bluuebunny/crossref_metadata_2025 huggingface dataset:
Dynamical downscaling and data assimilation for a cold-air outbreak in the European Alps during the Year Without Summer 18
Authors: Stucki Peter , Pfister Lucas , Brönnimann Stefan , Brugnara Yuri , Hari Chantal , Varga Renate
Published: March 2024

The “Year Without Summer” of 1816 was characterized by extraordinarily cold and wet periods in Central Europe, and it was associated with severe crop failures, famine, and socio-economic disruptions. From a modern perspective and beyond its tragic consequences, the summer of 1816 represents a rare occasion to analyze the adverse weather (and its impacts) after a major volcanic eruption. However, given the distant past, obtaining the high-resolution data needed for such studies is a challenge. In our approach, we use dynamical downscaling, in combination with 3D-variational data assimilation of early instrumental observations, for assessing a cold-air outbreak in early June 1816. Our downscaling simulations reproduce and explain meteorological processes well at regional to local scales, such as a foehn wind situation over the Alps with much lower temperatures on its northern side. Simulated weather variables, such as cloud cover or rainy days, are simulated in good agreement with (eye) observations and (independent) measurements, with small differences between the simulations with and without data assimilation. However, validations with partly independent station data show that simulations with assimilated pressure and temperature measurements are closer to the observations. In turn, data assimilation requires careful selection, preprocessing and bias-adjustment of the underlying observations. Our findings underline the great value of digitizing efforts of early instrumental data and provide novel opportunities to learn from extreme weather and climate events as far back as 200 years or more.
Durability and integrity of well and rock materials for large scale underground hydrogen storage projects in porous reservoir: Insights from laboratory experiments
Authors: ter Heege Jan , Corina Anisa , Soustelle Vincent , Groenenberg Remco
Published: March 2024

Large scale storage of hydrogen in porous reservoirs can buffer intermittent energy supply and demand in energy systems with large contributions of wind and solar energy. The efficiency of long term injection and withdrawal of hydrogen streams with large concentrations of hydrogen can be particularly affected by the long term interaction between hydrogen and rock or well materials in combination with cyclic pressure, temperature and stress changes during injection and withdrawal. Critical elements of hydrogen storage systems that may be affected are (1) the hydrogen gas stream, (2) the storage reservoir, (3) the caprock, (4) faults, (5) the well system, and (6) the surface environment. In particular, effects on the durability and integrity of well systems and on the mechanical and flow properties of porous sandstone reservoirs may impact the efficiency of storage operations. In this study, we show how results of laboratory experiments on rock and well materials at high pressure and temperature conditions can be used to assess effects of hydrogen exposure and cyclic pressure, temperature and stress changes on well systems and porous sandstone storage reservoirs. Key results of experiments on well cement (Portland type G), sandstone reservoirs, caprock and a scaled-down well system consisting of a casing, well cement and reservoir rock are reported. Samples were placed under relevant high pressure, temperature and stress conditions (100-200 bar, 50-100°C), both in an autoclave for reaction with H­2 and N2 and in a triaxial cell for testing injection/withdrawal scenarios. The results show (1) no major effects of H2 exposure or cyclic loading on mechanical properties of well cement and reservoir sandstone under investigated conditions, (2) different behavior for sandstones exposed to N2 (stiffer) and H2 (less stiff) during cyclic loading, (3) some cumulative plastic deformation during cyclic loading of sandstone that may affect flow and mechanical properties, even in the elastic regime, (4) indications of increasing stiffness in caprock due to cyclic loading, (5) importance of casing-cement-reservoir interfaces as potential leakage pathways for hydrogen along wells, and (6) large effects of sample variations that complicate disentangling effects of N2/H2 exposure and cyclic loading. These results suggest that effects of interaction between hydrogen and rock or well materials in combination with cyclic pressure, temperature and stress changes during injection and withdrawal are limited for the investigated materials and conditions. However, they also emphasize the need for further research to understand the long-term effects of H2 exposure and cyclic loading in different geological settings and under extended exposure durations.
Educational games to foster schoolchildren's understanding of natural hazards and raise their disaster risk awareness - Lessons learned from Central Africa
Authors: Michellier Caroline , Bahati Mutazihara Innocent , Bakulikira Steven , Ngunzi Kahashi Yves , Mafuko Nyandwi Blaise , Ulimwengu Biregeya Bernardin , Kervyn Matthieu , Kervyn François
Published: March 2024

Improving understanding and awareness of risks associated with natural hazards among the population at risk and DRR managers is essential for achieving the objectives of the Sendai Framework. This is particularly crucial in contexts where natural hazard risk knowledge is scarce and poorly disseminated, while the frequency of disasters and the severity of their impacts are high.Highly interactive, educational games are an engaging method for exposing players to disaster risk situation by allowing them to observe and acquire knowledge, train their problem-solving and decision-making skills, and test different disaster risk reduction (DRR) strategies, while experiencing the consequences of disasters in a safe and entertaining environment.Such an approach based on educational games is experimented in eastern DRC, with the Hazagora and Chukuwa games. Hazagora is a board game originally designed for secondary school children. It is used not only as a knowledge-building tool, but also to raise awareness regarding the potential impacts of disasters and how to reduce them, through active engagement of participants in discussion on DRR strategies. As such, this approach sits at the science-policy-practice interface, involving not only children, but also teachers, scientists, civil society organisations and civil protection representatives. Building on this experience, the Chukuwa card game was developed as a disaster risk awareness tool for primary school children, whose ability to take their new understanding back to their families is recognized as a vector for disseminating knowledge.After several years of experimentation, some practical limitations linked to the contextualisation and institutionalisation of these games have however been identified. Based on the lessons learned, adaptations of the Hazagora game are being considered, as is the translation of the Chukuwa card game into local languages, alongside the strengthening of the involvement of secondary and primary education authorities and the integration of these tools into school (extra-)curricula.Educational games are therefore an effective learning tool for introducing participants to the concepts of natural hazards, risks and disasters, as well as for actively and sustainably engaging them in discussions and reflections on DRR strategies conducive to strengthening the risk culture within the community.
Relating excess and redistributed temperature to the Turner Angle in the subtropical North Atlantic using GO-SHIP observations and Machine Learning
Authors: Clark Matthew , Evans Dafydd G. , McDonagh Elaine , Jebri Fatma
Published: March 2024

The ocean takes up 93% of the warming in the climate system. Here, we develop methods to isolate this warming signature using multidecadal observations in the North Atlantic. As part of GO-SHIP, repeat ship-based CTD hydrographic observations have been made across the A05 section in the North Atlantic at 24.5˚N. These are climate quality observations of relatively high spatial resolution along the section, providing a unique opportunity to monitor the state of Atlantic physical properties and biogeochemistry. The A05 section has been occupied approximately every 5 years since 1992. Temperature and salinity variability across A05 is influenced by several factors, including air-sea interaction and the effects of anthropogenically driven climate change. Excess temperature is a measure of the amount of extra temperature in the ocean due to post-industrial atmospheric CO2, whereas redistributed temperature quantifies the reorganisation of ocean temperature structure by ocean circulation and mixing. Existing methods to decompose the excess and redistributed temperature changes rely on estimates of the anthropogenic carbon change. The Turner angle, which represents the angle between the theta-s curve and an isopycnal in theta-s space, provides an index of the relative contributions of temperature and salinity on stratification, and thus, on water column stability. Using data from A05, we explore how temporal shifts in temperature and salinity affect the Turner angle, with the aim of using this relationship to separate the excess and redistributed components of change without relying on estimates of anthropogenic carbon. We will establish the relationship between excess and redistributed temperature and Turner angle using Machine Learning tools and the known link between anthropogenic carbon and excess temperature. This approach will enable the use of the Turner angle-based method in areas without any carbon data.
Application of Machine Learning Statistical Downscaling to Seasonal Climate Forecasts for the Alpine Region
Authors: Suriyah Dhinakaran , Alice Crespi , Alexander Jacob , Edzer Pebesma
Published: March 2024

Climate change is a pressing global challenge, notably impacting sensitive regions like the Alpine area. Its diverse terrain and ecology make it vulnerable to heightened climate risks, including intensified weather extremes due to global warming. Precise local climate predictions are vital for managing risks in vulnerable areas like the Alpine region, necessitating reliable high-resolution climate data and forecasts. Global products often fall short in providing the fine-grained information needed for accurate localized assessments. This work aims to address the critical need for refined, high-resolution seasonal climate forecasts in the Alpine region as a tool to increase the ability to manage and anticipate climate variability and hazardous conditions. The study endeavors to utilize Perfect Prognosis (PP) within Statistical Downscaling (SD), leveraging regression-based Machine Learning (ML) algorithms to enhance the spatial resolution of daily temperature and total precipitation of ECMWF (European Centre for Medium Range Weather Forecasts) SEAS5 (Seasonal Forecast System 5) seasonal forecasts. Four ensemble learning methods — random forest, light gradient-boosting machine (LGBM), Adaptive Boosting (AdaBoost) and Extreme Gradient Boosting (XGBoost) are considered, while CERRA (Copernicus European Regional Reanalysis) reanalysis (5.5 km) is used as reference target. In order to define the optimal ML model and configuration, a preparatory phase is performed in which ML methods are implemented, optimized and inter-compared by considering ERA5 reanalysis predictor fields (~ 31 km) for the training period 1985-2015 and validation period 2016-2020. Initial findings show that LGBM reports better performance in training and validation, demonstrating superior computational speed and efficiency with respect to the others. LGBM reconstructs daily variability with R2 scores of 0.95 for mean temperature and 0.67 for precipitation. Remaining bias as yearly average is -0.05°C fo daily mean temperature and 5.34% for daily precipitation. Other error metrics, e.g., mean absolute error (MAE) and root mean squared error (RMSE) suggest room for improvements, especially in extreme value predictions and annual precipitation averages. LGBM is thus applied and further optimized on SEAS5. The contribution will further elaborate the inter-comparison of ML models and their downscaling skills for seasonal forecasts will be presented and discussed. The expected outcomes of this study in particular will serve as a crucial input of a drought prediction module in the framework of the EU-funded interTwin project. This research has been funded by the European Union through the interTwin project (101058386).
Repeated multibeam surveys and direct observations for the characterization of fluid-related features off Scoglio d’Affrica islet (Northern Tyrrhenian Sea)
Authors: Casalbore Daniele , Pierdomenico Martina , Spatola Daniele , Saroni Anna , Maurantonio Federica , Coltorti Massimo , Ivaldi Roberta , Demarte Maurizio , Petronelli Denise , Chiocci Francesco
Published: March 2024

Scoglio d’Affrica islet lies in the southern part of the Elba-Pianosa Ridge, a north-south elongated morpho-structural between the Tuscany shelf and the Corsica Basin. A violent gas outburst occurred in 2017 offshore Scoglio d’Affrica islet, with the formation of columns of dirty water rising up to 10 m above the sea surface as reported by local fishermen. Since then, the collection of multibeam bathymetries coupled with seafloor observations realized through remotely operated vehicles and scuba dives showed the occurrence of widespread fluid-related morphological features, including mud volcanoes of variable size and morphology as well as hundreds of pockmarks. In this work, we present the preliminary results of this integrated analysis, providing insights on the small-scale morphological evolution of these features in the last 5 years linked to fluid seepage processes. This is a particularly relevant issue considering the few studies on shallow-water mud volcanoes as well as the potential hazard associated with these processes.
Role of pore fluids in time-dependent deformation and microcracking of rock under high deviatoric stress
Authors: Bondarenko Nikita , Makhnenko Roman , Podladchikov Yury
Published: March 2024

Rock underground may be exposed to elevated deviatoric stress over prolonged time period resulting in time-dependent deformation and microcracking. This process of subcritical time-dependent deformation is sensitive to environmental conditions, such as applied state of stress, presence and chemical composition of pore fluids, and drainage conditions. To improve the understanding of processes occurring at subcritical stress, the laboratory brittle creep experiments are conducted on Berea sandstone specimens under various conditions. Strong correlation between time-dependent deformation and microcracking activity is observed in all conducted tests. Significant variation of magnitude-frequency relation of the acoustic emission signals occurs during macroscopic failure preparation, which can serve as a potential prognostic feature. The collected data on time-dependent deformation is interpreted by introducing viscosity as a coefficient of proportionality between deviatoric strain rate and applied deviatoric stress. It appears that viscosity is exponentially decreasing when the state of stress is approaching critical conditions associated with macroscopic failure. Empirically-based relationship is established describing the impact of mean and deviatoric stress on viscosity in wide range of applied stress. The presence of non-aqueous fluids (oil or CO2) appears to have significantly weaker impact on the creep deformation compared to aqueous fluids (deionized water and water with dissolved CO2). Finally, the drainage condition appears to be essential. If the mass of pore fluid inside the specimen remains constant throughout the experiment (undrained condition), the microcracking results in phenomena similar to dilatant hardening of the material observed at constant applied state of stress. This effect might be qualitatively similar to the ones occurring in the off-fault plasticity zones and provide the fault stabilization mechanism.
A generic crustal architecture data model for rift and passive margin analysis: Application to the conjugate South Atlantic margins
Authors: Heine Christian , McDermott Ken , Eldrett James , Grant Colin , Thompson Philip
Published: March 2024

The spatio-temporal analysis of rifts and passive margin evolution is often done based on regional case studies, using non-standardized terminology and classification models to characterize crustal boundaries and basin infill. As example, the use of “continent-ocean boundary” to delineate crustal types or “syn-rift” as basin infill characterization has proven to be no longer adequate, given our evolved understanding of passive margins. In general, such local approaches do not lean themselves to aggregate data for global and large-scale comparative analysis and often struggle to reconcile the spatially varying magmatic/weakly magmatic margin architecture in a rift system context. They also do not allow efficient deployment of spatio-temporal data analytic models due to a lack of standardized data classification.To overcome these limitations, we have designed a novel “data science-ready” data model for crustal architecture that is based on commonly accepted terminologies, can be used independent of input data heterogeneity and can be deployed globally across the whole spectrum of margin types and complex 3D margin geometries/microplate settings. We classify two key crustal boundaries, the oceanward limit of continental crust ("OLCC") and the landward limit of oceanic crust ("LaLOC"), along with several key crustal interfaces, such as the top basement and base crust which are further subdivided into sub-categories. This approach allows us to easily generate standardized data products on rift system scale, which quantitatively describe key parameters relevant to understand lithosphere extension dynamics, such as volumes, ratio, and distribution of continental and magmatic crust, crustal stretching factors, and amount of crustal embrittlement. Coupled with plate kinematic models, these data products allow to build reproducible, extensible, and quantitative models of rift and margin evolution through time and highlight the dynamics of stretching, localization of deformation, the basin infill response, and spatio-temporally varying patterns and types of magmatism.Applying this data model, we have characterized the crustal architecture of the conjugate South Atlantic passive margins, interpreting more than 100k line-kilometers of 2D and 3D seismic reflection data. Our findings highlight substantial shortcomings of current plate models to reconcile the crustal type distributions in the southern South Atlantic with a tight pre-breakup fit, the temporal emplacement dynamics of SDRs and plume-related magmatism along the whole South Atlantic rift, as well as the localization of deformation and dynamics of basin infill.
Interactive Climate Atlas of Climate Change: an application tool for informing practitioners and policy-maker decisions in Ukraine
Authors: Kryshtop Lidiia , Krakovska Svitlana , Chyhareva Anastasia , Shpytal Tetiana
Published: March 2024

The Interactive Climate Atlas of Climate Change serves as a pivotal application tool designed to empower practitioners and policy-makers in Ukraine by providing dynamic, user-friendly access to crucial climate information. This innovative platform amalgamates scientific data, visualizations, and interactive features to elucidate the multifaceted impacts of climate change on the Ukrainian landscape. The atlas not only enhances climate literacy but also fosters a collaborative approach to address environmental challenges, thereby enabling practitioners and policy-makers to formulate effective strategies for sustainable development in the face of a changing climate. This application not only bolsters the resilience of Ukrainian communities but also exemplifies a scalable model for informed decision-making in regions globally affected by the profound impacts of climate change.

 

 
 
Rapid dietary change can foster desired food system transformations: lessons from past evolutions of dietary patterns.
Authors: Giordano Vittorio , Tuninetti Marta , Laio Francesco
Published: March 2024

The global food system is currently at a critical turning point as it is driving the planet’s trajectory towards exceeding 1.5 °C warming and crossing tipping points in the Earth system. It is responsible for one-third of global emissions and the primary cause of freshwater consumption and pollution, biodiversity loss and terrestrial ecosystem destruction. The prevalence of undernourishment is persistent, while unhealthy diets and widespread overnutrition cause diet-related chronic diseases and health damages. To achieve international agreements’ targets on climate and biodiversity its transformation is essential.Rapid dietary change to more plant-based diets and reduced animal products consumption is a powerful leverage for plummeting the environmental and climate impacts of food habits. It has been referred to as one of the potential positive tipping points that can be harnessed to transform the global food system, profoundly altering its modes of operation. Nevertheless, there is limited empirical evidence regarding whether such non-linear dynamics occur in the food sector, resulting in an important gap in the identification of specific factors that can trigger a desired transition.We propose a quantitative framework to identify historic and ongoing tipping dynamics in food system transformation. We first implement statistical analyses to explore the past evolution of the dominant dietary patterns within historical data series (1961-2020) of country-scale food supply quantities, across different food categories. We then unravel the drivers behind dietary patterns evolution in time (e.g., per capita GDP, cultural and social factors, supply patterns), also highlighting significant similarities across different countries, possibly suggesting coupled dietary evolutions. The outputs of our statistical framework provide ground for the analysis of past shifts in dietary patterns and the role that potential tipping elements driving dietary shifts - changes of normative consumer beliefs and behaviours, agricultural practices and policies - had in triggering food system transformations, or that may have in accelerating future desired transitions towards a more sustainable food system.
Coupled climate effects of eddy rich model resolution in and south of the Agulhas
Authors: Ödalen Malin , Savita Abhishek , Kjellsson Joakim , Wahl Sebastian , Ferreira David , Ayres Holly , Roquet Fabien , Park Wonsun
Published: March 2024

In this study, we compare global coupled climate simulations (1950’s and abrupt 4xCO2) with different ocean resolution in the Atlantic sector of the Southern Ocean (ASO), including the Agulhas, with parameterised and explicitly simulated eddies respectively. We find that the eddy-rich 1950’s simulation has a reduced South Atlantic warm bias, because of a more defined Agulhas retroflection, and coupled climate effects are observed outside the region with increased ocean resolution where e.g. equatorial precipitation changes markedly.The Agulhas leakage plays a key role in connecting the Indian and the Atlantic oceans, with mesoscale eddies carrying heat and salt into the South Atlantic. In most state-of-the-art coupled climate models, the ocean resolution is insufficient to explicitly simulate those eddies, and they are instead represented through a parameterisation of the eddy induced flow. We use the coupled climate model FOCI, which combines a NEMO3.6 ocean with an ECHAM6 atmosphere, LIM2 sea ice, and a JSBACH land module, via an OASIS coupler. Through AGRIF nesting, we increase the ocean resolution from 1/2° to 1/10° in the Atlantic sector of the Southern Ocean.The eddy-rich 1950’s simulation exhibits a reduced warm bias in the South Atlantic compared to the simulation without it. The bias reduction is a result of a more defined Agulhas retroflection which reduces ocean heat transport into the South Atlantic while increasing heat transport poleward. This change in ocean temperature distribution is anticipated from previous studies with ocean-only models. However, we also see coupled climate effects extending to the equatorial region, well outside the region with increased ocean resolution. We observe changes in precipitation and surface wind fields over both the tropical Atlantic and tropical/South Pacific. The changes over the tropical Atlantic are likely linked to a direct response to changes in sea surface temperature that extend across the South Atlantic. The eddy-rich 1950’s simulation also shows significant reduction of surface air temperature (SAT) biases, mostly in the Northern Hemisphere, and winds in the Southern Hemisphere, w.r.t. observationally based reanalysis products. In the strong warming scenario (abrupt 4xCO2), the eddy-rich simulation shows less SAT increase over the Atlantic and a larger seasonality in the response of the westerly wind fields over the Southern Ocean. In conclusion, increased resolution of the ASO, allowing for explicit simulation of mesoscale eddies e.g. in the Agulhas, leads to reduction of model biases and coupled climate effects.
Evaluation of seamless forecasts for severe weather warnings 
Authors: Bessenbacher Verena , Bhend Jonas , Beusch Lea , Nerini Daniele , Siegenthaler Colombe , Spirig Christoph , Moret Lionel
Published: March 2024

At MeteoSwiss, NWP and ML-based models are run operationally on a daily basis to provide weather forecasts and weather warnings for the general public. These forecasts come from various models that differ in lead times, initialization frequency, spatial resolution, and extents. We aim at combining those sources into a probabilistic, gridded weather forecast that is seamless in space and time. Creating a seamless forecast needs careful post-processing so as not to introduce cut-offs or unphysical behavior at the seams between the model runs. This includes using multiple forecast sources and forecast initializations (called lagged ensembles) and combining these using comprehensive blending methods. The first minimal viable product of a seamless forecast is currently being produced at MeteoSwiss, and will soon be available to the forecasters in real time. We evaluate the merit of these forecasts in terms of warning thresholds for rain and wind gusts. To do so, we compare reforecasts and observations from ground stations as well as rain radar observations from a set of past severe weather events over Switzerland. We benchmark the seamless forecast with individual forecast sources and post-processed products to evaluate the added value of seamlessly combining different forecast sources into one blended product. We furthermore plan to compare different methods for blending between sources soon.
Infiltration as dynamic non-uniform stochastic flow field – repeatable, high-resolution 4D GPR measurements at the plot scale
Authors: Jackisch Conrad , Stephan Sophie Marie , Tronicke Jens , Allroggen Niklas
Published: March 2024

Infiltration is a central concern in soil physics. The advective and diffusive redistribution of event water depends on various factors such as initial wetting, the establishment of film connectivity, and capillary gradients and hydraulic conductivity. Non-uniform infiltration patterns are prevalent. However, direct infiltration measurements do not account for this reality and tracer experiments require a destruction of the experimental plot. We developed a data acquisition strategy based on time-lapse 3D ground-penetrating radar (GPR) to monitor fast and small-scale subsurface flow processes during irrigation in a non-invasive manner.The technique combines an irrigation pad (1 m2 drip irrigation to simulate moderate, non-erosive rain events) with a GPR measurement platform (manually driven two-channel GPR antenna array with positioning guides). We will present a systematic field experiment consisting of two recurrent irrigations (40 mm/2 h, 1 irrigation per day) and a respective replicate. For evaluation, the GPR measurements were sidelined with soil moisture measurements (TDR profile) and tracer applications (dye and salt). Our data show that the achieved high resolution of less than 5 cm in space and 10 minutes in time makes it possible to monitor and quantify infiltration processes in their spatial and temporal non-uniformity.The experiment supports the hypothesis from earlier experiments at various sites: Non-uniform infiltration patterns and dynamically connected flow-fields are highly heterogeneous but share stochastic features, such as distribution, randomness, and skewness. Our approach opens new options for repeated, spatially resolved infiltration measurements and theory development for soil hydrology and land surface models.
Morphosedimentary evolution of a beach spit system (Punta Rasa, Argentina)
Authors: Guisado-Pintado Emilia , Isla Manuel
Published: March 2024

Spits constitute sand-rich, elongated barriers extending laterally through the construction of progradational beach-ridges. Spits are constructed by angular wave approach and longshore currents, which results in the transport of sediment to the spit end and hence their growth. If sediment supply isn’t enough cannibalization can occur causing a narrowing and further breaching of the spit. One of the main controlling factors of sediment supply to spits are waves and particularly high energy events such as storms.The spit of Punta Rasa, located in the northeast coast of the Buenos Aires province, represents the coastal outer extreme of the Río de La Plata estuary. Towards the north the spit is bordered by the southern extreme of the Samborombón Bay, whereas, to the south, the spit extents along the Oriental Barrier which ends towards the locality of Punta Medanos. The wave-built deposits interact with marshes and tidal channels transgressing the shoreline from the north. Besides, the coastal plain exhibits the interaction between beach-ridge systems, dune fields and sandy beaches.In this work, coastline changes and recent evolution of the system of spits in Punta Rasa are analyzed using sedimentalogical profiles and aerial photographs. Results show an evolution marked by periods of erosion and significant changes in its morphology. Firther a general trend (since approx. 500 years) of the spit to curve towards the internal part of Bay is also found which could indicate a deficit in the contribution of sediment among with increasing mean sea level.
Diffuse CO2 and H2S degassing monitoring at the summit crater of Teide volcano, Tenerife, Canary Islands
Authors: Asensio-Ramos María , Keeley Natasha , Reichrath Oranna , Riddell Alexander , Martín-Lorenzo Alba , Rodríguez Fátima , Melián Gladys V. , Di Nardo Daniel , Padilla Germán D. , Padrón Eleazar , Pérez Nemesio M. , Hernández Pedro A. , D'Auria Luca
Published: March 2024

Tenerife, the largest and highest island in the Canarian archipelago, houses the active Teide-Pico Viejo volcanic system. Its structure is shaped by a rift-system with various directions intersecting at this volcanic system. The system’s last eruption in 1798 expelled approximately 12 million m³ of lava across a three-month period, resulting in the formation of a distinct black surface that contrasts sharply with the surrounding. While Teide volcano exhibits a faint fumarolic system, the observed volcanic gas emissions mainly consist of diffuse CO2 degassing.Spanning from 1999 to 2024, over 200 surveys meticulously assessed CO2 and H2S emissions across 38 strategic sites within the Teide Volcano's summit crater. Portable fluxmeters, equipped with CO2 and H2S sensors, estimated emission rates via the accumulation chamber method. These rates fluctuated between 2.0 and 1,257 tons per day over a 25-year span. Following a seismic swarm in October 2016, there was a general marked escalation in CO2 and H2S emissions, aligning with heightened seismic activity. This shift led to relatively high CO2 emissions, possibly attributed to fresh magma injection and convective mixing catalyzed by the seismic swarm.It is pertinent to note a distinct event in the latter half of 2023, marked by a notable surge in CO2 and H2S emissions (ranging between 222 and up to 1,257 tons/day for CO2, and 40 to 270 tons/day for H2S), despite a relatively unchanged seismic activity compared to preceding years.This study highlights the value of examining diffuse degassing in understanding volcanic behavior and forecasting potential volcanic activity. Monitoring these emissions has become a crucial tool in predicting seismic and volcanic unrest, contributing significantly to mitigating volcanic risks in Tenerife.
An Offline Biogeochemical Model within the Regional Ocean Modelling System (ROMS): application to the Northwestern Mediterranean Sea
Authors: Crespin Esteve Júlia , Solé Ollé Jordi , Canals Artigas Miquel
Published: March 2024

Modelling the distribution of biogeochemical components in the ocean is essential for further understanding climate change impacts and assessing the functioning of marine ecosystems. This requires robust and efficient physical-biological simulations of coupled ocean-ecosystem models, which are often hindered by limited data availability and computational resources. The option of running biological tracer fields offline, independently from the physical ocean simulation, is appealing due to increased computational efficiency. Here, we present an assessment and implementation of an offline biogeochemical model — the Offline Fennel model — within the Regional Ocean Modeling System (ROMS). Our methodology employs ROMS hydrodynamic outputs to run the biogeochemical model offline. This work also includes the first evaluation exercise of the referred offline biogeochemical model. We used a variety of skill metrics to compare the simulated surface chlorophyll to an ocean colour dataset (CMEMS-Mediterranean Ocean Colour) and BGC-ARGO floats for the 2015-2020 period. The model is able to reproduce the temporal and spatial structures of the main chlorophyll fluctuation patterns in the study area, the Northwestern Mediterranean Sea, as well as the vertical distribution of chlorophyll and nitrate. This area is of particular interest as it is one of the most productive regions in the entire Mediterranean Basin, with open-ocean upwellings and deep winter convection events occurring seasonally. The typical behaviour of the region is likewise effectively represented in the implementation, including offshore primary production, nutrient supplies from the Rhone and Ebro rivers, and mesoscale hydrographic structures. This study provides a baseline for ROMS users in need of executing more biogeochemical simulations independently from more computationally demanding physical simulations.
Brake and Tire Emission Analysis with the Zero-Emission-Drive-Unit-Demonstrator for Battery Electric Vehicles
Authors: Reiland Sven , Philipps Franz , Arens Lukas
Published: March 2024

Within the scope of the ZEDU1 (Zero Emission Drive Unit Generation 1) project, both a conventional electric vehicle as a reference model and a prototype of the Zero Emission Drive Unit were developed for measurement characterizations. Concurrently with the demonstrator development, examinations of cast iron and hard-coated brake discs were conducted under real operating conditions and on test benches. Special attention was paid to the influence of recuperation on the airborne particle emissions from the brakes. Advanced on-board measurement methods were developed and effectively utilized.The results highlight that the brake temperature significantly influences particle generation in the range of 10 nm, while the braking process primarily produces particles between 200 nm and 300 nm. Impressively, the use of regenerative braking during real driving led to a reduction in abrasion emissions of up to nearly 90%. Furthermore, a reduction of up to 83% in airborne brake abrasions for particle sizes ranging from 300 nm to 10 µm was observed with hard-coated brake discs.Moreover, a novel brake system without airborne abrasion emissions was developed and validated. A demonstrator vehicle, equipped with the newly developed ZEDU1 unit, was designed, measured, and assessed for its everyday usability. Comprehensive tests confirm the complete functionality and durability of the developed brake system, thus showcasing its practicality
Carbon provenance study of Irish saltmarshes using bacteriohopanepolyol biomarkers
Authors: Akhmetkaliyeva Saule , Fairchild Eliza , Cott Grace
Published: March 2024

Coastal blue carbon ecosystems (BCEs) are one the of largest carbon sinks and play a significant role in the global carbon cycle. Approximately 40 km2 of coastline in Ireland are saltmarshes. Despite their importance, globally BCEs are being lost at an alarming rate of 1–2% for tidal marshes and 0.4–2.6% for seagrass beds annually, primarily due to anthropogenic activity, which is exacerbating climate impacts. Understanding the relative contributions of allochthonous and autochthonous carbon sources to saltmarsh carbon sequestration and the origin and sources of organic carbon, termed “carbon provenance”, is essential for accurately assessing the carbon sequestration potential of saltmarshes and developing effective strategies for climate change mitigation. This study aims to develop our understanding of the carbon sequestration mechanisms in saltmarshes in Ireland using organic carbon (OC) concentration and bacteriohopanepolyol biomarkers (BHPs, a group of membrane lipids that can be used to trace major microbial groups). We sampled two estuarine saltmarsh sites, one on the east coast (North Bull Island, county Dublin) and one on the west coast (Derrymore island, county Kerry) of Ireland. Initial OC concentrations ranged from 0.40 to 23.69 wt% in samples from North Bull Island and from 0.40 to 28.53 wt% in Derrymore island. Further, we expect to gain a better understanding of terrestrial versus marine input of OC using an Rsoil index using relative distribution of soil specific BHPs and bacteriohopanetetrol (used as a marine signature). These results will guide management and successful saltmarsh restoration schemes aimed at enhancing blue carbon sequestration in Ireland.
Velocity field in a groin field: implications for sediment and nutrients transport
Authors: Fuchs Yannic , Rüther Nils , Chen Margaret , Aleixo Rui
Published: March 2024

Groins are devices used for riverbank protection. These macrostructures change the river flow, which impacts sediment and nutrient transport. Furthermore, in the inter-groin space, flow recirculations are observed. Aiming at characterizing the flow field in and along a groin field, a comprehensive experimental program is put forward by considering, at this stage, a river reach modeled with a fixed bed and targeting to characterize different flow parameters: mean velocity distribution, streamlines in the function of the flow rate.Using a Lagrangian technique, an analysis is carried out to determine relevant flow statistics to compute turbulent variables. Additionally, we assess the probability of particle entrapment in the inter-groin area and the distribution of residence times of particles in that area. The scale effects and limitations of the experimental approach are presented and discussed. Future lines of work regarding the interaction between the groin field and a loose bed are discussed, improving the understanding of the transport and distribution of suspension load, contaminants, and nutrients in the river regions of groins.
Revising carbon budgets in a 1.5 degree world
Authors: Sanderson Benjamin , Smith Chris , Koven Charles , Nicholls Zeb , Steinert Norman , Sandstad Marit
Published: March 2024

The concept of a remaining carbon budget associated with global warming levels has underpinned mitigation efforts since the Paris Agreement.  However, as observed temperatures near 1.5 degrees, a number of challenges have emerged for the continued use of carbon budgets to frame mitigation needs.  Firstly, while the transient response to cumulative emissions describes the temperature response to constant emissions - Paris-compatible pathways require deep emissions cuts and potentially extended periods of negative emissions, the temperature outcome of which is complicated by zero emissions commitments and non-CO2 responses.  Understanding of Zero emissions commitments has been thus far been primarily informed by idealised experiments which terminate emissions during an idealised concentration ramp - but these metrics are subject to unrealistic termination shocks and model-specific emissions pathways.  Second, non-CO2 responses remain highly uncertain, and recent satellite observations of global radiative imbalance raise further questions on the adequacy of current modeling platforms to describe the warming which should be expected due to aerosol phaseout. Here, we consider how two novel developments impact carbon budgets beyond estimates presented in the IPCC 6th Assessment.  Firstly, we present an ESM ensemble of climate reversibility experiments which provides a more realistic proxy for non-TCRE carbon dynamics during a net zero transition for use in carbon budgets.  Secondly, we consider how the inclusion of recent global mean temperature measurements and CERES top of atmosphere radiative flux measurements would impacts the calibration of simple climate models - with subsequent impacts on both estimates of both TCRE and expected warming due to non-CO2 effects.  Synthesising this information, we provide an updated estimate of carbon budgets and timing with respect to the 1.5 and 2 degree thresholds.
Use of multiple atmospheric chemistry transport models to interpret high frequency methane isotope ratio measurements at independently managed sites
Authors: Chung Eunchong , Arnold Tim , Rennick Chris , Safi Emmal , Kikaj Dafina , Thornton Brett , Manning Alistair , Henne Stephan , Ganesan Anita , Karstens Ute
Published: March 2024

Greenhouse gas (GHG) emissions require accurate quantification for the development of effective mitigation strategies. Top-down methods to estimate GHG emissions combine ambient GHG measurements, atmospheric chemical transport models (ACTMs), and prior independent information on what is understood of fluxes (including isotopic source signatures where applicable). High frequency stable isotope ratio measurements of δ13C-CH4 and δH-CH4 have potential to help differentiate changes in the sources of CH4 emissions at regional scales. While independent efforts to make in situ, high frequency observations are being made at multiple locations, currently there is no network of harmonised measurements across Europe (with each site using different calibration and traceability strategies tailored to their specific analytical setup). In this work we study CH4 isotope ratio measurements made at independently managed sites (Heathfield, UK; Heidelberg, Germany; and Zeppelin, Norway) using three different combinations of ACTMs and associated meteorology: NAME with the UK Met Office Unified Model; FLEXPART with ECMWF IFS analysis and short-term forecasts; and STILT with ECMWF IFS analysis and short-term forecasts. The use of multiple models aims to investigate the magnitude of simulated differences to evaluate model uncertainty in this system. We will demonstrate the extent to which model simulations can be used to investigate analytical problems (e.g. measurement offsets between sites) as well as provide initial results on the potential for a network of high-frequency in situ isotope ratio measurements to understand changes in European CH4 emissions over the coming decades.
Arctic Ocean, North and Baltic Sea GHRSST-compliant SST and IST products for the Copernicus Marine Service
Authors: Karagali Ioanna , Barfod Suhr Magnus , Nielsen-Englyst Pia , Kolbe Wiebke , Høyer Jacob
Published: March 2024

Satellite missions carrying Thermal Infrared (TIR) and Passive Microwave Sensors (PMW) allow for high-resolution Sea Surface Temperature (SST) and Sea-Ice Surface Temperature (IST) retrievals under clear skies (TIR) and all weather retrievals (PMW) albeit with coarser resolution. This allows the continuous provision of SST and IST to operational Numerical Weather Prediction systems, climate models and to the wider scientific community. DMI is a Production Unit (PU) for the Sea Ice (SI) and SST Thematic Assembly Centers (TAC) of the Copernicus Marine Monitoring Service (CMS) providing a suite of level 4 SST products for the Arctic Ocean, the Baltic and North Sea daily, hourly and as multi-year products.The L4 Near-Real-Time (NRT) SST product SST-BAL-SST-L4-NRT-OBSERVATIONS-010-007-b is a daily, multi-sensor, gap-free, optimally interpolated product derived from night-time SST retrievals at high resolution (0.02o), available from 2016 onward. The L4 Multi-Year SST product SST-BAL-SST-L4-REP-OBSERVATIONS-010-016 is a daily, multi-sensor, level 4 optimally interpolated product using infra-red satellite observations from the ESA CCI and Copernicus C3S projects and high resolution sea ice information from SMHI and the SI TAC available from 1982 to 2022. The L4 Near-Real-Time Diurnal SST product SST-BAL-PHY-SUBSKIN-L4-NRT-010-034 is an hourly, gap-free satellite sub-skin SST analysis using L2P and L3 single-sensor SST data as input.For the Arctic Ocean, the L4 NRT SST/IST product ARC-SEAICE-L4-NRT-011-008 is a daily, multi-sensor, gap-free and optimally interpolated analysis of sea surface and sea-ice surface temperatures at a resolution of 0.05o extending north of 58 oN and available from 2018 onwards. The corresponding MY product, ARC-SEAICE-L4-NRT-011-016, is the first combined SST and IST analysis of the Arctic available from 1982 and up to 2023.Within the current C3S portfolio, DMI will provide the SST ECV, i.e. a global (up to 90o latitude), sub-skin product (20 cm) with a 0.05o spatial resolution. The aim of the present study is to provide an overview of the available products and their performance along with insights on future developments and products.
The ultimate 1631 CE sub-plinian eruption of Mt. Vesuvius: hints on pre-eruptive magmatic processes from zoned clinopyroxenes                               
Authors: Pelullo Carlo , Balcone-Boissard Hélène , Cariddi Bruna , Chakraborty Sumit , D'Antonio Massimo , De Lucia Maddalena , de Vita Sandro , Di Vito Mauro Antonio , Petrosino Paola , Piochi Monica , Rividi Nicolas , Solomita Germano , Sparice Domenico , Zanon Vittorio , Arienzo Ilenia
Published: March 2024

The 1631 CE eruption is the most violent and destructive event of the last millennium at Mt. Vesuvius, followed by a persistent small magnitude activity that has lasted until the 1944 CE. Selected units of the proximal stratigraphic section cropping out at Cognoli di Ottaviano (Monte Somma),