bluuebunny/crossref_metadata_2025 huggingface dataset:
Ocean Acidification: Weaves to be tied on European and global scale
Authors: Kubin Elisabeth , Lipizer Marina , Molina Jack Maria Eugenia , French Megan Anne , Giorgetti Alessandra
Published: March 2024

Oceanic uptake of anthropogenic CO2 is altering the seawater chemistry of the oceans, leading to a decrease in pH and thus to ocean acidification (OA). This has multiple consequences not only for marine biogeochemistry, but also for marine biota and ecosystems. Therefore, the Sustainable Development Goal SDG Target 14.3 addresses OA and the SDG 14.3.1 calls for the average marine acidity (pH) and on guidance on monitoring and reporting OA data.Here we want to present the international collaboration between the European Marine Observation and Data Network (EMODnet Chemistry), NOAA and UNESCO on how to observe and report OA data, following the FAIR (Findable, Accessible, Interoperable and Reusable) principles. The final aim is to enable global comparisons of the changes in ocean chemistry and to provide a unified, globally coordinated, sustained, long-term observation network and database. Detailed vocabularies and the according metadata will guarantee the correct description of the carbonate system and thus also the long term usability of the data, including reliable trend calculations.This global collaboration will provide more accurate and detailed OA data and will help policy and decision makers to communicate more clearly and precisely about the impacts of climate change on marine ecosystems and resources, enabling holistic approaches.
The tectonic evolution of the western North American margin since the Devonian
Authors: Rodriguez Corcho Andres Felipe , Zahirovic Sabin , Anthony Michele , Tarkyth Dene , Alfonso Christopher , Seton Maria , Muller Dietmar , Eglington Bruce , Tikoff Basil
Published: March 2024

The western North American margin records multiple phases of rifting and convergence, resulting from the interaction between western Laurentia, rifted continental fragments, and intra-oceanic terranes originating in the Panthalassa and Pacific oceanic plates. Quantitative plate reconstructions of this margin have prioritised diverging interpretations regarding the subduction polarities of eastern Panthalassa terranes during Jurassic to Cretaceous times. These discrepancies arise from the reliance on either seismic tomography or surface geology as the first-order constraint for determining subduction polarity. We present an updated tectonic reconstruction for western North America from the Devonian to present day. In this new model, we reconcile geological histories based on surface geology, geochronology, paleomagnetism and isotopic data, with interpretations of seismic tomography. The new reconstructions account for the tectonic evolution of the Alaska orocline, western Canada and western United States (US) and south-western (SW) North America, which have not been implemented in detail in previous tectonic models. Our model suggests that most of the terranes of western North America were rifted off Laurentia and Baltica during Devonian to Triassic extension and trench-retreat. Following back-arc rifting and opening, many of the terranes (e.g. Insular, Intermontane, Angayucham) experienced an intra-oceanic phase before accreting to the continental margin of North America at different times, between Early Triassic to Late Cretaceous times. The model illustrates the collision of the Angayucham Terrane, counterclockwise rotation and orocline formation in Alaska during the middle Jurassic. In western US and SW North America, the model showcases Jurassic to Cretaceous extension and rifting. Extension starts first in western US (170-145 Ma) and is then propagated south, causing the opening of the Bisbee Basin (161-105 Ma). The model also captures the Late Cretaceous collision of the Insular Terrane, which triggered transpression, terrane translation for thousands of kilometers and clockwise rotation in western US during Late Cretaceous to Paleogene times. Our updated model highlights the importance of surface geology in constraining the polarity of ancient subduction zones interpreted from seismic tomography.
New insights on the meteoric recharge at the Le Biancane area (Larderello geothermal system) from fluid geochemistry
Authors: Dallara Evelina , Lelli Matteo , Fulignati Paolo , Gioncada Anna
Published: March 2024

Geothermal energy represents an important aspect of the ongoing green transition; therefore, geothermal reservoirs have to be properly investigated and studied in many and different aspects. In this frame, the Larderello geothermal field represents an important energy resource for the Tuscan region, and the first geothermal reservoir to be used for energy production. It is a vapor-dominated reservoir producing superheated steam and characterized by areas where the permeable formations of the shallower reservoir outcrops, with thermal manifestations at the surface, such as fumaroles and steaming-ground. In particular, the Le Biancane area, one of the main outcropping zones, represents a potential recharge point where meteoric water can infiltrate through the carbonate-anhydrite formations of the Tuscan Nappe.Although the Larderello geothermal system has been studied since the beginning of the last century, a detailed and systematic investigation of the recharge in the infiltration potential areas is still missing. Indeed, only few chemical and isotopic data of meteoric waters and geothermal fluids in the Le Biancane area are available. These are not enough to give information on the main infiltration areas and origin of the geothermal fluids, considering also the re-injection of spent fluids that has been introduced since the ’70 in some of the wells. Therefore, with the aim to analyse in detail the recharge in the Le Biancane area, 11 fumaroles and 37 cold and thermal springs were sampled. In order to be able to well define the isotopic marker of this area, the investigated springs were selected on a wider area surrounding Le Biancane, on a regional scale. Two sampling campaigns have been carried out, one after the rainy season in May/June 2023 and one after the dry season in October 2023.From isotopic analyses on fumarole condensates, differences in δD and δ18O were evident highlighting the possibility that these fluids undergo different processes before reaching the surface. Furthermore, fumaroles were analysed, among the many components, also for COS, which represents a new potential geo-indicator. On the other hand, regarding the water recharge investigation, in this work we will present the results of the isotopic hydrological approach on the spring samples.  
Quantification Of Mercury (Hg) In Riparian Trees Along The Paglia River, Monte Amiata Hg Mining District (Italy): Implications For A Sustainable Environmental Management And Risks
Authors: Morelli Guia , Ciani Francesco , Costagliola Pilar , Fagotti Cesare , Lattanzi Pierfranco , Monnanni Alessio , Nannoni Alessia , Rimondi Valentina
Published: March 2024

Riparian vegetation plays an important role in fluvial ecosystems. River drainage in abandoned mine sites is often source of heavy metals through transport of contaminated sediments. In those areas riparian vegetation may take up contaminants from riverbanks soil, acting as a temporary storage of metals. In this study, the potential mercury (Hg) in plants growing on soil anomalous in Hg was quantified to evaluate its storage effectiveness, and the potential as a secondary Hg source to the atmosphere in case of fire, or upon anthropic utilization as biomass.Riparian trees along a section of the Paglia River (Tuscany, Italy), draining the abandoned Monte Amiata Hg mining district, the 3rd Hg producer worldwide in the past, were sampled from the riverbanks. The riparian vegetation is occasionally cut during bank maintenance, and the resulting wood may end up into wood chips for solid biofuel. Poplars (Populus spp.) are the most abundant species naturally widespread along the Paglia riverbanks, together with Robinia spp. and Quercus spp.. Cores of trunks (8/10 cm long, 0.5 cm diameter) from 50 trees were sampled from fives sites using a drill corer. At each site, a soil sample was collected. In soils, Hg ranged from 3.5 to 52.8 mg/kg, above the Italian limit for soil (1 mg/kg; D.Lgs.152/2006). Preliminary data in trees, show Hg ranges between 0.5 and 93 ug/kg. Anomalous Hg concentrations (195-353 ug/kg) in few samples are probably associated to soil particles trapped in the tree barks. Except for these values, Hg concentrations in trees are below the recommended Hg limit (100 ug/kg) for high quality solid biofuels (European EN ISO 17225, 2021), thus posing little to moderate impact on the value of the locally harvested wood chips and the potential health risk for Hg0 emissions. On the other hand, in case of wildfires, Hg stored in trees bole wood (about 0.6 kg estimated in the studied area) can be released from the burning trees and from the subjacent soil. Thus, vegetation represents a potential secondary source of Hg0 to the atmosphere. Results highlight the importance in similar contaminated areas of metals fate investigation in soil and plants to assess the actual risks to the surrounding environment (biota, human health, and animals) posed by Hg emissions in case of fire, or for example by biomass used for energy production. Remediation strategies in these areas should include a wise management of riparian vegetation as a tool for mitigation of Hg release in the environment.
Accelerating Geocomputing with Julia at Scale
Authors: Omlin Samuel , Räss Ludovic , Utkin Ivan
Published: March 2024

The ongoing digitalisation in geosciences, along with higher resolution data and more powerful computers, necessitates efficient workflows and tools for processing large amounts of data, modelling processes, and addressing new problems and challenges.The Julia language offers an great basis for this by combining the benefits of a high-level language, such as ease of use and interactivity, with the features of a low-level language, including speed, efficiency, scalability, and native GPU support.We will present recent efforts to accelerate geocomputing using Julia at scale. These efforts are supported by the PASC-funded GPU4GEO project, in collaboration with the Swiss National Supercomputing Centre. We will showcase the current HPC building blocks that we have developed, which enables geoscientists to write high-performance stencil codes that can scale from their laptops to the largest supercomputers. Additionally, we will demonstrate preliminary results on using automatic differentiation to perform inverse modelling. This allows us to efficiently constrain models with data.Additionally, we discuss how these recent developments, along with future ones, will accelerate geocomputing and enable the education of the next generation of geoscientists.
GNSS for geodynamics in Antarctica: Sensitivity to reference frame realizations
Authors: Heidrich-Meisner Karl , Buchta Eric , Scheinert Mirko
Published: March 2024

Determining time series of bedrock motion from global navigation satellite systems (GNSS) in Antarctica is one method to investigate geodynamical processes (e. g. glacial isostatic adjustment (GIA)). To achieve coordinate time series with the highest possible precision, a stable realization of the International Terrestrial Reference Frame (ITRF) is a crucial precondition. Regional networks of GNSS stations have the advantage of exhibiting small common mode errors and allowing to infer accurate velocity estimates. However, to achieve high consistency, it is necessary to base the analysis on a global network of International GNSS Service (IGS) stations, constraining them to their ITRF positions. Various approaches can be found in the literature on how the global solution is constrained to the ITRF and how the regional solution is transformed to the global solution. These approaches have different effects on the resulting time series and inferred parameters, e. g. absolute coordinates, linear trends, and noise properties. In this study, approximately 30 Antarctic GNSS stations are processed together with a global GNSS network of overall 200 IGS stations. We investigate different approaches to realize the ITRF and discuss the inferred results. To be consistent w. r. t. the general processing, we use a consistent set of GNSS observation data, GNSS products (e. g. orbit corrections), and apply the Bernese GNSS Software v5.4. In this way, the residuals between the different coordinate time series can be assumed to be due to the differences in reference frame realization. In our time series analysis, we put particular emphasis on linear trends because these are most important for GIA studies.
Making atmospheric measurements of difficult-to-separate isomers of CFCs routine: a case study of CFC-113 and CFC-113a that refines our understanding of recent atmospheric changes for both of these chemicals.
Authors: Montzka Stephen , Vimont Isaac , Hall Bradley , Clingan Scott
Published: March 2024

Ethane-based chlorofluorocarbons and hydrochlorofluorocarbons can have multiple isomers that are difficult to separate using gas chromatography with detection by electron capture (GC-ECD) or even mass spectrometry (GC-MS). Examples include CFC-113 and CFC-113a; CFC-114 and CFC-114a; CFC-112 and CFC-112a; and HCFC-124 and HCFC-124a.  As a result, atmospheric histories reported in the past by most laboratories for the more abundant isomer can represent an ill-defined combination of both chemicals.  This is especially true for CFC-113 over the past decade, as mole fractions of CFC-113a have increased rapidly during that time and the contribution of this isomer to our understanding of atmospheric changes measured ostensibly for CFC-113 has not been known. Being able to accurately and routinely determine atmospheric abundances for each of these isomers separately from one another is important as these isomers have different environmental impacts (ozone-depleting potentials and global warming potentials) and different sources likely contribute to their emissions.  Here we demonstrate a technique for quantifying the abundances of co-eluting isomers using GC-MS even when ions unique to the different isomers are unavailable.  Initial results for CFC-113 and 113a will be presented that allow a reassessment of the atmospheric decline and global emission rate of CFC-113 over the past decade, and they confirm the rapid increases in the atmospheric abundance of CFC-113a.  Co-variations between the measured CFC-113a atmospheric mole fractions and other gases are observed at particular sites (e.g., Mauna Loa, Hawaii) that help identify regions where CFC-113a emissions are currently substantial, contributing to its rapid global increase.
Passenger transport decarbonisation under different equity considerations
Authors: Van de Ven Dirk-Jan , Sampedro Jon
Published: March 2024

Climate change is often seen as an equity problem, as it is caused primarily by richer countries and households, while its impacts are generally expected to affect poorer countries and households significantly stronger. Climate policy aiming at mitigating these impacts, however, can also have a regressive impact on societies, unless it is designed such that the costs of mitigation are shared progressively depending on wealth differences. At the same time, historical energy transitions have often been driven by wealthy consumers demanding higher quality goods and services, which consequently grew from niche to mainstream technologies. Particularly the transportation sector is a sector difficult to decarbonise, while there are significant differences in contribution between poorer and wealthier users. This study uses a global integrated assessment model (GCAM) with 10 different income groups for each of the 32 regions to compare several decarbonisation scenarios for passenger transportation. On the one hand, implementing a general cap-and-trade policy for transport emissions, while traditionally seen as the economically optimal policy, affects poorer individuals significantly more in terms of access to transport services in a decarbonised world. On the other hand, implementing fixed caps for each country and income group, which cannot be traded with consumers at lower other income groups or countries, and are globally equal for each individual, leads to significantly higher costs for higher income individuals, but does not affect the access to transport services of poorer individuals as strongly. Also, this last alternative leads to a significantly faster take-up of modern clean technologies in transport.
The Zabargad Fracture Zone and Mabahiss Deep, Northern Red Sea: new insights from new high-resolution bathymetric mapping
Authors: Fittipaldi Margherita , Moulin Adrien , Trippanera Daniele , Augustin Nico , van der Zwan Froukje , Parisi Laura , Jonsson Sigurjon
Published: March 2024

The Red Sea axis hosts an oceanic ultra-slow spreading ridge which is generally arranged into right-stepping segments. The largest apparent ridge offset runs at the transition between the northern and central Red Sea, amounts to ~ 100 km along a N-S trend, and is referred as to the Zabargad Fracture Zone (ZFZ). The ZFZ separates ridge segments characterized by exposed oceanic crust (the Mabahiss “Deep” in the north and the central Red Sea further south), but its nature and precise geometry are debated owing to the extensive Miocene evaporites that cover the basement structures. The ZFZ is the location of the most intensive seismic activity in the northern Red Sea, with a reported historical magnitude 6.5 earthquake. Due to its proximity with coastal communities, the ZFZ thus potentially poses a significant hazard. In order to better characterize the seismic potential of the ZFZ, we collected new high-resolution bathymetric data of the Mabahiss Deep and ZFZ, and use them to map the tectonic structures over both exposed-basement and salt-covered areas.Our findings reveal typical slow spreading-ridge features in the Mabahiss area, such as an axial MORB volcano with a summit caldera located in the middle of a 9 x15 km axial valley bounded by up to ~300-m-high normal fault escarpments. In addition, our results highlight a highly deformed salt cover in the ZFZ area and several salt diapirs outcropping near its eastern edge. The orientation of salt-deformation fabrics records a clear rotation from rift-parallel to rift-normal in the vicinity of the ZFZ, suggesting a potential control by underlying basement structures. Overall, the deformed area indicates that the ZFZ is a 70 km long and 15 km wide fracture zone, oriented roughly N-S, and potentially consisting of several NE-SW rift-perpendicular faults. These new data provide the first step to characterize the geometry and seismic potential of the ZFZ and to constrain the segmentation of the ridge axis in the northern Red Sea, emphasizing the importance of continued research to improve our understanding of this complex region and its potential impact on coastal communities.
Integrating Morphological and Molecular Approaches for Assessing Soil Biodiversity in Agroecosystems
Authors: F. Dornellas Luísa , Mata Vanessa A. , Bartz Marie , Leitão Ricardo , Nascimento Eduardo , Mendes Sara , Costa Joana , Sousa José Paulo , Cunha Luís
Published: March 2024

The One Health paradigm, emphasizing the interdependence of human, animal, and environmental health, demands a comprehensive approach for ecosystem monitoring. This study underscores the vulnerability of Mediterranean ecosystems to desertification and climate change, emphasizing the critical role of soil biodiversity in agroecosystems. Interdisciplinary collaboration is imperative to mitigate these challenges and foster a resilient balance between human, animal, and environmental well-being in the region. In this context, monitoring soil biodiversity, an essential component in ecosystem functioning, remains relatively understudied compared to above-ground organisms, posing conservation and management challenges. Depending on the land management practices, agroecosystems can pose a significant impact on various aspects of the environment, including soil biodiversity, food security, and the provision of essential ecosystem services. Molecular methods (e.g. barcoding, metabarcoding) offer promising results in assessing soil biodiversity more efficiently. This study addresses the problem of thoroughly evaluating soil macrofauna diversity in agroecosystems with differing management intensities; morphotaxonomy and metabarcoding methods were used to explore their validation and integration. In this study, we morphologically identified 9418 individuals, representing 13 taxonomic groups; metabarcoding identified more than 800 OTUs (Operational taxonomic Units) , belonging to seven different classes. Significantly higher levels of biodiversity were recorded in the traditional agroecosystems, while improved pastures had the lowest. Moreover, metabarcoding results showed that all sites differ significantly from each other regarding OTU communities, with a separation into two clusters: one encompassing extensively managed agroforests and another with intensive, hyperintense, and improved pastures agroecosystems. This study underscores the importance of an integrative approach that combines morphotaxonomy and molecular methods to improve species identification accuracy, shedding light on the potential of molecular techniques such as metabarcoding to provide fast and precise species identification. However, further refinement of molecular methods is still required, and collaboration between researchers and taxonomists is essential. The data gathered here might help define efficient management practices according to the different land-use types, to promote a sustainable balance between biodiversity and productivity. By adopting an integrative and interdisciplinary approach, we can better understand and conserve soil biodiversity in agroecosystems, ultimately contributing to a more sustainable and secure world.
Spatial variability of Soil Organic Matter and Carbon content in the salt marshes of the Venice Lagoon
Authors: D'Alpaos Andrea , Puppin Alice , Tognin Davide , Ghinassi Massimiliano , Franceschinis Erica , Realdon Nicola , Marani Marco
Published: March 2024

Salt marshes are crucial eco-geomorphic features of tidal environments, providing numerous important ecological functions and delivering a wide range of ecosystem services that contribute to human well-being. Salt-marsh evolution is controlled by the interplay between hydrodynamics, geomorphology, and vegetation, as marshes accrete vertically through the deposition of both organic matter (OM) and inorganic sediments. This allows marshes to keep pace with relative sea-level rise, and likewise capture and store carbon (C), making them valuable allies in climate mitigation strategies. Thus, Soil Organic Matter (SOM) plays a key role within salt-marsh environments, directly contributing to soil formation and supporting C storage. Distribution patterns of SOM in salt marshes may vary in space and time across and within tidal wetland types depending on different factors including vegetation, sediment, and morphodynamics. To better understand variations in SOM distribution and further comprehend physical and biological factors driving OM and C dynamics in salt-marsh soils, we analyzed soil organic content in 10 salt marshes of the microtidal sediment-starved Venice Lagoon (Italy), from 60 sediment cores to the depth of 1 m. These analyses allowed us to relate SOM patterns to soil, vegetation, and morphological variables, as well as depositional patterns testified by recent sedimentary successions. Our results reveal two scales of variations in sedimentary OM content in salt-marsh soils. At the marsh scale, OM variability is influenced by the interplay between surface elevation and changes in sediment supply linked with the distance from tidal channels. At the system scale, OM content distribution is dominated by the gradient generated by marine and fluvial influence. Variations in inorganic and organic inputs, both autochthonous and allochthonous, sediment grain size, and preservation conditions may explain the observed variations in SOM. Our results highlight marsh importance as carbon sink environments, furthermore emphasizing that environmental conditions within a tidal system may generate strongly variable and site-specific carbon accumulation patterns, enhancing blue carbon assessment complexity.
Variations and causal interactions in the eco-hydrological system of Yellow River basin, China: A Network Perspective
Authors: Xu Yueping , Wang Lu , Gu Haiting , Liu Li
Published: March 2024

The Yellow River basin (YRB), as a crucial ecological corridor in the northern part of China, has experienced profound changes in multiple eco-hydrological processes. However, there is still lack of a global view on the variations and causal interactions in the complex hydro-ecological system of YRB. In this study, a set of eco-hydrological variables, regarding water resources (surface water, soil water, groundwater) and ecological environment (vegetation growth, productivity, water use efficiency) are used to represent the main characteristics of the eco-hydrological system in different sub-regions of YRB. The objective of this study is three-fold. Firstly, the individual variation of each eco-hydrological variable was unraveled using trend analysis. Secondly, network analysis was used to analyze the synergistic variations among variables. Finally, an advanced causal discovery tool incorporating prior knowledge was used to investigate the potential causal interactions in eco-hydrological system. The results indicate the decrease of terrestrial water storage anomalies (TWSA) in most parts of the YRB, which is mostly due to the substantial depletions in ground water. The vegetation growth and productivity have noticed prominent increasing trends in YRB, and such increase in the source region is largely due to the warmer climate condition and in the middle reaches is mainly because of the large-scale vegetation restoration. However, the ecosystem water use efficiency (WUE) is not very optimistic, especially in the source region. The causal discovery method captures the inhibitory effect of evapotranspiration on WUE in the upper and some parts of the middle reaches of YRB. Our study provides a new perspective to recognize the complicated eco-hydrological conditions and their variations in YRB during 2001-2019, as well as the potential mechanisms driving these variations. 
Modelling Stellar Energetic Particles effects on the atmospheres of terrestrial (exo)planets: INCREASE
Authors: Grenfell Lee , Iro Nicolas , Sinnhuber Miriam , herbst Konstantin , Bartenschlager Andreas , Scherer Klaus , Taysum Benjamin
Published: March 2024

We present numerical studies of star/planet interactions, specifically the effects of Stellar Energetic Particles (SEPs) on the atmospheres of terrestrial (exo)planets. This work was performed as part of the INCREASE project (INfluence of strong stellar particle Events and galactic Cosmic Rays on Exoplanetary AtmoSpherEs) funded by the German Research Council (DFG). We have developed and applied a new Model Suite which couples magnetospheric and atmospheric propagation and interaction models PLANETOCOSMICS (Desorgher et al. 2006) and AtRIS (Banjac et al. 2019) with the atmospheric chemistry and climate models 1D-TERRA (e.g., Wunderlich et al. 2020) and ExoTIC (Sinnhuber et al., 2012). We are able to assess the influence of the stellar activity on the planetary atmospheric structure, its chemical composition, and infer spectroscopic observables as well as the effects on biosignatures.
Latest advances and reflections on 10 years of open-source development and applications
Authors: Tomlinson James , Harou Julien
Published: March 2024

Pywr is an open-source water resource system simulation model. It was created almost 10 years ago. Since that time it has been widely adopted in the UK water resources planning community and also used by several researchers around the world. The original design goals were to create a fast, free and extendable library that could handle running large datasets on complex real-world problems. Pywr’s speed has made it popular with researchers and practitioners simulating large water systems under uncertainty (where many future scenarios must be considered).Here we present an extension, a new simulation approach that exploits modern CPU hardware and instructions. The new method simulates multiple scenarios in parallel using “single instruction, multiple data” (SIMD) techniques. We apply SIMD to a simple interior point method that is capable of solving multiple similar linear programs in parallel. We compare our method against a conventional non-SIMD linear program solver (CLP) and demonstrate that it can provide significant speed-ups for some water resource simulations. We benchmark this method using a GPU using 100s of thousands of scenarios. Our results demonstrate that by exploiting modern CPU features it is possible to achieve further speed-ups for water resource simulations. More efficient (faster) simulation allow practitioners to explore more scenarios, find more robust solutions and/or use more complex models. Some existing and on-going applications will be briefly introduced.Finally, we reflect on the adoption and evolution of Pywr over the last 10 years, and look at its current usage in UK water resources planning. We explain how the advances above will help planners and developers alike, hopefully setting the foundation of Pywr for the next 10 years. 
Numerical Study on the Circulation in the Gulf of Thailand and Its Seasonal Water Exchange with the South China Sea
Authors: Xia Changshui , wu Youting , Qiao Fangli , Sangmanee Chalermrat
Published: March 2024

      Gulf of Thailand is a semi-closed shallow water basin connected to the South China Sea. The seasonal Circulation patterns in the Gulf of Thailand and its water exchange with the South China Sea are studied using the CROCO model from 2017 to 2020. The simulated temperature, salinity, Sea surface height and current field agree with the observation well.  Based on the model result, the upper flow velocity of the horizontal flow field in the Gulf of Thailand a is greater than the lower flow velocity, which means that the Ekman flow driven by the monsoon dominates the upper flow field. Winter and summer are the strongest periods of the monsoon in the sea area, as well as the strongest periods of water exchange between the Gulf of Thailand and the South China Sea. In winter, the upper layer of South China Sea water flows into the Gulf of Thailand, causing an increase in SSH, causing the middle layer of seawater to sink and flow out from the bottom; In summer, the upper layer of Gulf of Thailand water flows out, SSH decreases, the middle layer of seawater surges up to supplement the surface deficiency, and the bottom layer of South China Sea water flows in to compensate.  Keywords: Gulf of Thailand, Circulation patterns, Gulf of Thailand, South China Sea
In-depth analysis of extreme event of rainfall erosivity over mainland China
Authors: Chen Liutong , Xiao Yuanyuan , Yin Shuiqing , Wang Wenting , Strohmeier Stefan , Vásquez Cristina , Klik Andreas , Strauß Peter
Published: March 2024

The majority of soil loss was triggered by several extreme rainfall events. Global warming may lead to an intensification of the surface water cycle and an increase in the probability and intensity of extreme rainfall events. An in-depth analysis of extreme event rainfall erosivity is valuable to help decision-makers take targeted measures to deal with future risks to soil and water resources protection. Cumulative rainfall erosivity from extreme events and characteristics of the 20- largest extreme events were analyzed based on the hourly rainfall data of 2420 meteorological stations over mainland China from 1951 to 2020. We sorted events at each site in descending order and calculated the percentage of events with accumulated erosivity (rainfall) accounting for 80% of total erosivity (rainfall) to all events (D80). Analysis on D80 shows 57% and 27% of extreme events of total events contribute 80% of rainfall and rainfall erosivity averaged over China, respectively, which indicates the impact of extreme erosivity is more predominant than that of extreme rainfall. The northern rock soil region (NR) and southwestern rock mountain region (SWR) were two regions with the least D80 among the six water erosion regions, which indicated fewer extreme events contributed to 80% of rainfall or rainfall erosivity compared with the other regions. D50 varies from 3% to 25% with a mean of 8% averaged over mainland China, which is more extreme than Europe (from 1% to 24 with a mean of 11%). TOP20_erosivity for extreme events with a descending order of event erosivity accumulates 29% of total erosivity, which is compared with 12% of TOP20_erosive for extreme events with a descending order of event rainfall. The average amount, duration and peak hourly intensity for TOP20_erosivity extreme events in summer are 14.6 mm,2.8 h, and 5.0 mm/h, respectively, while those for TOP20_rainfall are 16.5 mm, 4.4 h, and 3.4 mm/h, respectively, which indicate extreme erosive events are with a larger amount, shorter duration and greater peak intensity, comparing with extreme rainfall events. We further compared the synchronicity of the month with the maximum occurring frequency of extreme erosivity events and extreme rainfall events and found there are 33% of stations with not the same month. There were 19% of stations with the maximum month for erosive events preceding that for rainfall events and 14% of stations with the maximum month for erosive events lag behind rainfall events. 
Insight in high alpine soil carbon dynamics from compound-specific and soil fraction radiocarbon analysis on a glacier forefield chronosequence 
Authors: Smittenberg Rienk , Schwab Valerie , Sanden Hans , Christl Iso , Hagedorn Frank , Hajdas Irka , Wacker Lukas , Haghipour Negar , Trumbore Susan , Xu Xiaomei , Bernasconi Stefano
Published: March 2024

The ecosystem carbon balance of high latitude and high altitude ecosystems is particularly sensitive to climate change, where increasing temperatures generally lead to a rise of the ecosystem carbon storage, but also increasing carbon turnover times. In this study, we investigated the carbon dynamics of the 150-year long Damma Glacier forefield chronosequence, Switzerland. Specifically, we performed radiocarbon analysis of a range of organic matter fractions, sampled in 2007, 2017 and 2022 from soils developing on areas having been exposed for 20-150 years due to the retreat of the glacier. To characterize the age spectrum of material making up the bulk soil carbon, we isolated a range of different fractions, from supposedly 'stable' carbon pools (fine mineral-bound, and peroxide-resistant carbon), microbially ‘labile’ respired CO2, dissolved soil organic carbon (DOC), hydrophobic leaf wax-derived alkanes, and microbial-derived fatty acids. Comparison of our results with the penetration of the radiocarbon bomb spike and the increase of soil and ecosystem carbon over the both the chronosequence (space-for-time) and over the sampling period (time-for-time) allowed us to make the following inferences: (i) A small but persistent contribution of ancient carbon is present in the forefield area exposed by the glacier, which is particularly visible in the hydrophobic leaf wax 14C data. From this we conclude that this old carbon pool is at least in part a remnant of ancient soil carbon from a previous warm and glacier-free period, potentially adding to contributions of fossil-fuel derived black carbon deposition. (ii) There is a significant portion of soil carbon with a decadal-scale carbon turnover rate, and (iii) mineral-bound carbon clearly has a slower turnover time. (iv) Microbial lipids, soil CO2 and DOC 14C content reflect different carbon sources: in younger soils, relatively low 14C contents indicate a higher relative contribution of ancient carbon decomposition, while in older soils this signal is swamped by decomposition of freshly photosynthesized organic matter.
A Satellite-derived Peatland Ecotype Classification Method Using Artificial Neural Network Hierarchical Ensembles
Authors: Grappiolo Corrado , Gurusiddappa Veeresh , Regan Shane , Boydell Oisín , Holohan Eoghan
Published: March 2024

Being able to identify, map and monitor areas of different ecological quality of peatland habitats, or ecotypes, provides important information on spatial peatland condition, the potential for restoration of degraded areas and ecotype carbon (C) emission and/or sequestration capacity when coupled with known C-flux factors. Regular and accurate mapping of such ecotypes is also a requirement under the European Union (EU) Habitats Directive, and will be required in some form to help guide the framework and implementation of the upcoming EU Nature Restoration Law.Although the most precise way to identify the presence of certain ecotypes is via in-situ surveying, this approach clearly suffers from scaling issues, as it is only feasible in small selected peatlands (or even portions of them) and requires a lot of resources, e.g. skilled domain experts and time. A solution might come from remote sensing and Earth Observation technologies, which have been increasingly utilised to map the occurrence and extent of peatland environments in recent years. With this respect, the European Space Agency's Copernicus Program's Sentinel-2 satellite constellation could be a viable data source, as it allows for a multi-spectral, systematic and regular coverage of land surfaces with a spatial resolution up to 10 square metres and 5 days of revisit frequency. Nevertheless, the remote detection and mapping of ecotypes within the peatland complex itself is relatively under-studied and there is no currently accepted method that can be deployed at landscape scale. In this work we present a rather simple machine learning pipeline for ecotype detection at scale. The focus of this study are lowland peatlands, or raised bogs, in the Republic of Ireland. The pipeline assumes the existence of ground truth ecotype data (for machine learning training purposes), raised bogs map boundaries (shapefiles) and Sentinel-2 imagery. Both training, testing and validation datasets undergo the same pre-processing procedure. In the training step we train an ensemble of binary classifiers - specifically one multilayer perceptron network per ecotype - organised in a hierarchical fashion, to reduce the complexity of the problem. The ecotype classification would be done in a cascade - in accordance with the hierarchy - via canonical ensemble learning classification. The preliminary results gathered not only seems to indicate that our approach could provide reliable estimations about raised bog ecotype composition at scale, they also highlight the potential need for seasonal ensembles. Furthermore, we will present the results of a crowdsourcing experiment, in which domain experts were: (1) presented with ecotype map images, resulting from the inference of a plethora of ensemble classifiers of different settings and hyperparameters, and (2) asked to cast a vote on which image most closely resembled the related ground truth image.
Spatiotemporal trends in microplastic pollution of surface waters of the Eurasian Arctic
Authors: Pakhomova Svetlana , Zhdanov Igor , Berezina Anfisa , Polivanova Tatiana , Yakushev Evgeny
Published: March 2024

The present study addresses spatial and temporal distribution of floating microplastics (MPs) in the Eurasian part of the Arctic Ocean. In this study we used a harmonized methods from sample collection to data reporting according to the latest recommendations of AMAP for MPs research. Studies were carried out in 6 cruises: in August-October 2019, 2020, 2021 and 2022 onboard R/V Akademik Mstislav Keldysh and R/V Akademik Ioffe. A total of 200 surface water samples were collected in the Barents, Kara, Laptev, and East-Siberian seas, comprising by far the most extensive dataset on floating microplastics in the Eurasian Arctic. Floating debris were sampled using a Neuston net with mesh size 0.33 mm, each catch lasted an average 20 minutes. All potential plastic particles were identified on ATR -FTIR (Spectrum Two, Perkin Elmer).It was revealed that MPs pollution significantly decreases from the West to East in the Eurasian Arctic, from 19.0 µg/m3 in the Barents Sea to 11.2 µg/m3 in the Kara Sea, 3.6 µg/m3 in the Laptev Sea and 2.0 µg/m3 in the East-Siberian Sea. Less MPs were found in the Great Siberian River plumes than in high saline water. The maximum concentration of MPs was found in the Kara Gates Straight (640 µg/m3) in August in the waters flowing from the Barents Sea. This can indicate that the main source of MPs in the Siberian Arctic is located in the Barents Sea.Variability of MPs abundance was found in the Kara Sea for different years, 1000 – 5000 items/km2 on average without a clear trend. Possible influence of several factors effecting MPs fate here was discussed, i.e. interannual changes in riverine discharge, shipping activity, Atlantic water inflow, ice cover. 
Multi-seasonal land cover changes of South Peruvian Highland Andean ecosystems
Authors: Castro Joshua , Fyffe Catriona L. , Varghese Vinisha , Miles Evan , Hoelzle Martin , Pellicciotti Francesca
Published: March 2024

The highland ecosystems in the southern Peruvian Andes represent an important resource for people who depend on them for water regulation, agriculture, and energy generation. These ecosystems change over time due to natural causes, climate variations, or anthropic intervention. Remote sensing studies have quantified land cover changes in this domain annually, but have neglected the seasonal ecosystem variations, which are conditioned by seasonal weather patterns, species phenology, or applied management. One high-elevation headwater in this region, the Vilcanota-Urubamba Basin (VUB) in Cusco-Peru is characterized by glaciers surrounded by barren areas, flooded areas such as lakes and wetlands, and vegetation ranging from sparse grasslands to forests in the northwest of the catchment.In this study, we used a land cover classification model at a multi-seasonal scale over 10 years to observe the seasonal dynamics and links between the land cover classes in VUB. We applied the Random Forest classification model on Landsat 7 and 8 imagery (30 m/pixel), trained with selecting 10 points for seven land cover classes, to discriminate land cover every 3 months from 2013 to 2022 over an extended area of the VUB system. We ran the model in the Google Earth Engine platform, using as inputs six spectral indices and three topographic indices obtained from an SRTM DEM.Our overall results indicate that the VUB area (11,047 km2) is mainly occupied by Agriculture and Pasture (~52.5%) distributed in the upper-middle areas above 3000 masl, followed by Barren (~18.9%). Shrub (~8.4%) and Forest (~8.25%) areas which are more concentrated in the northwest region, and Wetland (~3.94%), Water (~2%), and Snow and Ice (~1.88%) areas, which are mostly located in the Southeast region. We apply two general accuracy assessments based on a set of collected validation points (0.74) and random points (0.72). The results show limited availability of high-quality images during January to March of almost every year, related to the high cloudiness, but much better image availability in the other months.We find strong seasonal variations in the Snow/Ice, Water, and Wetland classes related to the precipitation regime of the region; but Barren, Shrub, and Forest areas do not vary much seasonally. We determined the correlation between land cover classes for each season and considering all seasons together to identify relevant interrelationships between classes. We find that Snow/Ice changes are correlated (p
Risk of the Underwater Cultural Heritage in the Bay of Cadiz due to Waves: Impact of Climate Change
Authors: Ferrero Martín Carmen , Izquierdo Alfredo , Fernández Montablanc Tomás
Published: March 2024

The  underwater cultural heritage (UCH) is constantly subjected to the impact of marine agents capable of degrading its materials. Among these factors, waves stand out as one of the main elements affecting the preservation and evolution of UCH in shallow-water areas. Despite the relevance and high density of cultural heritage in littoral areas, there is a lack of comprehensive assessment of the long term evolution of risks induced by waves. This becomes particularly relevant because the frequency and intensity of coastal storm and waves could be altered by climate change. Therefore, this study aims to assess the impact of climate change in UCH preservation produced by modifications in the  wave conditions in the Bay of Cadiz. The three most influential hazards in the shallow UCH sites have been analyzed: decontextualization, scouring, and wear erosion. To achieve this, extreme wave conditions were analyzed for a historical period (1970-2005), a near future (2035-2060), and a distant future (2074-2099), considering the RCP 4.5 and RCP 8.5 scenarios, using five global wave models (ACCESS 1.0, CSIRO-Mk3.6.0, EC-EARTH, GFDL-ESM2G, and GFDL-ESM2M). The  choice to use five models aims to provide a more robust basis for decision-making and planning to preserve and conserve UCH. The global wave models output are calibrated using a wave buoy record and the Quantil-Mapping method.Subsequently, a hybrid downscaling methodology combining a numerical wave model with statistical tools is used to transfer wave climate from intermediate to shallow waters. In this process, the wave time series were reconstructed in each computational cell, taking into account the sea level rise for each period and for each model. This methodology was validated using SIMAR points located inside the Bay of Cadiz.  After obtaining the necessary variables for the characterization of wave climate and for calculating the risk, an ensemble is performed to reduce uncertainties in the projections. To assess and quantify the wave impact on UCH, a  the risk assessment is performed as a function of vulnerability (depending on archaeological materials, slope, and type of seabed) and the hazard generated by waves. This study reveals that, despite the general trend towards less intense waves in the North Atlantic, significant changes in risk indices and material degradation rates in UCH can occur. This is due, in part, to the increase in wave energy in shallow areas caused by the rise in sea level.   Although there are still significant uncertainties in extreme wave projections in coastal regions, these studies can facilitate   the identification of UCH sites at risk in the present and future conditions and the implementation of mitigation measures to protect UCH sites from the impact of climate change.