bluuebunny/crossref_metadata_2025 huggingface dataset:
Climatic predictors of speleothem deposition in SW Asia
Authors: Nicholson Samuel , Jacobson Matthew , Markowska Monika , Schroeder Julian , Vonhof Hubert , Haug Gerald
Published: March 2024

Speleothems (stalagmites, stalactites and flowstones) are a powerful archive for reconstructing past climate conditions. These are secondary calcium-carbonate deposits that form in caves from the adequate supply of rainwater, soil CO2 and dissolved bicarbonate. They have been used extensively in arid regions, such as SW Asia, to reconstruct and benchmark past hydroclimatic conditions. Analysis of the distribution of active and inactive speleothem deposition across the Negev desert suggested a precipitation threshold of ~300-350 mm yr-1 is required for speleothems to deposit. This threshold has been applied to the broader SW Asia region to understand the minimum rainfall during periods of climate amelioration but has lacked specific region-wide analysis. Here, we apply logistic regression techniques and machine-learning methods to understand the climatic parameters which predict speleothem deposition across SW Asia. We show a gradual, rather than threshold response between speleothem deposition and rainfall amount, suggesting 1) precipitation over 300-350 mm yr is not a simple predictor of speleothem deposition across SW Asia, and 2) sites specific climates/environments and processes play an important role. We then apply a Random Forest machine-learning algorithm to our dataset to create a prediction of speleothem deposition. We show that minimum and maximum monthly rainfall, elevation, and a terrain roughness index are the most important variables, suggesting that water availability and topography are important predictors of speleothem deposition. Climate indices associated with temperature and evaporation contribute but play a less important role in the prediction. We emphasise the need for additional monitoring of external and internal cave environments to refine the climatic predictors of speleothem deposition in SW Asia and understand the site-specific processes that lead to the activation or cessation of speleothem growth. Importantly, our prediction provides a model which includes a range of climate-environmental data and may be used by researchers to locate new speleothem-bearing cave sites for study.
Enabling km-scale coupled climate simulations with ICON on GPUs
Authors: Enkovaara Jussi , Frauen Claudia , Klocke Daniel , Kluft Lukas , Kornblueh Luis , Kosukhin Sergey , Lunttila Tuomas , Redler Rene , Schnur Reiner
Published: March 2024

The Icosahedral Nonhydrostatic (ICON) weather and climate model is a modelling framework for numerical weather prediction and climate simulations. ICON is implemented mostly in Fortran 2008 with the GPU version based mainly on OpenACC. ICON is used on a large variety of hardware, ranging from classical CPU cluster to vector architecture and different GPU systems.An ICON model configuration developed for km-scale climate simulations is used as a scientific prototype for the digital twin of the Earth for climate adaptation with in the Destination Earth program of the European Comission. Here we focus on our effort to run these coupled ICON configurations at km-scale on LUMI, a HPE Cray EX system with a GPU partition based on AMD MI250x’s.We present the model configuration, performance results and scalability of the simulation system on Lumi and compare it with results on other GPU and CPU based systems.
Nitrogen deposition effects on forest ecosystems: Linking N leaching patterns to long-term dynamics of soil C/N ratios in Swiss ICP Forests Level II Plots
Authors: Waldner Peter , Musso Alessandra , Moreno Duborgel Margaux , Minich Luisa Isabell , Thimonier Anne , Schmitt Maria , Rigling Andreas , Brunmayr Alexander S. , Meusburger Katrin
Published: March 2024

Forests play a major role in wood production and other ecosystem services, such as carbon (C) sequestration and filling reservoirs in drinking water quality. However, it is still under discussion to what extent environmental changes, such as elevated nitrogen (N) deposition and related eutrophication, may affect such services.Our study aimed to assess long-term changes in N and C storage in Swiss forest soils along a gradient in N deposition (about 10 to 30 kg N/ha/y). At five long-term forest ecosystem research plots in Switzerland, which are part of the ICP Forests Level II network, nutrient fluxes (atmospheric deposition, litterfall, soil solution) have continuously been measured since the 1990s. Soil samples were taken from fixed depth layers in the course of soil inventories in the 1990s and 2022.The observed flux patterns indicated that the forests had reached nitrogen saturation on some sites, resulting in nitrogen leaching. At sites with a higher carbon-to-nitrogen ratio (C/N), we found comparatively lower levels of N leaching. The comparison of the two soil inventories showed that the N concentration in soils has actually increased (and the C/N ratio decreased) on the sites with high C/N ratio and high N deposition. We will discuss the observed accumulation and transformations of organic C and N in these soils and the potential impacts on selected ecosystem services. 
Rising CO2 and warming reduce global canopy demand for nitrogen
Authors: Dong Ning , Prentice Iain Colin
Published: March 2024

Nitrogen (N) limitation has been considered as a constraint on terrestrial carbon uptake in response to rising CO2 and climate change. By extension, it has been suggested that declining carboxylation capacity (Vcmax) and leaf N content in enhanced-CO2­ experiments and satellite records signify increasing N limitation of primary production. We estimated changes in Vcmax andbased on optimality principles over decades, and the changes in leaf-level photosynthetic N assuming proportionality with leaf-level Vcmax at 25˚C. using satellite-based and predicted , and converted to annual N demand using estimated leaf turnover times.The predicted spatial pattern of Vcmax shares key features with an independent reconstruction based on remotely-sensed leaf chlorophyll content. Leaf-level responses to rising CO2, and to a lesser extent temperature, may have reduced the canopy requirement for N by more than greening has increased it. Our finding provides an alternative explanation for declining N that does not depend on increasing N limitation, also could use as evidence for recently increasing N limitation on primary production.  
Investigating Atmospheric Dynamics of Uranus and Neptune: A General Circulation Model Approach with a Parametrization of Convection
Authors: Le Saux Arthur , Guerlet Sandrine , Spiga Aymeric , Leconte Jeremy , Clement Noe , Milcareck Gwenael
Published: March 2024

Understanding the atmospheric dynamics of Uranus and Neptune remains a challenging endeavour due to the limited observational data available. In this study, we employ a sophisticated General Circulation Model (GCM), known as the Generic Planetary Circulation Model, to investigate the complex meteorological phenomena of the Ice Giants, with a focus on the role of convection in the troposphere Our attention is directed towards the parametrization of convection, a crucial driver of atmospheric circulation, as it significantly impacts the transport of energy and the distribution of chemical species throughout the atmosphere. One of the unique aspects of our study lies in the consideration of methane condensation in the convection parametrization scheme based on a thermal plume model initially developed for the Earth atmospheric boundary layer (Rio & Hourdin 2008). However, unlike for the Earth, the condensable species are heavier than the surrounding atmosphere mainly composed of hydrogen. This phenomenon is suggested to be a powerful driver of intermittent storms activity detected in the atmospheres of the Ice Giants (Guillot 2022). The improved fidelity of our GCM simulations offers valuable implications for interpreting observational data and refining our understanding of the atmospheric processes governing these enigmatic outer planets.
Developing a straightforward precipitation-runoff model for monthly-based nutrient emission modeling in river systems
Authors: Oprei Anna , Huk Victoria , Venohr Markus
Published: March 2024

Nutrient emission modeling in river basins includes the estimation of nutrient fluxes and retention in streams and forms a vital part for the management of water resources as well as the exploration of ecological impacts of increased nutrient input in river systems. The nutrient emission model MONERIS (Venohr et al., 2011, Lemm et al., 2021) calculates landuse-specific nutrient fluxes for entire river basins on a monthly basis and a spatial resolution of 1km x 1km and requires an ensemble of input data such as land use, atmospheric deposition, tile drainage cover, connection to sewer systems, and many more. Hydrological flows majorly drive nutrient fluxes and emission pathway composition. Consequently, runoff is one of the key constituents that needs to fit to the emission model requirements in terms of represented pathways and environmental compartments (e.g. land-use types, groundwater-surface water boundaries, spatial-temporal resolution). Using available runoff data derived by third party models can introduce large uncertainties to the resulting nutrient fluxes and water quality. Our aim was to develop a novel runoff model that operates on a monthly basis, provides runoff components for all considered emission pathways and can be applied with commonly available input data. These include, beyond the typical hydrological components (snow storage/melt, surface runoff, natural/artificial interflow, lower interflow and groundwater), flow estimates from urban areas (separate sewers, combined sewer overflows, decentralized/large treatment plants, point sources). The overall goal is to set up a data base for a Europe wide water quantity and quality model. In the presented pilot study, the runoff model was applied to the Odra River Basin (119,000 km²), calibrated against observed runoff data from 11 independent upstream gauges, and validated by runoff data from 36 additional gauges for the years 2010-2020. We compared input data sensitivity and model performance of three available daily gridded precipitation and air temperature datasets (E-OBS, EURADKLIM and CHELSA). Results showed a good model accuracy (NSE: > 0.9, PBIAS: < 7 %) and suggest that, despite its simplicity, the runoff model complements the nutrient emission model MONERIS. The next step will be the modelling of water quantity and quality for Central Europe, and, ultimately, providing an open modelling platform that allows emission modelling of other parameters and substances (e.g. salinity, heavy metals or priority substances) or be extended by additional modules for phytoplankton growth or floodplain retention.
Future global temperature impact of global aviation in ICAO scenarios
Authors: Aamaas Borgar , Lund Marianne T. , Fuglestvedt Jan S. , Totterdill Anna , Lee David S. , Owen Bethan
Published: March 2024

We model the global temperature change due to global aviation based on the recently developed International Civil Aviation Organization (ICAO) Long Term Aspirational Goal (LTAG) emissions scenarios. ICAO has produced four different “scenarios”, including a baseline scenario with frozen technology and three “integrated scenarios” with varying levels of in-sector CO2 reductions from technology and operational improvements and including different fuel mixes. Aviation activity leads to a mix of long-lived CO2 effects and several short-lived effects. Our analysis includes CO2, contrails/cirrus, NOx, water vapor, and black carbon. The non-CO2 emissions and activity are developed in this study to be consistent with each of the ICAO CO2 scenarios.We combine these fuel and emission data with recent knowledge on radiative forcing, including uncertainties. By using the simple climate model CICERO-SCM, we model the change in global temperature until 2100 given the different scenarios. We will show how scenario range, uncertainty in RF, effect of background conditions, and uncertainties in other parameter choices impact the temperature calculations. For NOx, we include scenarios that account for the effect of background NOx emissions. We also compile CO2 emission aviation scenarios available in the literature from the past decade and compare these with ICAO’s.Our results confirm the temperature impact of the aviation sector estimated by other studies, but also show large uncertainties. When accounting for the impact of aviation NOx being dependent on the background conditions, we find a large variation in global temperature change based on what SSP is used as background. While NOx emissions from aviation will likely grow according to the ICAO scenarios, global emissions of NOx are declining in the SSPs, making this issue important to study further. With a growing share of SAF and LH2 in the fuel mix, we also observe a large range in temperature impact accounting for the literature range on contrail formation for different types of fuels.Our overarching study shows that better understanding is needed to more robustly estimate the climate impact of aviation, including estimating RF of non-CO2 and in going from aviation activity to RF from contrails for different types of fuels.
New scenario for structural segmentation and subduction modeling in Makran (Iran and Pakistan)
Authors: Namdarsehat Peyman , Milczarek Wojciech
Published: March 2024

The Makran subduction zone is located in southeastern Iran and southern Pakistan. It was formed by the subduction of part of the oceanic crust of the Arabian Plate beneath the Eurasian Plate. In the eastern part of this zone, the convergence rate, coastal uplift and seismicity are higher than in the western part of this zone. In addition, there are a larger number of Quaternary volcanoes in the western part due to a subduction arc of the oceanic lithosphere. The study of the velocity vectors shows that the asymmetric pressure impressed the Makran and in addition a number of tectonic evidences were attributed to different dip angles of subduction. The results indicate that the segmentation of the Makran is influenced by two key factors: asymmetric pressure, resulting in varying convergence rates, and different subduction dip angles. These factors are identified as the origin parameters that contribute to the formation of two distinct blocks with contrasting structures. Based on the considerations made in this study, subduction in the Makran was modeled. And a new structural segmentation was presented in this zone. The results indicate a propagation of the eastern boundary of the Lut block in Makran. The model presented in this paper was able to show the tectonic problems of the Makran and furthermore demonstrate the discrepancy between the tectonic features of the western and eastern blocks of the Makran.
A simple approach to upscale methane emissions from peatlands using Planetscope satellite data and machine learning algorithm
Authors: Ingle Ruchita , Saunders Matthew , Habib Wahaj , Connolly John , Bataille Laurent , Hutjes Ronald , Biermann Jan , Jans Wilma , Franssen Wietse , vander Poel Laura , Kruijt Bart
Published: March 2024

Peatland plays a significant role in methane (CH4) emissions, and methane dynamics are governed by ecohydrological variables and site heterogeneity. Emission quantification from different stages of peatland is vital to understanding the impacts of peatland on climatic feedbacks for effective rehabilitation of these sensitive ecosystems. Chamber measurement and eddy covariance techniques are widely used to understand methane dynamics. These measurements are either at a point or footprint scale, making it challenging to upscale these emissions to the site scale considering the heterogeneity of peatlands. Here, we present a simple approach to upscale methane emissions from closed chambers using PlanetScope high-resolution satellite data along with the random forest algorithm and weighted-area approach. This methodology was tested at three peatlands covering near-natural, under-rehabilitation, and degraded sites in Ireland for a span of two years. The annual vegetation maps were mapped with an accuracy of 83% at the near-natural site and around 98-99% at the under-rehabilitation and degraded sites. The highest site-scale fluxes were observed at the near-natural site (2.25 and 3.80 gC m−2 y−1), and the site-scale fluxes were close to net zero for the under-rehabilitation (0.17 and 0.31 gC m−2 y−1) and the degraded site (0.15 and 0.27 gC m−2 y−1). As a step forward, this approach will be applied to upscale eddy covariance fluxes from three fen sites in the Netherlands. Overall, the easy-to-implement methodology proposed in this study shows potential to apply it across various heterogeneous land-use types to assess the impact of peatland rehabilitation on methane emissions.
Fresh water sources for submarine groundwater discharge to the southern Baltic Sea 
Authors: Jenner Anna-Kathrina , Saban Rhodelyn , Ehlert von Ahn Catia Milene , Westphal Julia , Roeser Patricia , Schmiedinger Iris , Sültenfuss Jürgen , Böttcher Michael Ernst
Published: March 2024

The impact of freshwater sources like surface river and submarine groundwater discharge (SGD) on the coastal water, the element balance therein, and the associated biogeochemical transformations within the subterranean estuary is currently a matter of intense debate and investigation. A quantification of freshwater mixing in coastal areas has been found to be challenging. In this sense the combination of stable water isotopes with further (isotope) hydro(bio)geochemical tracers provides a fundamental valuable tool to identify different freshwater sources found in the mixing zone with seawater.Here, we report the geochemical and isotopic composition of porewaters of permeable sediments in front of a coastal peatland, the Huetelmoor (southern Baltic Sea). Gradients in pore water measurements from 5 m long stationary porewater lances are used to calculate the zero-salinity (ZS) component. The application of binary mixing approaches on water isotopes and conservative elements on the compositional gradients yields temporarily relatively stable ZS compositions but with substantial isotope differences for spatially distant lances. This indicates a subterranean estuary under steady-state conditions with different fresh waters entering the coastal area. At least two freshwater sources can be identified for sediments impacted by SGD without substantial impact of short-term hydrological or meteorologic processes. These results are compared to the composition of potential endmembers, such as the local surface and groundwaters, the local meteoric water line, and the open brackish Baltic Sea.Besides stable isotopes, also dissolved major and minor elements were used to characterize the biogeochemical processes leading to the non-conservative behavior of nutrients, the carbon system, and trace elements. In addition, tritium-noble gas dating of the pore waters allows for an estimate of the fresh water residence time before mixing with the brackish Baltic Sea water.Results will be discussed in the context of other SGD sites along the northern German coast. Acknowledgement for support by DFG RTG Baltic TRANSCOAST, DFG-KiSNet, BMBF COOLSTYLE/CARBOSTORE, DAAD, and Leibniz IOW
Landslide Identification in UAV Images Through Recognition of Landslide Boundaries and Ground Surface Cracks
Authors: Cheng Zhan , Jaboyedoff michel , gong wenping
Published: March 2024

Landslides represent one of the most pervasive and detrimental geohazards worldwide. Precise detection of potential landslides is imperative for effective landslide risk management. While the utilization of Unmanned Aerial Vehicles (UAVs) has seen a recent surge in landslide evaluation, the majority of contemporary UAV image-based identifications predominantly depend on visual inspections. This study introduces a sophisticated image analysis framework tailored for landslide identification in UAV-captured imagery. This framework not only discerns landslide boundaries but also detects ground surface fractures. Employing an object-oriented image analysis approach, potential landslide boundaries within UAV images are identified. Concurrently, an automated model, refined through a deep transfer learning methodology, recognizes ground surface fractures in these images. Subsequent to this, a fusion of identified landslide boundaries and ground fractures is achieved through Boolean operations, facilitating nuanced landslide detection within UAV imagery. To underscore the proficiency of our proposed framework, we selected the Heifangtai Terrace in Gansu, China, as a case study. The resultant identifications are cross-referenced with field survey data to confirm the validity.
A comprehensive study on the sputtering of the lunar surface
Authors: Brötzner Johannes , Biber Herbert , Jäggi Noah , Nenning Andreas , Fuchs Lea , Szabo Paul Stefan , Galli André , Wurz Peter , Aumayr Friedrich
Published: March 2024

The Moon is subjected to a variety of influences in the space environment. One of these is the solar wind, a plasma stream consisting of mostly H+ and He2+ ions, that impinges on the lunar surface. As a consequence, material is released through the process of ion sputtering, mostly on an atomic level. These ejecta subsequently take part in the formation of the lunar exosphere [1]. Constraining their physical properties, most notably the parameters sputtering yield, ejecta angular distribution and their energy distribution, is thus crucial to properly model the exosphere creation [2]. Such investigations have been of interest for decades and have recently been carried out with samples representative for the lunar mineralogy [3–6].In this contribution, we present our current investigations on the aforementioned parameters using samples prepared from material collected during the Apollo 16 mission. Using a quartz crystal microbalance (QCM), we are able to measure mass changes due to sputtering caused by H and He ions and therefore also the sputtering yield. Additionally, we place another QCM in the experimentation chamber in a rotatable manner that collects the ejecta. Doing so enables us to probe the angular distribution of the ejecta. For these experiments, we use two types of samples: flat vitreous films as well as pellets pressed from lunar regolith and prepared according to [7]. Along with numerical simulations considering the sample morphology, this allows us to untangle intrinsic material properties from modifications thereof due to surface roughness. Lastly, we will present plans for future measurements to experimentally resolve the ejecta energy distribution. These energy distributions of particles sputtered from compound materials (rather than monatomic ones) are an actively researched area, especially from a numerical standpoint [8–11] – experimental data are scarce, however. This study combining the three physical quantities describing the sputtering process will therefore close a knowledge gap and be applicable not only to the Moon, but also to the sputtering of other planetary bodies.[1] B. Hapke, J. Geophys. Res. Planets 106 (2001) 10039–10073[2] P. Wurz, et al., Icarus 191 (2007) 486–496[3] P.S. Szabo, et al., Icarus 314 (2018) 98–105[4] H. Biber, et al., Nucl. Instrum. Methods. Phys. Res. B 480 (2020) 10–15[5] H. Biber, et al., Planet. Sci. J. 3 (2022) 271[6] M.J. Schaible, et al., J. Geophys. Res. Planets 122 (2017) 1968–1983[7] N. Jäggi, et al., Icarus 365 (2021) 114492[8] L.S. Morrissey, et al., J. Appl. Phys. 130 (2021) 013302[9] H. Hofsäss, A. Stegmaier, Nucl. Instrum. Methods. Phys. Res. B 517 (2022) 49–62[10] L.S. Morrissey, et al., ApJL 925 (2022) L6[11] R.M. Killen, et al., Planet. Sci. J. 3 (2022) 139
Potential matrix-matched reference material for in-situ garnet U-Pb dating
Authors: Beranoaguirre Aratz , Millonig Leo J. , Stifeeva Maria V. , Albert Richard , Marschall Horst , Gerdes Axel
Published: March 2024

Well-characterized matrix-matched reference materials are an indispensable requisite for mineral dating by LA-ICPMS. Recently, the in-situ U-Pb dating of low-U minerals (
An attempt to capture diverse tidewater glacier calving styles within a single framework
Authors: Slater Donald , Benn Doug , Wagner Till
Published: March 2024

The complexity of the processes and the difficulty of collecting observations mean that the treatment of the ice-ocean boundary remains one of the most challenging aspects of running models of the Greenland ice sheet. With geometry, climate forcing, ice properties and feedbacks between these factors all playing a role, tidewater glaciers display a range of calving styles that are hard to capture within the simple parameterisations that are necessary for large-scale ice sheet modeling.Here we attempt to place some dominant calving styles within a single framework. We study submarine melt undercut-driven calving using linear elastic fracture mechanics within 2D elastic simulations, together with analytical approaches to calving driven by the intersection of basal and surface crevasses and to ice cliff failure. Taken together, these approaches give a prediction of calving style as a function of the calving front ice thickness, ocean depth and submarine melt undercut length, or equivalently as a function of the frontal tension, bending moment and shear. We discuss possible implementations in ice sheet models.
Implementation of Boundary Conditions for Nonlinear Force-Free Field Computations Using Vector Potentials
Authors: Lee Minseon , Choe Gwangson , Yi Sibaek
Published: March 2024

A nonlinear force-free field is solely determined by the normal components of magnetic field and current density on the entire boundary of the domain. Methods using three components of magnetic field suffer from either overspecification of boundary conditions and/or a nonzero divergence B problem. A vector potential formulation eliminates the latter issue, yet poses difficulties in imposing normal components of both magnetic field and current density on the boundary. This challenge arises due to the inability to fix all three components of the vector potential at the boundary while the vector potential within the interior domain undergoes iterative changes.This paper explores four distinct boundary treatment approaches within the vector potential formulation. In two methods, the normal component of the vector potential is adjusted to satisfy the prescribed boundary-normal component of current density at each iteration, while the tangential components remain fixed throughout. In the other two methods, the tangential components of the vector potential are modified at each iteration, while the normal component remains fixed. Each group comprises both first-order and second-order boundary treatments. We conduct a comparative analysis of these methods against our established poloidal-toroidal formulation code and the optimization code in Solar Software.While none of the four methods outperform our poloidal-toroidal formulation code, they demonstrate comparable or superior performance compared to the latter. This research is regarded to provide insights into optimizing boundary conditions for data-driven simulations using vector potentials. 
Investigating the sensitivity of a profile laser scanner
Authors: Kostjak Victoria , Neuner Hans
Published: March 2024

The deformation analysis of infrastructural objects like dams, bridges or tunnels is a dominant topic in engineering geodesy. Employing cost-efficient devices that react sensitively to deformations in the sub-millimeter range enables a more efficient geodetic monitoring.To achieve this objective, the performance of a profile laser scanner, which was manufactured for use in the automation technology, was examined and analyzed for the use in geodetic monitoring.The promising results of laboratory and large-scale field tests performed on concrete test specimens show the high sensitivity of the profile laser scanner in detecting deformations. Reference measurements with a high-precision distance measuring device (laser tracker) underline the detection of deformations in the sub-millimeter range by the tested profile laser scanner.
Analysis of the 2016 Central Italy earthquake sequence by using a refined earthquake catalog 
Authors: Xiang Louise , Marsan David
Published: March 2024

The 2016 Central Italy seismic sequence occurred within an area dominated by normal-fault systems present along the Apennines. The sequence began with the Mw6.0 Amatrice event on the 24 August 2016, followed by the Mw5.9 Visso event on the 26 October 2016 and then, four days later, the Mw6.5 Norcia event. In this study, we aim at modeling the seismicity of this complex earthquake sequence in order to determine the location of highly-pressurized fluids under the studied area through swarms occurring during the sequence. To do so, we take advantage of a high-resolution earthquake catalog based on arrival times derived using a deep-neural-network-based picker. As a first step, we apply a density-based clustering approach to group earthquakes into dense clusters. The majority of the resulting clusters highlight distinct fault planes which indicates an activation of a complex fault network. We further define a 4-dimensional seismicity model based on the « Epidemic-Type-Aftershock- Sequence » (ETAS) model, in which we introduced an earthquake detection probability to accommodate observed rapid fluctuations in earthquake detection throughout the sequence. By computing the ratio between the observed and ETAS-modeled rates of high-density clusters, we can identify candidate seismic swarms. To evaluate their consistency, we compute the weighted index of the largest seismic event and the magnitude difference between the largest and the 4th-largest earthquakes occurring within a target candidate. Furthermore, to analyze their migration behavior, eigenvectors are computed to identify primary and secondary directions, and swarm earthquakes are projected onto these directions, in which we fit a linear regression model. Observed slope values are compared to those from a distribution of simulated slopes generated by 1000 random shuffling, and statistical significance is assessed. The results reveal among the 40 seismic swarms, 29 of them show significant migration with a significance level of 95%. Migration velocity is determined by components representing velocities along primary and secondary directions, measured in kilometers per day based on slope and earthquake count. Our swarms exhibiting significant migration suggest the implications of variations in pore fluid pressure influenced by structural complexity and intense faulting in the region. Before Norcia mainshock, we observe that swarms are detected in shallow depth with z = [0;5] km, whereas after the mainshock, swarms are found deeper with z > 8 km where the detachment plane is located.
Reducing the carbon footprint of a research lab: how to move from individual initiatives to collective actions?
Authors: Lauvernet Claire , Berni Céline , Coquery Marina , Gauthier Leslie , Héraut Louis , Masson Matthieu , Mimeau Louise , Vidal Jean-Philippe ,   Riverly Downstream team
Published: March 2024

This communication aims at exposing the steps taken by a research lab – in this case INRAE RiverLy – to reduce its carbon footprint. INRAE RiverLy is an interdisciplinary research unit for the functioning of hydrosystems. The environmental transition process originates in 2020 with the creation of the RiverLy Downstream group launched to address the downstream impacts of research practices (see Vidal et al., 2023).The first step taken by the RiverLy Downstream group relates to monitoring the laboratory's carbon footprint and identifying the main emission sources. Yearly carbon accountings carried out since 2019 using the GES1.5 tool (https://apps.labos1point5.org/ges-1point5) show that purchases (equipment, consumables, etc.) account for the majority (>50%) of the lab footprint. They also highlight the impact of changes in individual practices related to business travel, with -63% of travel-related emissions in 2022 compared to 2019.A second step focused on raising awareness through a Climate Day and testing the willingness to change within our research unit through an opinion poll. Results led to writing down a lab charter which was unanimously adopted by the lab council in October 2023. This charter sets a collective 10%/year cut-down trajectory with respect to the 2022 carbon accounting, while affirming the determination to preserve the positive impact of our research on society.A third step now being undertaken by the RiverLy Downstream team is to come up with concrete collective actions to effectively reduce the lab footprint. Participatory workshops are being organised in January and February 2024 to specify agreed actions for the various research activities: long-distance travelling, purchasing scientific and IT equipment, setting up a research project, doing lab and field experiments, performing biological and chemical analyses, performing scientific computations, and organising seminars and conferences. Consolidated and agreed propositions will then be submitted to the lab council for formal acceptation and implementation.The whole process benefits from rich interactions with the INRAE national to regional strategy for reducing its environmental footprint (https://www.inrae.fr/en/corporate-social-responsibility-inrae), and with the French national initiative Labos1point5 which set up a national network of labs in transition (https://apps.labos1point5.org/transition-1point5).Vidal, J.-P., Berni, C., Coquery, M., Devers, A., Gauthier, L., Lauvernet, C., Masson, M., Mimeau, L., and Turlan, M. and the RiverLy Downstream team: How to collectively engage in reducing the carbon footprint of a research lab?, EGU General Assembly 2023, Vienna, Austria, 24–28 Apr 2023, EGU23-3462, https://doi.org/10.5194/egusphere-egu23-3462, 2023.
Improving SO2 emissions from the point sources over the Middle East using satellite observations and inverse modeling.
Authors: Ukhov Alexander , Hoteit Ibrahim , Stenchikov Georgiy
Published: March 2024

The Middle East faces important challenges from severe air pollution, marked by natural factors from frequent dust storms and human-induced emissions, notably SO2 from power and desalination plants. These emissions significantly degrade air quality and contribute to sulfate aerosol formation, impacting climate and cloud formation. Accurate SO2 emissions representation in this challenging environment is crucial. We aim to enhance the current SO2 emission inventory by integrating satellite SO2 observations and the FLEXPART-WRF model, driven by meteorological data from the WRF 10km resolution model run in 2016. In particular, we adapted the WRF-Chem’s code for simulating the major SO2 sinks (in cloud scavenging, dry and wet deposition, SO2 oxidation by OH and H2O2) into the FLEXPART-WRF model. It allowed us to exclude the “background” SO2 column loadings caused by the spatially distributed emissions and to invert the SO2 emissions from the strong point sources on a daily basis. The improved SO2 emission inventory is open to the community.
An agent-based model for testing the impact of policy options on flood displacement in Sudan
Authors: Panizza Eleonora , Abebe Yared Abayneh , Rudari Roberto , Spotorno Mauro
Published: March 2024

The IGAD region in East Africa has experienced a rise in the occurrence and severity of floods over time, as a consequence of climate variability and change. Among member states, Sudan stands out as one of the most affected by recurrent floods, suffering significant damage to houses, livelihoods, infrastructure, and economic activities. Areas along the River Nile, in particular, are often affected by riverine flooding. These events continue to displace thousands of people annually in the country, while immobility in the face of disasters is also an issue. In response to this challenge, the design and implementation of effective flood risk mitigation policies have become paramount, addressing both physical and socio-economic perspectives. The aim of this research was to develop an agent-based model (ABM) to simulate human behavior and assess the impact of policies on flood displacement patterns in seven locations in Khartoum State, Sudan. To lay the groundwork for the ABM, a household survey was conducted to collect information about the socioeconomic characteristics, flood displacement experience, and risk perceptions of the resident population. The ABM operates as a tool for modeling the behavior of autonomous household entities in various 30-year hazard and policy scenarios. Policies, tested both individually and in combination, include the Early Warning System, the Awareness Programme, the Basic Income Programme, the House Repair Programme and the Build Back Better Programme. In the model, households’ actions and decisions within the different flood and policy scenarios depend on their personal characteristics. Elements that influence the decision to move or stay include risk perception, socioeconomic characteristics, and flood damage. This innovative model serves as an instrument for estimating the volume of displacement, evacuation, and immobility across different scenarios. It supports the identification of the most effective intervention strategy for the context under consideration. The focus of the presentation is on the results of the comparative policy analysis derived from the ABM simulations. These findings are also instrumental in supporting local and national decision-makers in mitigating the risk of flood displacement and immobility, thereby strengthening the resilience of communities to flood challenges.
Effects of improved land surface processes in the regional climate model REMO on climate means and extremes in Mainland Southeast Asia
Authors: Abel Daniel , Ziegler Katrin , Pollinger Felix , Paeth Heiko
Published: March 2024

The representation of land surface processes is crucial to reduce biases of climate model simulations and increase their reliability. Thus, our study examines the effects of recent improvements of the regional climate model REMO2015 related to soil hydrological and vegetation processes and their interactions with the atmosphere. In detail, a multilayer soil scheme and an interactive vegetation module are combined with each other and substitute the former single layer scheme and static vegetation being used in the recent CORDEX-CORE simulations.We investigate the effect of the improvements on the climatology and the annual cycle of different variables relevant for the land surface-atmosphere process chain including soil moisture, LAI, evapotranspiration, and 2m temperature. We further study the simulation’s performance of selected warm and dry events. As benchmarks, we consider different validation datasets and compare our simulations with the former REMO2015 model version as well as with recent simulations from CORDEX-CORE covering the study area.
Unveiling Tomorrow's Climate: Indus River Basin in Focus - A Comprehensive Assessment using Cutting-edge CMIP6 Data for SSP126 and SSP585 Scenarios
Authors: Pyarali Karim , Zhang Lulu , Al-Qubati Abdulhakeem
Published: March 2024

Indus River Basin supports approximately 268 million inhabitants, covering four different countries, including Pakistan, India, China and Afghanistan. Most countries situated in this basin are highly vulnerable to the impacts of climate change, even though their emissions are low. The basin has a large agriculture-based economy; therefore, we are interested in assessing the impacts of climate change on agriculture under best- and worst-case scenarios. In this study, a mean ensemble of four CMIP6 climate models was used with a resolution of 50km, and the analysis was conducted on a subbasin scale through delineation of the entire Indus basin. The climate indices estimated are extreme maximum temperature (TXx), extreme minimum temperature (TNn), heat stress (TR), maximum 5-day precipitation (RX5day), 95th percentile of precipitation (R95pTot), consecutive dry days (CDD), growing season length (GSL), and heat sum (HS). The climate indices data was analyzed spatially and temporally by estimating trends, their significance, areal mean time series and plotting Hovmuller diagrams. Temperature-based indices TXx and TNn show a significant increase across the basin, while TR seems to increase mostly in the Lower Indus Basin plain. This may lead to crop failure due to excess heat and put more pressure on available water resources. Precipitation-based indices RX5day and R95pTot show a rise in flood risks in the eastern subbasins, while the number of CDD will vary across the region. The Hovmuller diagrams show that spatial precipitation patterns will be irregular across the basin, making it difficult to follow traditional agricultural practices. A significant increase in GSL and HS is noted in the Upper Indus Basin, making the region more suitable for agriculture, and the seasonal differences plot showed that the summer months of July, August & September will have the largest increase in extreme precipitation with high spatial variability. To conclude, climate adaptation measures are necessary, and a nexus-based resource management approach should be considered in the decision-making process. 
Autocalibration of hydraulically simplified model for urban drainage systems
Authors: Palmitessa Rocco , Murray Ryan W. , Andersson Henrik , Mariegaard Jesper S.
Published: March 2024

Detailed hydrodynamic models like MIKE+ provide accurate representations of the complex behavior of urban drainage systems. Surrogate models simplify this high-resolution representation to minimize the computational cost at the expense of reduced accuracy. As such, they are particularly useful when timely and repetitive simulations are needed.Physics-based models of urban drainage systems typically include both hydrological (surface runoff) and hydraulic (network collection) components, with the computational cost mostly associated with the latter. The constructed surrogate model retains the hydrological representation of the original MIKE+ model but lumps the hydraulic network to a single collector downstream. This approach caters use cases where the full catchment description is needed.We apply Muskingum routing to the catchment runoff to emulate the hydraulic routing between the catchment and the collector. The parameters of the routing function (delay and smoothing factor) are defined for each catchment as a function of the distance from the collector. We calibrate two global proxy parameters to optimize the performance of the surrogate: average velocity as a proxy of the individual delay, and smoothing range as a proxy of the individual smoothing factor.The calibration of the proxy parameters is fully automated, given upper and lower bounds and the number of trials, and utilizes a Bayesian optimization algorithm. The objective of the autocalibration is minimizing the RMSE of the collector discharge for a synthetic rainfall event with 1-year return period.To validate the calibrated surrogate, we simulated synthetic rainfalls with return periods both lower and higher than the calibration one and compared the modelled discharge with the results of the original model.Our results for the 1-year rainfall show that the surrogate achieves a 25 times speedup in execution time compared to the original model, while introducing and 0.1% error in the accumulated volume of the event, a 3 minute error in the peak time, and a 5,8 % error in the peak discharge. A similar or better performance was obtained with lower return periods, but the performance of the surrogate quickly degrades with higher return periods.Further research could focus on testing additional calibration objectives, e.g. timing and magnitude of the peak, as well as investigate methods to extend the validity of the surrogate beyond the calibration return period.
On the validation of wave/ice interactions in the model MFWAM : Analysis with CFOSAT data
Authors: Aouf Lotfi , Bedossa Emma , Law Chune Stephane , Rabault Jean , Carasco Ana , Hauser Danièle
Published: March 2024

Improving wave forecasting in the polar oceans is crucial for coupled earth system and climate monitoring. There is still a strong uncertainties on wave variability in the Marginal Ice Zone (MIZ) and polar oceans. The wave scatterometer SWIM of CFOSAT, provide directional wave spectra, which are very useful to improve the wave forecast in the MIZ and the validation of using wave/ice interactions source term in the MFWAM model. The aim of this work is firstly to assess the impact of using the ice probability products provided by CFOSAT in the MFWAM wave model, and secondly to calibrate and validate the source term for wave attenuation induced by sea ice based on Yue et al (2022) implemented in the MFWAM model. Several MFWAM model simulations have been performed in a global configuration during boreal and austral winter and summer seasons. Different ice probability or fraction forcings provided by the IFS atmospheric system and CFOSAT have been tested in the MFWAM model, while sea ice thickness is provided by the Copernicus Marine Service global ocean reanalysis GLORYS. Significant Wave height (SWH) validation of MFWAM model simulations have been carried out using Sentinel-3 altimetry data, which has good coverage of polar regions. The results show a significant improvement in the bias and scatter index of SWH in Antarctica for Weddell and Ross Seas. The assimilation of SWIM wave spectra enhances the improvement of SWH in the polar oceans, particularly in the Ross Sea, Weddell Sea in Antarctica and Beaufort Sea in the Arctic ocean.In this work we also analyzed wave attenuation by sea ice. Validation with Sentinel-3 in the Weddell Sea during the boreal summer shows a good performance of the MFWAM model with the wave/ice ineractions term compared with the simulation without interactions. The analysis of wave attenuation by sea ice was carried out in the Arctic in the Sprtizbergen archipelago area, where observations from drifting buoys (Open Met buoys) have been used to validate the MFWAM model performance. The results show good consistency between the MFWAM model and the drifting buoys. Further analysis regarding to the impact of using wave/ice interactions on ocean circulation has been conducted with ocean mixed layer model.More discussions and conclusions will be summarized in the final presentation.