bluuebunny/crossref_metadata_2025 huggingface dataset:
Using stable water isotopes to trace cereal water use in agricultural co-cropping systems under contrasting hydro-climatological conditions
Authors: Durodola Oludare , Rothfuss Youri , Hawes Cathy , Smith Jo , Valentine Tracy , Geris Josie
Published: March 2024

Agricultural co-cropping, which is the cultivation of two or more crops simultaneously on the same field, is gaining rapid attention in temperate agroecosystems as a viable nature-based solution to improve agricultural productivity. However, relatively little is known about plant water use patterns in temperate agricultural co-cropping systems. Specifically, the functioning and resilience of these systems compared to their equivalent monocultures is likely to depend on whether water use is complementary for the different crops and how this might change during the growing season and under different hydro-climatological conditions.This study focused on addressing these knowledge gaps by using water stable isotopes to trace the sources of vegetation water uptake (shallow or deep soil water) in 5 different cereal-legume co-cropping systems and 4 of their respective cereal monocultures under field conditions in North-East Scotland. For each treatment, we extracted vegetation water, and soil water from 5 different depths for analysis of isotopic composition. We then performed MixSIAR end-member mixing modelling to explore proportional water uptake patterns for cereal vegetation throughout the growing season and under wet and dry conditions.The results showed that cereals in all the monocultures and co-cropping systems predominantly used shallow soil water (upper 5 cm), regardless of growth stage and hydro-climatological conditions. Cereal water uptake patterns in monocultures and co-cropping systems were comparable during wet hydrological conditions. However, the analyses revealed that cereals in co-cropping systems exhibited plasticity and increased their water uptake up from deeper soil water (5 – 30 cm) compared to cereals in monocultures during dry conditions. Furthermore, during dry conditions, we found different seasonal responses in the co-cropping systems between cereal genotypes traits. Understanding of plant water use patterns for different cropping systems could inform the design of resilient and sustainable water management practices and agricultural policies. The plasticity observed in co-cropping systems could potentially contribute to optimised water use under climate change.
Explicit representation of cities in the ORCHIDEE land surface model
Authors: Lalonde Morgane , Oudin Ludovic , Ducharne Agnès , Bastin Sophie , Arboleda-Obando Pedro
Published: March 2024

Cities alter the interactions between the surface and the atmosphere by modifying energy and water budgets. This is caused by the low albedo of urban environments, its high thermal conductivity, the increased surface roughness, and by greater surface imperviousness. Since the beginning of the 21st century, advances in high-performance computing allowed steady refinement of the numerical grids of climate models at the kilometer scale. At this resolution, representing the urban environment explicitly is necessary, as simplifying it to bare soil no longer suffices for accurate energy and water budget assessments and satisfies e.g. the representation of heat waves or urban runoff. In the ORCHIDEE model of the IPSL, cities are currently represented as bare soil, which fails to account for specific urban processes. To enhance ORCHIDEE's performance and study the impacts of specific urban processes on energy and water fluxes, an urban land cover was added to the existing land cover classes taken into account by the model. For this urban class, we prescribed specific parameters for soil imperviousness (though hydraulic conductivity), surface roughness, albedo, and thermal conductivity. All those parameters are cell-dependent, i.e. they account for the diversity of urban environments and cities as characterized by the WUDAPT database (Ching et al., 2018). By comparing model simulations with and without the urban module, we assess the sensitivity of simulated turbulent fluxes, infiltration, soil moisture, runoff, drainage, temperature, and compare them to available observations over France.
Hominin Technology Flourished amid Pliocene Environmental Variance in the Turkana Basin
Authors: Palcu Dan V. , Braun David R. , Advokaat Eldert , Archer Will S. , Bobe René , Carvalho Susana , Forrest Frances , Hammond Ashley S. , Kinyanjui Rahab , Martini Ana , Mason Paul , Patterson David B. , Sier Mark , Srivastava Priyeshu , Uno Kevin , Villaseñor Amelia , Wynn Jonathan , Jovane Luigi , Harris John W. K. ,   Koobi Fora Research & Training Program (KFRTP)
Published: March 2024

This study explores the emergence of Oldowan technology in the northeastern part of the Koobi Fora Formation, focusing on a poorly understood spatial and temporal context. It highlights the dynamic interplay between hominins, landscapes, and climate during the late Pliocene. The archaeological findings present a comprehensive analysis of stone artifacts from the FwJj52 locality that spans the terminal Pliocene- earliest Pleistocene. The technological patterns at the archeological site FwJj52 align with early Oldowan sites, emphasizing an astute understanding of raw material properties by hominins in the region.Chrono-stratigraphic investigations reveal that the FwJj52 represents a unique locality, corresponding to the Tulu-Bor and Burgi Members of the Koobi Fora Formation, the latter member containing a stratigraphic interval largely absent in the geologic record of East Turkana due to a widespread unconformity. Multi-proxy geochronology (paleomagnetism, tephrostratigraphy) establishes a robust late Pliocene age estimate for the artifact-bearing horizons from FwJj52. Paleoenvironmental proxies (e.g., phytoliths, microcharcoals, plant biomarkers, pedogenic carbonates, soil geochemistry) indicate the area around FwJj52 experienced significant environmental changes. This includes shifts from humid floodplains to semi-arid plains alternating with paleoriver systems, probably triggered by the retreat of paleo-lake shorelines. This Interdisciplinary approach, combining archaeology, chrono-stratigraphy, and paleoenvironmental reconstructions, unveils a complex paleoecological narrative, indicating changes in vegetation, water availability, and climate, coinciding with the emergence of Oldowan stone tool technology in East Turkana. The landscape and climatic shifts we document in the northeastern Turkana Basin, Kenya mirror broader trends in eastern Africa during the late Pliocene, influenced by orbitally- forced climate change, tectonics, and reorganizations of paleogeography. These changes had cascading effects on ecosystems, including the expansion of grasslands and alterations in plant and animal species composition in the late Pliocene.Paleogeographical and paleoecological shifts in the late Pliocene in eastern Africa likely imposed selective pressures on early hominins that could have influenced their behavior. This study emphasizes the reciprocal relationship between landscapes and tool-making endeavors, suggesting that the environments associated with ancient river systems acted as both witnesses to, and catalysts for, the evolution of stone tool technology.
Contribution of LARES-2 to the realization of reference frames, deriving Earth rotation and gravity field parameters
Authors: Sośnica Krzysztof , Gałdyn Filip , Najder Joanna , Zajdel Radosław , Strugarek Dariusz
Published: March 2024

LAser RElativity Satellite 2 (LARES-2) successfully joined the constellation of geodetic satellites tracked by Satellite Laser Ranging (SLR) stations on July 13, 2022. LARES-2 has a spherical shape and a very favorable area-to-mass ratio that minimizes the non-gravitational orbit perturbations. Due to very small retroreflectors, the spread of center-of-mass corrections for different detectors installed at SLR sites is much smaller than for LAGEOS satellites. LARES-2 orbits at a similar height as LAGEOS-1, however, with a complementary inclination angle of 70° forming a butterfly configuration together with LAGEOS-1.Although the primary objective of LARES-2 is verification of the Lense-Thirring effect emerging from general relativity, the satellite also has a substantial impact on the geodetic parameters derived from SLR observations. We process 18 months of LARES-2 data and compare the LAGEOS-1/2 solutions with the combined LAGEOS-1/2+LARES-2 solutions. We show the impact of LARES-2 on the (1) SLR station coordinates, (2) pole coordinates, (3) length-of-day excess, (4) low-degree gravity field parameters focusing on C20 and C30 coefficients, (5) scale of the reference frame, (6) geocenter motion. We show that LARES-2 can especially improve the Z component of the geocenter coordinates and de-correlate C20 from the length-of-day parameter. The secular drifts of the ascending nodes for LARES-1 and LAGEOS-1 caused by C20 are the same in terms of absolute values but with opposite signs. This allows us to successfully separate the measurements of length-of-day excess (or the UT rate) from the C20-induced changes. We also analyze the empirical accelerations acting on LARES-2 which result from unmodeled non-gravitational orbit perturbations, such as thermal effects, and compare them to those observed for LAGEOS satellites. The observation geometry of LARES-2 is especially beneficial for stations located at high and medium latitudes, which allows it to improve the estimation of station coordinates provided by LAGEOS-1/2. Therefore, LARES-2 substantially contributes not only to general relativity and fundamental physics but also to space geodesy improving the future realizations of the international terrestrial reference frames.
Estimating Flood Risk under Global Warming: An Approach from the Insurance Industry
Authors: Kulkarni Sumeet , Choudhary Shubham , Zuccarello Francesco , Ekström Marie , Giani Giulia
Published: March 2024

The (re)insurance sector has established methods and tools to assess historical and current risk for several weather driven hazards in many geographical regions. Using those same methods to estimate risk under global warming is fraught with challenges as one may expect complex changes to all four risk components (hazard, exposure, vulnerability, and disaster response capability).Nevertheless, despite much uncertainty about how weather hazards may change under climate change, the insurance sector is increasingly expected to include risk estimates for future-looking business strategies. Supervisors (across different regulatory domains) are currently working with the insurance sector to better understand the transmission channels for climate risk and provide guidance on how to meaningfully estimate future risk due to weather driven hazards.To encourage discussion and transparency on methodology used to assess risk for insurance purposes (such as developing underwriting layers, or portfolio management) we demonstrate a recent approach developed by the global (re)insurance broker Gallagher Re to estimate risk scores of future floods aligned, and therefore comparable, with current flood risk estimates. We demonstrate the approach for both pluvial and fluvial flood and discuss how challenges (such as those detailed above) were addressed to derive a methodology that can be deployed globally, given access to robust and credible projections of extreme precipitation and streamflow.
A 335-year Coral-Based Reconstruction of Sea Surface Temperature along the Route of the Northeast Madagascar Current in the Tropical Southwestern Indian Ocean
Authors: Zhang Manlin , Zinke Jens , Boom Arnoud , Garbe-Schönberg Dieter , Watanabe Takaaki , Frick Daniel
Published: March 2024

Over the past century, the Indian Ocean stands out as the fastest warming ocean in the world. Yet, the southwestern Indian Ocean (SWIO) faces challenges in acquiring in-situ observational data, both spatially and temporally. The limited availability of long term continuous high-resolution instrumental data in the SWIO hinders a comprehensive understanding of sea surface temperature (SST) variability and its intricate relationship with large-scale atmospheric and oceanic modes. This scarcity further hinders efforts to disentangle natural variability from anthropogenic influences. To address these limitations, we present a 335 yr continuous coral record of monthly SST reconstruction in the Indian Ocean based on proxy Sr/Ca, obtained from Ambodivahibe Bay, northeast of Madagascar.Sampled from a strategic region under the control of the NW monsoon during austral summer and trade winds for the rest of the year, this unique long record provides insights into coral resilience in a coastal upwelling zone amidst the rapid pace of ocean warming, as well as long-term trade wind variability, which significantly impacts the temperature signature of the South Equatorial Current and the downstream Northeast Madagascar current (NEMC), subsequently influencing moisture delivery to the East African and Asian Monsoon regions.Our SST reconstruction uncovers annual to multidecadal variations in the tropical SWIO spanning from 1672 to 2007, highlighting the dynamic interplay between local and remote climate processes, each dominating at different time scales. Furthermore, this new record extends the existing coral Sr/Ca-SST monthly reconstructions in the SWIO back to the 17th century and underscores the enhanced capacity to reconstruct regional climate variability using proxy records from multiple sites. Particularly noteworthy is its ability to capture SST variations under the alternating influence of monsoon and trade winds. This new coral Sr/Ca record provides valuable initial SST reconstruction along the route of the NEMC, serving as an indicator of the long-term NEMC strength variability.
Deep learning forecast of rainfall-induced shallow landslides in Italy
Authors: Guzzetti Fausto , Mondini Alessandro C. , Melillo Massimo
Published: March 2024

Rainfall induced landslides occur in all mountain ranges posing severe threats to people, property, and the environment. Given the projected climate changes, in many areas the risk posed by rainfall induced landslides is expected to increase. For this reason, the ability to anticipate their occurrence is key for effective landslide risk reduction. Empirical rainfall thresholds and coupled slope-stability and rainfall infiltration models are commonly adopted to anticipate the short-term (from hours to days) occurrence of rainfall induced shallow landslides. However, empirical evidence suggests that they may not be effective for operational forecasting over large and very large areas. We proposed a deep learning based modelling strategy to link hourly rainfall measurements to landslide occurrence. We constructed a large ensemble of 2400 neural network models which we informed using hourly rainfall measurements taken by more than 2000 rain gauges and information on more than 2400 landslides in the period from February 2002 to December 2020 in Italy. Our results have indicated that (a) it is possible to effectively anticipate the occurrence of the rainfall induced shallow landslides in Italy, and (b) the location and timing of the rainfall-induced shallow landslides are controlled primarily by the precipitation. Our results open to the possibility of operational landslide forecasting in Italy, and possibly elsewhere, based on rainfall measurements and quantitative meteorological forecasts aided by deep learning based modelling.
Acceleration and transport of solar energetic particles in the inner heliosphere
Authors: Rodríguez-García Laura
Published: March 2024

A new era of spacecraft probing the inner heliosphere make now possible the study of the spatial distribution of solar energetic particle (SEP) events closer to the Sun. Recent missions, such as Solar Orbiter, along with the constellations of spacecraft near 1 au facilitate the study of the radial dependence of SEP parameters, such as the peak intensity and spectrum. In this work, we use the solar energetic electrons (SEE) measured by the MESSENGER mission from 2011 to 2015 to derive statistical results about the radial dependence of some SEE parameters, which are compared with the results from Solar Orbiter near its first nominal perihelion in March 2022.  The main conclusions are: (1) There is a wide variability in the radial dependence of the electron peak intensities, but on average and within uncertainties, the radial dependence can be expressed as R-3, being R the heliocentric distance to the Sun. (2) Between near 0.3 au and 1 au, the energy spectrum of the near-relativistic electrons becomes softer.We also analyse the relations between the solar activity and the SEE peak intensities measured by MESSENGER, STEREO and ACE spacecraft during 2010-2015. We investigate the 3D early kinematic profile of the CME and associated wave and determine their main morphological (size) and dynamic (propagation and expansion speeds, acceleration) properties and study their relationship with the particle (electron and proton) energies and timing measured in situ. A summary of the results, implications for the Space Weather research, and comparison with previous works is presented.
Advances in Urban Greenhouse Gas Monitoring: Integrating Slow-Response Atmospheric Towers and Wavelet-Based Techniques for Flux Measurements and Attribution
Authors: Herig Coimbra Pedro Henrique , Loubet Benjamin , Laurent Olivier , Bignotti Laura , Lozano Mathis , Mauder Matthias , Heinesch Bernard , Bitton Jonathan , Ramonet Michel
Published: March 2024

Global surface temperatures continue to rise, with projections indicating over 2°C warming by 2100, primarily attributed to anthropogenic greenhouse gas emissions. Urban areas, responsible for 70% of global emissions, are focal points for climate change mitigation. The PAUL Cities project aims to monitor emissions reduction in megapoles. Current monitoring infrastructures like ICOS focus on atmospheric, oceanic, and ecosystem measurements. This study explores the potential of using slow-response analyzers on tall atmospheric towers for Eddy Covariance flux computations, addressing technical challenges and height-induced complexities. Additionally, a novel wavelet-based method is proposed for attributing fluxes to biogenic and anthropogenic sources, using carbon monoxide as a distinctive tracer. Results from sites near Paris demonstrate the feasibility and versatility of these approaches, offering valuable insights for urban emission monitoring strategies worldwide.
The skeleton of the Mediterranean Sea
Authors: Rubino Angelo , Pierini Stefano , Rubinetti Sara , Gnesotto Michele , Zanchettin Davide
Published: March 2024

The atmosphere forces oceanic motions. However, direct atmospheric forcing is not able to explain several observed features of the mean Mediterranean circulation like, for instance, the large-scale meridional sea level inclination, a strong and persistent feature of the Mediterranean oceanography. Low-frequency changes in the Mediterranean Sea have also been observed that cannot be explained by a mere response of the ocean to atmospheric changes. However, model studies of the intrinsic mean state and variability of the Mediterranean Sea appear to be lacking.Here, we start filling this gap of knowledge. We demonstrate [1] that a conspicuous part of the observed Mediterranean mean state and variability belongs to a skeleton captured for the first time by a multi-centennial ocean simulation without atmospheric forcing. An eddy-permitting nonlinear, shallow-water multilayer numerical model was only forced by steady transports of Atlantic Water and Levantine Intermediate Water at its western and eastern open boundaries located along meridional sections crossing the strait of Gibraltar and the Levantine basin, respectively. The lack of any atmospheric forcing is very peculiar of our approach and is crucial for revealing the intrinsic mean state.Comparison of the simulated annual mean surface displacement with the corresponding absolute dynamic topography altimetric data for the period 1993–2020 provided by the Copernicus Climate Data Store, yields large patterns of coherent correlation -including a large-scale meridional sea level inclination- that are clearly all of intrinsic origin. This result paves the way to the recognition of a noticeable contribution exerted by intrinsic oceanic mechanisms to the sea level rise observed in recent years over the Mediterranean Sea. In addition, a strong and previously unknown intrinsic oceanic variability appears, which contributes to explaining a conspicuous part of the poorly understood observed interior low-frequency oceanic variability.[1] Rubino A, S. Pierini, S. Rubinetti, M. Gnesotto and D. Zanchettin, 2023: The skeleton of the Mediterranean Sea. J. Mar. Sci. Eng., 11, 2098; https://doi.org/10.3390/jmse11112098.
Monitoring aquifers and subsidence with the chronometric leveling
Authors: Lion Guillaume , chanard Kristel , Pajot Gwendoline , Diament Michel , Jamet Olivier
Published: March 2024

Subsidence poses a significant global threat to the viability and economic development of approximately one-fifth of the world's population, especially in coastal or heavily urbanized regions experiencing ground settlements ranging from centimeters per month to meters per decade. This phenomenon, driven by natural or anthropogenic factors, is intricately linked to hydrology, geology, tectonics, and the geotechnical properties of underlying formations. Multiple triggers, including underground cave collapses, organic soil oxidation, natural gas and oil extraction, and aquifer consolidation, contribute to subsidence, disrupting vital water reserves crucial for societal needs. Spatial and temporal limitations of conventional techniques like gravimetry, positioning, and spatial imaging in resolving the effects of extreme weather events and resource exploitation on subsidence prompt an exploration of their complementarity and the emergence of quantum sensors—specifically, atomic clocks sensitive to gravitational potential variations.Since 2021, the SYRTE, IPGP, IGN, and SHOM participate in the ANR ROYMAGE project (Optical Ytterbium Mobile Atomic Clock Applied to Geodetic Exploration). The project aims to develop a transportable atomic clock prototype with sufficient performance to determine altitude differences within the T-REFIMEVE fiber network, achieving a centimeter-level uncertainty in just a few hours across points separated by hundreds of kilometers for geodetic applications. As optical atomic clocks become integral to fieldwork, their sensitivity to mass anomalies and vertical displacement becomes a crucial consideration.Within the ANR framework, we have initiated digital tool implementation to model the signal generated by remote clock comparisons, mainly gravitationally and geometrically influenced by mass and altitude variations. The challenge lies in identifying and decorrelating signal sources to reveal the studied phenomenon. Geopotential differences, a novel geodetic observable, necessitate modeling considering gravitational signatures at the Earth's surface from buried mass anomalies (e.g., aquifers), the (in)elastic medium response to pressure changes causing vertical crust displacement, and other effects like solid Earth tides, ocean tide loading, polar motion, etc. Preliminary results suggest that clock comparisons with centimeter-level uncertainties could detect variations in regional groundwater levels.This work proposes to assess whether chronometric leveling, in France, can complement gravimetric, spatial imaging and levelling techniques to study vertical soil displacements resulting from disturbances in underground water resources due to climatic or anthropogenic origins.The authors acknowledge the support of the French Agence Nationale de la Recherche (ANR) under reference ANR-20-CE47-0006.
Paired coral Sr/Ca and δ18O records reveal increasing ENSO influence on Malaysian Borneo’s hydroclimate
Authors: Naciri Walid , Boom Arnoud , Watanabe Takaaki K. , Garbe-Schönberg Deiter , Hathorne Edmund , Browne Nicola , Evans Noreen J. , Nagarajan Ramasamy , Zinke Jens
Published: March 2024

The El Niño Southern Oscillation (ENSO) is a worldwide climate phenomenon impacting temperatures and precipitation regimes in Australia, Southeast Asia, and America. Previous studies have shown this climate phenomenon and the Indo–Australian monsoon to have a strong influence on Malaysian Borneo’s hydroclimate. In a context of climate change and increasingly strong extreme ENSO events, understanding the influence of ENSO on this region, as well as its evolution through time, is essential to better constrain the possible future impacts it will have on the Maritime Continent’s hydroclimate. To compensate for the limited availability of dependable instrumental data in the first half of the 20th century, we used coupled δ18O and Sr/Ca records from massive corals’ carbonate calcium skeletons to build a proxy for past hydroclimate: δ18Oseawater (δ18Osw). We first assessed our two 90 and 60-year-long δ18Osw records’ quality as proxies for hydroclimate by correlating them with different instrumental datasets before performing moving windowed correlations with the NINO3.4 index, an indicator of ENSO state. Results show variable agreement with local instrumental data depending on the distance from the river mouth, monsoon season, and instrumental dataset used. When correlated against the NINO3.4 index, our δ18Osw records showed a nonstationary increasing influence of ENSO from the 1980s and onwards on the local hydroclimate with correlation coefficients r > 0.8 using month groups towards the end of the year. Our findings highlight the differences in results depending on the chosen dataset, time scale, or period of the year, as well as the usefulness of these geochemical archives to better understand the impacts of climate phenomena across periods predating reliable instrumental data.
Relationships between non-structural carbohydrates reserves and growth resilience of Fagus sylvatica to extreme drought events
Authors: Gaertner Pierre-Antoine , Bréda Nathalie , Gérard Bastien , Badeau Vincent , Levillain Joseph , von Arx Georg , Vitasse Yann , Saintonge François-Xavier , Massonnet Catherine
Published: March 2024

Following the 2018’s extreme drought summer in Central Europe and the recurrent episodes of drought in the summers 2019 and 2020, a massive dieback of European beech (Fagus sylvatica) has been observed over the following years in the core of its distribution range. This ecological and ecophysiological study aims at evaluating the role of carbon reserves in tree survival and resilience to extreme drought and recurrent soil water deficit using tree ring width analyses combined with measures of non-structural carbohydrates (NSC) concentrations from 2020 to 2022.In 2019, 20 study plots were selected in North-Eastern France and 15 beech trees per plot were selected according to contrasted crown condition. The crown transparency of these 300 selected trees was then assessed annually from 2019 to 2023. Each autumn, from 2020 to 2022, trees were sampled at the base of the trunk with an increment borer to measure NSC concentrations. In 2022, an additional core was sampled from each tree at breast height and until the tree heart for a tree-ring growth analysis and to determine tree age, the resistance, recovery and resilience of radial stem growth to soil water deficit. The daily soil water balance was parameterized for each plot with the model Biljou© to compute retrospectively the soil water deficit of each plot from 1959 to 2022.Our results show that NSC concentrations from 2020 to 2022 were negatively correlated with the crown transparency of the same year. Trees whose crown transparency increased during the monitoring presented lower NSC concentrations in 2021 and 2022.Trees showing a better resistance, recovery and resilience of the radial growth to the 2018-2020 water shortage period had higher NSC concentrations and trees with higher mean basal area increment during the past 10 years exhibited higher NSC concentrations. During the monitoring, 31 trees died and their NSC reserves were significantly depleted after 3 successive years of soil water deficit. Moreover, 59 % of the trees whose NSC concentrations were below 10  in 2020 died in the three next years while only 2 % of the trees showing NSC concentrations higher than 10  in 2020 died in the next three years. A possible carbon starvation threshold has been identified for the Fagus sylvatica species.Our results suggest that NSC storage is important for the survival and the resilience of beech radial growth to soil water deficit. The depletion of NSC reserves will be discussed as a key component in the process of beech tree mortality. 
Open geospatial research software in 2024: Assessing service quality with technology readiness levels 
Authors: Löwe Peter
Published: March 2024

To initiate, maintain and accelerate behavioral change towards Open and FAIR practices, tangible benefits for scientific communities and especially early career scientists are a critical key success factor. The realization of such benefits, by due credit, funding, or other means requires underlying workflows, enabled by underlying infrastructures and standards, which are operational, reliable and trusted. Many education efforts are under way to educate and motivate researchers how to embrace and particpate in Open and FAIR efforts, including the open geospatial community software projects of the OSGeo foundation. Still, from the perspective of a developer of research software, the current general service quality of offerings for PID-/citation-based credit remains limited, fickle, partially unpredictable and frustrating. This presentation demonstrates these challenges by real world examples from OSGeo open geospatial projects, such as QGIS, GRASS GIS and proj and resulting PID-references in publications. Further, a service centered approach is introduced to enable both end users and Open/FAIR communities to assess the overall service quality through Technological Readiness Levels (TRL), to improve the user experience by building trust and to focus further development ressources.
Investigating the independently derived tropospheric parameters at GNSS-VLBI co-located sites
Authors: Walenta Anastasiia , Flohrer Claudia , Dach Rolf , Thaller Daniela , Engelhardt Gerald
Published: March 2024

This paper presents the next step of the recently undertaken comparison of the tropospheric parameters independently derived from the analysis of Very Long Baseline Interferometry (VLBI) and Global Navigation Satellite Systems (GNSS) data. We established a concept of cross-validation of the tropospheric parameters which allows us to focus now on the investigation of the discrepancies detected in the cross-validation. In particular, the dataset and its parameterization are examined in view of their impact on the obtained biases. The most recent 5 years of observations are considered, during which the sufficiently dense time series of observations are available for the legacy VLBI stations as well as for the new generation antennas following the VLBI Global Observing System (VGOS) specifications. In our study the co-location sites are limited to those observatories, where the legacy VLBI antenna, VGOS antenna and GNSS receiver are present. Furthermore, the tropospheric parameters are compared only at the common epochs, which are chosen to include the independently conducted observations of the legacy VLBI antenna, VGOS antenna and GNSS receiver during a defined time span. The corresponding solution parametrization is varied between intervals of VGOS, legacy and GNSS solution parametrizations in order to identify the most optimal duration. While the parameterization of the GNSS solution considers the tropospheric variations stable over 2 hours, the parameterization of VLBI solutions for legacy antennas is known to be reliable over a shorter 1-hour interval. The highly dense VGOS observations allow us to reach up to 20-minute duration without losing performance.
Role of urban wetlands in improving catchment river water quality with implications for management
Authors: Peng Fangjun , Liu Leyang , Mijic Ana
Published: March 2024

The theme for World Wetlands Day in 2024 is centred on the symbiotic relationship between wetlands and human wellbeing. The urban wetland, as a nature-based solution, notably intertwines with human activities, distinguishing itself among various wetland types. Examining urban wetlands through the aspect of water quality reveals their ability to purify nitrogen and phosphorus from water sources. However, human activities affect river water quality via various sources and processes within an urban environment, including land surface and wastewater discharge, exhibiting significant complexity. Understanding how urban wetlands interact with these processes and their impacts on water quality is needed. To explore the role of wetlands in integrated urban water quality management, our study enhanced the representation of nutrient processes in wetlands and incorporated it into the whole-water cycle simulation tool – the Water Systems Integration Modelling framework (WSIMOD). This is done by quantifying the wetland-urban system interactions within subcatchments, between subcatchments, and at the catchment scale. Our study aims to (1) evaluate urban wetland benefits in water quality improvement via statistical analysis; (2) simulate such impacts through integrated modelling; (3) explore the pipe connections of wetlands and their impacts on systems-level water quality improvement to inform design and management. Analysis of observed water quality data reveals that the nitrogen concentration in a catchment influenced by the urban wetlands network is reduced by approximately 18% to 28%, with the phosphorus concentration showing a reduction of about 4% to 11%. At a local scale, within a single subcatchment, the model is demonstrted to capture the water quality dynamics and the observed impacts well by validating against the sampling data. Furthermore, at a broader scale encompassing the entire catchment, the connectivity of urban wetlands through pipes is expected to achieve better system-level water quality performance. This research emphasises the need to explore how urban wetlands influence and are influenced by various water elements, informing future urban wetland design and management strategies.
Fault Slip Distribution and Inhomogeneous Frictional Properties in the Southeastern Zagros Mountains of the 2022 Iran doublet Earthquakes Inferred from Bayesian Inference and InSAR observations
Authors: zhao xiong , dahm Torsten , xu Caijun
Published: March 2024

On July 1, 2022, a doublet of earthquakes, with a magnitude of Mw6.0 and a Mw5.7 aftershock between them, occurred within a two-hour period in the southeastern part of the Zagros Mountains near the Persian Gulf in Iran. This doublet earthquake event provides a unique opportunity to study the geometric properties of geological faults and the frictional attributes of rocks in the southeastern of the Zagros Mountains, particularly in the vicinity of the Hormoz salt layer. Here, we acquired co-seismic and post-seismic InSAR ascending and descending observations to simultaneously determine fault geometry and slip distribution models for the doublet earthquakes based on Bayesian inference. The inversion results reveal that the doublet earthquakes occurred on two distinct faults with similar strike (101.93°, 93.7°) but notable differences in dip (56.2°, 31.3°), and the slip distribution of the mainshock 2 is shallower and more westward compared to the mainshock 1. Moreover, the reliability of the fault geometry and slip distribution was confirmed through detailed discussions on the distributions of post-seismic kinematic afterslip, the relocated aftershocks beyond five months after the mainshocks, and the changes in positive Coulomb stress triggered by co-seismic events. Additionally, our post-seismic deformation modeling elucidated that post-seismic deformation is predominantly driven by stress induced by co-seismic event, accompanied by the release of both afterslip and aftershocks. Afterslip is distributed both up- and down-dip of the coseismic region on the two faults, with the maximum afterslip concentrated in the shallow portions, reaching approximately 0.45 m. By comparing the temporal evolution characteristics of stress-driven afterslip distributions with those of kinematic afterslip, we observed significant inconsistencies in the frictional properties within the southeastern Zagros Mountains, particularly between the Hormoz salt layer and its upper region. Specifically, above the Hormoz salt layer, the friction is stronger, and the relaxation time of afterslip is shorter. Finally, we also discussed the triggering potential of the mainshock 1 and the Mw5.7 aftershocks on mainshock 2, and from the perspective of Coulomb stress transfer, we found that mainshock 1 and Mw5.7 aftershocks may have triggering effects on mainshock 2. 
Study of the contribution of groundwater to hydrosedimentary processes in two Mediterranean mountainous watersheds using the high frequency conductivity signal as a tracer of water origin
Authors: Fischer Ophélie , Legout Cédric , Le Bouteiller Caroline , Nord Guillaume
Published: March 2024

Understanding erosion and sediment transport is essential for the sustainable management of water and soil resources in the critical zone. Soil erosion is considered as the main threat to soils and poses food security problems. Given these significant challenges, it is important to understand and prioritize the processes that control erosion dynamics and sediment transfers within watersheds.However, these dynamics exhibit strong spatio-temporal variability, as illustrated by the wide dispersion of relationships between suspended sediment concentrations and liquid discharge (Q) at catchment outlets. However, these dispersions are often interpreted based on the variability along the sediment axis (e.g., origin and availability of particles), while very few studies have focused on the variability along the discharge axis (water origin). In particular, the interactions between groundwater flow and sediment transport have been little studied.The aim of this study is to assess the impact of groundwater flow on sediment transport dynamics in two headwater catchments (respectively 1.07 km² at Brusquet and 0.86 km² at Laval) of the Draix-Bléone observatory with different vegetation cover rate (respectively 80% at Brusquet and 30% at Laval). The work first involved developing an EMMA (End-Member Mixing Analysis) method for decomposing flood hydrographs and separating the respective contributions of groundwater flow and surface runoff for each flood using the high-frequency conductivity signal, highly correlated to sulfate concentrations, as a tracer discriminating these two water compartments.This EMMA method was used to calculate groundwater contributions during 120 floods between 2015 and 2020 in the Laval catchment and 116 floods between 2013 and 2020 in the Brusquet catchment. Analysis of the results of these decompositions revealed seasonal variations in groundwater contributions in both catchments, with winter and spring floods showing higher groundwater contributions than summer and autumn floods. These decompositions made it possible to examine the dynamics of fine sediment transport during floods as a function of surface runoff rate and to identify the impact of groundwater on hydrosedimentary processes (effect of dilution or of remobilization of riverbed sediment). By comparing the results of the decompositions from the two catchments, it was possible to assess the impact of vegetation cover on the contribution of groundwater to flood and on each catchment sediment dynamics.Overall, this study suggests that the use of high frequency conductivity signals as tracer of water origin offers a promising approach to performing high frequency decompositions of flood hydrographs. The results of the decompositions highlight the importance of groundwater flows for understanding hydrosedimentary processes in headwater catchments (~km²).
Can we identify evidence of subduction initiation beneath the Macquarie Ridge Complex from teleseismic tomography?
Authors: Han Jifei , Rawlinson Nick , Tkalčić Hrvoje , Eakin Caroline , Coffin Mike , Stock Joann
Published: March 2024

Subduction is a key process in both the recycling and creation of new oceanic crust, the exchange of water between the Earth, oceans and atmosphere, and the distribution of earthquakes and volcanoes. However, the formation of new subduction zones - or subduction initiation - remains a poorly understood process. Macquarie Island, which lies along the Macquarie Ridge Complex (MRC) that forms the transpressional boundary between the Australian and Pacific plates in the southwest Pacific, is one location on Earth where subduction initiation is thought to be taking place. Several studies have suggested that the northern and southern segments of the MRC may be experiencing incipient subduction, but it is unclear what is happening in the central section, which includes Macquarie Island.Indirect evidence for at least incipient subduction beneath Macquarie Island includes (i) ophiolite (oceanic crust) being exposed above sea level; (2) extreme topography, with Macquarie Island lying  ~5 km above the surrounding ocean basin; (3) thrust faults on either side of the island. To help investigate whether subduction may have been initiated in the neighborhood of Macquarie Island, we analyze teleseismic body wave data recorded by a network consisting of land stations and oceanic bottom seismometers deployed between October 2021 and November 2022. We extract teleseismic P-wave arrival time residuals across the combined array from ~20 events with epicentral distances between 30 and 90 degrees and invert them using FMTOMO to obtain 3-D P-wave velocity anomalies in the upper mantle. Preliminary results indicate that higher velocities are present to the east of the MRC in the vicinity of Macquarie Island, although further refinement is required before a detailed interpretation is possible.
Monitoring and Assessment of Salt Marsh Restoration Using Field and Remotely Sensed Data
Authors: Agate Joe , Ward Ray , Joyce Chris , Burnside Niall
Published: March 2024

The number of salt marsh restoration schemes is set to increase substantially this decade, driven by three key factors: a) legislative requirements to compensate for losses; b) a transition to a natural approach for coastal management; and c) growing interest in ecosystem services salt marshes provide. Monitoring is key to evaluating the success of restoration projects and can inform future projects. However, many schemes have been found to use ineffective monitoring strategies. A major barrier to developing effective monitoring programmes has been the resources required to carry out frequent, spatially explicit surveys using traditional survey methods, which will become an even greater problem as more schemes are created. Consequently, improvements to survey methods are required.This project aims to improve our understanding of the role that remote sensing combined with field data can play in assessing the development of salt marsh restoration programmes. To address this aim, monitoring has been carried out at a new restoration site in the Adur estuary, on the south coast of the UK, since its creation in 2019. Field data has been collected, including biannual changes in species cover along transects. These surveys have found positive development at the Adur site, with clear successional changes in vegetation cover. Drone flights have also been carried out at the site to accompany the transect surveys, with machine learning algorithms used to develop models of the observed changes. Preliminary testing has found the machine learning models produce accurate results, demonstrating that remote sensing can be a valuable asset to existing monitoring practices.
The Relevance of the Subgrid-Scale-Model in Large-Eddy-Simulations of the Stably Stratified Atmospheric Boundary Layer
Authors: Bührend Lukas , Englberger Antonia , Dörnbrack Andreas
Published: March 2024

A realistic representation of the stable (nocturnal) boundary layer (SBL) is challenging for large-eddy simulations (LES) due to the small turbulence intensity and size of turbulent eddies compared to the daytime convective boundary layer. This increases the relevance of the subgrid scale (SGS) model, which parameterizes turbulent fluxes with a size smaller than the numerical grid. The SGS parameterization influences the shape of the mean wind and temperature profiles, especially close to the surface. The turbulence intensity also influences the SBL height. It is important to note that in the SBL, the mean wind and temperature profiles are different from the Monin-Obukhov similarity forms, especially within the roughness sublayer, which becomes relevant approaching to finer vertical resolution. Additionally, typical SBL characteristics like supergeostrophic mean windspeeds (low-level jets) and the rotation of the mean wind direction with height (Ekman spiral) are influenced by the SGS model.In our work, we use the TKE (turbulent kinetic energy) closure model as described by Schumann (1990). To obtain resolved turbulence, a modification as described by Sullivan (1994) is used, which takes account of the turbulence anisotropy and the enhanced influence of mean shear close to the surface. We use an intercomparison of SBL-LES by the GABLS-initiative as reference.  The numerical results are produced with the multiscale flow solver EULAG (see Prusa et al. (2008)), solving the governing Boussinesq equations for velocity components and potential temperature perturbation.  Periodic boundary conditions (BC) are used for the horizontal border planes. For the surface, free slip Neumann BC (NBC) with surface fluxes for the potential temperature are applied. The combination of a sensible heat flux and a stably stratified regime is compliant due to the NBC at the surface. The use of NBC did not require the Monin-Obukhov similarity theory. This makes EULAG suitable for a detailed investigation of the dependency of the resulting mean wind, temperature and TKE profiles on numerical and physical parameters. The results thereof will be presented, with special emphasis placed on the SGS model in highly resolved LESs.
Enhancing Methane Source Attribution through Co-Assimilation of Ethane Observations in Atmospheric Inversion Methods
Authors: Martinez Adrien , Saunois Marielle , Berchet Antoine , Pison Isabelle , Bousquet Philippe
Published: March 2024

Estimating methane emissions using atmospheric inversion methods that assimilate only methane observations presents challenges in accurately attributing methane sources and sinks to specific emission sectors.We explore the potential of co-assimilating observations of co-emitted species alongside methane observations to address this challenge and provide improved sectoral distribution of methane emissions.Ethane is a promising candidate for this purpose. It is primarily co-emitted with methane in the fossil fuel emission sector, particularly through fugitive emissions from natural gas extraction, and is also co-emitted in the biomass and biofuel burning emission sectors, with negligible emissions in other sectors.To assess the potential of co-assimilating ethane observations with methane observations, we use a global chemistry-transport model, LMDZ-SACS, with the Community Inversion Framework (CIF) to perform response functions analysis on methane and ethane emissions over a multi-year period.We utilize the response functions results to meaningfully construct full source-receptor relationship matrices at available observation site, as well as, error covariance matrices for a control vector that includes both species emissions and initial conditions, and perform a large set of analytical inversions that assimilate in-situ and flask observations of both methane and ethane, as well as methane-only observations.This methodology can not only provide improved estimates of the sectoral distribution of methane sources and sinks, but also extends the scope of the analysis to include ethane emissions.