bluuebunny/crossref_metadata_2025 huggingface dataset:
Supervised and unsupervised machine learning techniques to map seismic site amplification
Authors: Panzera Francesco , Bergamo Paolo , Janusz Paulina , Perron Vincent , Fäh Donat
Published: March 2024

Switzerland experienced earthquakes mainly in the Basel area and within its Alpine region, with the Canton Valais standing out as one of the most active zones. The Rhone Valley, crossing the entire canton, is characterized by sediment deposits with a thickness reaching up to 800 meters. The valley’s topography and the significant contrast in seismic wave velocities between sediments and the surrounding rock, make it susceptible to 2D/3D effects, leading to significant site amplification phenomena. To develop local amplification models that integrate geological and geophysical data, specific areas – of relevance from the risk point of view - in the Rhone Valley were selected. One area is Sion, where geophysical data were acquired during the earthquake risk model for Switzerland project (ERM-CH). The dataset encompasses 313 single station noise measurements and seismic records from 10 seismic stations. The single station measurements were employed to compute horizontal to vertical spectral ratios (HVSR), while earthquake recordings were utilized to derive empirical spectral modelling amplification functions (ESM). Our approach involves the application of the canonical correlation (CC) statistical method, which explores the correlation between two sets of variables by identifying linear combinations that exhibit maximum correlation. Specifically, we conducted CC analysis between the sets of HVSR and ESM using as calibration dataset of 172 free-field and urban free-field stations run by the Swiss Seismological Service over the entire Swiss territory. Using canonical correlation, we developed a method to predict the ESM for a specific site based on its HVSR information. Additionally, we employed a correlation analysis based on the Pearson cross-correlation coefficient as an alternative method. This approach was utilized to group the Sion HVSR, with the seismic station HVSR, for which ESM is available, serving as the centroid. This grouping resulted in the assignment of each of the 313 HVSRs to one of the 10 amplification functions. Consequently, we extrapolated amplification values to various locations and employed kriging for interpolation to generate amplification maps at specific frequencies. The utilization of different amplification models at defined frequencies allows for the assessment and definition of epistemic uncertainties in our findings.
The Jovian Electron and Ion Spectrometer (PEP-JEI) for the JUICE mission
Authors: Fränz Markus , Bambach Patrick , Fischer Henning , Heumüller Philipp , Krupp Norbert , Kühne Wolfgang , Roussos Elias , Labudda Robert , Barabash Stas
Published: March 2024

The magnetosphere of Jupiter is apart from the Sun the strongest source of charged particles in the Solar system. The interaction of these particles with the exospheres of the Jovian moons forms one of the most complex plasma laboratories encountered by human space flight. For this reason the plasma analyzer package forms a crucial experiment of the Jupiter Icy Moon Explorer (JUICE). As part of the Plasma Environment Package (PEP) we describe a combined electron and ion spectrometer which is able to measure the electron and ion distribution functions in the energy range 1 to 50000 eV with high sensitivity and time resolution. This instrument is called the Jovian Electron and Ion Analyzer, JEI. We report on the general performance of the instrument and on first observations of the solar wind during commissioning of the instrument in space.
Influence of Possible Bulk Compositions on the Long-Term Evolution and Outgassing of Venus
Authors: Louro Lourenço Diogo , Tackley Paul , Rolf Tobias , Grünenfelder Maria , Shah Oliver , Helled Ravit
Published: March 2024

Venus’ mass and radius are similar to those of Earth. However, Venus’ interior structure and chemical composition are poorly constrained. Seemingly small deviations from the Earth might have important impacts in the long-term evolution and dynamics of Venus when compared to our planet and could help to explain the different present-day surface and atmospheric conditions and geophysical activity between these two planets. Shah et al. (ApJ 2022) presented a range of possible bulk compositions and internal structures for Venus. Their models, designed to fit Venus’ moment of inertia and total mass, predict core radii ranging from 2930-4350 km and include substantial variations in mantle and core composition. In this study, we pick ten different Venus models from Shah et al. (ApJ 2022) that range from a small to a big, and from a S-free to a S-rich core. We run mantle convection evolution models for the different scenarios using the code StagYY (Tackley, PEPI 2008; Armann and Tackley, JGR 2012) and explore how different interior structures and chemical compositions affect the long-term evolution and dynamics of Venus. In our models, the bulk composition of the mantle affects the basalt fraction and the solidus and liquidus temperature profiles. We investigate how the composition and size of the core affects magmatism hence outgassing of water and other volatiles to the atmosphere, the basalt distribution, heat flow, temperature of the mantle and lithosphere, and observables such as the moment of inertia and Love numbers. Since the tectonic regime active on Venus is still unknown, we test different evolution scenarios for a planet covered by a stagnant lid, an episodic lid, and a plutonic-squishy lid. The models produce a range of predictions that can be compared to observations by planned missions to Venus, including EnVision measurements by the VenSpec spectrometers, comprising outgassing of water and other volatiles and surface composition. These can be used to constrain Venus’ interior composition and structure, and reveal key information on the differences between Earth and Venus.
Advancements in Lysimeters and Ecotrons: A Novel Platform for Investigating Climate Change Parameters in Laboratory and Field Settings
Authors: Reth Sascha
Published: March 2024

The ongoing global concern regarding climate change necessitates innovative approaches to understand its complex dynamics. This presentation outlines the evolution of lysimeters and ecotrons, culminating in the development of a cutting-edge platform designed for comprehensive research on climate change parameters in both laboratory and field environments.Lysimeters, traditionally employed to measure water movement and nutrient transport in soil, have undergone significant advancements. Enhanced instrumentation and sensor integration now allow for precise monitoring of multiple environmental factors, including soil moisture, temperature, and gas exchange. These improvements enable researchers to simulate and analyze various climate change scenarios in a controlled laboratory setting.Simultaneously, ecotrons, specialized chambers designed to replicate natural ecosystems, have evolved to provide a more realistic representation of climate interactions. By incorporating advanced technologies such as remote sensing, automated data acquisition, and controlled environmental conditions, ecotrons now offer a holistic approach to studying the impact of climate change on ecosystems.The integration of lysimeters under natural conditions and ecotrons into a unified platform represents a paradigm shift in climate change research. This new platform facilitates a seamless transition between controlled laboratory experiments and real-world field studies, allowing for a more comprehensive understanding of the intricate relationships between climate change parameters.Researchers can now explore the effects of elevated temperatures, altered precipitation patterns, and increased greenhouse gas concentrations on soil health, plant growth, and ecosystem dynamics with unprecedented precision. The platform's adaptability and versatility make it a valuable tool for addressing urgent questions related to climate change impact mitigation and adaptation strategies.In conclusion, the fusion of outdoor lysimeters and indoor ecotrons into a unified platform signifies a milestone in climate change research. This innovative approach provides researchers with a powerful tool to investigate and address the complex challenges posed by climate change, fostering a more sustainable and resilient future.
Enhanced global weathering in response to Central Atlantic Magmatic Province volcanism across the Triassic–Jurassic transition: an osmium isotope record from the Prees borehole (UK)
Authors: Ballabio Giorgia , Xu Weimu , Hnatyshin Daniel , Ruhl Micha , van Acken David , Dickson Alex J , Hesselbo Stephen P
Published: March 2024

The Triassic–Jurassic transition (~201.5 Ma) is marked by abrupt positive and negative Carbon-isotope excursions in marine and terrestrial sedimentary records. These excursions reflect global carbon cycle perturbations occurring in response to the massive volume of carbon released from the Central Atlantic Magmatic Province (CAMP). The subsequent doubling to tripling in atmospheric pCO2 led to ocean acidification and the development of marine anoxia, thought to have caused the end-Triassic mass extinction, one of the biggest mass extinctions of the Phanerozoic. Organic-rich sediments can record the evolution of the seawater osmium (Os) isotopic composition, which is controlled by the balance between weathering inputs from continental crustal rocks (187Os/188Os ~ 1.4) and from mafic and ultramafic basalts (187Os/188Os ~ 0.13). Here, we present the first 187Os/188Os isotope data across the Triassic–Jurassic transition from the Prees core (Cheshire Basin, UK), drilled for the International Continental Scientific Drilling Program (ICDP) Early Jurassic Earth System and Time-scale (JET) project. Our new Os-isotope data show two major excursions towards mantle 187Os/188Os signature across the Triassic–Jurassic transition which we interpret to be the result of the emplacement of CAMP and the fast weathering of juvenile basalts.
Reservoir characterization by push-pull tests employing Kinetic Interface Sensitive tracers
Authors: Gao Huhao , Tatomir Alexandru , Abdullah Hiwa , Sauter Martin
Published: March 2024

The kinetic interface-sensitive (KIS) tracer test is a newly developed tracer approach to measure the fluid-fluid interfacial area (IFA) during dynamic two-phase flow in porous media. This new tracer approach can be applied for multiple geological applications, where dynamic two-phase flow is involved, e.g. monitoring the plume during geological storage of carbon dioxide. The obtained concentration breakthrough curves by measuring reacted tracer concentration in water samples are interpreted with a specialized Darcy-scale numerical model to determine the IFA. The previous design of the drainage experiments has one major limitation that the volume of the usable water sample after breakthrough for the measurement is often insufficient. An alternative is to employ KIS tracers in a “push-pull” experimental set-up, i.e. primary drainage is followed by a consequent main imbibition process, with the flow direction being reversed. This study applies both the pore-scale numerical simulation and the core-scale column experiments to study the KIS tracer reactive transport during push-pull processes. The pore-scale numerical simulation is done with a phase-field method-based continuous species transport model. The reactive transport of the tracer and the characteristics of the concentration breakthrough curves are analyzed. The Darcy-scale reactive transport model is validated by comparing it to the pore-scale results. Finally, the new method is applied in the column experiment, where the determined specific interfacial area is found to be close to the literature data.
Rethinking operational VGOS observations
Authors: Schartner Matthias , Petrachenko Bill , Charlot Patrick , Xu Minghui , Collioud Arnaud , Krasna Hana , Benedikt Soja
Published: March 2024

The VLBI Global Observing System (VGOS) was created to meet the ambitious requirements set by the Global Geodetic Observing System (GGOS). Its primary objective is achieving millimeter-level precision while maintaining continuous 24/7 observations. Currently, both aims remain unfulfilled. Simultaneously, new requirements, such as the development of a dedicated VGOS Celestial Reference Frame (CRF), have emerged. Thus, a reevaluation of our current VGOS observational framework is necessary to reach the VGOS goals.This study addresses three pivotal challenges within VGOS: attaining millimeter precision, providing observations for a CRF, and achieving uninterrupted 24/7 observations. Each of these topics demand a readjustment of our current observation scheduling methodology.Based on insight from VGOS R&D sessions, this work discusses potential approaches to meet the requisite precision through shorter, signal-to-noise-driven observations. Additionally, it explores the combination of this methodology with source-based scheduling to facilitate the creation of essential observations for establishing a dedicated VGOS CRF. Finally, it addresses the issue of reaching 24/7 observations, currently limited by data transfer and correlation capacities. To overcome this, a potential solution involves a significant reduction in the recorded data volume per session by temporarily thinning out the schedule. Thus, it comes with a trade-off in precision. This concept might be seen as a paradigm shift in VLBI observations, traditionally striving for the highest precision possible, which we believe is worth being discussed. Based on observation statistics and Monte-Carlo simulations, we will elaborate on the expected impact of this approach. 
Bridging the gap between intangible science and society through geoheritage
Authors: Shajahan Rasia , van Wyk de Vries Benjamin , Zanella Elena , Harris Andrew
Published: March 2024

The realm of science and its outcomes is frequently perceived as esoteric by individuals outside the scientific field. This perception largely stems from the presentation of results, as scientists often convey their findings in a refined manner using strong technical terminology. However, this approach can be challenging for individuals with diverse backgrounds, both within and outside the scientific field. The absence of comprehension isolates such scientific work from our everyday life experiences, resulting in limited applicability and utilization of its findings. Hence, it is crucial to discover means of conveying research and findings in a more accessible and engaging manner. Achieving this can foster greater societal involvement in research, promoting participatory science—an integral yet often undervalued scientific endeavour.Geoheritage bridges geoscience and society, facilitating the accessible communication of geoscientific results. In our study, we create three levels of simple and clear explanations (doing, seeing and theory) to illustrate one of the most useful techniques in studying the rock-forming process, AMS (Anisotropy of magnetic susceptibility), to all based on their background. AMS is an extremely useful technique with diverse applications, including identifying strain and flow sense in rocks. We studied three distinct volcanic settings serving different visitor contexts—wild trekkers, beach visitors, and walkers and created an inventory that includes both tangible geological features of outcrops and intangible elements (AMS results). The M-GAM technique enabled us to create a comprehensive geoheritage inventory and to identify the most likely candidates for presenting these results effectively to the community, ensuring an optimal strategy for subsequent outreach and interaction with both tourists and locals. This method could be useful for studies involving a wider public, using their input in the simple explanations stage to con-construct a narrative that can then be consolidated with the inventory alongside the science.
The variability and predictability of regional Antarctic sea ice on seasonal timescale
Authors: Xiu Yongwu , Wang Yiguo , Luo Hao , Garcia-Oliva Lilian , Yang Qinghua
Published: March 2024

Antarctic sea ice is an important part of the Earth's system and provides key habitats for wild animals. This study assesses the variability and predictability of regional Antarctic sea ice, particularly focusing on the impact of the initialization of different components on its seasonal predictions. We run three hindcasts (retrospective forecast) experiments within the Norwegian Climate Prediction Model (NorCPM), whose atmosphere, ocean, or sea ice is initialized, respectively. These hindcasts are conducted four times per year over 1985-2010 and last for 13 months. We first evaluate three reanalyses that provide initial conditions for the hindcasts. It shows that solely constraining the ocean or atmosphere cannot reproduce the overall observed sea ice concentration (SIC) trend, but has some skill in capturing the variability of the SIC and Antarctic sea ice extent (SIE). Sea ice assimilation further improves the estimate of the SIC/SIE trend and variability, but the performance in the Pacific section is degraded. According to the hindcast experiments, the predictive skill varies with region and season. For example, winter SIE in the Weddell Sea and Amundsen-Bellingshausen Sea can be skillfully predicted 12 months in advance and the predictive skill in the Pacific Section is lower. Among the three hindcast experiments, atmosphere initialization generally yields comparable or even more prolonged prediction skills when compared to ocean or ocean/sea-ice initialization. Compared to ocean initialization, additional sea ice initialization improves prediction in the Indian Section, Pacific Section, and the Ross Sea, but degrades in the Amundsen-Bellingshausen Sea. Further analysis demonstrates that a large part of regional SIE predictability can be explained by high SST predictability on seasonal timescale. In addition, sea ice thickness plays a key role in prolonging the prediction skill in the Ross Sea until the summer season due to the memory of thick ice.
Modeling inland flooding caused by tropical cyclones in the US using AI-based synthetic events
Authors: Addor Nans , Lord Natalie , Mani Balaji , Loridan Thomas , Mizukami Naoki , Hoch Jannis , Haylock Malcolm
Published: March 2024

Tropical cyclones (TCs) are a key driver of flooding in the US. Here we present a modeling approach to simulate their associated inundation footprint under present and future climate and generate the hazard data necessary to run a CAT model. We developed an AI-based model called RainCyc that learns from the TC rainfall fields dynamically generated by the WRF model as well as from observations. RainCyc is orders of magnitudes faster than WRF, meaning that orders of magnitude more events can be simulated for the same computational cost. This is essential to capture the tail of the distribution, i.e., to generate synthetic events over a period longer than the longest return period of interest. Future boundary conditions for RainCyc are provided by the CESM2-LENS ensemble, which covers the 21st century under SSP370 levels of warming using 50 model realizations started from slightly perturbed initial conditions.The rainfall fields produced by RainCyc are used to simulate inland flooding, i.e., pluvial and fluvial. The inundation footprint for each event is generated by sampling from flood hazard maps simulated by the LISFLOOD hydraulic model. The sampling for pluvial is informed by RainCyc precipitation, while for fluvial, it relies on hydrological simulations driven by the FUSE and mizuRoute models. FUSE is a frugal rainfall-runoff model that is run at 10km over a domain encompassing each event to generate its associated runoff. This runoff is then provided to the vector-based routing model mizuRoute to generate flow time series from which peak flow is extracted and used to sample fluvial hazard maps.We present this modeling framework and test it for thousands of years of synthetic events under present and future climate. We benchmark the hydrological simulations for historical events using runs from other models, including GloFAS. We also test the ability of the framework to generate synthetic events spanning the intensities covered by hazard maps for a wide range of return periods.
German-wide analysis of high-frequency, continuous concentration-discharge relationships
Authors: Kiesel Jens , Houska Tobias , Müller-Hillebrand Janosch , Fohrer Nicola
Published: March 2024

High-frequency observations of solute and particulate concentrations (C) and associated discharge (Q) measurements allow the analysis of C-Q relationships on the event-scale. Together with catchment attributes and event properties, C-Q relationships can be used to disentangle the fine-grained dependencies between catchment properties, hydrologic processes and water quality.We collected 72 high-frequency (sub-hourly), continuous C and Q time series across Germany in catchments ranging from 8 to 122.000km² (median of 6.051km²). Besides discharge at all 72 locations, the database contains water temperature (60 locations), turbidity (34), conductivity (59), oxygen (57), pH (53), ammonia (16), nitrate (22), phosphate (10) and chlorophyll (12) in varying lengths over a maximum period of 20 years. Event filters were used to extract single discharge events. Hysteresis indices and classes of each event were used to describe the C-Q relationships. Event properties such as season, magnitude, variability, length, antecedent conditions, rise- and fall characteristics and physical catchment characteristics were assigned to each C-Q relationship.We used a Random Forest model to explain the hysteresis properties based on the event- and catchment characteristics. Particularly the variables turbidity and conductivity revealed spatio-temporal dependencies, which we relate to interplays of land use and soil characteristics. We further found that the C-Q patterns are significantly impacted by the identifiability and definition of the extracted discharge events across the heterogeneous catchments as well as the resolution and quality of the measurements of the different C variables.
Slender Wood Jamming at bridge piers: Finite-infinite retention time regimes
Authors: Pratama Muhammad Iqbal , Schnauder Ingo , Blanckaert Koen
Published: March 2024

Wood accumulating at bridge piers is a safety risk as it leads to accelerated scour and flow blockage. Wood accumulation starts with a first wood element and the (retention) time that this element is retained controls if a jam accumulation further develops or not.In flume experiments, we investigated the parameters and processes that determine the retention time of a single wood and developed a parameter-based predictive model for it. The experiments were based on eccentricity (the lateral distance between the centre of the wood and the centre of the pier) tests, measuring the retention time for varying eccentricities of the arriving element relative to the pier.The experiments revealed that the accumulation of single wood element can be categorized into three different phases: impact, rotation, and separation. The first impact phase starts when the wood hits the bridge pier. In the subsequent rotation phase, the wood element rotates around the bridge pier and possible also slides. Finally, the wood element separates from the bridge pier.A distinction can be made between an infinite and a finite regime. In the infinite regime, the rotation phase lasts very long and the wood element is in a metastable state. The diverging flow field around the bridge pier is key to the metastability since it causes stabilizing compensatory movements of the wood element around the bridge pier that include rotational swaying, vertical dipping or bouncing, and vibrations related to vortex shedding. The compensatory movements correlate with the Richardson number (the ratio of buoyancy force over inertia force), which is defined as the behaviour of the wood during a collision around bridge pier. The infinite regime only occurs for low eccentricities, i.e., eccentricities below one-third of the wood length.In the finite regime, the rotation phase is rather short, and the wood element separates from the bridge pier after a short time. The finite regime is controlled by the friction between the wood element and the bridge pier, flow velocity and eccentricityThis study provides a conceptualization of the retention time of wood elements and a quantitative estimation of the retention time in the finite regime. These findings provide a step forward in explaining and predicting the processes and phenomena of wood jamming at bridge piers. The developed concept and will be further developed for the wood jamming involving multiple interacting wood elements.
Machine learning for atmospheric delay correction in geodesy
Authors: Wang Duo , Wang Lingke , Kutterer Hansjörg
Published: March 2024

In recent years, geodesy based on spaceborne microwave remote sensing has gained significant advances. However, whether the observations from the Global Navigation Satellite System (GNSS) or Interferometric Synthetic Aperture Radar (InSAR), the results are inevitably influenced by atmospheric tropospheric delay. Although the tropospheric zenith total delay (ZTD) can be estimated through the gridded meteorological data products and empirical models provided by the ERA5 reanalysis product, its accuracy is still insufficient to meet the needs of modern geodesy. To overcome this challenge, we propose leveraging machine learning techniques to learn local spatio-temporal patterns of tropospheric delay for inferring total zenith delay (ZTD) and zenith wet delay (ZWD) at any location within the learning area.Our findings indicate that artificial neural networks can establish a robust mapping between ZTD estimated by empirical models and GNSS-measured ZTD. Then employing the ensemble learning strategy and the time series dynamics model, the ZTD at any location within the sample area can be inferred. To evaluate our approach, we conducted tests during the active water vapor season in the Tübingen region of Baden-Württemberg, Germany, from June 25 to July 9, 2022. In comparative experiments with the root mean square error (RMSE) of Zenith Total Delay (ZTD) derived from ERA5, our proposed method yielded a significant reduction in RMSE, decreasing it from 16.4292mm to 7.2108mm. This reflects a remarkable accuracy improvement of 56.11%.The proposed approach holds promise for enhancing the precision of GNSS positioning, InSAR earth observation, and generating more dependable water vapor products.
Assessing the role of cultural heritage in water management and land adaptation facing climate change: Pantelleria's case study.
Authors: De Agostini Carla
Published: March 2024

For communities to adapt, effective water management and governance strategies are necessary due to climate change's pressing challenges. Specifically, the proposed study examines the role of traditional water management systems in supporting land adaptation to harsh climate conditions on Pantelleria, a volcanic island in the Sicilian Channel.On the island of Pantelleria, there is a rich cultural heritage of water management, exemplifying a complex interaction between desertification, climate change, biodiversity, ecosystem services and land adaptation. As a result of Pantelleria's traditional water management, the landscape mosaic has been able to adapt and remain resilient to climate change impacts. Considering its successful application over time, the ingenious rainwater accumulation, storage, and distribution system demonstrates that this heritage serves not only as a legacy of the past, but as a critical organizing principle for the present. From a social-ecological perspective, preserving cultural heritage shifts the paradigm from innovating traditional knowledge toward reclaiming traditional water management methods that already contribute to the sustainability of local and environmental communities and incorporating them into a perspective of land adaptation to climate change.This study combines scientific research on desertification and land degradation in Southern Italy with interviews with local stakeholders in an effort to emphasize the importance of cultural heritage knowledge along with bottom-up actions by citizens, and advocates for the systemic vision of rural landscapes by mapping the distribution and abundance of traditional water systems in order to assess their functions in preserving and enhancing ecosystem services in an environment of constant land changing.Pantelleria serves as a model to demonstrate how similar regions experiencing water-related issues may benefit from its solutions and this study examines the barriers to integrating traditional and modern water management systems based on political, cultural, and institutional factors in order to improve water management and governance in similar harsh environments.
Why does stratospheric aerosol forcing strongly cool the warm pool?
Authors: Günther Moritz , Schmidt Hauke , Timmreck Claudia , Toohey Matthew
Published: March 2024

Stratospheric aerosol forcing causes only a small global-mean temperature change compared to CO2 forcing of equal magnitude. It has been shown that the dampened temperature response to aerosol forcing originates from enhanced surface temperature change in the tropical Indian and Western Pacific Ocean, relative to the global mean. Due to the pronounced temperature change in this “warm pool” region, strong negative feedback processes are activated. These stabilizing processes strengthen the global mean radiative feedback and abate Earth’s global mean temperature response. In comparison, CO2 forcing has a smaller effect on warm pool temperatures and therefore produces relatively weak feedback, i.e. a strong temperature change.However, it has remained unclear why stratospheric aerosol forcing affects warm pool temperatures more strongly than CO2 forcing. We address this problem using simulations of aerosol and CO2 forcing in MPI-ESM. At the top of the atmosphere (TOA), aerosol forcing is stronger in the warm pool than in the global mean, while CO2 forcing is relatively homogeneous, which could explain the different temperature patterns. However, we find that the forcing pattern at the TOA is not sufficient to explain the aerosols’ strong influence on warm pool temperatures. The effect can only be explained when taking into account the effective forcing pattern at the surface, which is substantially different from the effective forcing at the TOA. In the case of stratospheric aerosol forcing, the stratospheric heating causes an acceleration of the Brewer-Dobson circulation, which induces an enhanced energy transport from the tropics to the extratropics. Although the transport occurs in the stratosphere, it affects the troposphere and causes a strongly negative forcing at the surface of the tropics. In contrast, CO2 does not substantially affect the Brewer-Dobson circulation, and therefore the surface response is not amplified in the tropics.Our results stress the importance of circulation adjustments for the climate response. In the case of stratospheric aerosol forcing, the troposphere is impacted by changes to the wave-driven stratospheric circulation. The accelerated Brewer-Dobson circulation affects the forcing pattern at the surface, and in consequence the pattern of surface temperatures and the climate feedback. Furthermore, we argue that the commonly used method of measuring effective forcing at the TOA is not sufficient for understanding the evolution of surface temperature patterns.
A tracer-aided criterion to discretize pluvial and fluvial flood hazard maps in catchment scale shallow water models
Authors: Perrini Pasquale , Cea Luis , Gioia Andrea , Iacobellis Vito
Published: March 2024

Knowing the nature of the flood hazard is a crucial factor for improving the resilience of the urban areas, since awareness, preparedness and early warning systems are based on the scientific tools such as the 2D depth-averaged shallow water models. Inland flood hazard primarily stems from pluvial and fluvial inundations, typically modeled separately respecting the pertaining spatial domains of the assessment, namely the urban areas and the riverine floodplains. Considering the high computational power and efficiency of both hardware and codes, the catchment scale hydrological-hydrodynamic modeling is becoming an increasingly adopted approach in flood hazard assessments. Since a complete rainfall-induced routing is preserved, these simulators determine fluvial, pluvial and compound inundations caused by heavy storm events within the entire watershed.However, this approach leads to flood extent maps in which the inundations such as those resulting from pluvial and fluvial processes, are usually not differentiated, even if significant disparity in the space-time scales and volumes of water are involved. Indeed, these two hazards follow distinct normative and regulatory flood risk management rules among different countries. With such a rationale we established a tracer-aided criterion to systematically categorize and map pluvial and fluvial hazard in a catchment scale shallow water model, exploiting the advection process of a conservative tracer. The physically based methodology, implemented in the GPU-parallelized Iber+ software and its water-quality module (IberWQ+), is applied in a small urban catchment for multiple probabilistic scenarios. The results demonstrate the effectiveness of nesting transport and shallow water equations, univocally discretizing the two inundation sources in function of the computational cells reached by the tracer. This enables to define the spatial domains of the pluvial and fluvial processes, providing valuable insights for holistic catchment-scale flood risk management. Additionally, the advancements achieved by the proposed method are showcased in comparison to commonly employed modeling techniques for mapping fluvial inundations. As the tracers continue to improve our understanding of catchment sciences, we conceptualized them role through an abstraction that can aid surface hydrodynamic modelling to identify pluvial and fluvial sources of hazard.
Fluxible: an R package to calculate ecosystem gas fluxes in a reproducible and automated workflow.
Authors: Gaudard Joseph , Telford Richard , Vandvik Vigdis , Halbritter Aud Helen
Published: March 2024

Measurements of gas fluxes are widely used when assessing the impact of global-change drivers on key aspects of ecosystem dynamics, especially carbon. It shows whether an ecosystem is a source or a sink of atmospheric carbon, and how the storage dynamics could change in the future. Ecosystem gas fluxes are typically calculated from field-measured gas concentrations over time, using a linear or exponential model and manually selecting good quality data. This approach is highly time consuming and prone to potential bias that might be amplified in further steps, as well as having major reproducibility issues. The lack of a reproducible and bias-free approach creates challenges when combining global-change studies to make biome and landscape scale comparisons.The Fluxible R package aims to fill this critical gap by providing a workflow that removes individual evaluation of each flux, reducing risk of bias, and making it reproducible. Users set specific data quality standards and selection parameters as function arguments that are applied to the entire dataset. The package runs the calculations automatically, without prompting the user to take decisions mid-way, and provides quality flags and graphs at the end of the process for a visual check. This makes it easier to use with large flux datasets and to integrate into a reproducible workflow. Using the Fluxible R package makes the workflow reproducible, increases compatibility across studies, and is more time efficient.
Solar Energetic Proton forecasting with REleASE during STEREO-A’s flyby of Earth
Authors: Dröge Henrik , Heber Bernd , Kollhoff Alexander , Kühl Patrick , Malandraki Olga , Posner Arik
Published: March 2024

Solar Energetic Particle (SEP) events can pose a significant radiation hazard for human and robotic space exploration activities. Therefore SEP forecasting systems are needed to support operations. The REleASE system (A. Posner, 2007) utilizes the fact that near relativistic electrons (1 MeV electrons have 94% of the speed of light) travel faster than ions (30 MeV protons have 25% of the speed of light) and are always present in hazardous SEP events. Their early arrival can be used to forecast the expected proton flux. Originally REleASE uses real time data from SOHO/EPHIN near Earth. Since the instrument is aging we recently adapted the method to STEREO-A/HET and used the period from June to November 2023 when STEREO-A passed the Earth to compare the REleASE forecasts from the different instruments.This study has received funding from the National Aeronautics and Space Administration under grant agreement No. TXS0150642 (HESPERIA RELEASE).
Unveiling Tiber River's Influence on the Tyrrhenian Coastal Ocean and Marine Bio-Optical Properties with Sentinel-2
Authors: Varghese Dani , Piermattei Viviana , Madonia Alice , Marcelli Marco
Published: March 2024

Chlorophyll and suspended sediments are the main indicators of the marine ecosystem’s bio-optical properties. Chlorophyll is directly connected with primary productivity, while the suspended sediments are associated with water quality; both factors are influenced by climate change. The present research is mainly focused on testing the capability of Sentinel-2 on estimating the Tiber River driven spatial dynamics of chlorophyll and suspended sediment. The present research also aims to identify suitable methods for estimating chlorophyll and suspended sediment levels in the Tyrrhenian coastal ocean and seas. Algorithms including SNAP-bound C2RCC-Nets, C2X-Nets, C2X-COMPLEX-Nets, and ACOLITE-bound OC2, OC3, SPM_Nechad2010 and SPM_Nechad2016 algorithms were applied to estimate the dynamic distribution of chlorophyll and suspended sediment in the Tyrrhenian region. C2RCC-Nets outperformed all other and a statistically significant positive correlation observed with in situ-derived chlorophyll and suspended sediment, with coefficients of 0.903 and 0.966, respectively. Additionally, a positive seasonal spatial correlation was estimated between chlorophyll and suspended sediments, indicating that Tiber River discharge have positive impacts by accelerating the chlorophyll level on the Tyrrhenian coastline compared to the negative trend observed in the Mediterranean region.Keywords: Sentinel-2, C2RCC, chlorophyll, Suspended sediments, Tiber River, Tyrrhenian region.
On the importance of Mongolian cyclones to East Asian dust storm activities
Authors: Mu Feifei , Fiedler Stephanie
Published: March 2024

Desert-dust aerosols affect the climate, human health, and socio-ecomomic activities. In East Asia, the passage of Mongolian cyclones induce dust-emitting winds in the Gobi Desert. While cyclones are known as driver of dust outbreaks, the relative contribution of Mongolian cyclones to the total East Asian dust emission amount and the dust aerosol optical depth has not been quantified from a climatological perspective. To address this gap in knowledge, the present study systematically assesses the co-occurrence of Mongolian cyclones and dust aerosols in East Asia for 2001 to 2022. This study pairs output of the automated detection algorithm for extra-tropical cyclones in ERA5 re-analysis from the ETH Zürich with data for dust aerosols from multiple sources. Through the use of multiple dust data sets, we account for the substantial data uncertainty for dust aerosols in term of the spatial pattern and the absolute emission magnitudes, which can differ by an order of magnitude. The climatological analysis shows a high frequency and intensity for the occurrence of Mongolian cyclones in the lee of the Altai-Sayan Mountains (100Eo–125Eo and 37No–53No), favouring the seasonal dust activity in the Gobi Desert. The results highlight a tight constraint on the mean Mongolian cyclone contribution to the total dust emission amount of 39-47% in the spatial mean for spring based on data from MERRA-2 and Wu et. al. (2022), despite substantial differences in the absolute emission magnitudes. The dust-laden air from the Gobi Desert during such events typically moves southeastwards over China in the wake of the cyclones affecting the aerosol optical depth. For southern Mongolia and Northeastern China (105Eo–130Eo and 37No–52No), we estimate 34% (MERRA-2) to 43% (CAMS) of the dust aerosol optical depth (DOD) being associated with Mongolian cyclones. A decrease in dust emission fluxes and dust storm frequencies have been reported for Northern China in the past two decades and is thought to be connected to decreasing near-surface winds. Our results point to a negative trend in the dust emission flux and DOD associated with the occurrence of Mongolian cyclones. However, our results also point to the co-occurrence of particularly intense Mongolian cyclones, measured by the 99th percentile of the wind speed, with exceptionally strong dust storms in recent years, e.g., in March 2021, despite a mean negative trend in dust activity. Given the connection of Mongolian cyclone to high-impact dust storms in East Asia, the potential future development of such events should be addressed in future research.
Unraveling the Influence of Snow Phenology on Vegetation across Alaskan Plant Communities
Authors: Mu yaqiong , che tao
Published: March 2024

Plant phenology is highly sensitive to climate change, and the Arctic region is experiencing rapid changes in vegetation and snowpack. However, the specific climatic drivers of these changes are poorly understood. This study aimed to investigate the effects of snowpack phenology and environmental variables on the onset of vegetation phenology in the Alaskan Arctic. The results showed that Snow cover end date (SCED) had a stronger correlation with the Start of the growing season (SOS) compared to other factors, with consistent spatial and temporal patterns. Forested vegetation exhibited strong positive feedback between SCED and SOS, while grassland, shrub, and tundra communities showed insignificant positive feedback. Temperature and Fractional photosynthetically active radiation (FPAR) also significantly affected SOS. Snow density and snow depth played a larger role in SOS variation during the short pre-season period. These findings highlight the need for further investigation into the role of snowpack in specific vegetation types, particularly after observing widespread greening. Future studies should consider factors such as changes in snowmelt timing and photoperiod and traditional climatic factors like temperature and precipitation.
Towards a novel water budget partitioning framework to better characterize the impact of climate and storage change on water fluxes.
Authors: Shaw Balaram , Sharma Pushkar , Vishwakarma Bramha Dutt
Published: March 2024

The Budyko hypothesis provides a useful framework for comprehending the behaviour of long-term water balance for a natural and closed catchment. It is widely used for partitioning precipitation into other water-cycle components, characterising hydrological response, and assessing long-term water availability.Since, Budyko framework was developed for natural catchments assuming no storage change, its suitability for studying catchments with human-intervention in a changing climate is debated. This study aims to contribute to this debate by assessing appropriateness of Budyko framework for studying and predicting long-term water cycle changes stemming from climate change and human-driven storage changes. We simulate various climate and anthropogenic scenarios in a closed-loop environment using SWAT (Soil and Water Assessment Tool) model across three climate zones (humid, semi-arid, and arid) for more than 70 years. The scenarios reflect secular changes in climatic variables such as precipitation and temperature, and anthropogenic changes such as change in storage. The long-term time-series data for climatic variables were synthetically generated by obtaining the best-fit probability distribution, which were used to create various scenarios by trend-injection method. The model outputs were used for both steady and unsteady-state conditions to get the Budyko plots and to understand the deviation from the Budyko curve for various climate and storage change scenarios from the reference scenario.We found that for small changes in precipitation and temperature, catchments translate along the reference Budyko curve but deviates away from the curve for a large climatic change and even a small storage change. The Budyko framework is more sensitive to precipitation change compared to temperature change. For realistic long-term storage change, particularly in arid or semi-arid regions, Budyko points in the traditional framework breach water limit. We observed that when the storage change is considered in the Budyko framework, the points again constrain itself in the Budyko space. Therefore, we developed a generalised Budyko framework by incorporating storage change in a mathematical equation considering water and energy balance. The traditional Budyko framework is a special case within it. The novel generalised Budyko framework proposed here could prove to be an indispensable tool for effective water resources management and studying catchment response to various climate change projections.