bluuebunny/crossref_metadata_2025 huggingface dataset:
How do convective cold pools influence the stability and turbulence conditions in the vicinity of wind turbines in Northern Germany?
Authors: Thayer Jeffrey , Kilroy Gerard , Wildmann Norman , Englberger Antonia
Published: March 2024

Convective cold pools routinely pass over the dense network of wind turbines in northern Germany, causing short-term changes in boundary-layer wind speeds (i.e., wind ramp events) and atmospheric stability. These large, rapid, and more-localized variations in the low-level kinematic and thermodynamic structure are difficult for numerical weather prediction models to forecast with sufficient spatial and temporal accuracy for utilization by wind turbine operators. As boundary-layer stability and winds strongly influence wind turbine structural loads, downstream turbulent wake behavior, and power generation, it is important to better understand how rapid changes in dynamic processes evolve within the vertical layer of wind turbine rotor blades (~50 - 150 meters altitude).Using in-situ observations and high-resolution modeling focused on the WiValdi research wind park in Krummendeich, Germany, we examine how convective cold pool passages during July 2023 impact the inflow and turbulent wakes for two installed turbines with a hub height of 92 meters. Meteorological mast, Doppler wind lidar, and microwave radiometer observations provide upstream and downstream measurements of stability, vertical shear, and turbulence variations at ~1-minute resolution. While this measurement coverage adequately captures the cold pool evolution relative to each turbine, we remain somewhat limited by the fixed instrument locations for measuring upstream conditions and the three-dimensional turbulent wake structure. Therefore, we also utilize the mesoscale model WRF in large-eddy-simulation mode, with inserted generalized actuator disks acting as proxy wind turbines, to analyze far-upstream inflow conditions and three-dimensional wake characteristics during cold pool passages. The proposed work will provide a foundation for future analysis which will more robustly verify WRF output using additional WiValdi instrumentation.
Structure and kinematics of the Danakil Depression, Afar, Ethiopia: insights into the formation of a magma-rich margin
Authors: Rime Valentin , Foubert Anneleen , Keir Derek , Kidane Tesfaye
Published: March 2024

The Danakil Depression is situated in the northern part of the Afar Depression in Ethiopia and Eritrea and is in an advanced phase of rifting close to continental breakup. It forms the equivalent of a magma-rich margin. As it is currently active and emerged, it offers a unique opportunity to study the processes of formation of these types of passive margins.We combine seismic reflection data, field data, and remote sensing to constrain the structure and kinematics of this basin. Seismic data reveal the formation of Seaward Dipping Reflectors (SDRs). Surprisingly, field data show that these SDRs are dominated by clastic sediments and only contain relatively minor amount of magmatic material. Paleoshorelines and other proxies allow to quantify uplift and subsidence rates across the basin. These data highlight high spatial variability and allow to better understand the structure and evolution of older, deeply buried passive margins.
Towards an improved treatment of (semi) volatile particle activation in contrail models
Authors: Ponsonby Joel , Teoh Roger , Stettler Marc
Published: March 2024

Contrails are estimated to account for the majority of the present-day warming by the aviation industry. Their formation relies on the availability of aerosol in the exhaust plume, upon which water vapour can condense and subsequently freeze to form contrail ice crystals Most modern aircraft operate in the soot-rich regime, releasing soot particles with a number emission index (EIn) of between 1014 and1016 (kg-fuel)-1. Under these conditions, the number concentration of soot particles and contrail ice crystals scales linearly. For this reason, existing global contrail simulations typically assume that the number concentration of ice crystals and soot particles are equivalent. However, the use of alternative fuels such as sustainable aviation fuel (SAF) and liquid hydrogen, and the adoption of cleaner lean-burn combustors in the existing fleet are likely to drive the soot EIn into the soot-poor regime < 1013 (kg-fuel)-1. Here, (semi) volatile material and entrained ambient particles can compete with soot for plume supersaturation and the relationship between the number concentration of soot particles and contrail ice crystals is non-linear. These effects are not currently accounted for in existing contrail models used to simulate regional and global contrail climate forcing.  In this work, we extend the parcel model proposed by Kärcher et al. [1] to account for the activation of volatile particulate matter (vPM) in the soot-poor regime and integrate this into the contrail cirrus prediction model (CoCiP) [2]. We explore the relationship between the soot EIn and the apparent ice emissions index (AEI) in the soot-rich and soot-poor regimes, evaluating the model’s sensitivity to different aerosol properties, including particle hygroscopicity and characteristics of the particle size distribution. Preliminary results show a linear relationship between the soot EIn and AEI in the soot-rich regime, consistent with previous work [1]. However, in the soot-poor regime, the AEI: (i) could be up to two orders of magnitude larger than the soot EIn; (ii) increases with decreasing ambient temperatures and (iii) depends on the assumed particle properties of the (semi) volatile and ambient particle modes. These results suggest that existing global contrail simulations may underestimate the contrail climate forcing for a small subset of flights with soot EIn < 1014 (kg-fuel)-1.The model developed in this work will be implemented in a global contrail simulation, incorporating activation of vPM. A sensitivity analysis will also be performed, and the results validated with in-situ measurements from the recent Emissions and Climate Impact of Alternative Fuels (ECLIF) III experimental campaign [3].References[1] Bernd Kärcher et al., Journal of Geophysical Research: Atmospheres, 2015, 120, 7893–7927.[2] Ulrich Schumann, Geoscientific Model Development, 2012, 5, 43–580.[3] Raphael Märkl et al., [EGUsphere preprint].
Lake ice seismicity: seismic and acoustic observations
Authors: Schmelzbach Cedric , Wetter Christoph , Stähler Simon , Clinton John , Lyu Zinan , Mesimeri Maria , Massin Frédérick
Published: March 2024

Seismic events (icequakes) associated with floating ice sheets on lakes are a frequently observed phenomenon. We find at our study site on the frozen Lake St. Moritz in the Swiss Alps typically a clear diurnal pattern with hundreds to thousands of icequake signals per hour during night time, while the rate of observed events during daytime is about two orders of magnitude smaller. The seismicity rate shows a significant correlation with temperature changes. It is therefore assumed that the generation of the ice quakes is related to melting and freezing processes as well as the extension and contraction of the ice. Potentially the seismicity rate is also moderated by loading and unloading due to human activities on the ice and/or lake level changes.These ice quakes generate seismic waves that propagate through the thin ice sheet as plate waves modulated by the air and water half-spaces above and below the ice (quasi-guided waves). One member of this wave-type family, the quasi-Scholte waves, are characterised by distinct dispersion that can be observed with seismic sensors on the ice. Furthermore, the seismic waves traveling through the ice couple into the air leading to audible seismo-acoustic signals. One particularity of the ice-air coupling is a so-called coincidence phenomenon. The particular velocity-frequency combination where the seismic wavelength in the ice matches the apparent acoustic wavelength in the air leads to a resonance phenomenon. Observation of the related coincidence frequency allows us, for example, to infer on the ice thickness from the acoustic observations with a low cost microphone above the ice only. Recording the acoustic signals with small microphone arrays enables additionally, for example, locating the source of the seismo-acoustic signal.Combined observations of the seismic and acoustic signals provide new insights into the seismicity of lake ice which has rarely been studied in the past. The seismo-acoustic signals have the potential to provide information about the ice properties such as thickness and ice quality as well as waxing and waning processes of ice sheets. These observations are relevant for safe operations on the ice but also to complement other remote-sensing observations with autonomous in situ seismo-acoustic measurements for climate studies.
Propagation of hydro-geomorphic disturbances through continental-scale river basins
Authors: Gasparotto Andrea , Nicholas Andrew , Aalto Rolf , Ashworth Phil , Best James , Brückner Muriel , Paes de Almeida Renato
Published: March 2024

Hundreds of millions of people live close to, and depend upon, the world's large rivers for water, food, transport and the maintenance of a thriving ecosystem. However, these rivers are increasingly vulnerable to the effects of a wide range of natural and human-induced disturbances, including climate change, construction of large dams, river engineering works, deforestation, agricultural intensification, and mining activity. Over the past two decades, climate change and deforestation have impacted on the hydrology and sediment fluxes within the Amazon River Basin, and yet, the Amazon has remained one of the few large river systems that has been largely unaffected by dams. Nevertheless, because of extensive hydropower dam construction in Brazil, Bolivia, Peru and Ecuador now threatens the basin, with more 300 dams planned or under construction, this situation is changing rapidly. These dams are expected to trigger severe hydro-physical and ecological disturbances throughout the basin, including massive reductions in sediment and nutrient delivery to the lowland Amazon and its floodplains, substantial degradation of riverbeds and banks, significant changes in river water levels and flooding, and adverse impacts on river and floodplain ecosystems, on which the human population depends. There is a pressing need for action to assess and mitigate these impacts. However, our capacity to do this is severely restricted by an absence of quantitative models that can predict how environmental disturbances propagate through large rivers and floodplains, over continental distances, and decadal to centennial time periods. A key challenge in this respect is the need to develop models that are both physically-realistic and also computationally-efficient. The latter is critical for model application at the basin scale, and in order to derive large simulation ensembles that account for the substantial uncertainty in model parameters and environmental boundary conditions. We report here on the development and evaluation of such a model that operates at coarse spatial (10 km) and temporal (daily to annual) resolutions. Our new modelling approach simulates changes in river morphology (mean width, depth and slope), channel-belt topography (expressed as an elevation frequency distribution), and associated changes in flow conveyance, channel-floodplain connectivity and sediment delivery to downstream reaches. Model predictions are compared with, and evaluated against, simulations of river response to dam construction generated using a high-resolution physics-based modelling approach (with spatial and temporal resolutions of 50 m and
Exploration of elemental details of single mineral dust particles in the EPICA Dome C ice core during interglacial and glacial periods
Authors: Lee Geunwoo , Erhardt Tobias , Zeppenfeld Chantal , Larkman Piers , Bohleber Pascal , Fischer Hubertus
Published: March 2024

The single particle inductively coupled plasma time-of-flight mass spectrometer (sp-ICP-TOFMS, model: icpTOF R from TOFWERK, Switzerland) coupled to the Bern continuous flow analysis (CFA) has demonstrated its ability to resolve signals of individual insoluble particles in the meltwater. This offers valuable insights into the characteristics of mineral dust obtained from the elemental composition of the mineral dust as - in contrast to bulk analyses - it allows deciphering of the complete elemental range of particle composition, which can be a mixture of different minerals (Erhardt et al. 2019). To apply this new technique for the first time to sections of an Antarctic ice core covering several glacial and interglacial stages, we conducted aerosol chemical CFA measurements on a selection of 18 Antarctic EPICA Dome C (EDC) 55 cm ice core sections, from both glacial and interglacial periods over the last 800 kyr using CFA-sp-ICP-TOFMS.We present the new preliminary results of our CFA campaign with a nominal 55 cm bag mean resolution (or 110 cm where two consecutive bags were measured). The depth resolution corresponds to a time period in the range of 40 to 602 years of precipitation history in the Holocene, the last glacial period, and various marine isotope stages (MIS 9, 11, 15, 16, 17, and 18). Our goal is to extract detailed information about changes in climate and environmental conditions from individual elemental mineral dust particles. We compare the element-bearing particle number concentration (PNC) measured with sp-ICP-TOFMS for both major and minor crustal elements to the dust PNC optically measured with a laser absorption particle sensor (Abakus from Klotz, Germany), irrespective of its elemental composition, providing a complementary perspective. Furthermore, we examine the variability of dust composition using the elemental mass ratio of individual mineral dust particles during different warm and cold periods.
UV-weathering affects heteroaggregation and subsequent sedimentation of polystyrene microplastic particles with ferrihydrite
Authors: Schmidtmann Johanna , Weishäupl Hannah , Hopp Luisa , Peiffer Stefan
Published: March 2024

Microplastic (MP) particles are ubiquitous in aquatic environments. There they interact with naturally occurring particles and colloids. Processes like aggregation affect not only MP surface properties but also removal from the water column. Additionally, MP particles are exposed to UV radiation, which alters their surface properties and thus their interactions with environmental particles. We studied heteroaggregation and subsequent sedimentation of 1 µm polystyrene (PS) (pristine and UV-weathered) with ferrihydrite, an iron (oxy)hydroxide commonly found in nature. Pristine PS particles were highly negatively charged at pH 3-11. After reaction with ferrihydrite, at neutral pH values, strong heteroaggregation with ferrihydrite caused sedimentation of almost all PS particles. At acidic pH, negatively charged PS particles were coated with positively charged ferrihydrite leading to charge reversal. UV-weathering of PS led to lower negative surface charge, and particle size decreased with increasing weathering time. These changes in surface properties and particle size resulted in differences in aggregation behavior with ferrihydrite. With increasing weathering time, the isoelectric point (pHIEP) of samples with PS and ferrihydrite shifted from slightly alkaline pH to pH 3-4. Furthermore, we observed aggregation and subsequent sedimentation of weathered PS and ferrihydrite for larger pH ranges (3-7) compared to pristine PS. We attribute this to the fact that zeta potential values of the mixture of weathered PS and ferrihydrite were rather low in this pH range. Thus, particle repulsion was low, leading to aggregation. Overall, UV-weathering but also interactions of MP with environmental particles cause changes of MP surface properties, which influence its environmental behavior in water and contribute to removal from the water column.
Electron heating at quasi-perpendicular collisionless shocks: adiabatic vs non-adiabatic 
Authors: Lalti Ahmad , Khotyaintsev Yuri V. , Graham Daniel B.
Published: March 2024

The mechanism of electron heating across collisionless shocks remains an open question. The mechanisms suggested to address this problem revolve around the adiabatic or the non-adiabatic\stochastic dynamics of electrons across the shock. In this letter, we analyze the evolution of the electron velocity distribution function observed across 313 shocks with 1.7
Atmospheric aerosol characterization at Princess Elisabeth station, East Antarctica and identifying source regions using backward trajectory modelling
Authors: Mangold Alexander , De Causmaecker Karen , Laffineur Quentin , Van Overmeiren Preben , Deramaix Charlotte , Walgraeve Christophe , Mattielli Nadine , Delcloo Andy
Published: March 2024

Atmospheric composition plays an important role in present and near-future climate change. Airborne particles exert direct and indirect radiative impacts and can serve as cloud condensation and ice nuclei, having therefore a strong influence on cloud formation and precipitation. Furthermore, a detailed understanding of present-day atmospheric transport pathways of particles from source to deposition in Antarctica remains essential.Since 2010, the aerosol total number and size distribution, aerosol absorption coefficient and mass concentration of light-absorbing aerosols and the aerosol total scattering coefficient have been monitored at the Belgian research station Princess Elisabeth Antarctica (PEA). The station is situated in Dronning Maud Land, East Antarctica (71.95° S, 23.35° E, 1390 m asl). Besides these instruments, a cloud condensation nuclei counter was operated during three austral summers. Meteorological data come from an automatic weather station. In this work, we investigate the climatology of the particle properties with respect to the air mass origin. To that end, we used the FLEXTRA trajectory model to investigate transport pathways into Antarctica. The model was driven with ECMWF ERA-5 meteorological fields. 10-days 3D backward trajectories, starting from PEA, were calculated for the period 01/01/2010 to 31/12/2020, in 3-hour-intervals. A k-means cluster analysis has been done based on latitude, longitude and altitude, resulting in four clusters of air mass origin.We will present results for the climatology of particle properties and the air mass origin. In addition, the backward trajectories have been combined with measured atmospheric particle properties and parameters like potential vorticity and exposure to sunshine duration, showing the distribution of the measured atmospheric particle properties between and within the air mass origin clusters. Some distinct features could be seen in the air mass origin clustering. Source regions from South America, Southern Africa and Australia, New Zealand were limited and the Southern Ocean was a main source region, as was the Antarctic continent itself. For each season, the dominating cluster represented mainly air masses of Antarctic continental origin with a large influence of upper tropospheric air. We will show further results of our analysis on air mass origin and atmospheric and particle properties, with respect to differentiations between seasons, clusters, continental and maritime origin and source altitude compartments.
Organic carbon stored in pavement joint material of paved urban soils
Authors: Kollmann Carlotta Marga , Nehls Thomas
Published: March 2024

Cities emit large amounts of CO2 while urban soils can be crucial sinks for organic carbon (Corg), spatially highly variable due to human activities. In cities, paved soils - streets, sidewalks, plazas - account for about 1/3 of the surface area but little is known about its Corg. It is for instance stored in the soil between the pavers. As the pavement joint material, also called Dialeimmasol, is highly exposed to anthropogenic influences, we assumed that its Corg is not only natural e.g. humus but of technogenic nature, among it black carbon (BC).Soil mapping guidelines propose to use the Munsell Soil Color chart and pedotransfer functions to predict humus contents. Subsequently, Corg can be calculated using conversion factors. To assess whether this method, designed for natural soil, is applicable to the seam material of paved urban soils, predicted contents were compared to measured Corg and BC of seam material from cities worldwide. The results are used to adjust the model accordingly and to discuss the sink function of paved soils regarding organic carbon.Acknowledgements: We used data from soil samples that were provided from numerous international colleagues and data from samples that were partly analysed by late Sonja Brodowski, Institute of Crop Science and Resource Conservation, Soil Science and Soil Ecology, University of Bonn 
Spatially explicit active learning for crop-type mapping from satellite image time series
Authors: Belgiu Mariana , Kaijage Beatrice , Bijker Wietske
Published: March 2024

The availability of sufficient annotated samples is one of the main challenges of the supervised methods used to classify crop types from remote sensing images. Generating a large number of annotated samples is a time-consuming and expensive task. Active Learning (AL) is one of the solutions that can be used to optimize the sample annotation, resulting in an efficiently trained supervised method with less effort. Unfortunately, most of the developed AL methods do not account for the spatial information inherent in remote-sensing images. We propose a novel spatially-explicit AL that uses a semi-variogram to identify and discard the spatially adjacent and, consequently, redundant samples. It was evaluated using Random Forest (RF) and Sentinel-2 Satellite Image Time Series (SITS) in two study areas from the Netherlands and Belgium. In the Netherlands, the spatially explicit AL selected a total number of 97 samples as being relevant for the classification task which led to an overall accuracy of 80%, while the traditional AL method selected a total number of 169 samples achieving an accuracy of 82%. In Belgium, spatially explicit AL selected 223 samples and obtained an overall accuracy of 60%, compared to the traditional AL that selected 327 samples which yielded an accuracy of 63%. We concluded that the developed AL method helped RF achieve a good performance mostly for the classes consisting of individual crops with a relatively distinctive growth pattern such as sugar beets or cereals. Aggregated classes such as ‘fruits and nuts’ represented, however, a challenge. The proposed AL method reveals that accounting for spatial information is an efficient solution to map target crops since it facilitates high accuracy with a low number of samples and, consequently, lower computational resources and time and financial resources for annotation.
Modeling northeast Atlantic marine food webs under global change scenarios.
Authors: Shurety Amy , O'Gorman Eoin , Thompson Murray , Couce Elena
Published: March 2024

Climate change and commercial fishing are prominent contributors to global change and can cause gradients in numerous biotic and abiotic variables, all of which can alter food web dynamics. This study aimed to predict future northeast Atlantic marine food webs based on allometric foraging behaviour. More than one thousand food webs from 1992 to 2016 spanning 2035 km2 were modelled and calibrated based on a novel empirical dietary database containing >400,000 individual predator stomachs. A suite of flow and structural ecological metrics, such as connectance, mean trophic level, redundancy, and total energy flux, were calculated from the food web models, which due to their systemic nature can be used to infer ecological resilience of northeast Atlantic ecosystems. The relationship between the suite of ecological metrics, sea surface temperature and mean yearly fishing effort were tested using Bayesian Additive Regression Tree Models. Spatial and temporal variation was found in both structural and flow-based metrics providing evidence that climate change and commercial fishing are potential drivers of northeast Atlantic food web dynamics and in turn ecosystem resilience. For example, redundancy in trophic interactions, which provides buffering capacity to ecosystems in the face of stress, was found to increase with sea surface temperature. A primary goal is to provide robust understanding of food web structure and ecological resilience across multiple scales, helping to highlight vulnerable systems, communities, and species across the northeast Atlantic. This project has the potential to provide the scientific advice needed for climate change and sustainable fisheries management to be effective despite the uncertainty of global change.
Stirred-tank reactor bioleaching of nickel and cobalt from Brazilian laterite ores
Authors: Hetz Stefanie , Schippers Axel
Published: March 2024

Laterite ore deposits in Brazil and other tropical countries harbor large amounts of nickel and cobalt resources, along with other critical raw materials. The conventional methods of recovering nickel and cobalt, such as pyrometallurgy or high-pressure acid leaching, entail high energy, reagent costs, and expensive equipment. To address this, the German-Brazilian project BioProLat aims to develop an integrated, low-energy, and environmentally friendly biohydrometallurgical process for metal recovery from Brazilian laterite ores.The process involves leveraging acidophilic bacteria that use sulfur as an electron donor, coupling sulfur oxidation to the reduction of ferric iron, ultimately converting insoluble metal compounds into water-soluble forms. This generates sulfuric acid, creating the necessary acidic conditions to keep iron and other metals soluble. Laboratory-scale bioreactor experiments optimized parameters like pH, temperature, and a suitable bacterial consortium for bioleaching nickel and cobalt. Results from aerobic bioleaching of laterite with a consortium of Acidithiobacillus thiooxidans strains showed an extraction of 85% for both cobalt and nickel. Mineralogical and geochemical analyses were conducted to identify mineral phases, which are attacked by bioleaching, and estimate the portions of cobalt and nickel released by bioleaching of different mineral phases. The goal is to scale up the optimized process, converting untapped ores and limonite stockpiles into valuable resources and unlocking new raw material reserves by enhancing metal recovery from existing mines.
Assessing climatic impacts of shipping fuels: integrating MariTeam emission inventories with Earth system modeling 
Authors: Muri Helene , Kramel Diogo , Strømman Anders Hammer
Published: March 2024

Shipping plays a substantial role in global anthropogenic emissions and is a particularly challenging sector to decarbonize. COP28 emphasized the urgent need for accelerated emissions reduction in such sectors, and the IMO has a net-zero goal for 2050. Hence tools such as the MariTeam model presented here are essential in order to understand not only current emissions from shipping, but also the effect of decarbonization efforts like alternative fuels. The MariTeam model, a high-resolution AIS-based ship emission model, emerges as a crucial tool. It goes beyond merely assessing current shipping emissions, delving into the impact of decarbonization strategies, such as alternative fuels. 

Utilizing ship technical data, including engine size and vessel dimensions, MariTeam calculates emissions for various species like CO2, CH4, N2O, BC, OC, CO, NOx, and SOx on a global scale. Our presentation includes a comprehensive inventory of current shipping emissions in addition to the changes when alternative fuels are introduced. 

To understand the climate effects, we employed the Norwegian Earth System Model (NorESM), coupled with MariTeam. Notably, shipping emissions lead to significant pollutant transport, particularly black carbon (BC) to the Arctic, with a 40% surface concentration increase, with the potential to accelerate cryosphere melt. Current shipping emissions are also found to mask global warming, impacting multiple aspects of the climate system. When exploring alternatives like blue ammonia and LNG, methane and nitrous oxide gain significance. Our results emphasize the importance of considering well-to-wake versus tank-to-wake, indicating the complexities when considering mitigation efforts for the shipping sector. 
Changes in salinity driven stratification and impacts on the deep-water CO2 ventilation in the Southern Ocean
Authors: Olivier Léa , Haumann Alexander
Published: March 2024

The Southern Ocean considerably influences the global climate by exchanging heat and carbon between the deep ocean and the surface. Historically, it mitigated surface warming by absorbing 70% of excess heat and over 10% of human-induced CO2 emissions. The future of this role is strongly linked to salinity changes, as salinity controls, through its influence on the density stratification, the vertical exchange of water masses, heat and carbon.  A strong freshening of the Southern Ocean surface waters in the decades before 2016 has resulted in increased surface density stratification all around Antarctica. This enhanced stratification reduces the mixing between deep and surface waters, and in particular the vertical mixing of carbon-rich deep waters into the surface layer. By comparing post-2010 hydrographic sections in the GLODAP database to the climatology, we observe consistent and significant anomalies in the biogeochemical properties of the top 500 m of all the sectors of the Southern Ocean. While the surface layer is freshening, salinity, temperature, dissolved inorganic carbon (DIC) and total alkalinity (TA) increase in the subsurface layer. We find that this increase results from the shallowing of upper circumpolar deep water south of 50°S. We investigate the variability in properties of the surface and subsurface layers over the last decade, as well as the impact of such changes on the potential fugacity of CO2 to better understand how the change in stratification may impact the air-sea CO2 flux.
A Data Space environment for big data and ML-based climate applications in the European Open Science Cloud
Authors: Elia Donatello , Antonio Fabrizio , Fiore Sandro , Donno Emanuele , Accarino Gabriele , Nassisi Paola , Aloisio Giovanni
Published: March 2024

Several scientific fields, including climate science, have undergone radical changes in the last years due to the increase in the data volumes and the emergence of data science and Machine Learning (ML) approaches. In this context, providing fast data access and analytics has become of paramount importance. The data space concept has emerged to address some of the key challenges and support scientific communities  towards a more sustainable and FAIR use of data.The ENES Data Space (EDS) represents a domain-specific example of this concept for the climate community developed under the umbrella of the European Open Science Cloud (EOSC) initiative by the European Commission. EDS provides an open, scalable, cloud-enabled data science environment for climate data analysis on top of the EOSC Compute Platform made available through a user-friendly JupyterLab GUI. The service integrates into a single environment climate datasets from well-known initiatives (e.g., CMIP6), compute resources, data science and ML tools. It was launched in the context of the EGI-ACE project, it is accessible through the EOSC Catalogue and Marketplace (https://marketplace.eosc-portal.eu/services/enes-data-space) and it also provides a web portal (https://enesdataspace.vm.fedcloud.eu) including information, tutorials and training materials. It has recently been added to the Data Spaces radar, an initiative launched by the IDSA (International Data Space Association) with the main goal of mapping data spaces from several domains into one easy-to-use tool.The EDS is being employed in climate applications targeting big data processing, interactive analytics and visualization, and recently it has been extended to support more advanced scientific applications based on ML. In particular, it has been enhanced to provide a cloud-based development and testing environment for the implementation of some data-driven Digital Twin applications for extreme climate events in the context of the interTwin project. Finally, the ENES Data Space will be also one of the pilots in EOSC Beyond, a Horizon Europe project where the EDS will integrate and validate the new EOSC Core capabilities developed by the project.This work has been supported in part by interTwin; interTwin is funded by the European Union (Horizon Europe) under grant agreement No 101058386.
A year-long gravity record at Astroni, Campi Flegrei (Southern Italy): some considerations on data processing for volcano monitoring and precise gravity tides
Authors: Fedele Alessandro , Riccardi Umberto , Pivetta Tommaso , Carlino Stefano , Ricciardi Giuseppe
Published: March 2024

High-precision observations of gravity plays a central role in modern approaches for active volcano monitoring. Time-lapse observations over a network of benchmarks are frequently used to detect underground mass redistribution in the plumbing system of active volcanoes. Such approach however does not allow to retrieve small mass variations occurring over short terms (i.e. few hours or days). To fill this gap, continuous gravity monitoring at a fixed station may be employed. In January 2023 the relative gravimeter gPhoneX#116 was installed at the WWF Nature Reserve of Astroni volcano, in the Campi Flegrei caldera, to further complement time-lapse observations periodically performed over a network of benchmarks. During the 1-year of recordings, the gPhone has continuously recorded the relative gravity changes, only shortly interrupted by a few technical issues. The purpose of the observations is to monitor continuously the short-term gravity signals in one of the world's highest-risk volcanoes; to pursue this objective targeted and meticulous corrections need to be applied to remove the effect of several other geophysical effects, such as tides and atmospheric effects, which may superpose on the signals of interest. Special effort was devoted to the study of instrumental drift, which can mask actual gravity changes due to mass variations occurring in the volcanic and geothermal systems. In this contribution we report the various processing steps and analysis performed to obtain reliable parameters of the Earth tides, non-tidal corrections and gravity residuals. The retrieved Earth tide model is then used to properly reduce tidal effects in high-precision relative and absolute gravity measurements.
Geological significance of early cements: insight from laboratory simulated diagenesis
Authors: Douçot Julien , Regnet Jean-Baptiste , Robion Philippe , Fortin Jérôme , Bourdelle Franck , Corvisier Jérôme , David Christian , Passelègue François , Richoz Sylvain
Published: March 2024

Little is known about the evolution of petrophysical properties (porosity, permeability, mechanical resistance) associated with the growth of microstructures produced during the early stages of diagenesis. To gain a better understanding of these processes, we set out to recreate the microstructures resulting from early carbonate diagenesis in the laboratory. We reproduce a meteoric phreatic environment by heating a sorted aragonitic ooid sand saturated with distilled water. During an initial phase of mineralogical stabilization, we rapidly observe internal dissolution of the ooids and the formation of a calcitic rim at the periphery of the grains. Dissolution occurs along the laminated structures of the ooids. The outer calcite crystals are regular in shape and size. This is followed by a second phase, in which the internal structure of the oolite disappears. Large, sparitic calcite crystals appear in place of the internal laminations. These two phases can be explained in terms of the evolution of CaCO3 saturation in the fluid, and by a competition between nucleation and crystal growth. In the geological record, those structures are often interpreted as the beginning of burial diagenesis. We show that those features can appear very early in the system and are likely to be the cause of the chemical and thermodynamic isolation of the ooids from the fluid in the pore space. We can also conclude from these observations that the creation of internal porosity inside grains is very early, and can appear in a stationary fluid, at shallow depth.
Folds in evaporites. What can we learn about the rock-salt rheology?
Authors: Adamuszek Marta , Barabasch Jessica , Urai Janos L. , Dabrowski Marcin
Published: March 2024

Due to the presence of low-viscosity rock-salt, evaporite sequences show a remarkable susceptibility to deformation across diverse geological settings. These sequences often exhibit intercalations of rock-salt with siliciclastic rocks, anhydrite, and sometimes various bittern salts like carnallite and bischofite. Their distinct layering serves as invaluable markers, facilitating a comprehensive analysis of internal salt deformation. The extensive deformation of the evaporites often gives rise to complex internal architectures within the salt body, characterized by commonly observed fold structures. The geometries of these structures are highly sensitive to the mechanical properties of the layers, thus offering profound insights into rock-salt rheology. Unravelling the rheological behaviour of rock-salt holds significant implications, particularly in salt mining, salt cavern operation, and advancing our understanding of salt tectonics.In this project, we focus on specific outcrops within salt mines located in Romania, Austria, and Poland, where prominently exposed fold structures offer unique field laboratories. These sites hold significant potential for deciphering the mechanical behaviour of rocks during their long-term deformation. In our study, we combined field observations, detailed mapping and microstructural analysis of various single and multilayer folds complemented by numerical models of fold evolution. In our numerical simulations, we use the Carreau model for rock-salt, which captures two primary deformation mechanisms: pressure solution and dislocation creep. The mechanisms correspondingly result in the linear (Newtonian) and non-linear (power-law) rheological regimes, influenced by rock grain size and differential stress. Varying the rock-salt grain size enabled us to analyse fold evolution in both regimes as well as in the transitional domain. By systematically comparing our numerical analysis with field observations, we refine our understanding of the mechanical properties of evaporites, contributing to advancements in the study of rock deformation.
Plant macrophenological dynamics - from individuals to plant group behaviour using citizen science data
Authors: Mora Karin , Rzanny Michael , Wäldchen Jana , Feilhauer Hannes , Kattenborn Teja , Kraemer Guido , Mäder Patrick , Svidzinska Daria , Wolf Sophie , Mahecha Miguel D.
Published: March 2024

Understanding the implications of climate change on ecosystems necessitates continuous monitoring of plant phenology. While citizen science data collected through smartphone applications offer a rich source of information, existing phenology studies predominantly focus on individual species.This study introduces a pioneering data science approach to quantify plant group behaviour from individual observations. Leveraging over ten million ground measurements of plant observations obtained through the Flora Incognita plant identification app in Germany from 2018 to 2023, our analysis unveils macrophenological patterns arising from plant group behaviour. The findings indicate nonlinear changes in group behaviour across the annual cycle.Furthermore, we explore the relationship between these macrophenological patterns on the ground and phenology derived from remote sensing data. The growing databases of citizen science holds great potential to investigate climate-induced phenological shifts and provide valuable insights into plant group behaviour.
Digital twins – fast flyby-X-ray CT measurements of polar firn
Authors: Freitag Johannes , Salamon Michael
Published: March 2024

In this study we report on the first continuous records of three dimensional firn structure reconstructions using archive pieces of firn cores that cover the whole depth range of firn starting from surface down to the transition to bubbly ice. The CT-measurements have been performed on 1m-core segments with the means of the AWI-X-ray-computer tomograph especially designed for ice applications. Flyby recording in helical mode under a time-optimized measurement protocol enabled us to reduce the scanning time to 25 minutes per meter firn. The reconstructed volumes have a spatial resolution of 120 µm, giving about 1 million cross-section images per firn core. The analytical work flow includes three steps of pre-processing with denoising, image segmentation and a manual check for outliers at break positions and a layer-wise (5.5 mm thick) calculation of several geometrical parameters like density, ice and pore cluster sizes, intercept lengths, autocorrelation functions, structural anisotropy, Euler number (connectivity), coordination number, bubble number density, closed and open porosity.The method was applied to archive pieces of EGRIP-S6 (firn air pumping site, 2018, North-East-Greenland, 75.6°N ,35.9°W), B40 (Kohnen station, 2013, Dronning Maud Land, East Antarctica, 75.0°S, 0.1°E) and B51 (CoFi-Traverse 2013, Dronning Maud Land, East Antarctica, 75.1°S ,15.4°E). Temperature and accumulation rates at the different core sites vary between -30°C and -50°C and 130 mm w.eq./a and 40 mm w.eq./a respectively. The selected sites cover a wide range of recent environmental conditions of polar regions.In this contribution we present several fundamental relationships between the derived geometrical parameters. The evolution of firn structure with depth will be discussed in respect to the dominant processes acting at different sintering/densification stages. The potential value for densification modelling, gas transport and enclosure modelling will be highlighted.
Sediment source and transport along the Iberian Margin
Authors: Campderrós Sara , Pena Leopoldo D. , Frigola Jaime , Garcia-Solsona Ester , Paredes Eduardo , Haghipour Negar , Stoll Heather M. , Cacho Isabel
Published: March 2024

The Iberian Margin is a dynamic margin, affected by complex sedimentary and oceanographic processes. The Mediterranean Outflow Water (MOW) is a prominent water mass that flows along the Iberian margin and interacts with the sediment on the slope. However, more information about how MOW interacts with sediment delivery, distribution, deposition along the margin is needed. In this study we combine Nd, Sr and Pb isotopes on fine-grained detrital sediments (< 63 μm) and 14C measurements in planktonic foraminifera (G. bulloides) in 25 coretop sediment samples collected along the entire Iberian Margin (from the Gulf of Cadiz to the “Cachucho” mount in the Cantabrian Sea). Nd, Sr and Pb isotopes were used to (i) identify the main source areas of terrigenous sediments coming from the Iberian Peninsula and (ii) trace the distribution of these sediments along the Iberian Margin. Additionally, 14C data in planktonic foraminifera were used to obtain radiocarbon ages, that allowed us to date the coretop sediments. Results from Nd, Sr and Pb isotopes allow us to identify three main terrigenous sediment source provinces in the Iberian margin, depicting a prominent south to north gradient. Moreover, large age discrepancies in coretop sediments are strongly associated with the main pathway of MOW, thus suggesting erosion and lateral transport of sediments along the main path of the MOW.
Transient atmosphere-ocean-carbon simulations through the Penultimate Deglaciation and Last Interglacial
Authors: Cutler Tim , Holden Philip , Edwards Neil , Anand Pallavi
Published: March 2024

The Penultimate Deglaciation saw climatic warming from a glacial state into the Last Interglacial, which saw warmer-than-preindustrial temperatures and extreme northern hemisphere monsoons. Here a fast, intermediate-complexity 3D dynamic atmosphere-ocean model is used to study the Atlantic Meridional Overturning Circulation (AMOC), Indian and Southeast Asian Summer Monsoons and the carbon cycle during the Penultimate Deglaciation and Last Interglacial in steady state and transient simulations between 140,000 and 122,000 years before present. We find two weak phases of AMOC, the second longer than the first. Indian Summer Monsoon starts in a weak state and reaches a maximum around 127,000 years ago (where northern summer insolation is at a maximum) before declining. The Southeast Asian Monsoon displays smaller changes and an earlier peak. The timing of AMOC collapse and recovery is strongly affected by choice of freshwater forcing timeseries. Sensitivity experiments where individual forcings are varied, find that the timing of AMOC recovery is further influenced by precession, and by ice sheet retreat independent of meltwater flux. Indian monsoon strengthening is mainly driven by precession, with further contribution from CO2, obliquity and the timing of AMOC recovery. Transient simulations find later warming compared to steady state experiments. Experiments with freely evolving CO2 fail to replicate ice core-inferred deglacial CO2 increase.
Impact of climate extremes on peatland carbon dynamics across Northern Europe
Authors: Gottschalk Pia , Kalhori Aram , Aurela Mika , Juutinen Sari , Lohila Annalea , Mammarella Ivan , Tuittila Eeva-Stiina , Nielsen Claudia , Wille Christian , Sachs Torsten
Published: March 2024

Climate change and concurrent climate extremes lead to rapid changes in environmental conditions globally. These changes impact the role of terrestrial ecosystems in the global carbon (C) cycle, thus creating a feedback mechanism to climate. Peatlands, specifically, play a critical role in the terrestrial C cycle due to their high-density organic C stocks, thus, slight changes in the environmental drivers can trigger strong responses in their C dynamics. Here, we investigate the impact of climate extremes, such as hydrological and temperature anomalies on the C emission dynamics of a series of peatlands across Northern Europe. We use long-term datasets of high-resolution carbon exchange measurements and environmental variables of peatlands to systematically identify extreme events in the carbon fluxes as well as in their environmental drivers and how they connect. We subsequently quantify the impact of drivers’ anomalies on CO2 and CH4 exchange of peatland ecosystems. We specifically focus on the response of C-emissions to changes in water level, temperature and vegetation development before, during, and after the 2018 European summer drought to show the combined effect on the annual CO2 and CH4 balances in rewetted and pristine peatlands. Categorizing these impacts according to the environmental conditions and/or their changes, duration, frequency and severity of anomalies and peatland type will help to refine common peatland emission factors used to estimate C dynamics for national and international greenhouse gas emission inventories.