bluuebunny/crossref_metadata_2025 huggingface dataset:
Radar tomography of asteroid deep interior. JuRa / HERA to DIDYMOS and Ra proposed to APOPHIS 
Authors: Herique Alain , Plettemeier Dirk , Kofman Wlodek
Published: March 2024

Our knowledge of the internal structure of asteroids relies entirely on inferences from remote sensing observations of the surface and theoretical modeling. Is the body a monolithic piece of rock or a rubble-pile, and how high is the porosity? What is the typical size distribution of the constituent blocks? Are these blocks homogeneous or heterogeneous? Direct measurements of an asteroid’s deep interior structure are needed to better understand asteroid accretion and their dynamic evolution. The characterization of the asteroids’ internal structure is crucial for science, planetary defense and exploration. In orbit Radar sounding is the most mature instruments capable of achieving the objective of characterizing the internal structure and heterogeneity, for the benefit of science as well as for planetary defense or exploration.This is the goal of JuRa, the Juventas radar, onboard the ESA HERA mission. JuRa is a monostatic radar, BPSK coded at 60MHz carrier frequency and 20MHz bandwidth, inherited from CONSERT/Rosetta. The instrument design is under integration on Juventas cubesat for the ESA HERA mission. HERA will be launched this autumn to deeply investigate the Didymos binary system and especially its moonlet Dimorphos, five years after the DART/NASA impact. The main objective of JuRA is to characterize the asteroid interior, to identify internal geological structure such as layers, voids and sub-aggregates, to bring out the aggregate structure and to characterize its constituent blocks in terms of size distribution from submetric to global scale. The second objective is to estimate the average permittivity and to monitor its spatial variation in order to retrieve information on its composition and porosity.This radar is also proposed to probe Asteroid 99942 Apophis in 2029, a potentially dangerous asteroid which will then approach Earth as close as 32000 kilometers on the DROID JPL/CNES and the RAMSES ESA proposed missions. This radar, which is a modified version of JuRa, will be able to operate in both monostatic and bistatic modes between orbiting or landed CubeSats. The knowledge of Apophis’ internal structure is crucial to improve our ability to study its stability conditions and to model its response to the gravitational constraints induced by Earth close approach. The Multipass processing will allow us to build a 3D tomographic image of the interior at different scales from submeter to global.In this talk will present the instrument, its status, performances and goals as well as the science objectives in the context of the different targets.
Drinking plastic: a study of microplastic concentrations in drinking water from rural and urban sources in Mali, Africa
Authors: Kelleher Liam , Phillips Alice , Schneidewind Uwe , Mobido Telly , Haverson Lee , Asamane Evans , Sidibe Cheick , Diarra Youssouf , Koilta Ousmane , Manaseki-Holland Semira , Krause Stefan
Published: March 2024

Drinking water (DW) is a necessity for life, and its pollution is of global concern for public health. Whilst the global occurrence of microplastic (MP) pollution in various environmental matrices is a focal point for research, the focus on microplastics in drinking water sources is somewhat less. Previous research has shown orders of magnitude difference in MP contamination of drinking water in residential areas, owing to local water source, water contamination, and container material.Here we explore the exposure of residents living in rural and urban areas of Mali in Africa to microplastics in drinking water from varying sources. DW samples were taken from 83 homes, from urban residents in the city of Bamako and those in several rural settlements to the east of Bamako. These homes received their drinking water from traditional open wells, boreholes (narrower and deeper canals, often newer sources) and taps. Urban areas often had taps in each home, whereas rural areas had communal well and borehole water points.A litre of DW was collected from each source which was subsequently sieved at 63 um and then washed with deionised water into a 20ml vial before shipping to the UK. Wet hydroxide digestion was carried out using 30% hydrogen peroxide at a minimum ratio of 1:1 sample to peroxide. After 24 hours the sample was filtered, and 80% of samples were mixed for 1 hour with Nile red, concentration 5 ug/ml, followed by filtering on glass fibre disk. These samples were assessed with fluorescence microscopy to assess polymer number and morphology. The remaining 20% were directly filtered onto Anodisc and assessed for polymer number and type using confocal Raman spectroscopy.Our results capture a range of polymer types, morphological properties, and concentrations in the studied water samples. A statistically significant mean value of 9.9 mp/l (range 1-34 mp/l) for urban DW compared to 6.5 mp/l (range 0-15 mp/l) for rural DW was found. A range in distribution of MP concentration was found across the study sites regardless of geographic assignment. Morphologically fibres were most identified, 69% for rural and 72% for urban. The primary polymer types found were PMMA, PE, PS, PA/nylon, and PET.The study sets the basis for a wider investigation of water sources in the region, followed by the perspective linking of health outcomes to the MP exposures found.
A New Gewex Regional Hydroclimate Activity in Central Asia
Authors: van Oevelen Peter , Orunbaev Sagynbek , Kulikov Maksim , Brody Michael
Published: March 2024

In the early 1990s a newly formed GEWEX Program (Then called the Global Energy and Water cycle Experiment now: Global Energy and Water EXchanges project) launched a regional study to measure and model regional variations in the water and energy cycle. A continental scale experiment was needed to develop the ability to measure and model the components of the water and energy cycles over a macroscale land surfaces from smaller scale observations. These projects are now called Regional Hydroclimate Projects and are much broader than just the geophysical science and cover the entire earth system.In this presentation an overview of the evolution of these RHPs  is shown along with a vision on the current and future relevance and importance of such projects along with the necessary additional activities such as cross cutting activities to link regional science to global efforts. In particular the development of a new RHP in Central Asia will be highlighted and how it links to regional activities such as AsiaPEX and Third Pole Environment – Water Sustainability (TPE-WS) RHPs as well as other large scale activities in the region focused on  or related to high mountains, water sustainability and ecosystem health.
Comparison of geomagnetic activity in solar cycle 12 and 13 with that in cycle 23 and 24.
Authors: Kirov Boian , Georgieva Katya , Obridko Vladimir , Asenovski Simeon
Published: March 2024

This study compares the geomagnetic activity observed during the last two secular solar activity maxima: solar cycles 12 and 13,  and 23 and 24, respectively, highlighting the differing patterns of dual and single maxima. In sunspot cycles 12 and 13, we observe a distinct dual-maximum pattern in geomagnetic activity. This pattern contrasts sharply with the singular peaks evident in sunspot cycles 23 and 24. As is well known, the dual peaks in the geomagnetic activity during a sunspot cycle result from the action of two different geoeffective manifestations of solar activity. The peak around sunspot maximum is driven by the Coronal Mass Ejections (CMEs) which are maximium in number and intensity in sunspot maximum. The second peak is due to high-speed solar wind streams (HSS’s) originating from extended coronal holes which maximize during the sunspot declining phase.This well studied picture is observed during the secular solar minimum between the 19th and 20th centuries (sunspot cycles 12 and 13). In contrast, sunspot cycles 23 and 24 in the minimum between the 20th and 21st centuries present a different scenario. Despite reaching sunspot maxima, these cycles did not witness corresponding peaks in geomagnetic activity. Our research focuses on unraveling the reasons behind the absence of a geomagnetic peak concurrent with the solar activity maxima in these latter cycles
The importance of headwater catchments for water availability in the lower Athabasca River Basin, Canada.
Authors: Ketcheson Scott , Attema Jennifer
Published: March 2024

In Canada’s Western Boreal Plain, catchment runoff is typically low but spatially variable. Localized landscape soil and vegetation cover types, along with the hydrophysical properties of underlying glacial deposits and regional slopes, are important controls for the partitioning of precipitation into runoff, evapotranspiration, and soil water storage. Wetlands are abundant, covering up to 50% of the landscape, despite a regional sub-humid climate. Local topographic highs, including Stony Mountain, have been identified as water generation hotspots, with the goal of this research to evaluate the hydrology and importance of small headwater catchments on a local topographic high for water generation and availability in downgradient systems.Hydrologic interactions between forestlands and adjacent wetlands were characterized and related to observations of small-scale (headwater) catchment runoff dynamics within the Stony Mountain Headwater Catchment Observatory (SMHCO) in northern Alberta, Canada. Catchment runoff efficiency, or runoff coefficients (i.e., the proportion of rainfall the is produced as runoff), were evaluated for 40 events across six wetland-dominated catchments ranging in size from
Monitoring hydrographic changes in the mid-latitudinal Northeast Atlantic Ocean using seawater stable isotope data
Authors: Voelker Antje H. L. , Salgueiro Emilia , Reverdin Gilles , Fontela Marcos , Abrantes Fatima , van Geldern Robert
Published: March 2024

Since 2010 seawater samples for stable carbon and water isotope measurements were collected during various hydrographic cruises in the NE Atlantic between 29° and 60°N and 9° and 33°W, including pluriannual sampling in the Madeira basin, along the western Iberian margin and along the OVIDE/BOCATS (A25) transect between Portugal and Greenland. The samples cover the complete depth range at the respective station. For all samples δ18O was analyzed, whereas δ2H (δD) measurements were more limited and mainly focused on the wide range of water masses encountered along the OVIDE/BOCATS transect. Carbon isotope values for the dissolved inorganic carbon (δ13C-DIC) was monitored over several years at selected stations of the OVIDE/BOCATS transect and in the waters along the Portuguese margin. For some stations along the OVIDE/BOCATS transects, the results of intercomparison measurements between the laboratories at the GeoZentrum Nordbayern (Erlangen) and at LOCEAN (Paris) will also be presented.The δ13C-DIC profiles show a clear signal of anthropogenic carbon entering the water column in the NE Atlantic and leading to lower isotopic values. Whereas data obtained for samples collected in 2010 more or less agree with the data from previous decades compiled in the GLODAP database, shifts to lower values became apparent in the subsurface waters already in 2012. The signal transfer is accelerated in the subsequent years with data from 2016 onwards showing penetration of anthropogenic carbon down to 2000 m and already all the way south to 31°N (Madeira basin). New data from a cruise to the southwestern Portuguese margin in 2022 indicate that the changes now already penetrate down to 2200 m.Changes in the δ18O/ δ2H data are less obvious and mostly linked to the subpolar gyre and water mass changes associated with the “North Atlantic cold blob” between winter 2013-2014 and 2016. The presence of surface and subsurface waters with lower isotopic signals clearly tracks the eastward displacement of the subarctic front in 2014 and 2016. Likewise, the front’s subsequent retraction to the west is reflected in the data from 2018 and 2021. Low δ18O and  δ2H values in depths down to 300 m in the region between the Rockall Plateau and the Reykjanes ridge also clearly distinguish the subpolar mode water formed during the previous “cold blob” winters. On the other hand, and in agreement with the δ13C-DIC evidence, hardly any isotope signal changes are observed in the depths of the North Atlantic Deep Water (NADW) and the Northeast Atlantic Bottom Water (NEABW).
Revolutionizing Igneous Rock Classification: Proportion-Based Deep Learning Analysis of Petrographic Thin Section Photomicrographs
Authors: Jaya Evelyn Jessica , Wang Xinbing , Zhou Chenghu , Ye Nanyang
Published: March 2024

In our study, we present a segmented-based, rule-driven classification of igneous rocks through the analysis of thin section photomicrographs, representing a significant advancement over traditional petrographic methods. This deep learning-based approach is especially innovative in its recognition that the naming of rocks is intrinsically linked to the proportion of minerals they contain, a vital aspect frequently overlooked in conventional classification techniques. By focusing on accurately quantifying these mineral proportions, our method effectively addresses the subjectivity and observer variability inherent in traditional petrography. Utilizing semantic image segmentation on 963 petrographic thin section photomicrographs, we have successfully identified 29 distinct minerals and classified 15 types of igneous rocks. This showcases the precision and scope of our approach, which automates the quantification of mineral proportions, thus ensuring a more objective and precise rock classification. The development of our proprietary dataset mask, despite its labor-intensive nature and the challenges with incomplete labelling, was crucial for achieving accurate segmentation based on the proportional regions of each mineral within the photomicrographs. This segmentation, key to our rule-driven classification, streamlines the rock naming process. Our method not only sets new standards in igneous rock classification but also signifies a transformative leap in geological research. By integrating advanced image processing with deep learning, we are opening new frontiers in Earth sciences, highlighting the transformative impact of technology in refining traditional geological methodologies. Considering the dataset's incomplete and highly imbalanced mask scenario, our method achieves an accuracy of 73.32%, significantly surpassing the baseline method using VGG16 as the backbone, which attains only 63.64% classification accuracy.
GNSS-based Observation of seasonal acceleration at 79°N Glacier (Greenland) 
Authors: Männel Benjamin , Humbert Angelika , Ramatschi Markus , Steinhage Daniel
Published: March 2024

The 79° North Glacier (Nioghalvfjerdsbrae, 79NG) is one of three glaciers with a floating tongue in Greenland. Recent investigations indicate an increased subglacial discharge due to a considerably enlarged area of summer surface melt due to the warming of the atmosphere, resulting in increased water input to the base of glaciers. Consequently, ice velocities measured at the surface respond directly to changes in water pressure, revealing detailed insights about the ice dynamics. Global Navigation Satellite System, like GPS and Galileo, can observe ice velocities with high temporal resolution in horizontal and vertical directions.We will present results from the 2022-2023 GNSS measurement campaign where two tinyBlack GNSS receivers were installed at 79NG. Firstly, data quality regarding common indicators like the number of tracked satellites, signal strength, and multipath will be discussed. Secondly, variations in the ice reflection characteristics will be presented based on the GNSS-reflectometry technique. The final processing was carried out as kinematic precise point processing (sampling rate 30s) using GFZ’s processing software EPOS.P8 and GFZ’s operational GNSS products. Thus, thirdly, the derived time series will be discussed with a focus on short-term variations in the surface velocity. We can link speed-up events in July 2022 to rapid lake drainage using optical satellite imagery and interferometrically derived digital elevation models.
Exploring Radiative Forcing from Pliocene Boundary Conditions and CO2
Authors: Kravette Noah , Feng Ran , Dvorak Michelle
Published: March 2024

Past climate states hold valuable insights into future climate change. Among those states, mid-Pliocene (3.3 - 3.0 Ma) is often studied as an important analog to near future climate change following an intermediate warming pathway. This time interval featured topography and geography like present-day, yet with retreated polar ice sheets and expanded boreal forests, potentially reflecting equilibrium earth system responses to CO2 forcing at a centennial to millennial time scale.  

Despite the prolific research on Pliocene climate, little is known about the amount of radiative forcing, especially from changing boundary conditions, that drives the Pliocene climate. Existing constraints mainly focused on well-mixed greenhouse gases and aerosols. Here, we applied the methodology commonly used to quantify radiative forcing of future climate and its sources to constrain radiative forcing of the mid-Pliocene climate using three generations of Community Earth System Models (CCSM4, CESM1.2, and CESM2).   

To calculate ERF, the difference in net top of the atmosphere radiative fluxes is computed between a pre-industrial control and a mid-Pliocene simulation. Both are carried out with prescribed pre-industrial sea surface temperature. The three mid-Pliocene simulations separately feature a 400 ppm CO2 (the level of mid-Pliocene), mid-Pliocene geography and topography, and mid-Pliocene ice and vegetation. Changing atmospheric temperature, water vapor, surface albedo, and clear vs total sky radiative fluxes are further extracted from these simulations to calculate radiative adjustments with published radiative kernels for CESM.  

In our preliminary results with CESM1.2, we found that ERF is 1.754 W m-2 for CO2 forcings, 1.143 W m-2 for vegetation and ice sheet forcing, and -0.339 W m-2 for geographic and topographic forcing. Further, ERF from boundary condition changes mostly arises from changing surface albedo with 1.626 W m-2 for vegetation and ice sheet changes and –0.54 W m-2 for geographic and topographic changes respectively. Radiative adjustments from water vapor responses tend to amplify the instantaneous forcing with the most profound effect induced by vegetation and ice sheet changes. These results underscore the importance of constraining radiative forcing from changes in boundary conditions, which is potentially key to understanding drivers of past climate warmth and inter-model spread in simulated past climate states.  
Exploring the future expansion of perennial firn aquifers in Antarctica using a random forest emulator
Authors: Veldhuijsen Sanne , van de Berg Willem Jan , Kuipers Munneke Peter , Hansen Nicolaj , Boberg Fredrik , van den Broeke Michiel
Published: March 2024

Perennial firn aquifers (PFAs) are year-round bodies of liquid water within firn. In Antarctica, they can cause hydrofracturing of ice shelves, leading to accelerated ice-sheet mass loss. PFAs were only recently discovered in the Antarctic Peninsula, at locations with high melt and snow accumulation rates. Likely, PFAs will expand in the future as both snowfall and melt increase. So far, this has not been considered when assessing the future vulnerability of Antarctic ice shelves. One could use a firn model to predict future Antarctic PFA evolution, but to do so for a wide range of climatic forcings is computationally expensive. Therefore, we set up a random forest emulator. The emulator represents both firn and surface climate processes, so that only 2 metre temperature and precipitation are required as input. To train the emulator, we use simulations of three scenarios (SSP1-2.6, SSP2-4.5 and SSP5-8.5) from firn densification model IMAU-FDM forced by the regional climate model RACMO2, which was driven by CESM2 in turn. The emulator successfully explains 98% of the PFAs variation, therefore we use its versatility and speed to predict Antarctic PFA evolution for 15 additional RCM/GCM model forcings. We find a range of solutions, highlighting the usefulness of the emulator. Until 2100, PFA occurrence remains restricted to ice shelves in the Antarctic Peninsula for SSP1-2.6 and SSP2-4.5. For SSP5-8.5, PFAs expand to the Bellingshausen Sea region in West-Antarctica, and to Enderby Land in East-Antarctica. The meteorological conditions in Enderby Land exhibit similarities to those observed in the Antarctic Peninsula. In contrast, Getz ice shelf, which experiences high snow accumulation rates, remains insensitive to PFA formation, because it is rather cold. Our results highlight the sensitivity of relatively warm, high-accumulation ice shelves to future PFA formation and subsequent hydrofracturing.
Mining-induced subsidence and fault reactivation due to open pit lignite mining in the Hambach region, North Rhine-Westphalia, Germany: Insights from Sentinel-1 based European Ground Motion Service (EGMS) and field surveys 
Authors: Motagh Mahdi , Haghshenas Haghighi Mahmud , Piter Andreas , Vassileva Magdalena
Published: March 2024

With an operating area of 4,380 ha producing approximately 40 million tons per year  of lignite , the Hambach mine is the largest open pit mine in Germany. To extract the lignite in open-cast mining, the groundwater level needs to be lowered down to below the deepest point of the open pit mine. This leads  to major changes in the aquifer conditions which may result in land subsidence that can affect the safety of built-up structures with significant socio-economic impacts.In this study we perform a regional analysis of ground surface deformation in the Hambach mining area using interferometric observations from the Copernicus Sentinel-1 satellite. We present results from our validation investigation,  where results provided by German and European Ground Motion Services are compared with those obtained from our local surveys using high-resolution TerraSAR-X SAR data. We further investigate the correlation between InSAR measurement points, in-situ observations, and damages to infrastructures, and show evidence for several cases of fault reactivation and damages to infrastructures within the area undergoing mining related subsidence. Fault reactivation has resulted in the formation of fault scarps (offsets > 1 m), with detrimental impacts on existing structures. Finally, we integrate between results from InSAR measurement points with open source geospatial data to create maps that support hazard, exposure and risk assessment related to subsidence at regional scale in the Hambach region. 
Soil carbon-concentration and carbon-climate feedbacks in CMIP6 Earth system models
Authors: Varney Rebecca , Cox Peter , Friedlingstein Pierre , Chadburn Sarah , Burke Eleanor
Published: March 2024

Achieving climate targets requires mitigation against climate change, but also understanding of the response of land and ocean carbon systems. In this context, global soil carbon stocks and its response to environmental changes is key. In this presentation, the global soil carbon feedbacks to both changes in atmospheric CO2 and associated climate changes for Earth system models (ESMs) in CMIP6 are quantified. A standard approach is used to calculate the carbon cycle feedbacks, which are defined as soil specific carbon-concentration (βs) and carbon-climate (γs) feedback parameters. Amongst CMIP6 ESMs, it is shown that the sensitivity to CO2 is found to dominate global soil carbon changes at least up to a doubling of atmospheric CO2. However, the sensitivity of soil carbon to climate change is found to become an increasingly important source of uncertainty under higher atmospheric CO2 concentrations.
Along-strike magma-poor/magma-rich spreading transitions
Authors: Nemcok Michal , Frost Brian
Published: March 2024

D/2D data-based studies of active spreading centres brought the knowledge of extension ratedependent stretching-dominated v. buoyancy-dominated spreading. 3D reflection seismic data from the extinct centre of an initial oceanic corridor in the Caribbean allow us to see an along-strike transition between stretching- and buoyancy-dominated spreading where the spreading through detachment faulting is a precursor to the magma-assisted spreading. Studying progressively more evolved portions of the spreading centre, going from its end towards its centre, we see a progressively higher ascent of the asthenosphere, which heats the developingcore complex in the exhuming footwall of the initial stretching-dominated system. The asthenospheric ascent is associated with thermal weakening of the core complex, which eventually results in ductile deformation reaching the upper portion of the complex. Subsequently, the core complex is penetrated by the dyke located at the top of the asthenospheric body. The dyke, which subsequently evolves to a diapir-shaped body, reaches the sea floorand establishes a magma-assisted steady-state seafloor spreading. These observations lead to a model explaining the initiation of the magma-assisted spreading in the initial oceanic corridor. Furthermore, they also improve our knowledge of multiple interacting mechanisms involved in the breakup of the last continental lithospheric layer, subsequent disorganized spreading and younger organized spreading.
An efficient and accurate deep learning approach to weather prediction
Authors: Bui-Thanh Tan , Seth Arjit
Published: March 2024

Machine learning is being increasingly applied as a surrogate modeling technique for weather prediction, providing fast forecasts with similar accuracy to numerical weather prediction models. However, developing accurate state-of-the-art machine learning models requires a significant allocation of high-performance computing resources for processing datasets and training. In this work, we investigate the essential components of a deep learning model architecture for accurate weather prediction and formulate strategies that reduce the number of parameters needed in such a model based on physical assumptions to lower training time. Specifically, we investigate autoencoder architectures with convolutional and attention-based neural network layers for capturing the necessary information provided by weather data for prediction. These architectures are incorporated within the neural ordinary differential equations framework and then trained based on reanalysis data constructed from simulation and observation data to provide forecasts. The results and conclusions based on these experiments are discussed, and recommendations for future work are provided.
The role of predisposing factors in determining the rainfall intensity necessary to cause flash floods in Portugal
Authors: Vidaurre Nassif Villaça Caio , Luís Zêzere José , Pinto Santos Pedro
Published: March 2024

Flash floods are often responsible for deaths and damage to infrastructure. The general objective of this work is to create data-based models to understand how the predisposing factors influence the triggering factor (precipitation) in the case of flash floods in the continental area of Portugal. Flash floods occurrences were extracted from the DISASTER database, which contains the location and date of historical flood events in the study region. Historical daily rainfall data was collected automatically from the Copernicus database. We extracted the accumulated precipitation for 3 days preceding each event and calculated the rainfall intensity. The predisposing factors were extracted considering the whole basin that corresponds to each flood event. The  analyzed predisposing factors were: accumulated flow, average slope, average elevation, predominant slope aspect, predominant lithology and soil properties (percentage of clay, coarse sand and coarse elements and field capacity). Elevation can often define different climatic and vegetation zones, while slope influences both the concentration and the infiltration capacity. The slope aspect can influence the amount and intensity of rainfall that affects the hillslope, as well as the amount and intensity of solar radiation. Lithology represents the properties of bedrock and the soils properties influence water infiltration and percolation. The Random Forest algorithm and the Leave-One-Out cross-validation technique were used to evaluate the model's performance and create a final model that identifies the relationship between the predisposing factors and the different rainfall intensities related to each flash flood occurrence. The final model obtained a root mean square error (RMSE) value of 3, an acceptable value for the objectives of the work. The percentage of coarse elements in the soil, average slope and field capacity were defined as the most important factors in the model for defining the amount of rainfall needed for flash floods to occur in mainland Portugal. The model developed can help to predict flash flood occurrence and future work involves combining the susceptibility model with the model created in this project to create a warning system that can be updated in real time, taking into account rainfall forecasts.Acknowledgements: This work was financed by national funds through the FCT – Fundação Portuguesa para a Ciência e Tecnologia, I.P., under the grant to support the completion of the doctoral dissertation with the reference 2022.14473.BD.
Assessment of sediment accumulation in la Baells water reservoir (Catalan Pre-Pyrenees, Spain)
Authors: Hürlimann Marcel , Abancó Clàudia , Ruiz Carulla Roger , Lantada Nieves , Urruela Aritz , Sendrós Alex , Martínez Joan , Moya José , Medina Vicente
Published: March 2024

Water reservoirs play a crucial role in providing important services, but they are facing increasing vulnerability due to the impacts of climate change. Changes in precipitation patterns are affecting the quantity and quality of water in the reservoirs. Sedimentation, which is one of the main impacts, reduces the reservoir's water storage capacity. Water reservoirs act as man-made sediment traps, with the amount of sediments trapped being directly proportional to the size of the water body. Most of the sediments produced in the watershed are accumulated at the bottom of the reservoir, leading to a decrease in water storage capacity. In the context of the SED4BUD project, we are analyzing the sediment stored in the Baells reservoir located in the Catalan Pre-Pyrenees region of Spain. The reservoir, which has a capacity of 109.4 hm3, was constructed in the 1960s.We have conducted a survey of the uppermost 20% area of the reservoir, which is approximately 0.62 km2 in size, that has emerged during the 2023 drought. The purpose of the survey is to measure the amount of material that has accumulated since the last bathymetry conducted in 2001. Additionally, we aim to classify sediment fractions into coarse and fine categories to calibrate a sediment transport model. To achieve this, we have employed four observational techniques: UAV photogrammetry, boreholes, stratigraphic description, and electric resistivity tomography (ERT).According to the UAV photogrammetry analysis, it has been observed that sediment accumulation of up to four meters is present in the surrounding areas of the active river channel. The ERT profiles reveal that the majority of the material in the top four meters of soil is fine, with sandy layers present in some areas. In the deeper layers, coarse material can be observed, and the basement is estimated to be between 15 and 20 meters deep.The analysis of the boreholes and stratigraphic description aligns with the findings from the geophysics and the UAV in terms of sediment accumulation and granulometry. However, it was not possible to apply these techniques in the active channel area due to inaccessibility. This area, where the highest sediment accumulations were detected by the UAV, remains unexplored due to limited accessibility.Boreholes and stratigraphic descriptions are precise but punctual measures, while UAV and ERT offer the spatial component. UAV is useful for surface measurements, and tomography provides precision in depth.
Spontaneous equatorial flow reversals at the equator in  moist shallow water turbulence
Authors: Harnik Nili , Schröttle Josef , Suhas Dl , Sukhatme Jai
Published: March 2024

Equatorial superrotation is a striking feature in planetary circulations, also found in atmospheric circulation models. Geological evidence shows that Earth was in a state of super-rotation during the Eocene and Pliocene. On Earth, such a time period of super-rotation is sometimes referred to as permanent El Niño. While it is well established that a tropical wave source is needed for superrotation, the mechanism that provides this wave source, and what conditions allow it to be maintained are still not understood, and vary between different models. Specifically, in shallow water models with Earth like parameters, superrotation has only been found when relatively strong thermal damping was added. In this study we examine the spontaneous evolution of super-rotation in fully developed isotropically forced two-dimensional moist shallow-water turbulence, and examine the role of moisture by varying the strength of moisture coupling, and performing large ensembles of simulations. We find that while the dry runs exhibit both superrotation and sub-rotation, with spontaneous transitions between the two states, moisture results in all runs eventually reaching a stable superrotating state. We further find that a stable superrotation develops in the dry runs when we strengthen the thermal damping. We find that a meridional mass flux from the equator to the subtropics, develops in the runs with stable superrotation, and examine the role of this mass flux, which is enabled by the latent heating and the thermal damping, for the maintenance of the stable superrotation. 
Feedback Effects in Positive Corona and Relativistic Runaway Discharges
Authors: Pasko Victor , Celestin Sebastien , Bourdon Anne , Janalizadeh Reza , Jansky Jaroslav
Published: March 2024

We discuss characteristic scales and direct physical analogy between the photoionization feedback in conventional positive corona discharges in air and the photoelectric feedback in discharges driven by relativistic runaway electrons in air. In a positive corona system the avalanche of electrons in bulk of discharge volume is initiated by specific distribution of photoionization far away from the electrode.  Under inception conditions in positive corona each electron arriving at the anode creates on average just enough seed electrons in discharge volume through photoionization to replicate itself. Under these self-sustained steady state conditions, photoionization feedback produces just enough secondary electrons upstream of the avalanche to maintain the system in steady state. Analogically, in case of relativistic electron avalanches a feedback process is realized when X-rays emitted by these electrons travel backwards with respect to the electron motion and generate new relativistic electron seeds due to the photoelectric absorption in air. It is demonstrated that terrestrial gamma-ray flashes are produced by growth of long bidirectional lightning leader system consisting of positive and stepping negative leaders. The spatial extent of streamer zones of a typical lightning leader with tip potential exceeding several tens of megavolts is on the order of 10–100 m. The photoelectric absorption of bremsstrahlung radiation generated by avalanching relativistic runaway electrons occurs efficiently on the same spatial scales. The intense multiplication of these electrons is triggered when the size of the negative leader streamer zone crosses a threshold of approximately 100 m (for sea-level air pressure conditions) allowing self-replication of these avalanches due to the upstream relativistic electron seeds generated by the photoelectric absorption.References: Pasko et al., GRL, 50, e2022GL102710, 2023, https://doi.org/10.1029/2022GL102710Pasko et al., PSST, 32, 075014, 2023, https://doi.org/10.1088/1361-6595/ace6d
Non-extensivity study of the seismicity along the Mexican Pacific coast based on the Tsallis q-statistical approach.
Authors: Ramírez-Rojas Alejandro , Flores-Márquez Elsa Leticia , Sigalotti Leonardo Di G.
Published: March 2024

The Mexican Pacific coast has presented significant seismic activity due to the tectonic processes that have generated it. This coast, from Baja California until Chiapas is matched with three tectonic settings, to the north, a dispersion zone is presented in Baja California and Cortes Sea, at the middle, conforming by Jalisco, Colima and Michoacan states, La Rivera Plate is the principal source of seismicity and, finally the seismic activity in Guerrero, Oaxaca and Chiapas is driven by the Cocos Plate subduction. According with the catalogues published by the SSN, the yearly number of earthquakes occurred is very different at each zone is very different being Cocos plate the subduction zone that has produced the major number of earthquakes. We analyzed the catalogues of six zones of the Mexican Pacific coast in the period between 2000 and 2023. Based on the Tsallis q-statistical approach it is possible to assess the temporal changes of the non-extensivity by fitting the cumulative number of earthquakes with the generalized Gutenberg-Richter. Our preliminary results show differences in the fitting of the q-values for the six studied regions. These results are consistent with a pervious analysis, where it was observed that the highest q-value was obtained in Jalisco zone, while Oaxaca region reported the lowest q-value.
A dynamic earthflow model
Authors: Pudasaini Shiva P. , Mergili Martin
Published: March 2024

Earthflows are landslide processes characterized by the viscous movement of predominantly fine-grained and often water-saturated material down a slope or gully. They occur at a broad range of velocities, but generally do not display extremely rapid movement (such as debris flows, snow avalanches, or rock avalanches). Examples include the Gschliefgraben earthflow in the Austrian Alps and the Chirlești earthflow in the Romanian Carpathians. Although earthflows are common mass movement processes, they have not received the same attention as extremely rapid flows when it comes the development of dynamic simulation models. Here, we present a novel mechanical model and dynamical solution technique for earthflows. We develop a strategy of balancing the flux, viscous, and other forces. Our model essentially employs the flux-controller, viscosity-controller, and the deformation-controller. Within a single unified frame, we can now simulate a broad range of earthflows for different viscous, plastic, or visco-plastic behaviors and any degree of mechanically controlled deformation over a wide spectrum of time scales. We demonstrate the performance of the new earthflow model and its applicability with the advanced open-source computational mass flow simulation tool r.avaflow. Simulated earthflow deformation and motion are very smooth, typical of a hugely viscous material, as it is anticipated for earthflows as commonly observed for real-world events. As expected, the motion and deformation are exceptionally sensitive to the changes in the viscosity of the earthflow.
Identifying the origins of magnetic field reversals: in-situ measurements from Solar Orbiter and connection to remote-sensing observations from SDO
Authors: Coburn Jesse , Yardley Stephanie , Dewey Ryan , Ngampoopun Nawin , Suen Gabriel , Verscharen Daniel , Owen Christopher , Trotta Domenico , Nicolaou Georgios , Rivera Yeimy , Livi Stefano , Lepri Sue , Raines Jim , De Marco Rossana , Ioannou Charalambos
Published: March 2024

Magnetic field reversals, where the radial component of the heliospheric magnetic field changes direction, are frequently observed in the near-Sun region. Theory and numerical simulations regarding these reversals suggest that possible generation mechanisms include interchange reconnection in the solar corona, or solar wind expansion and turbulence. Magnetic field reversals thus provide information about both the solar corona and solar wind acceleration and propagation. Previous observations, including magnetic field structure, He2+- abundance, and the so-called patchy-ness are not conclusive in revealing their origin. In this presentation we discuss in situ observations of protons, electrons, He2+, and heavy ions from Solar Orbiter's Solar Wind Analyser instrument , together with the magnetic field from the MAG instrument, during a long-duration magnetic field reversal. We identify the origin of the reversal using the in situ heavy ion data, magnetic connectivity tools, and plasma emission measurements from the Solar Dynamic Observatory. In addition, we study kinetic properties of the electrons, protons and heavy ions, in order to provide readily employable observational tests to help discern the origin of the magnetic field reversals.
Insights and Reflections: The 'Exploring Unprecedented Extremes' Workshop
Authors: Paquin Dominique , Matte Dominic , Christensen Jens H. , Drew Martin , Bisaillon Alexandrine
Published: March 2024

Due to the various regions and contexts around the world with distinct climatic characteristics, climate hazards vary significantly in their nature, frequency, and impact, causing property damage, population distress, communication failures, environmental damage, and economic losses. Unfortunately, 2023 showcased extreme weather and climate events that have surpassed previous records. These include heatwaves, floods, wildfires, tornadoes. The occurrence of these extreme events poses a challenge to our comprehension of future climates, primarily due to their divergence from our conventional thought patterns or their status as out-of-sample scenarios. With ongoing climate warming, the potential for more severe events in the future is a concern. Insufficient preparation may result in breakdowns within specific sectors or even societal collapse. Effective preparation involves multiple factors, with the initial challenge lying in forming expectations - a task complicated by events that fall outside our usual anticipations, such as out-of-sample occurrences.  In the face of those climate challenges, understanding and mitigating the impacts of unprecedented climate extremes has become a critical area of focus. To shed light on this challenge, a workshop titled "Exploring Unprecedented Extremes" was convened in November 2023. This event brought together experts from diverse fields to deliberate on innovative approaches to climate change adaptation and mitigation. Emphasizing co-creation and interdisciplinary collaboration, the workshop addressed key themes such as the integration of various sectors into climate change strategies, the complexities of decision-making under uncertainty, and the crucial role of transdisciplinary research in comprehensively understanding and effectively responding to climate extremes. This poster focuses on the key takeaways and strategic reflections that emerged following the workshop, capturing the essence of our collaborative discourse on climate challenges.
 Impact of Climate Change on the Thermohaline Properties in the Ria de Vigo (NW Iberian Peninsula) 
Authors: Ribeiro Clara , Sousa Magda Catarina , Ribeiro Américo , Pereira Humberto , Álvarez Inés , Dias João Miguel
Published: March 2024

Climate change will have far-reaching consequences on the environment, primary production, the economy, and society as a whole. Changes in hydrodynamic patterns pose a significant threat to low-lying coastal areas that often present high economic and biological value. The Ria de Vigo is part of the Rias Baixas, which are located in the NW of the Iberian Peninsula. This system, as well as the rest of the Galician coast, is an area of high primary production that is vulnerable to changes in hydrodynamics induced by climate change. These changes could have a detrimental effect on the system and the local communities as they strongly depend on the income brought by aquaculture, and therefore this study aims to understand how climate change will affect the thermohaline properties in the Ria de Vigo.To better understand these impacts, a hydrodynamic model of the Rias Baixas was implemented to analyse the effect of climate change on the Ria de Vigo’s thermohaline properties. The methodology followed consisted of the application of the Delft3D three-dimensional numerical model in the Rias Baixas and the adjacent ocean with variables obtained from global and regional climate models, in future scenarios provided by CMIP6. This was done for the summer season and for two scenarios, the present-day and CMIP6’s SSP5-8.5 future scenario.The results show that the water temperature in the Ria will increase in the future due to climate change, and it tended to be higher at the surface and lower at the bottom due to the intrusion of oceanic water from the Eastern North Atlantic Central Water (ENAWC). The salinity is expected to decrease and will be highest in the bottom layer near the connection with the ocean, and lowest in the surface layers and near the river, in the latter case, due to freshwater discharges. The density presented similar patterns, also decreasing in the future, and showing the expected stratification associated with the upwelling season.
Design of a new laboratory earthquake experiment
Authors: Aoude Abdallah , Stefanou Ioannis , Semblat Jean-François , Rubino Vito
Published: March 2024

In this study, we present a new apparatus for creating earthquake-like instabilities in the laboratory and testing earthquake control theories (Stefanou, 2019a; Stefanou & Tzortzopoulos, 2022; Gutiérrez-Oribio et al., 2022). This experimental setup incorporates an analogue fault surrounded by an elastic medium. The frictional properties of the analogue fault are imposed by 3D printing. The elastic medium was chosen such as to have a very low Young's modulus and allow reasonable sampling rates for testing the earthquake control theories, while enabling the upscaling of the results based on appropriate scaling laws.The apparatus allows the application of a slow, uniform deformation of the elastic medium through a system of pantographs installed at the lateral boundaries of the device. Then, when the critical state is reached, an earthquake-like instability occurs. The slip front and its propagation are measured using digital image correlation. Preliminary results show qualitative similarities with natural seismic slip, as expected.The next step is to adjust the effective stress over the analogue fault to achieve a controlled slow slip rate of prescribed amplitude, according to our earthquake control theories and compare the results with those from existing, but simpler, experiments we have performed in the past (Gutiérrez-Oribio et al., 2023).