bluuebunny/crossref_metadata_2025 huggingface dataset:
E3D-BRITE: EISCAT_3D-based reconstruction of ionosphere-thermosphere electrodynamics
Authors: Hatch Spencer Mark , Reistad Jone Peter , Laundal Karl Magnus , Virtanen Ilkka , Vanhamäki Heikki , Zettergren Matthew , Oksavik Kjellmar
Published: February 2023

In many experimental studies of ionosphere-thermosphere (IT) coupling and ionospheric electrodynamics, the limitations of existing observational data sets require one to represent the three-dimensional IT system as an infinitely thin, two-dimensional sheet. This 2D representation of the coupled IT system cannot however represent some of its most basic properties, such as the existence of different ionospheric layers. On the other hand, observing systems that are capable of probing the altitudinal structure of relevant quantities, such as plasma density and drift, often can only provide information within a very narrow overhead volume. This limitation typically requires one to assume that these quantities have no horizontal gradients. Measurements from the upcoming EISCAT_3D incoherent scatter radar therefore present an unprecedented opportunity to probe the 3D IT system in three dimensions and on relatively short time scales (of order minutes). Here we present a data assimilation technique, EISCAT_3D-based reconstruction of ionosphere-thermosphere electrodynamics (E3D-BRITE), for routine estimation of all three components of the ionospheric current density and their uncertainties. We illustrate the technique using synthetic EISCAT_3D measurements of the plasma density and ion drift. We describe how the E3D-BRITE technique can also be used to simultaneously estimate the neutral wind and the perpendicular electric field. The technique relies on a 3D generalization of curl-free and divergence-free Cartesian elementary current systems. We also discuss the limitations imposed on this technique by the geometry of the three EISCAT_3D sites in Skibotn, Karesuvanto, and Kaiseniemi.
Seawater Intrusion and Submarine Groundwater Discharge studies at the Argentona site in Spain
Authors: Carrera Jesús , Martínez-Pérez Laura , Luquot Linda , Goyetche Tybaud , Pool María , Palacios Andrea , del Val Laura , Pezard Philippe A. , Diego-Feliu Marc , Rodellas Valenti , Ledo Juanjo , Folch Albert
Published: February 2023

We describe an intermediate scale experimental field site located in a coastal alluvial aquifer at the mouth of the Argentona ephemeral stream on the Maresme coastline (Barcelona, Spain). We have been monitoring Seawater Intrusion (SWI) and Submarine Groundwater Discharge (SGD) for several years using geological (lithological description and core samples analyses), geophysical (downhole and cross-hole measurements), hydraulics (pumping and tidal response tests) and hydrochemical (major and minor elements), and geophysical methods (cross-hole electrical resistivity. We have found that apparently minor silt layers control the distribution of salinity, with SWI and freshwater SGD occurring at multiple layers. This multiplicity of salinity levels promotes unstable mixing, which is very active and leads to a surprising bio-geochemical activity in the mixing zone. In parallel, instability makes it hard to sample SGD and makes it clear that the traditional SWI-SGD paradigm needs to be revised.
Enhancing FAIRness for OBS data within the eFAIRs project
Authors: Hillmann Laura , Hemmleb Susanne , Strollo Angelo , Quinteros Javier , Heinloo Andres , Haberland Christian , Haxter Martin , Schmidt-Aursch Mechita , Ulmer Louis , Dannowski Anke , Kopp Heidrun , Crawford Wayne
Published: February 2023

Data from Ocean Bottom Seismometer (OBS) deployments nowadays are routinely integrated in federated seismological data centers, but often without following standardized procedures as recommended by the OBS community. This makes it difficult to locate and exploit these data mainly due to the restrictions imposed by the standard metadata format (stationXML) and the services.In the context of the Helmholtz Metadata Collaboration (HMC), supported by OBS experts, we selected AWI and GEOMAR datasets to be archived at the GEOFON data center with standardized procedures according to the FDSN straw man proposal of W. Crawford for OBS data and metadata using also the OBSinfo tools developed at IPGP. In addition, a special emphasis was put on enhancing FAIRness for the selected datasets, for example identifiers of individual instruments were included, which are linked to instrument databases. Keywords were also added to make the data more easily findable and interoperable. From these experiences we formulated guidelines for OBS data management, which should help researchers to archive their OBS data consistently throughout EIDA data centers.
Impact of mosses and lichens on future carbon emissions from permafrost soils
Authors: Porada Philipp , Beer Christian
Published: February 2023

Mosses and lichens may play an important role for the future release of carbon from permafrost soils in high-latitude ecosystems. They significantly increase ecosystem carbon sequestration through productivity, and they also reduce soil temperature through insulation, thereby preventing permafrost carbon from being emitted as CO2. However, quantitative, large-scale estimates of the contribution of mosses and lichens to the future state of soil carbon at high latitudes are rare so far. Here, we use a processed-based model of mosses and lichens, which is integrated into a global land surface model, to predict the overall effect of these organisms on the soil carbon balance. We find that mosses and lichens double the increase in total soil carbon by the year 2100 compared to a simulation without the organisms, which can be explained by two factors: First, the cooling effect of mosses and lichens on soil temperature increases by around 1 degree C from today to 2100. Secondly, increased productivity of mosses and lichens due to CO2-fertilisation results in a larger carbon flux into the soil. Hence, we predict that mosses and lichens will contribute substantially to the future carbon balance of northern ecosystems and should not be neglected in simulations of the future carbon cycle.
Experimental evidences of the influence of flood magnitude and duration on the morphological evolution of a river: Initial results from the EVOFLOOD project
Authors: Delorme Pauline , McLelland Stuart , Murphy Brendan , Parsons Daniel ,   EvoFlood Team
Published: February 2023

There is now a clear consensus that climate change will lead to an increase in the frequency and intensity of extreme rainfall events in many parts of the world, which, in turn, will lead to increased flood flows and thus flooding of large areas. Numerical simulation is one way to improve our understanding of flooding processes, especially through Global Flood Modelling (GFM). Current GFMs represent the morphology of river channels and floodplains in a very simplified way. In particular, GFM assumes that the channel morphology remains unchanged over time. However, rivers are dynamic, their morphology evolves by erosion and deposition of sediments carried by the flow. These morphological changes can radically alter the conveyance capacity of the channel and therefore the flood risk. Integrate these morphological changes in the new GFM framework is one of the main objectives of the NERC-funded EVOFLOOD project. Here we present the results of the experimental part of the project. We designed a controlled laboratory experiment to identify the factors controlling the morphodynamic response within river channel. In this experiment, we generate a succession of flood events characterised by different magnitudes and durations, and we quantify the evolution of the flooded area and channel width as a function of the duration, intensity and flood history. We find that the main parameters controlling morphological changes are flood intensity and flood history. The duration of the flood does not have a significant impact on the morphological changes because the main changes occur during the first period of the flood event. Finally, we show the importance of the upstream sediment discharge on the modification of the conveyance capacity. 
Improved ocean current measurements from gliders through in-situ compass calibration and improved flight models: dealing with strong gradients, shallow waters and no-surface dives
Authors: Queste Bastien , Melin Marcus
Published: February 2023

Measuring ocean currents from gliders, either as dive-averaged currents or with acoustic doppler current profilers, requires accurate knowledge of the glider’s subsurface position and trajectory. These are estimated using dead-reckoning flight models which rely on accurate heading and speed estimates. We present two easily applicable and complementary methods to improve heading and speed estimates. These methods can be applied post-mission assuming adequate data were collected.

Method 1: Heading is determined using geomagnetic compasses on gliders and ADCPs. Compasses require calibration as they are affected both by the magnetic field of the glider itself and the electromagnetic field generated by sensors and motors. As of 2022, the majority of glider users rely on land-based, pre-deployment calibrations which are known to be unreliable due to user error, magnetic contamination from tools used in the calibration and changes in the glider’s magnetic field during transport, storage, power cycling and transport. These heading errors can be as high as 10 degrees. A simple correction scheme applied to compass magnetometer data improves heading estimates and current estimation for gliders and ADCP. Validation using a GPS compass shows a reduction in heading error to 2 degrees. A demonstration of the correction scheme and validation of current estimates is followed by recommendations for glider pilots and manufacturers to make these corrections possible for all glider deployments.

Method 2: Speed through water is determined using ocean glider flight models. These models rely on steady-state assumptions and decrease in accuracy in shallow waters, repeated no-surface dives or exceptionally strong density gradients. Accounting for acceleration and deceleration is possible but existing algorithms are computationally expensive. We propose a rapid and simple filtering approach which permits simultaneous representation of dynamic forces and empirical regression of flight parameters. We demonstrate improvements by comparing ADCP-derived velocities to dead-reckoning model velocities in the highly-stratified shallow waters of the Baltic where gliders surfaced on average once every 6 dives.
Frontal fault growth and megafan construction control drainage development in the western Himalaya
Authors: Kordt Jonas , Dey Saptarshi , Bookhagen Bodo , Rugel Georg , Lachner Johannes , Vivo-Vilches Carlos , Thiede Rasmus
Published: February 2023

The evolution and course of Himalayan rivers when exiting the orogen is controlled by the interplay between tectonics, climate, and associated sediment flux. We investigate these interactions by studying a Late Pleistocene deflection of the Sutlej River at the southern margin of the western Himalayan. This part of the Himalaya is also referred to as Kangra Recess. Late Quaternary faulting and folding along the Main Frontal Thrust and related back thrusts has created anticlinal structures in the south and piggyback basins in the north. Combined field observations and chronological constraints have shown that the anticline evolved as multiple fault segments, which grew through lateral propagation and led to the permanent deflection of the Sutlej River by ~ 50 km to the southeast. In this work, we present new luminescence and cosmogenic nuclide chronologies combined with previously published data to better identify the sedimentation history. Most importantly, we focus on the cause and final timing of the permanent river deflection. We show evidence for widespread aggradation and sediment deposition by the Sutlej River megafan and its tributaries starting before 47 ka and continuing until ~ 26 ka. Our 10Be and 26Al results in combination with available OSL data document the last widespread throughflow of the Sutlej at ~ 30-25 ka. We argue that a combination of climate and tectonic factors, especially the variability of monsoonal strength, led to major changes in sediment supply at short time scales and therefore affected the course of the Sutlej River system.
Climate-driven local assessment of future irrigation requirements and available water resources in North-West Italy
Authors: Rolle Matteo , Tamea Stefania , Claps Pierluigi , Poggi Davide
Published: February 2023

The impact of climate change on agriculture is a major challenge for the food and water security of next decades. In the future, the Mediterranean area will be particularly exposed to water scarcity, which may lead to significant losses in agricultural yield. Climate projections show that many densely cultivated areas of Southern Europe will suffer decreases of precipitation intensity and frequency, with severe consequences in terms of irrigation requirements, i.e.  the amount of water needed to meet the evapotranspirative demand of crops during dry periods. Therefore, the modelling of climate-driven crop water requirements and available water resources is essential to understand future criticalities for agriculture and to adopt proper adaptation strategies.In this study, the agricultural irrigation requirement was estimated by modeling the daily water balance in the soil, on the basis of evapotranspirative demand and precipitation, over the densely irrigated basin of Demonte, in South Piedmont (Italy). The volumes of irrigation required by local agriculture were calculated for 30 main crops, taking into account the local information of yearly distribution of crops. The available surface water in the basin was compared to the present irrigation requirements, using flow discharge data from the river that feeds the local network of irrigation channels. In order to analyze future scenarios, precipitation and temperature data from five EURO-CORDEX regional climate models were used to estimate the irrigation requirements and the available surface water for the 2035-2055 period, considering multiple RCP scenarios.Results show that the current available water resources are little enough to meet the irrigation requirements over the Demonte basin for the months of July and August, when most of the cereals reach the maximum growing phase. The climate-driven assessment for the future decades shows that the water required for irrigation will gradually exceed the threshold of available resources, with different degrees of severity depending on the RCP scenario. Moreover, future scenarios highlight a progressive increase in the temporal lag between the period of maximum irrigation requirements (July-August) and the high-flow regime period in the hydrographic network (April-June). As a consequence, most of the surface freshwater in the Demonte basin will not be available for agriculture during summer, when most of the irrigation will be required. Modeling the future scenarios of agricultural water needs and available resources is an important step to understand the future implications of climate change on food production. Moreover, this is a valuable instrument to support proper adaptation strategies, both in terms of agricultural and water management planning policies.
Detection, identification and clustering of palynomorphs using AI and machine learning
Authors: Stefanowicz Sissa , Ask Marianne , Julian Cyril , Lindström Sofie
Published: February 2023

Palynology is widely used in both academic and industrial research for correlation and interpretation of subsurface geology on both local and regional scales. While most data gathering tools for the subsurface have undergone major technological developments during the last decades, palynological research has, apart from the use of more advanced microscopes, remained virtually unchanged and can be quite time consuming when large data sets are required. With increasing demand for faster, more high resolution and more detailed palynological analyses from the continuously developing technological industry as well as the academic science community, palynology is at risk of being left behind.
The answer could lie in adopting strategies of digitalisation and Artificial Intelligence (AI) originally developed for medical research. The technology of scanning microscope slides into a digital high-resolution image has already been developed, and AI software specifically developed for palynology can be utilised to examine the digital images and detect, identify and quantify the fossil content.
In this project we have designed and developed an AI software for clustering and classification of microfossils based on deep-learning based algorithms for detection of palynomorphs and algorithms based on autoencoders for extracting features predictive of different fossil types. The AI is trained to recognize and identify fossils from different angles, preservation levels and fragmentation stages, as well as partially obscured or folded specimens. The AI can then analyse specimens for morphological parameters such as texture, shape and/or RGB/HSV values and use these parameters to categorize the specimen into clusters. The clustering has many applications, e.g., identifying morphological variations within taxa and recognizing variations in colour and preservation related to reworking or caving during the drilling process. The project also explores the advantages and disadvantages of working with digitally scanned palynological slides and the use of AI software recognition. The project will establish if the digital scans of the palynological samples have the resolution needed to be used for quantitative analyses and develop a preparation process to reliably produce the best digital samples possible.
Past Evolution of the Earth-Moon System. The AstroGeo tools for geological proxies.
Authors: Laskar Jacques , Farhat Mohammad , Boué Gwenaël , Auclair-Desrotour Pierre , Sinnesael Matthias , Gastineau Mickaël , Bendjeddou Sem
Published: February 2023

In recent years, several groups have analyzed or re-analyzed stratigraphic data in order to derive astronomical information on the past evolution of the Earth-Moon system. Depending on the approach and on the type of sediment that is analyzed, the retrieved data are of different nature. For tidal deposits, one may attempt to obtain the number of lunar days in a lunar month, or the number of lunar months per year (e.g. Williams, 2000), or even retrieve the nodal period of the Moon (Walker & Zahnle, 1986). In contrast, for cyclostratigraphic analyses, the derived quantity is the precession frequency of the Earth (e.g. Meyers and Malinverno, 2018). The problem for the geologist is then to derive all the other parameters of the Earth-Moon system from this single initial observation. The AstroGeo tools (www.astrogeo.eu) are designed to help the geologists in this task by providing conversions from one geological proxy  to all the remaining parameters of the Earth-Moon system  that can be derived from this single observation.  These tools developed in the AstroGeo project rely on the physical model recently developed in Farhat et al. (2022). The AstroGeo lunar tool is the first of a series that will be available for the geologists and astronomers community. It allows to input any of the possible observables of the Earth-Moon system (age, semi-major axis, length of the day, precession frequency and angle of obliquity), with some uncertainty, and to derive all the other parameters by interpolating the results of Farhat et al. (2022). At the same time, new data can be plotted versus the nominal solution, together with the already known data that will be kept in an evolving data base. These tools will be available on the AstroGeo website (www.astrogeo.eu). I will present these new tools along with the recent progress of the AstroGeo project.Ref : Farhat, M., Auclair-Desrotour, P., Boué, G., Laskar, J., 2022, The resonant tidal evolution of the Earth-Moon distance Astronomy & Astrophysics, 665, L1https://www.aanda.org/articles/aa/pdf/2022/09/aa43445-22.pdf
Detection of Arctic rivers streamflow drivers through automatic feature selection
Authors: Zeno Mattia , Sangiorgio Matteo , Castelletti Andrea
Published: February 2023

Runoff from Arctic rivers has a direct influence on the sea ice dynamics in the Arctic Ocean, producing significant effects from local to global scales. Despite their key role, the knowledge of the processes that influence the Arctic rivers streamflow is still limited, and their behavior is not fully understood.In the literature, these analyses are usually performed adopting classical statistical methods and simple linear models, which are probably unable to fully capture underlying nonlinearities and redundancy of candidate drivers.In this study, we use automatic feature selection techniques to detect the main drivers of the five major Arctic Rivers’ runoff (Ob, Yenisei, and Lena in Asia, Mackenzie and Yukon in North America). Daily time series of temperature and precipitation recorded by several stations spread across the Arctic region, and the average snow cover of each basin are used as candidate input variables.The feature selection analysis is carried out with two algorithms: Wrapper for Quasi Equally Informative Subset Selection (W-QEISS) and Iterative Input Section (IIS). W-QEISS adopts neural predictive models to select alternative sets of drivers providing similar in terms of accuracy, but with different relevance, redundancy, and cardinality. Conversely, IIS directly produces a ranking of the input variables relying on tree-based models and combining computational efficiency and scalability to high input dimensionality.The two algorithms achieve noticeably consistent results, with minor differences that can be explained by numerical factors typical of machine learning. Results also show that autoregressive terms have a crucial role in all the hydrological basins, while the importance of the other drivers is different for each river.This preliminary research opens the floor for further analysis to broaden the knowledge of Arctic hydro-meteorological dynamics.
Impact of biomass burning on the chemical composition of Arctic aerosols using mass spectrometry
Authors: Gramlich Yvette , Siegel Karolina , Haslett Sophie L. , Krejci Radovan , Zieger Paul , Mohr Claudia
Published: February 2023

Biomass burning releases numerous aerosol particles into the air, influencing the radiative budget by scattering or absorbing solar radiation and by influencing cloud properties through acting as cloud condensation nuclei. These aerosol particles contain black and organic carbon and can be transported over large distances, reaching also pristine environments such as the Arctic. Due to the rising global temperature the fire activity has increased, and record-breaking black carbon concentrations have been observed in the Arctic (Stohl et al., 2007). Biomass burning events reaching the Arctic have been observed to increase the aerosol number concentration by about one to two orders of magnitude (Lathem et al., 2013). Although a lot of attention has been drawn to the physical characteristics of fire plumes, changes in chemical composition, specifically in the Arctic, are studied to a lesser extent. In this study we report molecular-level information on the chemical characteristics of biomass burning aerosol particles measured during different plumes reaching the island of Svalbard during 2020. These measurements were part of the year-long NASCENT (Ny-Ålesund aerosol cloud experiment; Pasquier et al., 2022) campaign, and were conducted using a filter inlet for gases and aerosols coupled to a high-resolution time-of-flight mass spectrometer (FIGAERO-CIMS) using iodide as reagent ion. We use the particle-phase levoglucosan, a well-known tracer for biomass burning released from cellulose combustion, obtained from the FIGAERO-CIMS to identify biomass burning events, and will discuss the chemical characteristics of the properties of the events compared to non-events and implications for aerosol radiative and hygroscopic properties. In addition to a better understanding of the chemical composition of aged fire plumes reaching the Arctic, our study will also give insights on the time scales on which the background Arctic air can be disturbed by fire activity. References:Stohl et al., Atmospheric Chem. Phys., 7, 511–534, 2007Lathem et al., Atmospheric Chem. Phys., 13, 2735–2756, 2013Pasquier et al., Bull. Am. Meteorol. Soc., 103, E2533–E2558, 2022
Comparative Analysis of Parameter Optimization of Theoretically Consistent IDF Models of Rainfall Intensity
Authors: Amin Bushra , Bárdossy András
Published: February 2023

In an attempt to get the best parameter estimations of the theoretically consistent IDF (Intensity Duration Frequency) models of rainfall intensity for the entire state of Baden Wuerttemberg, three well-defined optimization algorithms such as Differential Evolution (DE), Nelder Mead (NM), and TNC Truncated Newton (TNC) are taken into account for comparison.Seven-parametric IDF model contains mean intensity µ, intensity scale parameters λ1, λ2 , time scale parameter α, fractal/smoothness parameter Μ, Hurst parameter Η, exponent of the expression of probability dry θ,  and tail index ξ, which are obtained by minimizing the error between empirical k-moments and model quantiles. Error metric focusing on distribution quantiles x(k,T) is thus minimized for all available scales k and a series of return periods T . Non-linear solver is chosen to perform this step as these errors are non-linear functions of the parameters.All results are demonstrated visually, and a final decision is made on the basis of precisely fitted parameter values to the model. This crucial step will also assist us in finding the optimum design values for stormwater and floods.
Ancient carbonates as archives for global environmental changes during Ediacaran-Cambrian time: a geochemical perspective
Authors: Gerdes Axel , Cantine Marjorie , Eitel Sören
Published: February 2023

Aim: Using geochemical proxies to record changes in environmental conditions during the Ediacaran-Cambrian timeMethods: Thin section petrography combined with high-resolution analyses of trace elements and U-Pb, Sr, B and Li isotopes by LA-ICPMS (single and multi-collector)Problem: Identification of pristine early diagenetic carbonate phases and their distinction from late diagenetic and altered carbonates. In this study, we use high spatial resolution multi-element and isotope analyses to identify pristine carbonate phases in samples from recent drill cores from Namibia, drilled by International Continental Scientific Drilling Program project GRIND-ECT. GRIND-ECT aims to capture, in drill core, the Ediacaran-Cambrian transition in key successions worldwide.The method applied allows for relatively high sample throughput (>200) and precise detection of heterogeneous altered domains. Exclusion criteria are the presence or increased concentration of various trace elements (Al, Rb, LREE ...), heterogeneity of the 87Sr/86Sr isotope ratio, a lack of discernible populations in U/Pb isotope space, resulting in non-correlated scattering, and too young U-Pb dates.To date, about 10-15% of the samples analyzed yielded a U-Pb date consistent with depositional age or an early post-depositional age. Geochronologic control of ancient sedimentary sequences is critical for evaluating cause and effect and rates of change in ancient environments. However, precision of LA-ICPMS ages (ca. 1-2%, e.g., 6-11 Ma) is insufficient to resolve changes in the Ediacaran-Cambrian oceans on timescales relevant for biological and environmental change. Therefore, the ages of these pre-characterized samples need to be refined using high-precision methods (Cantine et al., EGU 2023).Analyses of Li and B isotopes are in progress on the pre-characterized, potentially pristine carbonate areas. We expect to see a change in the Li, B and Sr isotope records through Ediacaran-Cambrian time hopefully with significant anomalies. The correlation of the three isotope systems would be a confirmation for us that we are targeting pristine, early diagenetic carbonates.
A sensitivity analysis of stress changes related to geothermal direct heat production in clastic reservoirs and potential for fault reactivation and seismicity
Authors: Marelis Arjan , van Wees Jan-Diederik , Beekman Fred
Published: February 2023

Keywords: geothermal, high resolution, fault stability, induced seismicity.High resolution predictions of three-dimensional subsurface stress changes are required for the assessment of geothermal operations with respect to fault stability and the potential risk for induced seismicity. The effects of long-term cooling on reactivation and seismicity potential of faults near a geothermal doublet require quantification and management for safe and effective application of geothermal energy. This work presents a detailed analysis of the sensitivity for fault reactivation and induced seismicity based on different scenarios for reservoir characteristics and production parameters. To this end, analytical solutions are used as well as a TNO-proprietary tool known as MACRIS (Mechanical Analysis of Complex Reservoir for Induced Seismicity) (Van Wees et al., 2019) that allows for both poro- and thermo-elastic stress evaluations in structurally complex (i.e. highly faulted) reservoirs. The stress evaluations take as input the pressure and thermal field of the reservoir and over- and underburden which are obtained from the Open Porous Media (OPM) Flow reservoir simulator (Rasmussen et al., 2021). In this workflow, high resolution stress change solutions at the faults are available.The workflow has been applied to a high resolution three-dimensional reservoir model, including over- and underburden rock, marked by a single fault. Key elements in the dynamic and mechanical behaviour of the reservoir are varied, along with different production scenarios. Simulated stress evolutions in MACRIS and alternative analytical solutions show a predominant sensitivity for fault reactivation to the thermo-elastic parameters, i.e. the Young’s modulus and thermal expansion coefficient. Furthermore, in cooling reservoirs, the intersection area of the cold-water volume in direct contact with the fault plane is shown to be the main driver for fault reactivation and subsequent seismic potential. ReferencesRasmussen, A.F., Sandve, T.H., Bao, K., Lauser, A., Hove, J., Skaflestad, B., … and Thune, A. (2021). The Open Porous Media Flow reservoir simulator, Computers and Mathematics with Applications, 81, 159-185.Van Wees, J.D., Pluymaekers, M., Osinga, S., Fokker, P. A., van Thienen-Visser, K., Orlic, B., Wassing, B. B. T., Hegen, D., and Candela, T. (2019). 3-D mechanical analysis of complex reservoirs: a novel mesh-free approach, Geophysical Journal International, 219 (2), 1118-1130. 
The 1967 Steinsholtsjökull rockslide and GLOF event in light of climate change in Iceland
Authors: Sæmundsson Þorsteinn , Ben-Yehoshua Daniel , Smail Nathan , Hjartardóttir Ásta Rut , Wells Greta , Belart Joaquin M.C. , Toschka Sinah
Published: February 2023

One of the most visible consequences of climate changes in Iceland are retreating outlet glaciers and formation of proglacial lakes. It is estimated that Icelandic glaciers have lost about 16% of their mass since 1890 or over a 130-year time interval. Temperatures have been fluctuating over this period with exceptional warm period in the 1920s and 1930s followed by slightly colder interval until beginning of the 1980s. During this time outlet glacier retreated considerably but around 1970 glaciers begun to readvancing which continued until around 1995. At the end of the 20th century another turning point occurred, with higher temperatures and rapidly retreating outlet glaciers. Existing proglacial lakes expanded and many new were formed in front of the rapidly retreating ice margins. Over the last years temperature have become more stable and several outlet glaciers have been showing a readvancing phase. Glacial fluctuations have affected the stability of valley slopes above retreating outlet glaciers and their proglacial lakes. Resulting in increased frequency of mass movements and slope deformation in these high-mountain regions. In 1967 a large rockslide fell onto the Steinsholtsjökull outlet glacier and into its proglacial lake causing a GLOF.The rockslide was approximately 20 million m3 in volume. The head scarp was around 970 m long and up to 300 m high. It fell onto the western side of the glacier and broke up its snout. Part of the rockslide material fell into a proglacial lake, in front of the ice margin, causing a large GLOF down the valley. Large amounts of sediment were transported and redistributed down-valley with the GLOF. About 20km downstream a maximum flood discharge of 2100-2700 m3/s, was estimated.The Steinsholtsjökull 1967 GLOF, entirely overprinted the proglacial landscape in the Steinsholtsdalur valley. Similar circumstances to the valley prior to the event, now exist and are forming in glacial environments around Iceland’s present-day outlet glaciers, which highlights the urgent need to study and monitor these environments.
Modelling the atmospheric factors determining the evolution of the boundary layer during a wildfire event
Authors: Purificação Carolina , Campos Cátia , Henkes Alice , Couto Flavio T.
Published: February 2023

Over mountainous terrain, the atmospheric structure becomes much more complex than homogeneous terrain in terms of the Atmospheric Boundary Layer (ABL). In the context of interaction between fire and atmosphere, abrupt changes in the ABL wind often lead to erratic and turbulent flow in the fire environment and expose firefighters to dangerous conditions. The study aims to characterize the ABL conditions associated with the largest forest fire that occurred in Portugal in 2019. The fire event took place in Vila de Rei county, which is surrounded by hills and valleys with large differences in altitudes. In order to study the regional scale, a numerical simulation was performed using the Meso-NH atmospheric model, configured with 500 × 500 grid points at 2500 m horizontal resolution, between 19 July at 0000 UTC and 25 July 2019 at 0000 UTC. The simulation covered the Iberian Peninsula and corresponds to the period when the fire burned more than 9,000 hectares in Vila de Rei. Such a simulation helped to characterize the lower troposphere, which contributed to the evolution of the ABL height over the days. Results indicate that the simulated ABL evolution is characterized by the presence of a coastal low-level jet with a maximum wind speed of 10 meters per second at ~ 600 meters’ altitude (1800 UTC of 20 July).  ABL height calculated from Richardson number method depicted a growing in the morning that reached a peak height by mid-afternoon. The ABL height ranged from 500 to 900 m throughout the afternoon and evening during the entire study period. Besides the identification of the fire weather conditions, this study also highlights the factors that contributed to the lower values of the ABL height in the wildfire event. This study was funded by national funds through FCT-Foundation for Science and Technology, I.P. under the PyroC.pt project (Ref. PCIF/MPG/0175/2019).
High-resolution modelling of heavy precipitation runoff behavior in urban areas using a coupled rainfall-runoff and hydrodynamic modelling approach
Authors: Sauer Christoph , Nagrelli Saskia , Fröhle Peter
Published: February 2023

Flood damage is not only caused by river floods. In particular, highly sealed urban areas are repeatedly affected by flooding as a result of convective heavy precipitation, regardless of their proximity to surface waters. Floods are often very localized due to the small spatial extent of the heavy precipitation cells. However, the spatial and temporal prediction of these precipitation cells is subject to great uncertainty due to the multitude of meteorological influences. In many cases, only the affected large areas in which convective heavy precipitation events can occur are known. The spontaneous implementation of safety measures by municipalities and residents is therefore rarely effective, which has already led to high damages in the past.Hydrodynamic numerical (HN) models for simulating runoff, water levels and water velocity for heavy precipitation events require a high spatial and temporal resolution. Therefore, computational costs for pure HN models are high, so that a novel coupling approach with a hydrological rainfall-runoff (RR) model, which computes comparatively fast, is suggested. To represent the flooding events resulting from convective heavy precipitation events in highly heterogeneous inner-city areas, surface runoff can be simulated using RR models. Overloads of the existing drainage system are also identified. Averaging of, for example, sealing values, as is the case with conventional RR modelling, is dispensed with using high-resolution area information. A particularly detailed analysis of the study area at street level is thus possible as long as the flow directions are unambiguous. Subsequent coupling of the RR-simulated runoff to an HN model represents flooding of the area away from the fixed RR model runoff pathways. Due to the model concept developed for our study, runoff is represented with high temporal and spatial resolution and very short response times in the RR model. In the case of identified flooding of a road section, the flooding is then followed up with a non-uniform and transient HN model for the respective area. The combined approach reduces the model area of the HN model, which simulates dynamic flooding into the area, to the flood critical areas. In addition, this approach increases the accuracy of hindcasts compared to observations and delivers the opportunity to assess weak spots in the drainage system of complex urban areas. Municipalities may use the knowledge to create adapted and adequate risk management approaches for heavy precipitation events and make structural adjustments to reduce the now known risks.
Development of an automatic station for acoustic measurements to continuously evaluate the underwater volcanic degassing.
Authors: Vandemeulebrouck Jean , Daniel Romuald , Metral Laurent , Do Yann , Barrois Hervé , Besancon Simon , Dumouch Tom , Luc Ted , Bouvard Camille
Published: February 2023

Our project aims at designing and realizing an autonomous hydroacoustic measurement system (“Bubblephone”) allowing to passively monitor the bubbling activity in underwater or lake degassing areas. Hydroacoustic activity is usually measured by the hydrophones of Ocean Bottom Seismometers (OBS) only at low frequencies (1-100 Hz) and in a band disturbed by turbulence, while bubbling emits energetic acoustic activity at higher frequencies (~ 1 kHz) that depend on the size of the bubbles. The station's functions are to filter the hydrophone signals to acquire the high-frequency signals emitted by the bubbles, to calculate and store their frequency spectra and also raw data sequences. The post processing will allow to evaluate the variations of the volume of the bubbles and thus of the degassing in the course of time. The electronics will have an autonomy of 6 months and will be installed in a hyperbaric chamber to be able to go to depths of kilometres.  It will be able to be deployed for several months near active volcanoes and to monitor the degassing of a submarine volcano.
Mapping and characterisation of compound events in Sweden
Authors: Mård Johanna , Bodin Örjan , Nohrstedt Daniel
Published: February 2023

Compound events have significant environmental and societal impacts and bring new challenges to decision-making, planning, and management. Meanwhile, knowledge about compound events and their impacts are limited. Sweden, while being prone to various climate-related natural hazards (e.g., storms, floods, wildfires) have no coherent information on where these events and their impacts have occurred in the past, and less so on compound events. Here we present a new cohesive natural hazards impact database for Sweden, including compound events, to advance our understanding of how these events have unfold during the last 50 years. The impact database consists of available data from multiple sources on past climate-related natural hazard events (e.g., databases and reports from governmental organizations, county boards, and scientific reports). These data have further been geocoded using a Geographic Information System (GIS) to generate an integrated natural hazards map. These two products will help provide knowledge on the spatiotemporal distribution of natural hazard events, including compound events in Sweden, and further advance our understanding of their underlying drivers, and aid ongoing work to effectively plan and prepare for these events.
Sources of uncertainty in video-based flow observations, revealed by co-location experiment
Authors: Winsemius Hessel , Peña-Haro Salvador , Annor Frank , Hagenaars Rick , Luxemburg Wim , Van den Munckhof Gijs , Grimmeisen Felix , Van de Giesen Nick
Published: February 2023

In the last years, several methods to establish surface flow velocities and river flow from camera videos have been developed and codified into software. Together with a hardware setup, these may be used to establish near real-time observations of river flow. The hardware setup used and associated quality of the camera, methods to pre-process, process and post-process the videos may all result in errors, and uncertainties. In this contribution we assess what the main sources of uncertainty are, and under what conditions these may appear, focusing on both hardware and processing methods. We do this by co-locating two different camera setups, and using two different software processing methods. For camera setups we use a very simple and low cost FOSCAM FI9900EP running at its maximum of 4Mbps and a much better quality Vivotek IB9367-EHT running at 20Mbps. As systems we use the DischargeKeeper and pyOpenRiverCam.The cameras were co-located over a significantly long period at a site in Limburg in The Netherlands, and footage analyzed with 15-minute intervals. Videos were treated with as much as possible the same settings, reprojection resolution and window. Results were compared in terms of the ability to resolve velocities (amount and quality) and the impact of post-processing. Integrated flow over a cross-section is also compared. We assess under what conditions flow and velocity estimates are robust and similar and under what conditions these diverge focusing on the platform used, light conditions, and flow conditions.Keywords: River flow monitoring, stage-discharge relationships, OpenRiverCam, DischargeKeeper, computer visionThe work leading to these results has received funding from the German Federal Ministry of Education and Research (BMBF) and the CLIENT II program (Drought-ADAPT, FKZ: 01LZ2002B) and the European Horizon Europe Programme (2021-2027) under grant agreement no. 101086209 (TEMBO Africa). The opinions expressed in the document are of the authors only and no way reflect the European Commission’s opinions. The European Union is not liable for any use that may be made of the information.
Changes in Indian vegetation productivity under increasing CO2 concentration
Authors: Dubey Nivedita , Ghosh Subimal
Published: February 2023

Higher CO2 concentration improves vegetation's water use efficiency by CO2 fertilization effects. However, anthropogenic climate change increases temperature and thus atmospheric water demand and Evapotranspiration globally, which may cause more intense frequent agricultural and ecological droughts. India is an agriculture-dependent country, with most of the population working in the agriculture and allied sector. India is also the second-highest contributor to global greening, having two of the eight global hottest biodiversity hotspots. Studies have shown that the land-atmospheric feedbacks are strong in India, and climate drivers of Indian vegetation productivity vary from those of global tropical regions. However, the effects of changing climate on Indian vegetation are unclear. Here, using the Coupled Model Intercomparison Project, phase 6 (CMIP6) Earth System Models (ESMs), we project the changes in Indian vegetation productivity over India under Increasing CO2 concentrations. We partition the radiative and biogeochemical effects of increasing CO2 concentration and how these effects drive the changes in eco-hydrological processes over India. We also investigate the sensitivity of Indian vegetation in future drought scenarios.
Sensitivity of future projections of ice sheet retreat to initial conditions
Authors: Berends Tijn , Bernales Jorjo , van Calcar Caroline , van de Wal Roderik
Published: February 2023

Both the Greenland and Antarctic ice sheets are expected to experience substantial mass loss in the case of unmitigated anthropogenic climate change. The exact rate of future mass loss under high warming scenarios remains uncertain, depending strongly on physical quantities that are difficult to constrain from observations, such as basal sliding and sub-shelf melt. We apply a novel model initialisation protocol, that combines elements from existing approaches such as the equilibrium spin-up, basal inversion, and palaeo spin-up, to models of both the Greenland and Antarctic ice sheets. We show the results in term of sea-level projections including the uncertainties, under different warming scenarios, following the ISMIP6 protocol.This abstract is a companion to “On the initialisation of ice sheet models: equilibrium assumptions, thermal memory, and present-day states” by Bernales et al. We hope that, if both abstracts are lucky enough to be accepted, the conveners can program the two talks in sequence.
Influence of urban trees on the climate change adaptation in Boadilla del Monte (Spain)
Authors: Busca Francesco , Gómez-Villarino María Teresa , Revelli Roberto
Published: February 2023

Urban green infrastructures are considered useful tools to mitigate air pollution, increase the resistance of cities to climate change, optimize energy consumption expenses and promote the integral management of economic, social and cultural development, according to a "sustainable cooperation". However, there are few studies that quantitatively support this contribution and there is also a lack of knowledge about which species are the most suitable for an urban area in order to improve air quality.  Therefore, the research project proposes to analyze the improvement of air quality and the contribution to reducing the effects of climate change by trees of an entire urban area. i-Tree Eco software and the inventory of the urban trees of the Madrid Municipality of Boadilla del Monte, with which the project has been developed, have been used. Results about air pollutants reduction have been compared with the Municipality's emissions in order to see how urban greenery helps to the improvement of air quality. Finally, an annual monetary estimation of the Ecosystem Services (ES) offered by the urban trees of the city has been made through the software, then compared with the annual costs (planting, maintenance, removal) agreed with the Municipality of Boadilla, reaching a Cost-Benefit Analysis representative of the contribution given by urban green areas to the surroundings. 