bluuebunny/crossref_metadata_2025 huggingface dataset:
The climate control of soil organic carbon dynamics inferred from speleothem radiocarbon ages
Authors: Xue Gang , Cai Yanjun , Cheng Peng , Lechleitner Franziska , Zhang Haiwei , Zheng Yanhong , Wei Yingying , Huang Shouyi , Yang Ling , Cheng Xing , Lu Yanbin , Zhou Jie , Ma Le , Cheng Hai , Edwards Lawrence
Published: March 2024

The complexity of processes affecting soil organic carbon (SOC) turnover on spatio-temporal scales often hinders the extrapolation of results from specific sites to larger scales. This study presents Holocene speleothem U-Th ages paired with 14C ages of carbonate and dissolved organic carbon (DOC) through three caves located on a north-south transect through China. The deviations of speleothem 14CDOCages from the U-Th ages show clearly spatial variability, and they are positively correlated with mean ages of modern SOC and soil turnover time, suggesting that deviations can be used to infer the SOC turnover. We further demonstrate that slow SOC turnover (large deviation) was associated with weak monsoon (low temperature/less precipitation) on temporal scales. Our findings reveal that climate dominates the speleothem 14CDOCages and SOC turnover. As global warming likely will intensify, the accelerated turnover of SOC, particularly at higher latitude areas, may partially offset the existing soil carbon stock. 
GEOROC 2.0: A Globally Connected Geochemical Database to Facilitate Interdisciplinary, Data-Driven Research
Authors: Wörner Gerhard , Klöcking Marthe , Sturm Adrian , Sarbas Bärbel , Kallas Leander , Möller-McNett Stefan , Elger Kirsten , Kurzawe Daniel , Willbold Matthias
Published: March 2024

The GEOROC database is a leading, open-access source of geochemical and isotopic datasets that provides access to curated compilations of igneous and metamorphic rock and mineral compositions from >20,600 publications. It is a data resource that supports and facilitates hundreds of new research publications each year across multiple geoscientific and related disciplines.This presentation is to “advertise” to the geochemical community this data product and our ongoing efforts to improve the service by providing FAIR (findable, accessible, interoperable and reusable) geochemical data. We will also describe some recently published research where authors were using large geochemical data compilations such as GEOROC and PetDB for innovative approaches in digital geochemistry.To further support such research also in the future, the Digital Geochemical Data Infrastructure (DIGIS) initiative is developing a new IT and data infrastructure for GEOROC 2.0 to enable modern solutions to data submission, discovery and access. GEOROC data compilations are made accessible via a web search interface and an API. In addition, DIGIS maintains a direct data pipeline between the data compiled in GEOROC and the EarthChem Portal. Hence, GEOROC represents one of six different geochemical databases that can be queried and accessed synchronously within the EarthChem Portal. The DIGIS infrastructure further partners with GFZ Data Services, a domain repository for geosciences data, hosted at GFZ, offering data publication services with assigned digital object identifiers (DOI). Individual researchers can directly submit their geochemical datasets to the repository (using the EarthChem Data Templates) where they are archived for the long term. Regular thematic snapshots of the GEOROC synthesis database are archived in the GRO.data repository of the University of Göttingen.Part of this cooperation is the development of standardised vocabularies and data reporting to enhance interoperability of geo- and cosmochemical data systems. Harmonized data entry for the GEOROC, PetDB and Astromat synthesis databases will avoid duplication and ensure consistent data and metadata. With these efforts, and as a participant of the OneGeochemistry(1,2) initiative, DIGIS is working towards the goal of globally harmonised geochemical data to enable interdisciplinary, data-driven research. ReferencesKlöcking, M. et al. (2023). Community recommendations for geochemical data, services and analytical capabilities in the 21st century. In Geochimica et Cosmochimica Acta (Vol. 351, pp. 192–205).Prent, A. et al. (2023) Innovating and Networking Global Geochemical Data Resources Through OneGeochemistry. Elements 19, Issue 3, pp. 136–137.
Collection, Standardization and Attribution of Robust Disaster Event Information — A Demonstrator of a National Event-Based Loss and Damage Database in Austria
Authors: Imgrüth Dominik , Enigl Katharina , Themessl Matthias , Kienberger Stefan
Published: March 2024

Loss and damage databases are essential tools for disaster risk management in order to make informed decisions. However, even in data-rich countries such as Austria, there has been no consistent and curated multi-hazard database to date. Based on the demands of the United Nations, the European Union and national requirements for monitoring and managing the effects of disasters, the CESARE project (funded by KIRAS/FFG; project end 02/2022) designed and developed a demonstrator for a consistent national event-based damage database. This demonstrator enables event identification, loss and damage monitoring and assessment according to international standards and offers the possibility of disaster forensics. The CESARE system is based on existing data collected by administrations as well as federal authorities which are consolidated according to a common data model. By this means, the primary data and the data collection procedures are not affected and a sustainable exchange of data is made possible. The demonstrator currently focuses on two Austrian federal states, three hazard types - floods, storms and mass movements - and the period between 2005 and 2018. By analysing over 140,000 individual event descriptions, we demonstrated that - despite some limitations in retrospective data harmonisation - the implementation of an event-based national damage database is feasible and offers considerable added value compared to the use of individual data records. The demonstrator will in future substantially support quantitative analysis in the context of the national risk assessment, national UNDRR-Sendai monitoring and disaster risk management at federal level by providing the best possible harmonised damage information, tailored indicators and statistics as well as maps on the impact of hazards at municipal level. The CESARE system is currently being rolled out operationally as well as extended to other hazard categories and the remaining provinces of Austria. With its final implementation, CESARE will provide the most complete event and damage database in Austria.
Large Interferometer for Exoplanets (LIFE): characterizing the mid-infrared thermal emission of terrestrial exoplanets
Authors: Lichtenberg Tim , Quanz Sascha , Noack Lena , Angerhausen Daniel , Rugheimer Sarah , Glauser Adrian , Kammerer Jens , Fortier Andrea , Ireland Michael , Defrère Denis , Linz Hendrik , Iro Nicolas , Collaboration Life
Published: March 2024

The atmospheric characterization of a significant number of terrestrial exoplanets is a major goal of 21st century astrophysics. However, none of the currently adopted missions worldwide has the technical capabilities to achieve this goal. Here we present the LIFE mission concept, which addresses this issue by investigating the scientific potential and technological challenges of an ambitious mission employing a formation-flying nulling interferometer in space working at mid-infrared wavelengths. LIFE, in synergy with other planned future missions, will for the first time in human history enable us to understanding global biosignatures and planetary habitability in the context of the diversity of planetary systems. Breakthroughs in our understanding of the exoplanet population and relevant technologies justify the need, but also the feasibility, for future atmosphere characterization and life detection missions to investigate one of the most fundamental questions of humankind: how frequent and diverse are global biospheres in the galaxy?
Advancing EOP Prediction: Bridging the Gaps
Authors: Modiri Sadegh , Thaller Daniela , Belda Santiago , Halilovic Dzana , Klem Lisa , König Daniel , Bachmann Sabine , Flohrer Claudia , Walenta Anastasiia
Published: March 2024

Understanding Earth's orientation parameters (EOP) is paramount for unraveling intricate mass redistribution, gravitational interactions, and geodynamic processes within the Earth's system. With a growing interest in EOP across diverse scientific disciplines such as Earth science, astronomy, and climate change studies, the demand for accurate and timely real-time information has become increasingly crucial. This is particularly evident in applications like satellite navigation, interplanetary spacecraft tracking, and weather forecasting. Despite the precision enabled by modern space geodetic techniques (e.g., Very Long Baseline Interferometry - VLBI, Global Navigation Satellite Systems - GNSS, and Satellite Laser Ranging - SLR), the complexity of data processing and associated delays necessitates significant progress in EOP prediction, especially for applications requiring timely information.This study addresses these challenges by introducing a redesigned prediction package that effectively bridges the gap between observational data and final estimated products. Utilizing a sophisticated combination of deterministic and stochastic methods, our prediction algorithm is applied to both the official International Earth Rotation and Reference Systems Service (IERS) EOP series and the Federal Agency for Cartography and Geodesy (BKG) single-specific and combined technique time series.The results of this study make a significant contribution to efforts that aim to enhance the accuracy of predicted Earth Orientation Parameters (EOP). By thoroughly exploring the selection of input data and prediction methods, our research strives to improve the dependability of EOP forecasts, especially for short-term predictions. By tackling crucial challenges in the field, this work not only deepens our understanding of Earth's dynamic processes but also opens doors for more accurate and timely applications across various scientific disciplines that rely on EOP data.
Early Pleistocene onset of glacial incision in the Baltic Basin revealed by 10Be-26Al burial dating of the Hattem Beds
Authors: Wagner Kaleb , Ylä-Mella Lotta , Margold Martin , Faurschou Knudsen Mads , Busschers Freek , Bakker Marcel , Lindahl Eriksen Birte , Olsen Jesper , Lund Andersen Jane , Jansen John
Published: March 2024

In Northwest Europe, the earliest presence of the Fennoscandian Ice Sheet (FIS) is registered in the Dutch-German border region, where fluvio-deltaic sediments of the ancient Eridanos river system contain weathered Nordic erratics within the so-called “Hattem Beds” (Upper Pieze Fm. [f.k.a. Lower member of the Enschede Fm.]). The Eridanos operated from the Early Miocene, integrating drainage across the east Fennoscandian Shield and Baltic Platform, until its headwaters were overridden by the FIS for the first time. The Hattem Beds, conventionally attributed to the Dutch Menapian Stage (~MIS 34; 1.1 Ma), mark the onset of glacial erosion within the Baltic Basin and termination of the Eridanos system.Here we provide new sediment burial ages for this key stratum by exploiting the cosmogenic 10Be-26Al pair in quartz. We measure nuclide concentrations in archived drill-core samples obtained from the type locality at the Wapenveld quarry near Molenweg (NL), including those of the overlying Urk and underlying Lower Pieze Fms. (f.k.a. Harderwijk Fm).Results with our Particle Pathway Inversion of Nuclide Inventories (P-PINI) burial dating model suggest a significantly older age for the Upper Pieze Fm. than has been previously inferred, underscoring glacial incision of the Baltic Basin and collapse of the Eridanos river system beginning in the Early Pleistocene (~2 Ma). This initial advance of the FIS into the Baltic Basin tracks the overall intensification of Northern Hemisphere glaciation indicated by marine records and alludes to the expansion of European ice masses prior to the Middle Pleistocene Transition (MPT; ~1.2–0.8 Ma). These findings add to a growing sense of mismatch between large empirically-derived pre-MPT ice sheet extents and low coeval glacial-interglacial ice volumes implicit in the global δ18O record.
Unveiling the influence of slip-weakening laws' shapes on rupture dynamics: beyond fracture energy in controlling rupture profiles
Authors: Ferry Roxane , Molinari Jean-François
Published: March 2024

Friction plays a crucial role in rupture dynamics and yet its precise nature remains elusive. Consequently, a friction law must be assumed to model rupture. Commonly used constitutive laws for modeling friction include slip-weakening laws which are characterized by a drop from static to dynamic frictional strength. Within this framework, the prevailing understanding asserts that the frictional behaviour is solely controlled by the fracture energy - the area beneath the frictional strength versus the cumulated slip curve. In particular, it is claimed that the curve's shape itself has no influence on the system's response. Here we perform fully dynamic rupture simulations to challenge prevailing beliefs by demonstrating that the constitutive law shape exerts an intimate control over rupture profiles. For a consistent fracture energy but varying constitutive law shapes, the velocity profile is different: each abrupt slope transition leads to the localization of a distinct velocity peak. For example, in the case of a dual slip-weakening law featuring two different slopes, the rupture exhibits two distinct velocity peaks. This distinction significantly influences how a rupture responds to a stress barrier. These results are derived through two separate numerical schemes (spectral boundary integral and finite element methods) ensuring their independence from the computational approach employed.
Carbon dioxide fluxes from an Irish saltmarsh
Authors: Jessen Lisa , Eichelmann Elke , Fuchs Andrea , Cott Grace
Published: March 2024

Saltmarshes are important ecosystems for carbon capture and storage and play a vital role in carbon cycling processes. Despite their significance, the carbon fluxes within Irish saltmarshes remain poorly understood, with a notable absence of greenhouse gas flux data from coastal wetlands in the region. This study addresses this gap by employing the eddy covariance method to calculate carbon dioxide (CO2) fluxes from Derrymore saltmarsh, County Kerry, a natural estuarine saltmarsh on the west coast of Ireland, from May 2023 to the present. The tower is equipped with an open path CO2 and water vapour (H2O) infrared gas analyser (LI-7500, LI-COR biosciences) and a sonic anemometer (CSAT3, Campbell Scientific) set 3.2m above the marsh surface. This method allows us to get continuous high frequency CO2 and H2O data with measurements being taken ten times per second.Our findings reveal patterns in net ecosystem exchange (NEE), with higher values observed during autumn compared to summer months, attributed to reduced photosynthetic CO2 uptake. These findings are comparable to saltmarshes in other regions. With a project duration of 12 months, our hypothesis suggests Derrymore saltmarsh will act as a modest CO2 sink.The use of the eddy covariance method allows us to get an overall picture as to the extent to which this saltmarsh acts as a carbon sink, giving us a better understanding of the carbon dynamics from this Kerry saltmarsh. This ongoing project contributes vital data to a broader initiative in Irish saltmarsh research, aiming to establish a scientific foundation for a comprehensive management framework. The framework will guide efforts in saltmarsh protection, restoration, and optimisation of carbon sequestration. Our research underscores the importance of understanding local variations in carbon dynamics, paving the way for informed environmental strategies in the context of climate change.
Insights into geological and hydrogeological characteristics using airborne geophysical investigations of former opencast lignite mining areas
Authors: Schönfeldt Elisabeth , Cortes Arroyo Olaf , Fahle Marcus , Siemon Bernhard , Janetz Silvio , Nixdorf Erik
Published: March 2024

The region Lusatia in northeastern Germany, which is located about 100 km south of Berlin, is strongly affected by over a century of both former and on-going opencast lignite mining. Although, there is an abundance of borehole data from former excavation surveys both varying data quality and heterogeneous coverage is a challenge for deriving spatially continuous subsurface properties. To overcome these obstacles we combined airborne geophysical investigations with borehole data. Different machine learning-algorithms (Random Forest and K-means) are used to determine spatially and depth-related insights into the variability of geological and hydrogeological characteristics. An aeroelectromagnetic (AEM) survey was carried out in summer 2021 using BGR’s (German Federal Institute for Geosciences and Natural Resources) helicopter, which covered flight lines of 1680 km in an area of about 200 km². First results show that the machine learning approach can predict fine-grained sediments (clay and silt) in untrained areas and can distinguish between clusters of mining-affected regions and undisturbed ones. The results of the study will be further used to improve the parameterization of existing regional groundwater flow models to address challenges of water allocation in the region of Lusatia.
Long-range fiber-optic earthquake sensing by active phase noise cancellation
Authors: Noe Sebastian , Husmann Dominik , Müller Nils , Morel Jacques , Fichtner Andreas
Published: March 2024

We introduce a novel fiber-optic environmental deformation sensor operating on active phase-noise cancellation (PNC). Networks with PNC have been established over the last decade by national metrology institutes to enable state-of-the-art frequency dissemination of atomic clock signals. Utilizing this infrastructure, PNC sensing exploits recordings of a compensation frequency that arises in the frequency dissemination. As the recording operates simultaneously with the metrological service, the existing phase-stabilized metrological networks can be co-used with minimal effort as environmental sensors. The compatibility of PNC sensing with inline amplification enables the interrogation of cables with lengths beyond 1000 km, potentially contributing to earthquake detection and early warningsystems in the oceans.In a practical application, we analyze the recordings of a magnitude 3.9 earthquake in eastern France on a 123 km fiber-optic link between Bern and Basel, Switzerland. Through spectral-element seismic wavefield simulations, we compute the theoretical compensation frequency time series on the in-line strain rates resulting from the seismic wavefield and compare it to the observations. Simulations account for the complex cable geometry and topography. Observed and computed recordings match for periods above 3 s.As simulations appear to explain the data, we further deploy a moment tensor inversion for the same event. This involved computing Green’s functions for all moment tensor components based on the full waveform. Comparing the inversion results to conventional source solutions from public earthquake databases yields a good fit, despite relying on a single data trace only, suggesting that PNC can be used for quantitative seismology. We discuss the detection of other earthquakes with this instrument and future research directions, including tomography.
A satellite-based analysis of fog and low stratus life cycle processes in the Po valley, Italy
Authors: Pauli Eva , Cermak Jan , Andersen Hendrik , Schütz Michaela
Published: March 2024

A better understanding of fog and low stratus (FLS) life cycle processes can help traffic safety, improve solar power planning and enhance the understanding of ecosystem processes in fog-prone regions. Nevertheless, large-scale analyses of FLS life cycle processes are challenging due to the high spatial variability of FLS and complex interactions between the land surface and the atmosphere.Here, we use a satellite-based FLS formation and dissipation time data set, as well as reanalysis data to investigate regional variations in the FLS life cycle in the Po valley region in northern Italy. With its large spatial extent, relatively low topographic variability and high FLS occurrence, the Po valley is an ideal area to study FLS life cycle processes in central Europe. In a case study approach, we analyze FLS life cycle processes pertaining to variations in land surface characteristics and atmospheric drivers. First results reveal the importance of the temporal development of temperature, specific humidity and boundary layer height for FLS formation during radiation-driven FLS events. These effects are further modified by the local topography and the synoptic situation.This analysis provides a basis to set up further process-oriented sensitivity studies using explainable machine learning, which has shown to be an ideal tool to gain a deeper understanding of the effect of non-linear land-atmosphere interactions on the FLS life cycle.
Direct observation of wintertime secondary formation of sulfate in ambient aerosols in Fairbanks, Alaska
Authors: Mao Jingqiu , Bali Kunal , Campbell James , Robinson Ellis , DeCarlo Peter , Ijaz Amna , Temime-Roussel Brice , D’Anna Barbara , Simpson William , Weber Rodney
Published: March 2024

Sulfate comprises an average of 20% of the ambient PM2.5 mass during the winter months in Fairbanks, as indicated by 24-hour average filter measurements. During ALPACA 2022 field campaign (Jan 15th-Feb28th of 2022), we deployed two aerosol mass spectrometers (AMS) and one aerosol chemical speciation monitor (ACSM) at three urban sites, combined with Scanning Mobility Particle Sizer (SMPS), to examine the evolution of aerosol composition and size distribution at a sub-hourly time scale. During an intense pollution episode (ambient temperature is between -25 and -35 °C), all three instruments (two AMS and one ACSM) exhibit a sharp increase in sulfate mass within a matter of hours, while organic aerosols, black carbon and SO2 concentrations remain relatively stable. This notable increase in sulfate mass contributes to approximately half of the observed change in ambient PM2.5. The abrupt rise in sulfate mass is concurrent with a substantial increase in particle number density within the accumulation mode (100-1000 nm), suggesting the secondary formation of sulfate onto pre-existing aerosols. We further investigate possible mechanisms and have ruled out the possible role of cloud chemistry and transition metal ion. The rapid formation of sulfate seems to be linked to the ambient level of nitrogen oxides and, possibly, sunlight. Further investigation is underway to elucidate the intricate connections underlying this rapid sulfate formation.
System dynamics for water management in coastal cities under multi-risk scenarios
Authors: Perney Marion , Moreno Mauro , Giannino Francesco , Leone Mattia Federico
Published: March 2024

In the context of global warming, extreme weather events are rising in frequency and severity. Urban communities prosperity heavily depend on the balance of environmental and socio-technical systems to access to fundamental resources and services, making them more susceptible to the impacts of climate change. Coastal cities, in particular, are characterized by a high degree of vulnerability to climate variations, potentially leading to critical impacts if resilient and sustainable water management strategies and measures are not in place. To assess the significance of territorial adaptation and mitigation measures in a dynamic and holistic approach, the use of System Dynamics tools aims to study the effects and interactions of various sectors, examining the risks associated with flood management in coastal cities.This approach incorporates multidisciplinary, multi-scalar, and multi-operational dimensions, supporting stakeholders in identifying potential measures for building resilient pathways. By identifying interactions within the various interconnected sub-systems that influence the dynamic behaviour of the overall system, stock and flow models enable complex systems to be analysed through interdependent components that influence each other over time. It can be used to support decision-makers in getting insights about the potential effects of different policies and strategies.The model presented is a conceptual framework able to represent the impact of compound coastal flood (combination of pluvial, river and coastal flood) on sectors (transport, energy, landuse, etc.) and explores adaptation and mitigation measures (Nature Based, architectural and engineering solutions) to contrast coastal risks using dynamic tools and methods for assessing their relevance in urban coastal areas. The different types of water storage and flows/processes have been identified, namely: coastal flow, surface water, river/ponds, soil water, groundwater table, city drainage system. These are used to simulate different scenarios and study the interlinks among technical solutions, urban features, and coastal flood water management.The presentation explores SD thinking and tools for dialogue and decision-making on complex and interdisciplinary issues linked to Climate Change Adaptation and Disaster Risk Reduction actions. The quantitative developed stock and flow model contributes to study the climate impacts on coastal cities under a cross-sectorial approach.
Conditional Generative Models for OceanBench Sea Surface Height Interpolation
Authors: Lehmann Nils , Bamber Jonathan , Zhu Xiaoxiang
Published: March 2024

Rising sea levels are one of many consequences of anthropogenic climatechange. Over the past few decades, several global observational records havebecome available that give a more detailed picture of the increasingimpacts. Nevertheless, there continue to be data challenges, such assparsity or signal to noise ratio, that need to be dealt with. Machine Learning (ML)and specifically, Deep Learning (DL) approaches have presented themselves as valuabletools for such large-scale and complex data sources. To this end, the OceanBenchBenchmark suite was recently developed to provide astandardized pre-processing and evaluation framework for Sea Surface Height(SSH) interpolation tasks involving nadir and Surface Water and Ocean Topography(SWAT) Altimetry Tracks. From the methodological perspective, a reoccurringissue is the lack of uncertainty quantification for DL applications in EarthObservation. Therefore, we extend the suite of metrics provided by OceanBenchto probabilistic evaluation metrics and test state-of-the-art uncertaintyquantification models from the DL community. Specifically, we focus onConditional Convolutional Neural Processes (ConvCNP) andInpainting Diffusion models as methodologies to quantifyuncertainty for the interpolation task and demonstrate their viability andadvantages over other ML methods for both accuracy and probabilistic metrics.
Study of local accumulation patterns from a snow trench at Dome C
Authors: Ooms Adrien , Casado Mathieu , Picard Ghislain , Arnaud Laurent , Hörhold Maria , Spolaor Andrea , Traversi Rita , Savarino Joel , Masson-Delmotte Valérie
Published: March 2024

The center of Antarctica contains some of the oldest ice available on earth for paleo-climate reconstructions. This is due to very slow ice-flow and low accumulation. Yet, low accumulation comes with the drawback that annual snow layers are thin and subject to erosion and re-deposition by wind, inducing locally mixing and sometimes missing snow layers, leading to a highly variable time vs depth gradient at sub-decadal timescales. This greatly limits the interpretation of the climatic record in ice-cores at high temporal resolution. An important challenge thus consists in describing and quantifying these local accumulation patterns on the East Antarctic plateau.In our study, we combine observations of accumulation rate (stake farm and laser scanner), with chemical and isotopic measurements of a 50-m long snow trench to address the problem of accumulation patterns at Dome C. We suggest that high resolution alignment of the chemistry data, typically used at longer timescales with volcanic eruption alignment in deep ice-cores, is a good method for inter-annual dating of the trench profiles and reconstruction of accumulation time-series up to a 2 year resolution. We find typical annually-varying roughness as well as more persistent patterns with timescales of years, highlighting the complex dynamics of the snow accumulation in central Antarctica. We then use this dataset to explore post-deposition noise in the isotopic record (δ18O and δD) and its local spatial variability.
Numerical simulation of multicomponent multiphase reactive fluid flow in porous media
Authors: Isaeva Anna , Khakimova Lyudmila , Podladchikov Yury
Published: March 2024

Multicomponent multiphase reactive transport in porous media controls various phenomena in geological formations such as carbonization, fluid flow in a petroleum reservoir, mobility of radioactive waste in repositories, etc. Despite the obvious differences between these geological processes, they have much in common from a numerical simulation point of view.We draw parallels between mathematical models of processes from two different areas of research. Firstly, we study the process of carbonization. Secondly, we consider the process of retrograde condensation, which is known to occur when natural gas flows in reservoir rock (during isothermal pressure reduction). Retrograde condensation is a property of multicomponent mixtures, such as natural gas. Both systems considered exhibit complex behavior and phase  transitions. But both systems can be described by the same generalized equations. We discuss the differences and similarities between these mathematical models.
Forestline detection and treeline ecotone dynamics in the Italian Alps and Apennines by satellite remote sensing
Authors: Baglioni Lorena , Morresi Donato , Tonelli Enrico , Lingua Emanuele , Marzano Raffaella , Urbinati Carlo
Published: March 2024

Treelines are dynamic ecotones largely influenced by climate and land use changes. The increasing development of remote sensing techniques and the interest on the ecological effects of global warming on forest vegetation have raised the number of treeline studies.The aims of this study were: i) to define an automatic approach for mapping the current position of the upper forestlines in the Italian Alps and Apennines and ii) to locate hotspots of long-term vegetation dynamics using Landsat-based spectral trend analysis. Hotspots will serve us to analyse the ecological drivers of vegetation change and to predict future vegetation dynamics.We used the Tree Cover Density (TCD) dataset (Copernicus Land Monitoring Service) and a nationwide digital elevation model to define the polylines representing the forestlines for the reference year 2018. We used the main Italian mountain peaks, extracted from the Global Mountain Biodiversity Assessment (GMBA) dataset polygons, as reference points to detect only the upper forest ecotones based on the elevation difference between peaks and forest pixels. We defined our study areas by applying a positive and negative buffer around the forestlines and we calculated several spectral vegetation indices (e.g. NDVI, EVI, Tasseled Cap Angle) from Landsat timeseries of the last 40 years. In this way, we inferred inter-annual vegetation dynamics, discriminating two sub-areas of interest: the closed forest (below the current forestline) and the upper treeline ecotone (above the current forestline). It should be noted that on the Alps, treelines mainly host conifer species, whereas on the Apennines, broadleaf species (mostly European beach) prevail. We tested the significance of long-term spectral trends through a Mann-Kendall test for monotonicity that accounted for autocorrelation in space and time.An important outcome of the study was to set up a replicable and unsupervised method to enhance the study of vegetation dynamics at treeline ecotones. This approach will allow the delimitation of the forestlines on a global scale and an ecologically sound comparison between different treeline ecotones. This study is the first step in a nationwide project and will provide the basis for future local-scale investigations of treeline ecotones.
Conference of the Parties or Conference of the People? Introducing a series of alternative grassroots COPs
Authors: Kuppel Sylvain ,   Scientifiques en rebellion collective
Published: March 2024

The Conferences of the Parties (COP) annually assess progress in dealing with climate change and towards legally-binding obligations to reduce or limit greenhouse gas emissions. Despite almost three decades of COPs and landmark treaties such as the Kyoto protocol (1997) and the Paris agreement (2015), global greenhouse gas emissions are a far cry from the emission pathways limiting global warming below 1.5-2°C as defined by the scientific consensus synthesized by the Intergovernmental Panel on Climate Change (IPCC). The failure at igniting state-level actions for climate mitigation stems from many factors, including a politico-economic hegemony, vested interests and techno-economic mindsets (Stoddard et al., 2021), well-embodied in the meager, voluntarism-based outcomes of increasingly questioned COPs. It may make sense that leading scientists still go to COPs to carry the voice of scientific consensus and convey the need for rapid action. However, scientists may also consider taking part in transformative changes through bottom-up initiatives where the conversation between scientists, collectives, citizens and media is more easily insulated from intense lobbying and greenwashing, allowing to focus on fact-based and ethics-driven endeavors, while showcasing unbridled perspectives for policymakers. Here we report the example of alternative COPs that took place in France in parallel to the COP28 in Dubai, organized by the Scientifiques en rebellion collective during the international Scientist Rebellion campaign “How much more climate failure can we take?”. Articulating a series of short events across French cities culminating with a 4-day alterCOP in Bordeaux, this grassroots initiative by scientists and activists was an invitation to take time to germinate new imaginations and popular initiatives, in a certain way “slowing down” to catalyze action considering the broader picture. Topics covered by this alterCOP took a systemic approach, beyond the climate breakdown, to include the other intertwined planetary boundaries (ecosystem health, water cycle, land use, etc.), discussing other economic systems (e.g. degrowth), international solidarity, and stimulating various world representations (present or desirable) and communication media, from artistic performances to a mock trial of a fossil fuel company.ReferencesStoddard, I, et al. (2021). Three decades of climate mitigation: why haven't we bent the global emissions curve?. Annual Review of Environment and Resources 46, 653-689.
Shallow Crustal Structures of Mars Beneath the InSight Landing Site Revealed by Frequency-Dependent P-wave Particle Motions
Authors: Wang Xu , Chen Ling , Wang Xin
Published: March 2024

Exploring the shallow crustal structure of Mars can offer valuable insights into the planet’s geological evolution and climate history. The ambient wavefield data and marsquake records from NASA’s InSight mission have enabled the characterization of both fine-scale near-surface structures (less than 200 meters) and large-scale crustal structures (greater than a few kilometers) on Mars. However, the exploration of intermediate-scale structures has remained limited. In this study, we introduce a novel varying-parameter approach that integrates principal component analysis with receiver function techniques. This method allows for the effective extraction of P-wave particle motions across various frequencies from the InSight low-frequency marsquake data, facilitating the inversion for the S-wave velocity structure within the topfew kilometers beneath the lander. Our resulting models reveal a distinct discontinuity at a depth of approximately 0.7 km, marked by a sharp increase in S-wave velocity from about 1.4 km/s to roughly 1.9 km/s. This discontinuity is characterized by a sharp transition, approximately 0.1 km thick, rather than a wider gradient zone. Our models are generally consistent with existing data on Mars’ near-surface and large-scale crustal structures, effectively bridging these datasets. When combined with previous geological and seismic observations, the newly identified discontinuity may signify the top of less affected basaltic bedrock, and the overlying structures are interpreted as a composite of Noachian- to early Hesperian-aged sediments and Hesperian to Amazonian basalts. These insights provide new perspectives on the stratification at the InSight landing area, enhancing our understanding of Martian geological history.
Establishing glacier proximal meteorological and glacier ablation stations in different climatic zones along the South American Andes.
Authors: King Owen , Matthews Tom , Andrade Marcos , Garcia Juan-Luis , Bravo Claudio , Buytaert Wouter , Calle Juan Marcos , Dussaillant Alejandro , Edwards Tamsin , Irarrazaval Iñigo , Perry Baker , Potter Emily , Ticona Laura , Davies Bethan , Ely Jeremy
Published: March 2024

Climate change has had a significant impact on the behaviour of the high mountain cryosphere, with widespread glacier retreat and mass loss now occurring in most of the planet’s glacierised mountain ranges over multi-decadal timescales. If we are to accurately understand the impacts of deglaciation on freshwater availability to communities downstream, robust modelling of future glacier meltwater yield is paramount. Meteorological observations at glacierised elevations are essential to drive simulations of the energy balance at glacier surfaces, and therefore glacier melt, although such records are sparse in most high mountain regions due to the logistical challenges associated with making even short-term measurements. The scarcity of high-altitude meteorological observations has resulted in only limited understanding of factors such as the spatial and temporal variability of temperature lapse rates, precipitation amounts and phase, and the prevalence of conditions suited to sublimation, all of which have an important influence on glacier mass loss rates at high elevation.Here we summarise the installation of meteorological and glacier ablation stations in different climatic zones of the South American Andes - the Tropical Andes of Peru (Nevado Ausangate basecamp, 4800 m, (13°48'45.96"S, 71°12'53.18"W) and Bolivia (Laguna Glaciar, 5300 m, 15°50'10.59"S, 68°33'11.30"W), the Subtropical Andes (Glaciar Universidad, Chile, 2540 m, 34°43'10.07"S, 70°20'44.98"W) and Patagonian Andes (Lago Tranquillo, Chile, 280 m, 46°35'47.00"S, 72°47'38.91"W) – as part of the NERC-funded Deplete and Retreat Project. Meteorological station records include time series of air temperature and pressure, relative humidity, wind speed and direction, incoming and outgoing short- and longwave radiation, precipitation amount and phase. Coincident glacier ablation is monitored at each site using ‘Smart Stakes’, recording surface elevation change on-glacier. We describe station situation, installation and preliminary measurements, along with aims and objectives of analyses using the meteorological time series.
The effects of a severe storm on forests from the remote-sensing point of view
Authors: Kern Anikó , Marjanović Hrvoje , Birinyi Edina
Published: March 2024

On the 19th of July 2023, a severe thunderstorm passed over Croatia, causing remarkable wind damage in the forests along a ~300 km long track of the storm from the country’s western border, at first hitting Mount Medvednica and nearby capital Zagreb, passing along the Sava river lowlands, all the way to Croatia’s eastern border. One of the most affected and largest contiguous areas struck by the storm was the Spačva pedunculate oak forest in the eastern part of Croatia. However, many smaller areas were heavily affected across the country, too. Surveying the affected areas in the field might be a longer process, due to the need for cleaning after the considerable amount of debris and remaining dead wood which obstruct passage. Our aim was to support this survey of the damage by remote sensing measurements. Due to the fact, that the affected area is large, with a country-scale, the uniform detection and assessment of the damage can be made basically only with space-borne remote sensing. While the spatially explicit detection requires datasets with fine spatial resolution, the statistical methods rely on longer time series. In our study, to fulfil this need, we used the Harmonized Landsat Sentinel (HLS) v2.0 dataset with 30-meter spatial resolution to detect the damaged areas and with that the exact track of the storm along a 300 km long path and assess the magnitude of the caused damage. The main advantage of this dataset is its fine temporal resolution, which facilitated accurate temporal detection of the forests with damage related changes in their phenology. The damaged areas were identified based on the drop of vegetation indices (NDVI and EVI) after the storm, while to the damage assessment we used data for the whole joint Landsat & Sentinel era (2016‒2023) as well. As validation, the daily data of the commercial Planet satellites with 3-meter resolution were utilized. Beyond the remote sensing data, forestry data was also used as information on the species, age, wood volume stocks, and management operations (thinning or harvesting). Our results showed that the free HLS dataset is quite appropriate for the detection of storm damage in a wider area, but in the assessment of the damage the data from the existing forestry management plans and/or surveys are highly beneficial. Also, the detected areas are under the effects of several other factors as well, such the spreading invasive oak lace bug, making the detection more challenging.Funding: The research has been supported by the Hungarian Scientific Research Fund (OTKA FK-146600), by the Croatian Science Foundation project MODFLUX (HRZZ IP-2019-04-6325), and by the TKP2021-NVA-29 project of the Hungarian National Research, Development and Innovation Fund. Project no. 993788 has been implemented with the support provided by the Ministry of Culture and Innovation of Hungary from the National Research, Development and Innovation Fund, financed under the KDP-2020 funding scheme.
Combined use of evolutionary algorithms and hydrological models to simulate snow cover and flow in alpine basins
Authors: Hidalgo Hidalgo Jose David , Collados Lara Antonio Juan , Pulido Velazquez David , Pardo Iguzquiza Eulogio , Gomez Gomez Juan de Dios , Rueda Valdivia Francisco Jose
Published: March 2024

Snow cover area, which can be obtained from satellite, is a valuable information to simulate streamflow in snow-dominated mountain basins where snowmelt is a major runoff factor. However, usually satellite do not provide long completed snow cover area spatiotemporal series, which are required to calibrate and validate hydrological models. It is due to difference limitations, as presence of clouds, sensor failure, low revisit time or spatial resolution, or recent launch.Cellular automata models, which use precipitation and temperature as driving variables and some transition rules between cells through calibrated parameters, are capable of capturing the dynamics of snow cover area. Therefore, they can be used to complete and extend the information provided by satellite.In this work, we simulate long series of daily streamflow in the Canales basin (Sierra Nevada, south Spain) by combining a cellular automata model and the Snowmelt Runoff Model. The Snowmelt Runoff Model is a degree-day model that requires data of temperature, precipitation, and snow cover area and has been widely used in simulation of streamflow in snow-dominated mountainous basins around the world.The water resources in the Canales basin are regulated by a reservoir, which contributes to supply the Granada city water demand. The main resources stored in reservoir come from Sierra Nevada Mountains during the melting season. Therefore, the dynamics of snow is essential to simulate streamflow in the Canales basin.It has been also used to simulate future local climate scenarios generated for specific level of warming in peninsular Spain.Aknowledments: This research has been partially supported by the projects: STAGES-IPCC (TED2021-130744B-C21), SIGLO-PRO project (PID2021-128021OB-I00), SIERRA-CC project (PID2022-137623OA-I00) from the Spanish Ministry of Science, Innovation and Universities, and SER-PM (2908/22) from the National Park Research Program.
Paleoproductivity and surface water dynamics evolution during the MIS 31 in the Shackleton Site as revealed Coccolithophores
Authors: Flores Jose-Abel , Balestra Barbara , Clark William , Jiménez-Espejo Francisco José , Kuroda Junichiro , Salgueiro Emilia , Grimalt Joan , Herbert Timothy , Bárcena Maria Angeles , Abrantes Fatima , Hodell David , Alvarez Zarikian Carlos , 397 Scientific Party Expedition
Published: March 2024

Marine Isotope 31 Stage (MIS-31) records one of the highest high-latitude precession-paced insolation values of the last 5 million years (Laskar et al., 2004). According to this configuration, some studies (e.g. Raymo et al., 2006) predicts a +20 m eustatic sea-level rise for this time interval, reflecting significant retreat of some combination of the West Antarctic Ice Sheet, marginal East Antarctic ice, and the Greenland Ice Sheet, and consequently significant variations in the ocean and climate dynamics at global scale.In this study we show data of variability in the coccolithophore assemblage from IODP Site 1385 (Shackleton Site, IODP 339 and IODP 397) in the interval ca. 1 Ma (close to the Jaramillo event). These sediments are sensitive recorders of North Atlantic Deep Water (NADW) and Antarctic Bottom Water (AABW) oscillations, which makes this site a significant location to test the interhemispheric connection hypotheses.Peaks in abundance of Gephyrocapsa (