/April 2022 with the central goal of studying WAI events in the arctic regions of the Northern Hemisphere. For this campaign the German research aircraft HALO was equipped with remote sensing instrumentation, including the airborne LIDAR system WALES which we use in this study. WALES is a combined water vapor differential absorption and high spectral resolution lidar. It provides water vapor measurements in a 2D field along the flight track. We combine these measurements with ECMWF temperature data and calculate the Relative Humidity with respect to ice (RHi) inside and in the vicinity of cirrus clouds. For each flight we studied the synoptic situation and created two groups: One containing flights were cirrus that formed in arctic airmasses were measured and another were cirrus were measured during WAI events, henceforth arctic cirrus and WAI cirrus respectively. Our main goal is to compare the humidity characteristics inside and in the vicinity of arctic cirrus clouds and WAI cirrus clouds.For the arctic cirrus we find that 49 % of the in-cloud data points are supersaturated with RHi mostly below the lower threshold for heterogeneous nucleation (low HET). The cloud-free air around these clouds has a supersaturation percentage of 8.5 %. The WAI cirrus are measured in a wider temperature range and also have a significantly higher supersaturation percentage inside as well as in the cloud-free air, 61.7 % and 9.3 % respectively. The majority is again in the low HET regime. Additionally, WAI cirrus are on average geometrically thicker than arctic cirrus. Finally, regarding the vertical distribution of RHi within these clouds we find that WAI cirrus have their highest supersaturations near the cloud top and become gradually subsaturated towards cloud-bottom. On the other hand, arctic cirrus have their highest supersaturations near cloud-middle, with lower supersaturations at cloud-top and subsaturated cloud-bottom.
Backward particle tracking analysis for probabilistic contaminant source assessment
Authors: Tufoni Paolo , Costa Luís , Sousa Vânia S. , Monteiro José Paulo , Nunes Luís M.
Published: February 2023

Groundwater resources in the South of Portugal are under growing pressure due to an unbalanced water budget, mostly due to low natural recharge in recent years which, in some cases is leading to historically lowest observed groundwater levels. Additionally, groundwater quality issues have also been studied, mostly related to the use of fertilizers in agriculture, nonetheless, emerging contaminants such as pharmaceuticals are a growing risk and recent field campaigns have identified the occurrence of such substances in groundwater of South of Portugal. Moreover, the effects of climate change are expected to worsen the current situation. Modelling groundwater flow and contaminant transport with deterministic models is a practical tool to predict how groundwater might respond to climate change’s effects. However, to include uncertainty regarding highly complex geological heterogeneity units as well as input and outputs can be quite demanding and challenging with deterministic models. The stochastic approach is a promising technique that incorporates such uncertainties into the models. Markov chain transitions, a facies-based geostatistical approach represent a widely implemented stochastic approach for the generation of different scenarios with spatial distributions of hydraulic conductivity in heterogeneous aquifers. Particle tracking presents an alternative means of simulating the advective movement of a contaminant, offering the possibility of interpreting particle behavior. Backward particle tracking is computationally fast, numerically stable, and can reduce the uncertainties of source location estimates, optimizing the design of monitoring networks. In this work, a methodology consisting of a stochastic version of the backward particle tracking is applied to a multi-layered coastal aquifer in Faro (Algarve) to provide insight regarding the source of the pharmaceuticals detected in groundwater. To attain this task a three-dimensional flow and transport FEFLOW model for the study area (Campina de Faro aquifer system) was used.

KEYWORDS: Groundwater, Emerging contaminants, Pharmaceuticals, Portugal, Campina de Faro

ACKNOWLEDGMENTS
This work was supported by eGROUNDWATER – Citizen science and ICT-based enhanced information systems for groundwater assessment, modeling, and sustainable participatory management (GA n. 1921) and MIT Portugal Partnership 2030 (MPP2030-FCT) under the Doctoral Grant PRT/BD/153504/2021 Climate Science & Climate Change.
Shear Strength Development During Early Burial on Seismically Active Margins: A Geotechnical Investigation into Seismic Strengthening
Authors: Fitzgerald Bailey , Sawyer Derek , Reece Julia , Scott Wyatt
Published: February 2023

Recent work has demonstrated elevated shear strength in the uppermost 100 meters below seafloor (mbsf) on seismically active margins. This observation is consistent with the seismic strengthening hypothesis that repeated exposure to earthquake shaking progressively dewaters and densifies sediment, which leads to increased shear strength and slope stability.  However, the relative contribution of seismic strengthening versus intrinsic properties on shear strength remain largely unknown. Here, we compare sediments from seismically active and passive margins from scientific ocean drilling sites that exhibit significant shear strength differences. Active margin sites are Nankai (Site C0001), Cascadia (Site 1054), and Southern Alaska (Site U1418), and passive margin sites are Amazon Fan (Site 942), North Carolina Slope (Site 1054), and New Jersey (Site 1073). From each site, we sampled 500 g of sediment equally distributed throughout the top 100 mbsf. We combined samples to create a representative bulk sample per continental margin and reconstituted them with saltwater that matched field-measured salinity. We measured particle size (hydrometer), plasticity states (Atterberg limits), mineralogy (powder X-ray diffraction), compression behavior and permeability (1-D resedimentation experiments), and undrained shear strength (fall cone device). All samples are siliciclastic marine mud that classify as silty clay or clayey silt. Despite the apparent similarity in lithology, sand fraction varies from 0.8 wt. % (Amazon) to 10.3 wt. % (N. Carolina) and clay fraction (<2 mm) varies from 37.7 wt. % (N. Carolina) to 56.0 wt. % (Amazon). Void ratios, measured in resedimentation experiments range from 1.6 (porosity = 62%) (Nankai) to 1.0 (porosity = 50%) (S. Alaska) at a vertical effective stress of 100 kPa. Resedimentation experiments are followed by consolidation to 1 MPa (equivalent to 100 meters of burial depth) and undrained shear strength measurements, which are compared with field-measured shear strengths. We find the previously observed strengthening effect observed in the active margin field- strength is no longer present in the lab-strengths. This suggests that the exposure to seismicity in the field is potentially leading to enhanced shear strength during early burial.
Quantifying stress fields to better understand shallow tectonics of the Hikurangi Subduction Margin, NZ
Authors: Behboudi Effat , McNamara David , Lokmer Ivan
Published: February 2023

Quantitative stress data is crucial to understanding the mechanical behaviour of faults and the variation of  interface slip behaviours at subduction zones. The Hikurangi Subduction Margin (HSM), New Zealand is characterized by along-strike variations in subduction interface and fault slip behaviour, changing from shallow slow slip events (SSEs) and creep to interseismic locking and stress accumulation moving south. We quantify the shallow (<3km) HSM stress magnitudes and orientations and utilise this new data to determine tectonic variation along the HSM and discuss how this may relate to the large-scale observation in HSM subduction dynamics. For depths below ~650 mTVD results show σ3: Sv ratios of 0.92-1 along the entire HSM, and SHmax: Sv ratios of 0.95-1.81 in the central HSM, and 0.95-2.15 in the southern HSM. Such ratios infer that below ~650 mTVD a prevalent thrust to strike-slip (σ1=SHmax) faulting regime exists along the entire HSM. Our results also reveal a NE-SW (margin-parallel) SHmax orientation in the shallow central HSM, which rotates to a WNW- ESE/NW-SE (margin-perpendicular) SHmax orientation in the shallow southern HSM.In the central HSM, we determine the  NE-SW orientation of SHmax= σ1, which is inconsistent with  NNE/NE striking reverse faults (inferring a NW-SE oriented SHmax= σ1) in the region. This suggests that the stress state evolved over time from a contractional to a strike/oblique-slip state. This temporal change in stress state in the central HSM is likely driven by development of clockwise rotation of the Hikurangi forearc and upper plate overpressures. A contemporary NW-SE oriented SHmax in the southern HSM, associated with NNE/NE striking faults, suggests the stress regime here remains contractional over time, and is less effected by forearc rotation. The variation in stress state along the HSM spatially correlates with reported along-strike variation in subduction interface slip behaviour. This spatial correlation suggests that contemporary stresses in the overriding plate above the subduction interface may reflect contemporary elastic strain accumulation processes related to subduction megathrust locking. 
Establishing a relationship between rock control and rates of coastal erosion using high precision sequential UAV photogrammetry data and Leeb rebound impact hardness testing
Authors: Thrower Andrew , Barlow John , Moore Roger
Published: February 2023

In Northern Europe, chalk is an important material affecting many coastal communities. This has led to a great deal of research into coastline recession to quantify rates of coastal erosion and to understand the processes and mechanisms that control coastal rock mass instability of chalk cliffs. Along the UK and French chalk coastlines, estimates for rates of coastal retreat vary, but are generally understood to be between approximately 0.2 my-1 and 0.6 my-1.  Along the Sussex coastline rockfalls from the coastal chalk cliffs tend to be small in nature, typically producing less than 1,000 m3 of material. Larger rockfalls, however, do occasionally occur and can exceed 20,000 m3. Understanding the relationship between rock strength and wave energy is of great importance in predicting cliff recession. Although the importance of understanding the contribution of rock control on coastal erosion is widely recognised, establishing a direct link between rock material properties and rates of erosion has proven to be difficult.                                                               This study presents the findings from five years of coastal monitoring at a site in Sussex (United Kingdom) using UAV photogrammetry. Rates of coastal erosion have been calculated and are found to be in general agreement with those in the published literature. Sequential monitoring undertaken at the site enabled the identification of many rockfalls with calculated volumes ranging between <100 m3 and >4,000 m3. Sampling of rock materials in the field for laboratory testing was undertaken. Extracted dried core sub-samples were tested with a Leeb hardness tester (Equotip) to derive a surface hardness at regular intervals along the cliff-line. Previous research (Thrower et al, 2022) has already demonstrated that the Leeb hardness of chalk has a good relationship with intact dry density and can therefore be a useful tool for estimating rock strength. The results of this study show a good correlation between Leeb hardness and back-wear along the cliff-line at the study site, indicating a relationship between rock strength and rates of coastal erosion. The data show that sections of the study area characterised by softer relatively low-density chalk have been eroded at faster rate than areas characterised by harder relatively high-density chalk. This work demonstrates the potential that Leeb hardness testers have in the characterisation of rock mass properties for quantifying rock control in coastal studies. Furthermore, such testing could provide useful data in predicting future cliff recession behaviour at coastal sites.
A framework for improved near real-time flood mapping
Authors: Friberg Tapio , Khadka Ambika , Dupeyrat Arnaud
Published: February 2023

ICEYE has been a leader in the mapping and monitoring of global floods for the insurance sector and governments over the last two years. Current operational flood monitoring is based on the large-scale and systematic availability of synthetic aperture radar (SAR) data from the small satellite constellation deployed and operated by ICEYE. The main advantages of SAR images are that they provide synoptic views over wide areas, day and night and in all-weather conditions. However, SAR can be less suitable for providing flood extent information in dense urban areas and under tree canopy cover. In addition, SAR-based flood depth generation methods struggle to provide accurate depth estimations in steep terrain. There is currently a demand to aid observational flood models with physically-based flood modeling in urban areas.Most operational real-time flood estimates are based on predictions of discharges at river flow monitoring stations using 1D hydrological models. 2D inundation models are computationally expensive and thus require special tooling for creating rapid flood maps. In this presentation, ICEYE will describe a framework that can be used for improving the robustness and accuracy of near real-time flood predictions.
Sub-ionospheric VLF/LF waveguide variations related to magnitude M>5 earthquakes in the eastern Mediterranean area
Authors: Eichelberger Hans , Boudjada Mohammed Y. , Schwingenschuh Konrad , Besser Bruno P. , Wolbang Daniel , Solovieva Maria , Biagi Pier F. , Galopeau Patrick , Jaffer Ghulam , Aydogar Özer , Schirninger Christoph , Muck Cosima , Jernej Irmgard , Magnes Werner
Published: February 2023

In this study we examine earthquakes with magnitude M>5 in the year 2022 where the epicenters are crossed by sub-ionospheric narrowband VLF/LF radio links. The study regions are Italy, Aegean area, and the Balkan Peninsula. Ideal suited for this task are paths from the transmitters TBB (26.70 kHz, Bafa, Turkey), ITS (45.90 kHz, Niscemi, Sicily, Italy), and ICV (20.27 kHz, Tavolara, Italy) to the seismo-electromagnetic receiver facility GRZ (Graz, Austria). The receiver is part of a wider network, this gives the opportunity to have multiple simultaneous crossings of an earthquake event.We investigate electric field amplitude variations in the time span a few days around the main shock, in particular we apply the so-called night-time amplitude method. All electric field data sets have 1 sec temporal resolution. A crucial point is a certain threshold magnitude to obtain statistically significant results, but to firm up the results additional complementary investigations are necessary.In summary, VLF/LF investigations of strong earthquakes show the complex interplay between the lithospheric events and electric field amplitude waveguide variations, multi-parametric observations in a network could be a tool to derive robust results.
Quantifying the effects of coastal erosion on flooding projections at the climate change scale
Authors: Álvarez-Cuesta Moisés , Toimil Alexandra , Losada Iñigo
Published: February 2023

Coastal flooding and erosion threaten coastal communities and climate change boosts their effects to unprecedented levels. Even if coastal erosion has a direct effect on coastal flooding, their effects are normally studied in isolation due to the complex interplays among them, leading to potentially erroneous flood risk estimates (Toimil et al., 2022). To handle this challenge, an advanced shoreline evolution model enriched with observations (Álvarez-Cuesta et al., 2022) is coupled with a profile translation model to provide the boundary condition over which to run a 2D flood model. This suite of process and physics-based models enriched with observations is applied to a 40-km coastal stretch in the Spanish Mediterranean to develop erosion-enhanced flooding projections. In this study, the effects of neglecting erosion are studied at the storm scale and in the long term on two key flood magnitudes: the total water level and the flooded area. Additionally, the most relevant climate-related uncertainty sources are identified and their relative importance evaluated. At this particular coastal site where the suite is illustrated, results reveal that neglecting erosion has a more important effect on the flooded extent than the choice of the climate model and the sea level rise trajectory by the end of the century.  This application sets the basis for establishing general behavioural rules that may come to question the conclusions of erosion-uncoupled flooding studies. Toimil, A., Álvarez-Cuesta, M., & Losada, I. J. (2023). Neglecting the effect of long-and short-term erosion can lead to spurious coastal flood risk projections and maladaptation. Coastal Engineering, 179, 104248. Álvarez-Cuesta, M., Toimil, A., Losada, I.J. (2022). Modelling long-term shoreline evolution in highly anthropized coastal areas. Part 1: Model description and validation. Coastal Engineering, 169, 103960.
A 5-million-year record of (de)oxygenation and associated changes in basin restriction in the Mediterranean Sea
Authors: van der Hoeven Isabel , Grant Katharine , Rohling Eelco , Liebrand Diederik , Lourens Lucas , Reichart Gert-Jan , Hennekam Rick
Published: February 2023

Restricted basins are susceptible to develop anoxia because these land-locked basins can trap nutrients and the water column can easily become stratified. The Mediterranean basin has a limited connection to the open ocean and became increasingly restricted over time, making it suitable to study effect of basin configuration on anoxia development. Enhanced runoff, related to increased North-African monsoon intensity, regularly resulted in increased productivity and/or deep-water anoxia and deposition of organic-rich sediments, the so-called sapropels. Most depositional models for sapropel formation focus on the most recent sapropels (e.g. S1 and S5), outcrop samples or individual Pliocene sapropels from ODP leg 160. Until recently, continuous and high-resolution records were lacking, whereas such records can provide important constraints on the relationship between sapropel deposition and its environmental driving forces, such as climate and basin configuration. Here we present newly acquired XRF-scanning data of redox-sensitive trace elements and estimates for total organic carbon (TOC) from a 5 Myr record of the Eastern Mediterranean Sea (ODP Site 967), where reoccurring sapropels are recorded from 3.2 Ma onwards. Based on our geochemical proxies, we reconstruct (de)oxygenation and associated basin restriction over the last 5 Myr. This record allows us to elucidate which primary processes drove sapropel formation in this basin and whether these processes changed over time. We show that the first preserved Pliocene sapropels (~3.2-3.0 Ma) are highly enriched in redox-sensitive trace elements and have TOC values up to 25%, and likely formed in a much more open (i.e. with increased water renewal) depositional environment. Such a model of Mediterranean sapropel deposition differs significantly from that of the more recent sapropels, which are deposited in a much more restricted environment. Hence, the depositional model for recent sapropel formation cannot be directly extrapolated to these older sapropel deposits.
Validation of RegCM5 at convection parametrized resolution over the CORDEX-CORE domain and at convection permitting resolution over the Euro-CORDEX domain
Authors: Coppola Erika , Giuliani Graziano , Emanuela Pichelli , Nogherotto Rita , Raffaele Francesca , Ciarlò James , Abba Omar Sabina , Zazulie Natalia , Lu Chen , Vargas Luiza , Andrade Cardoso Andressa
Published: February 2023

New evaluation simulations with the ERA5 boundary conditions have been completed with the new model RegCM5 for all CORDEX-CORE domains at 25 km resolution. Model performances are satisfactory for all evaluation metrics for both the mean climate and extreme climate and for temperature, precipitation and cloud variables. For some of the domains the new model is able to remove some well know biases like the dry bias in the Amazon region in the CAM domain or the warm bias in the La Plata basin for the SAM domain. In other domains the RegCM5 performs consistently with the previous model version.  One simulation at convection permitting resolution (CP) has been completed for the first time for the whole Euro-CORDEX domain thanks to the new semi implicit dynamical core implemented in the RegCM5 that allow the model to remain stable at such resolution even with time steps of 30 seconds at 3 km resolution.   The evaluation of the CP simulation is comparable with the previous model evaluation over the ALPS domain with a tendency to improve both the dry and wet bias in summer and winter respectively. Over the whole Euro-CORDEX domain validation of the sub daily statistic for the precipitation frequency, intensity and diurnal cycle confirm the fitness for purposes of this new model version to run at such resolution for such extended region. A further CP configuration is also tested with two overlapping longitudinal stripe domains covering the Euro-CORDEX domain and the comparison is shown between the two CP simulations. 
Advancing science readiness for a new snow mass radar mission
Authors: Derksen Chris , Montpetit Benoit , Vionnet Vincent , Fortin Vincent , Lemmetyinen Juha , Kelly Richard , Thompson Aaron
Published: February 2023

Environment and Climate Change Canada (ECCC) and the Canadian Space Agency (CSA) continue to advance a new satellite Ku-band radar mission focused on providing moderate resolution (500 m) information on seasonal snow mass. Like many regions of the northern hemisphere, estimates of the amount of water stored as seasonal snow are highly uncertain across Canada. To address this gap, a technical concept capable of providing dual-polarization (VV/VH), moderate resolution (500 m), wide swath (~250 km), and high duty cycle (~25% SAR-on time) Ku-band radar measurements at two frequencies (13.5; 17.25 GHz) is under development. Parallel to engineering studies to address the technical readiness, a range of activities are in progress to advance scientific readiness. In this presentation, we will review how recent progress within the mission science team and across the snow community has provided a sound science foundation for the mission, and identify risks to meeting the required level of readiness within the required timeline for full mission implementation. Key areas include:Implementation of computationally efficient SWE retrieval techniques, including parameterized forward model simulations for prediction of snow volume scattering, physical snow modeling to provide initial estimates of snow microstructure, and consideration of background characteristics;
Incorporation of land surface model SWE estimates to infill gaps with no radar-derived SWE information due to dense forest, wet snow, and swath gaps;
Direct assimilation of Ku-band backscatter into environmental prediction systems (analogous to how SMOS and SMAP data have improved soil moisture analysis through radiance-based assimilation);
Segmentation of wet from dry snow;
Continued advancement of the understanding of the physics of Ku-band backscatter response to variations snow through new experimental tower and airborne measurements.
Ku-band radar is a viable approach for a terrestrial snow mass mission because these measurements are sensitive to SWE through the volume scattering properties of dry snow and can discriminate the wet versus dry state of snow cover. To justify investment in such a mission, however, the scientific pieces must be in place. Balanced and honest assessments of the state of scientific readiness, the likelihood for emerging capabilities, and the level of engagement across the snow community are essential to ensure a healthy mission development process.
Application of combined constructed wetland- microbial fuel cell system for simultaneous bioenergy generation and treatment of wastewater contaminated with sulfamethoxazole
Authors: Jain Mahak , Ghosal Partha Sarathi , Gupta Ashok Kumar
Published: February 2023

In recent times, the research trend has shifted towards identifying sustainable energy resources. Bioenergy generation employing wastewater and micro-organisms might be a potential solution to achieve this goal. In microbial fuel cells (MFC), the energy stored in the chemical bonds of contaminants present in wastewater is utilized by the micro-organisms for their metabolism in redox conditions. Furthermore, in this process, free electrons are released into the system, which are captured by the electrodes resulting in the generation of electricity in the external circuit. Hence, the system provides wastewater treatment along with bioenergy generation. However, the system finds difficulty in degrading recalcitrant organic compounds, such as pharmaceuticals and other emerging contaminants, which is possible in constructed wetland (CW) systems. However, CWs require a large footprint area. Recently, combined CW and MFC systems are being used for this purpose due to their resilience and capacity to produce electricity and provide a high level of wastewater treatment. Combined CW-MFC has been found to be more useful than either system alone by complimenting their issues as the redox conditions required for the proper functioning of the MFC system are available in the CW system. Furthermore, the high diversity of micro-organisms present in MFC improves the treatment efficiency of the CW system. This study involves the application of a combined CW-MFC system for the treatment of wastewater and the production of bioelectricity using Lemna minor as macrophyte species. Graphite plates were used as the anode and cathode for electricity production. In order to test the system's effectiveness in terms of removing recalcitrant organic compounds, synthetic wastewater was spiked with 5 mg/L of sulfamethoxazole. The influence of various parameters, such as electrode spacing, the substrate to water depth ratio, and the initial COD concentration of wastewater, was studied. Considerably high removal of around 99% for sulfamethoxazole and 90% for COD removal were observed, along with the production of 133 mV of voltage. It was observed that with the increase in initial COD concentration and substrate to water depth ratio, COD removal also increased. However, an increase in electrode spacing and substrate to water depth ratio after a certain limit showed a negative effect on voltage generation. The entire system could effectively generate bioenergy and treat the sulfamethoxazole-contaminated wastewater.Keywords- Constructed wetlands, Microbial fuel cell, Lemna minor, Emerging contaminants, Bioelectricity
Spatial and Temporal Evolution of Glacier Lakes in the Hindukush Region of Afghanistan (HKA)
Authors: Azizi Fayezurahman , Lane Stuart
Published: February 2023

Rapid climate change is leading to global loss of snow and ice from the world’s cryosphere and mountain glaciers. Of particular concern is the changing risk related to rapid melt of snow and ice, shrinking of glaciers, and eventual expansion and formation of new glacial lakes. If these breach then glacial lake outburst floods (GLOFs), potentially catastrophic, may result. One region in the Himalayas-Hindukush where glacier lake formation and GLOF behavior is very poorly known is Afghanistan. The country’s geographical location and climate leave it highly exposed to GLOFs. Several lakes have burst and caused GLOFs as reported across the HKH region. In Afghanistan, a catastrophic GLOF recently occurred in Panjshir, upstream of Kabul (on 12 July 2018), with an impact foot print of 55126m2 that devastated the village of Peshghor with significant socio- economic losses and also dammed the Panjshir River up to 1.7 km from the river confluence.The absence of an up-to-date, multi-temporal and high-resolution inventory of Afghanistan's glacier lakes is seen as a significant obstacle. Such lakes are extremely remote and difficult to map and to monitor in the ground. In this study the spatial and temporal evolution of glacier lakes in the Hindukush region of Afghanistan (HKA) is conducted from Landsat imagery to make a time series with three dates; 1990, 2015 and 2020. For this purpose, we applied geospatial techniques using Landsat 8, Operational Land Imager (OLI) and the Normalized Difference Water Index (NDWI) is proposed in this paper.Initial findings indicate that the number and area of glacial lakes increased continuously from 1990 to 2015, increased by 8% and 10% respectively to give a total of 1942 glacier lakes covering an area of 89km2 by 2015.The outcomes of the proposed study will be useful and effective for GLOF risk reduction management and development of an overall strategy to address possible risks from future GLOFs events in the country, in order to develop the capacity of downstream vulnerable communities to mitigate impacts of this events.Key words: Glacier Lakes, Glacier Lake outburst flood, Landsat data, NDWI, Peshghor GLOF, Hindukush region, Afghanistan.
Callisto’s atmosphere: First evidence for H2, and the implications this has for Europa’s and Ganymede’s atmosphere
Authors: Carberry Mogan Shane , Tucker Orenthal J. , Johnson Robert E. , Roth Lorenz , Alday Juan , Vorburger Audrey , Wurz Peter , Galli Andre , Smith H. Todd , Oza Apurva V. , Liuzzo Lucas , Poppe Andrew R.
Published: February 2023

We explore the parameter space for the contribution to Callisto's H corona observed by the Hubble Space Telescope from sublimated H2O and radiolytically produced H2 using the Direct Simulation Monte Carlo (DSMC) method. The spatial morphology of this corona produced via photo- and magnetospheric electron impact-induced dissociation is described by tracking the motion of and simulating collisions between the hot H atoms and thermal molecules including a near-surface O2 component. Our results presented indicate that sublimated H2O produced from the surface ice, whether assumed to be intimately mixed with or distinctly segregated from the dark non-ice or ice-poor regolith, cannot explain the observed structure of the H corona. On the other hand, a global H2 component can reproduce the observation, and is also capable of producing the enhanced electron densities observed at high altitudes by Galileo's plasma-wave instrument, providing the first evidence of H2 in Callisto's atmosphere. Finally, we discuss the implications of these results, in particular how they compare to Europa and Ganymede.