bluuebunny/crossref_metadata_2025 huggingface dataset:
Partitioning NEE from peatland vegetation into autotrophic and heterotrophic components
Authors: Kruijt Bart , Biermann Jan , van der Craats Daniel , Franssen Wietse , Jans Wilma , Rovers Marsha , Bataille Laurent , Nijman Tom , Buzacott Alexander , van Giersbergen Quint , Nauta Reinder , Hutjes Ronald
Published: March 2024

In ecosystems on organic soils such as peatlands and managed grasslands on peat, understanding the dynamics and controls of peat decomposition in drained soils or accumulation in wetlands is currently a topic of great interest because of their potential contribution to large CO2 emissions or sustained carbon storage. Net ecosystem carbon exchange fluxes (NEE) measured in such ecosystems are a combination of autotrophic processes, photosynthesis and respiration, in living plant material and heterotrophic respiration from all other organisms including those feeding on decomposing peat. Direct flux measurements from eddy covariance or chambers, however, are unable to distinguish the two co-occurring respiration components.In this study we assess two approaches to partition measured NEE of peatland ecosystems into respiration components and estimate peat decomposition rates. The traditional approach is to use the assumption that annual heterotrophic respiration equals the difference between NEE and NPP. In managed grasslands on peat soils this implies that annual NEE corrected for harvest removal and manure application represents the annual peat oxidation. The alternative proposed here is based on data at shorter time scales, making use of the information contained in day-to-day variability in fluxes and vegetation activity. We explore the use of correlations between night-time NEE and daily GPP as well as observed changes in NEE following abrupt vegetation changes and management events.Using multiple site-years of daily NEE measured over a range of managed and natural peatlands in The Netherlands we show that information contained in intra-annual variability carries sufficient information to derive a signal that comes close to heterotrophic respiration and peat decomposition-related carbon loss. The proposed partitioning could be used to understand in more detail the processes responsible for peat decomposition and apply such understanding in emission mitigation management.
Non-invasive detection and visualization of microplastic particles, films and fibers in sandy soils 
Authors: Tötzke Christian , Kardjilov Nikolay , Oswald Sascha E.
Published: March 2024

The continuous input of microplastics into terrestrial environments is altering the physico-chemical properties of soils. The wide variety of microplastic particles in terms of particle shape, size, polymer type and additives makes microplastic pollution a multifaceted problem. Recent research efforts aim to improve the mechanistic understanding of how microplastics change soil structure and function and how this affects plants and other soil biota. A number of analytical detection methods are now available, but these typically involve sampling or processing steps that destroy the integrity of the sample. As a result, essential information about the soil structure and the spatial distribution of microplastics in the sample is irretrievably lost. Non-invasive tools are needed to directly study the interplay between microplastic particles and the 3D structure of the soil matrix. We introduce a combination of neutron and X-ray tomography as a non-invasive method capable of detecting and localizing microplastic particles in sandy soils (by neutrons) and simultaneously analyzing the 3D microstructure of the surrounding soil (by X-rays). The feasibility and limitations were tested in a series of sandy soil samples containing organic matter and microplastics of different plastic types and shapes, including particles, films, or fibers. Pretreatment with H2O2 was tested to facilitate the image analysis for samples with higher organic content.Our three-dimensional imaging approach can provide detailed information about the spatial distribution of microplastics in the sample and can reproduce the size, shape, and orientation of particles, although it cannot distinguish between plastic types. Visualization of embedded polyethylene film fragments as well as fibers revealed perturbations in the soil matrix that can clearly affect its hydraulic and mechanical properties. Finally, we analyzed microplastics in the spatial context of plant-soil interactions for the root system of a lupine plant, demonstrating that it is also an attractive tool for in-situ studies of soil microplastic effects on plant roots. Overall, this approach offers the opportunity to study the impact of microplastics on soil hydromechanical properties, the interaction of biota with microplastics, and possibly also microplastics local fate in sandy soil, albeit not as a screening or high-throughput tool, but suited as powerful tool for dedicated process studies.
Lithium and molybdenum isotope systematic for Fushui complex and implications for the recycled oceanic crust in the source of arc magmatism
Authors: Hu Pan
Published: March 2024

The origin and extent of crustal material in arc magmas are critical for tracing the crust-mantle interaction at subduction zones. Arc volcanic rocks often have a characteristic range of trace elements and isotopic compositions that constrain the influx of crustal material, such as hydrous fluids derived from slab dehydration, melts of the subducted plate's veneer sediments, or heterogeneous mélange. Especially, the traditional geochemical proxies struggle to investigate the contribution of tectonic melange into the enriched subarc mantle source. Lithium and molybdenum isotope compositions provide a potential means of tracing the different components to the mantle wedge in subduction zones.Here, we report Li-Mo isotope compositions of the Fushui mafic complex in the Qinling orogen, central China, to trace their source nature and to constrain metasomatic component(s) transferred during the early Paleozoic subduction event. The Fushui mafic rocks exhibit typical arc-type trace element features and enriched radiogenic isotope compositions, suggesting a mantle source had incorporated subducted compenents. The Fushui rocks also exhibit a light Li isotope composition providing direct evidence for the contribution of dehydrated serpentinites and eclogite. The variable Mo isotope values further suggest the mantle source has been metasomatized by aqueous fluid and hydrous melt. This study, therefore, confirms the transportation of dehydrated oceanic plates from footwall to hanging wall and its critical role in the subarc mantle source. The interpretation provides a new perspective to study the recycling of subducted oceanic lithosphere and associated petrogenesis of arc magmatism.
Unravelling the intraplate 2019 Broome earthquake in the North West Shelf, Australia, through 3D CMT analysis
Authors: Mousavi Sima , Hejrani Babak , Miller Meghan S.
Published: March 2024

The July 14, 2019 Broome earthquake, with a magnitude of 6.6, was a significant seismic event in the North West Shelf (NWS) region of Western Australia where the dynamics of earthquakes are not well-understood. This study examines the focal mechanisms, centroid time, and locations of the Broome earthquake and its aftershocks using Centroid Moment Tensor (CMT) analysis.The NWS is located in an intraplate tectonic setting where the dynamics of earthquakes are not well-understood. The region has a complex history of fault activity, and it transitions from an active collisional plate boundary in the north to a passive continental margin in the west. These tectonic regimes have generated seismic zones along the plate interface and reactivated older faults.The Broome earthquake, a strike-slip event, exhibited a dominant NNE-SSW maximum horizontal stress orientation, prevalent across the NWS and responsible for numerous regional earthquakes. Despite the NWS's seismic activity, focal mechanism studies have been limited due to sparse seismic stations, significant azimuthal gaps, and considerable distances between stations and earthquake locations.We utilized CMT inversion with a high-resolution 3D AusREM velocity model of the region. This method offers enhanced accuracy in determining earthquake source parameters at frequency up to 0.1 Hz, which allows us to study smaller magnitude events, which pose challenges for traditional 1D models.  The results reveal primarily strike-slip faulting with considerable non-double-couple components, indicating complex rupture processes beyond planar assumptions. The 25-58% double-couple percentages highlight significant deviation from standard seismic models, underlining the NWS's geological complexity.
Predictive multivariate modelling for anticipatory drainage management in coastal lowlands
Authors: Müller Henning , Schröter Kai
Published: March 2024

Climate change related sea level rise and increased winter precipitation are contributing to an increase in flood hazards in low-lying coastal regions of Germany. The magnitude of flood events in these areas is largely dependent on the capacity of the drainage infrastructure such as canals, sluices or pumps. As the drainage capacity varies depending on the technical and environmental conditions, drainage operations are especially under pressure when compound events like an inland flood and a storm surge occur simultaneously. To gain insight into the factors that impact drainage system capacity, we analyse sea level, hydrometeorological and operational datasets from coastal lowland catchments using multivariate statistical and machine learning-based approaches, e.g. rank correlation and random forests. The analysis indicates complex multi-level correlations of rainfall, wind direction and speed, and tidal water levels with inland flooding and helps to identify combinations of influencing factors that reduce drainage capacity and increase flood hazards. This information is useful to anticipate flood events and assist water management bodies in adjusting drainage operations in advance to mitigate resulting risks.
Legacy of former land use and its effect on carbon content of soil in present forests
Authors: Balázs Pál , Bidló András , Horváth Adrienn , Katona Máté , Végh Péter
Published: March 2024

Increasing carbon presence in the atmosphere prompts scientists to understand carbon sequestration processes better. Forest is one of the most promising ecosystems where this sequestration can take place with higher efficiency. In this research, we analysed long-term land use change processes and carbon content of soils in present Hungarian forests, searching for the answer: is there any relationship between the former land use and the carbon content of soils?We selected 183 forest stands scattered across the country, where the age of the trees were approximately 60-70 years old. Soil samplings were carried out in the depth of 40-110 cm (in 10 cm layers). In order to derive long-term land use change information, we used historical map series dating back to the 18th century.Results will contribute to the understanding of the carbon sequestration processes of terrestrial ecosystems.This article was made in frame of the project TKP2021-NKTA-43 which has been implemented with the support provided by the Ministry of Innovation and Technology of Hungary (successor: Ministry of Culture and Innovation of Hungary) from the National Research, Development and Innovation Fund, financed under the TKP2021-NKTA funding scheme.
Ground truth generation for crop classification using Street View
Authors: Nath Chandan , Ismagilova Alfiya , Singh Renu , Deshpande Ishan , Talekar Alok
Published: March 2024

Land-use understanding at agricultural field level is critical for decision making and addressing food and water security challenges, especially in smallholder regions. Using remote sensing and modern machine learning practices for the same is an active area of research. Satellite crop classification models are built using ground truth from manual agricultural surveys namely location, timestamp and crop label. However manual surveys are prone to labeling errors and unlikely to be scalable due to cost prohibitions. Since machine learning models don’t generalize in a sparse data regime, this affects the accuracy and applicability of these models.
Google Streetview has captured a significant portion of field imagery next to roads across the globe. We propose large labeled ground truth data creation for satellite crop classification at planetary scale from a model which labels street view imagery. Since street view has wide coverage with data points spread across multiple years, and has reliable accuracy in terms of location and timestamp, our streetview labels dataset would be at least an order of magnitude larger than the next best dataset, allowing a single large satellite model to generalize for addressing crop classification. Recent studies have explored this method for pilots in the USA and South Korea, and we aim to generalize the work at planetary scale.
We use pre-trained vision models to generate the training labels for a satellite image based crop classification model. 
We aim to open source the labeled field polygons by the end of 2024 to enable the research community to use the dataset in other models.
 
Domain adaptation for deep learning ENSO forecasts
Authors: Rodriguez Miriam
Published: March 2024

In recent years, deep learning (DL) models have been shown to be able to make competitive forecasts of El Niño Southern Oscillation (ENSO). In most cases, due to the short observational record, the outputs of global circulation models (GCM) are used to train DL models. However, GCMs themselves show biases when modeling ENSO dynamics, such as the lack of phase-locking behavior, shifted precipitation trends, or missing El Niño - La Niña asymmetry. The biases of the GCMs are likely inherited by the DL models during pre-training, raising the question of how we can obtain unbiased DL ENSO models while pre-training on GCM output. In this study, we contend that a possible solution to correct these biases is to use well-established domain adaptation methods, which allow DL models to account for shifts in data distribution between training and validation data sets. In particular, we use a ConvLSTM network trained on CESM2 simulations where we first use a supervised objective to fine-tune our model to reanalysis data. Secondly, we employ test-time training to adapt our model for the domain shift between CESM2 and reanalysis data. This study serves as a first step toward comparing domain adaptation techniques for data-driven seasonal-to-annual DL models in a limited data regime.
Exploring the differing CO2 response to Dansgaard-Oeschger and Heinrich events
Authors: Willeit Matteo , Dalmonech Daniela , Liu Bo , Ilyina Tatiana , Ganopolski Andrey
Published: March 2024

Dansgaard-Oeschger (DO) and Heinrich (H) events are ubiquitous features of glacial climates involving abrupt and large changes in climate over the North Atlantic region, extending also to the Southern Hemisphere through the bipolar seesaw mechanism. Ice core data also indicate that the DO and H events are accompanied by pronounced changes in atmospheric CO2 concentration, but their origin remains uncertain. Here, we use simulations with the fast Earth system model CLIMBER-X, which produces self-sustained DO events as internal variability, to explore the processes involved in the atmospheric CO2 response. While the DO events are internally generated in the model, the Heinrich events are mimicked by adding a freshwater flux of 0.05 Sv over 1000 years in the latitudinal belt between 40°N and 60°N in the North Atlantic. The simulated Greenland temperature varies by ~7-8°C between stadials and interstadials, with only small differences between H and DO stadials, while Antarctic temperature responds substantially stronger to H than to DO events, broadly in agreement with observations. In the CLIMBER-X simulations, atmospheric CO2 varies by ~5 ppm during DO events, but by ~15 ppm during H events, comparable with ice core data. The peak in CO2 concentrations is delayed by several centuries relative to both the stadial-interstadial transition and the peak in Antarctic temperature. The CO2 rise during the H stadial is driven by ocean outgassing. In contrast, the rapid CO2 increase after the transition to the interstadial results from soil carbon release from high NH latitudes originating from substantial warming.
The apparent temperature sensitivity (Q10) of peat soil respiration: A synthesis study
Authors: Liu Haojie , Rezanezhad Fereidoun , Zhao Ying , He Hongxing , Van Cappellen Philippe , Lennartz Bernd
Published: March 2024

The temperature sensitivity (Q10) of soil respiration is a critical parameter in modeling soil carbon dynamics; yet the regulating factors and the underlying mechanisms of Q10 in peat soils remain unclear. To address this gap, we conducted a comprehensive synthesis data analysis from 87 peatland sites (361 observations) spanning boreal, temperate, and tropical zones, and investigated the spatial distribution pattern of Q10 and its correlation with climate conditions, soil properties, and hydrology. Findings revealed distinct Q10 values across climate zones: boreal peatlands exhibited the highest Q10, trailed by temperate and then tropical peatlands. Latitude presented a positive correlation with Q10, while mean annual air temperature and precipitation revealed a negative correlation. A noteworthy discovery was the pronounced negative relationship between the soil carbon-to-nitrogen ratio (C/N) and Q10, echoing the carbon-quality temperature hypothesis that decomposition is more temperature-sensitive in low-quality than in high-quality carbon. However, the relationship between C/N and Q10 varied significantly between peat types. Our data analyses also revealed that Q10 was influenced by soil moisture levels, with significantly lower values observed for peat soils under wet than dry conditions. Essentially, boreal and temperate peatlands seem more vulnerable to global warming-induced soil organic carbon decomposition than tropical counterparts, with wet peatlands showing higher climate resilience.
Titan’s surface chemical composition: what we learnt after 13 years of Cassini exploration
Authors: Solomonidou Anezina , Le Gall Alice , Hayne Paul , Coustenis Athena
Published: March 2024

The Cassini spacecraft spent 13 years in the Saturnian system and performed observations of Titan through 127 flybys, along with the in situ observations of the surface by Huygens. This led to the detailed investigation of Titan’s surface composition at both local and global scale. However, due to the complexity of Titan’s atmosphere and surface, the surface composition is only partially unveiled and is still considered to be one of Titan’s largest mysteries. Titan is resembling Earth like no other body in our solar system even though its mean surface temperature in -180 ºC (~93 K), and instead of silicate rocks like on Earth, water ice is abundant in the crust. Sedimentary deposits in the form of hydrocarbon grains cover the top layer of the surface, while liquid hydrocarbons are found in the polar lakes. Titan’s active geology with its resurfacing processes creates a surficial topography where exposed materials from the underlying ‘old’ crust along with new atmospheric sediments are present. After Cassini and Huygens with their several instruments investigated Titan for more than a decade one of the prevailing questions that still remains unanswered is whether and where water ice is exposed on the surface. Additionally, advanced knowledge with regards to the mixtures and the materials that create and cover the surface is yet to be gained from future missions and ground/space telescopes that would carry advanced technology. Here, we present an overview of what we have learnt so far about the composition as well as its correlation and constraints with regards to Titan’s astrobiology.
Effect of Multi-Walled Carbon Nanotubes on the Carbon and Nitrogen Cycling Processes in Saline Soil
Authors: Zuo Yutian , Zeng Wenzhi , Ao Chang , Lei Guoqing
Published: March 2024

 Soil salinization is a pressing issue that needs to be addressed in current agricultural production. In this study , we utilized novel materials, unfunctionalized multi-walled carbon nanotubes (MWCNT) and functionalized multi-walled carbon nanotubes (MWCNT-OH), to explore the effects of soil carbon and nitrogen cycles in saline soil. We set up four treatments, which were exposed to two exposure doses of 1 g/kg and 1 µg/kg and two MWCNT types of functionalized MWCNT-OH and unfunctionalized MWCNT. Our results demonstrate that exposure of saline soil to 1 g/kg functionalized MWCNT-OH significantly increased the soil inorganic nitrogen (p < 0.05), while also promoting the soil microbial biomass. This exposure can also potentially enhance greenhouse gas emissions from saline soil. Moreover, exposure to MWCNTs significantly increased the proportion of Actinobacteria and Proteobacteria, two dominant phyla (p < 0.05), which in turn improved their contribution to the carbon and nitrogen cycling processes within saline soil. High exposure dose treatments (1 g/kg) significantly increased the abundance of functional genes associated with carbon metabolism, carbon fixation, methane metabolism, and nitrogen cycling processes within saline soil. In contrast, low exposure dose treatments (1 µg/kg) had no significant effect on the abundance of functional genes related to nitrogen cycling, but significantly increased the abundance of special functional genes related to carbon cycling. Redundancy analysis revealed that the microbial community composition within saline soil was significantly impacted by the soil total carbon, total nitrogen, and nitrate nitrogen content. Furthermore, it was observed that over 80% of the carbon and nitrogen cycling processes within the saline soil were contributed by the dominant phyla. In summary , our research confirms the potential applicability of MWCNTs within saline soil. Notably, exposure of saline soil to 1 g/kg functionalized MWCNT-OH exhibited the most significant promoting effect on the carbon and nitrogen cycles.
Melting of hydrous and hydrous-carbonated eclogite in the mantle
Authors: Curtolo Andrea , Condamine Pierre , Bolfan-Casanova Nathalie , Schiavi Federica , Novella Davide
Published: March 2024

Water is a key component at Earth’s surface controlling geomorphological processes and establishing an environment capable of supporting life, but it is also present in the mantle as point defects in the lattice of nominally anhydrous minerals (NAMs). Even in trace amounts (i.e., ppm wt), H2O exerts a profound influence on rock properties such as decreasing the melting temperature, which allows melting to occur at much greater depths with respect to volatile-free conditions, impacting the geochemical evolution of the deep mantle. Therefore, precisely modelling melting processes as a function of volatiles content is of great interest in petrology and requires a precise knowledge of the behavior of volatiles at mantle pressure and temperature.A fundamental parameter used to investigate hydrous melting is the partition coefficient of H2O (DH2Omin/melt = CH2Omin/CH2Omelt), which can be studied at high-pressure high-temperature by performing laboratory experiments. A large number of studies have previously determined the DH2Omin/melt for major mantle phases and mantle conditions in a hydrous system. However, a more comprehensive investigation of the distribution of H2O in the mantle requires also the consideration of CO2, which is the 2nd most abundant volatile in the mantle and is expected to alter the activity of H2O of the system and, consequently, the DH2Omin/melt. Notably, the effect of CO2 on DH2Omin/melt at mantle conditions remains largely unconstrained today.We present the results of a series of 2 GPa-1200°C piston cylinder experiments investigating an eclogitic system, where clinopyroxene (+garnet) crystals were equilibrated with melt. The experiments were conducted at hydrous and hydrous-carbonated conditions with different amounts of CO2. The experimental charges were recovered, and minerals and melts were investigated by electron microprobe analyses, to determine chemical composition and Fourier Transform Infra-Red and Raman spectroscopy to determine the H2O contents. The experiments highlight a strong effect of CO2 content on decreasing DH2Omin/melt. The new results are used to discuss melting processes interesting eclogitic lithologies in the deep mantle and at representative chemical compositions.
Palaeo-groundwater levels in the sandy-soil landscapes of The Netherlands prior to human influence  
Authors: Chaulagain Laxmi , Candel Jasper , van der Meij Marijn , Wallinga Jakob , Larsen Annegret
Published: March 2024

The sandy soil regions often experience excess water during winters and scarcity during summers, contributing to a compromised water situation in the Netherlands. The declining groundwater table, influenced by meteorological drought and anthropogenic activities such as intensive drainage and groundwater extraction, is putting land use and biodiversity that rely on phreatic groundwater at risk. Currently, spatial planning hardly considers natural soil and water systems, rendering the sandy regions unsustainable for the future. Thus, there is a need for a paradigm shift: land use should align with natural potential rather than human needs. Understanding how landscapes function with minimal human influence is crucial for applying natural principles to future climate-robust land use planning. Therefore, a study will be conducted in the Wapserveensche Aa catchment, situated in the sandy regions of the Netherlands, with the aim of developing a spatially explicit quantitative understanding of the natural soil-water land use system. The methodology involves reconstructing palaeo-groundwater levels and relevant hydrology from the Middle Holocene (2000-4000 BCE), utilizing a regionally calibrated numerical model (MIPWA) combined with field observations. MIPWA is a groundwater model with the combination of MetaSWAP (unsaturated zone) and MODFLOW (saturated zone) having a resolution of 25 m. Existing data on climate, topography, hydrological network, and vegetation will serve as model inputs, and unavailable data will be reconstructed using existing knowledge and resources. Model output (historical groundwater levels) will be validated with historical maps and data, hydro-pedological data (soil profiles, redox features, podzolic features), and archaeological findings associated with groundwater (e.g., past settlements). The existing hydro-pedological data from soil surveys and/or research will be supplemented by additional fieldwork and data collection as needed. The results obtained can be utilized to determine nature-based land use, making sandy landscapes with a nature-based phreatic water table sustainable and climate-robust in the Netherlands or beyond. Additionally, this research will contribute to expand the method of palaeo-groundwater reconstructions and promote nature-based solutions.
Sentinel-1 Insights into interseismic coupling along the plate boundary of the Western Makran Subduction Zone
Authors: Sobouti Alireza , Samiei Esfahany Samie , Sharifi Mohammad Ali , Abolghasem Amir M. , Bahroudi Abbas , Friedrich Anke M.
Published: March 2024

The Makran Subduction Zone (MSZ) of Iran and Pakistan, where the oceanic Arabian plate is sinking beneath the overriding continental Eurasian plate, is among the least explored subduction zones. Limited geodetic measurements, especially in the Western MSZ (WMSZ) with lower seismicity, have posed challenges in assessing the potential for future seismic events. The extensive spatial coverage offered by the Interferometric Wide-Swath (IW) mode of Sentinel-1 Interferometric Synthetic Aperture Radar (InSAR) allows for measuring tectonic deformation at a scale of millimeters per year across distances spanning hundreds of kilometers. Nevertheless, the presence of other signals and errors­­­­­—with similar spatio-temporal patterns to the signal of interest—poses challenges to accurately estimating the low-amplitude, large-scale subduction-induced deformation from InSAR observations.In this contribution, we analyze more than eight years of continuous Sentinel-1 InSAR data from both ascending and descending orbits in the WMSZ area of Iran, to capture the Line-Of-Sight (LOS) interseismic crustal deformation rate. Our approach integrates a comprehensive and novel atmospheric mitigation strategy, accompanied by corrections for non-tectonic processes and rigid plate motion, aiming to isolate the tectonic-related signal from other non-tectonic signals and errors. In the following step, we investigate three trench-perpendicular profiles to infer the spatial and along-dip distribution of plate coupling from the Line-Of-Sight (LOS) deformation rates obtained through InSAR.Due to the limited InSAR coverage near the trench (as located beneath the sea), it is not possible to constraint coupling in that area that extends 150 km far from the trench and reaches a depth of 10 km. Our findings reveal significant variations in interseismic coupling from west to east. We observe regions of weak and strong coupling, located near Jask (the westernmost part of the WMSZ) and Chabahar (the easternmost part of the WMSZ), respectively. The middle profile, located near the epicenter of a 5.9 magnitude earthquake that occurred in 1989 (Mw 5.9), exhibits a moderate coupling of 65 percent. Additionally, the coupling is notably high at depths between 10 and 20 km, gradually decreasing to zero at depths between 30 and 40 km.In summary, the enhanced spatial resolution of InSAR, along with the high precision of deformation rates provided by the advanced error mitigation on the long time series of Sentinel-1 significantly improves our ability to characterize the locking depth at which the boundaries between two plates are accumulating stress in WMSZ.
The global distribution of ice-nucleating particles and their impacts on cirrus clouds and radiation derived from global model simulations
Authors: Beer Christof , Hendricks Johannes , Righi Mattia
Published: March 2024

Atmospheric aerosols can act as ice-nucleating particles (INPs) thereby influencing the formation and the microphysical properties of cirrus clouds. However, the knowledge on the atmospheric distribution of INPs is still limited and consequently the understanding of their climate impacts is highly uncertain. We perform model simulations with a global aerosol-climate model coupled to a two-moment cloud microphysical scheme and a parametrization for aerosol-induced ice formation in cirrus clouds and present a global climatology of INPs in the cirrus regime. In addition to the broadly considered mineral dust and soot INPs, this climatology also comprises crystalline ammonium sulfate and glassy organic particles. The simulated INP number concentrations range from about 1 to 100 L−1 and agree well with in-situ observations and other global model studies. Our model results show large ammonium sulfate INP concentrations, while the concentrations of glassy organic INPs are mostly low in the cirrus regime. By coupling the different INP-types to the microphysical cirrus cloud scheme, we analyze their ice nucleation potential under cirrus conditions, considering possible competition mechanisms between different INPs. The resulting radiative forcing of the total INP-cirrus effect, considering the difference between a simulation with all different INP-species and a simulation with purely homogeneous freezing, is simulated as −28 and −55 mW m−2, assuming a smaller and a larger ice-nucleating potential of INPs, respectively. While the simulated impact of glassy organic INPs is mostly small and not significant, ammonium sulfate INPs introduce a considerable radiative forcing, which is nearly as large as the combined effect of mineral dust and soot INPs. Assuming a larger ice-nucleating potential of INPs, the INP-cirrus effect due to anthropogenic INPs, considering the difference between present-day (2014) and pre-industrial (1750) conditions, is simulated as −29 mW m−2.
Estimating current and future saltmarsh areas and carbon storage in Irish Blue Carbon habitats
Authors: Fuchs Andrea , Burke Shannon , Delamer Isabelle , Cott Grace
Published: March 2024

Saltmarshes protect the coast against storm surges and erosion, are important ecosystems for breeding and sheltering birds and fishes, and sequester large amounts of carbon in their soils. Natural plant colonisation of mudflats as well as future sea-level rise will contribute to new saltmarsh formation and additional managed realignment projects can improve national capacities to meet climate targets. In this study, we’re investigating the current and future extent of saltmarshes in Ireland and estimate their carbon storage potential. The areas of current saltmarshes are identified based on literature and openly available GIS data. The potential natural development and expansion of existing saltmarshes is analysed using mean and extreme water level data from marine tidal gauges and topographic elevation data of the adjacent terrestrial areas. Further, carbon storage in up to 1 m deep soils was determined in various types of saltmarshes in a nationwide field campaign and upscaled to estimate future blue carbon potential. Results show that e.g. saltmarshes in County Dublin could increase from 181 ha to 227 ha due to natural saltmarsh expansion, with a potential increase of stored carbon by 22,688 Mg Corg and avoiding the emission of 83,264 t CO2. However, saltmarsh depth plays a significant role in carbon sequestration. Thus, when considering carbon storage in only 10 cm deep soils the estimated carbon storage increase is reduced to 1,588 Mg Corg and 5,828 t CO2 emission avoided. Further, our results indicate that Irish saltmarsh plants sequester less carbon than species in China or the United States, thus lowering global blue carbon estimates. Results of this study will serve as a basis for managers and policymakers estimating carbon credit potentials of saltmarshes and planning Managed Realignment projects.
Remote sensing data assimilation for in-season wheat yield predictions
Authors: Quade Maria , Attia Ahmed , Preidl Sebastian , Baatz Roland , Borrmann Peter , Feike Til
Published: March 2024

In-season information on expected crop yields is important for farmers' crop management and business planning, as well as for the entire agricultural and food sector. In addition, timely information on possible extreme yield losses in specific production regions allows early decisions in European agricultural policy, e.g. on possible aid payments to producers. Yield losses are mainly caused by adverse and extreme weather conditions such as heat, drought, late frost, heavy rainfall and floods as well as by pests and diseases. Such events are difficult to predict and their actual impact on yields depends on a variety of factors. With ongoing climate change, such adverse conditions and the risk of yield losses are likely to increase (Lüttger and Feike, 2018).Process-based crop simulation models (CSM) simulate crop growth, development and yield formation, taking into account local soil and weather conditions and potential abiotic stress. For local applications, where actual growth conditions and crop management (e.g., sowing date, cultivar, fertilisation) are known, CSM can be utilized during the season to provide insights into expected crop yields. However, for large-scale applications these information are mostly unknown, which hampers site-specific yield predictions on regional or even national scale. Furthermore, the accuracy of site-specific weather and soil data is limited and actual growing conditions may differ from those assumed in a CSM-based assessment based on such data from national databases.Point-specific current data on actual crop status derived from remote-sensing can be used to fill those data-gaps and inaccuracies (Guo et al., 2018). Utilizing the newly available high-resolution hyperspectral data from the Environmental Mapping and Analysis Program (EnMAP), a radiation-transfer-model is used to derive pixel-specific state variables of LAI. The actual LAI values are then integrated into a CSM for in-season crop yield predictions on pixel-level. As remote sensing derived crop status data will only be available in the second half of the project phase, we will first use existing observation data from field experiments to mimic the remote sensing data and establish two common data assimilation routines (ensemble Kalman and particle filter) and respective processing pipelines in an ex-post modeling study. After evaluation of the most promising data assimilation technique, the approach will be extended to develop a German-wide winter wheat yield forecast for the current season by using climate forecast data from the DWD. The approach can later be extended to other crops and crop state variables.
Viscoelastic relaxation of the lithosphere beneath the Martian polar caps: Implications for the polar caps’ formation history and planetary thermal evolution
Authors: Broquet Adrien , Wieczorek Mark A. , Breuer Doris
Published: March 2024

Mars harbors two geologically young (
Using Google Earth Engine to map landslide hazard and exposure across Nepal
Authors: Harvey Erin , Rosser Nick , Kincey Mark , Densmore Alexander , Shrestha Ram , Singh Pujara Dammar , Dunant Alexandre , Van Wyk de Vries Max , Arrell Katherine
Published: March 2024

Nepal is one of the most susceptible countries to landsliding, with much of the country characterised by steep topography, annual monsoon rainfall and active tectonics. Current understanding of landslides in Nepal is predominantly based on static, catchment-scale landslide inventories or centred around data from specific events, such as the 2015 Gorkha earthquakes. Whilst static inventories provide a useful snapshot of past landslide characteristics, we cannot use these to infer how long landslides persist or how the hazard posed by landslides may evolve through time. In addition, the large number of small-scale inventories that currently exist cannot be readily compared, making it difficult to assess whether trends observed in specific catchments can be applied on a national scale. In this study, we aim to utilise advances in openly accessible remote sensing of large geospatial datasets, namely Google Earth Engine, to record the spatial and temporal evolution of landslides across the full extent of Nepal. We build on an existing automated landslide detection algorithm in Google Earth Engine to compile a national scale landslide probability map, which is re-mapped annually. This allows us to capture changes in landslide hazard both spatially and temporally across the country. The algorithm uses NDVI differencing to identify possible new landslides. Our work seeks to refine this output by using landslide-specific information obtained from a series of existing manually mapped landslide inventories. This step includes applying spectral and object-based filters as well as using susceptibility metrics, such as topography, trained using manually mapped landslide inventories. By adding a landslide-specific filtering step, we aim to build on existing NDVI differencing approaches and improve per pixel landslide probability values. We present preliminary findings using this record of landslide hazard through time to better understand controls on slope failure evolution and persistence, to tackle questions such as whether new landslides evolve and runout from existing landslides, to consider how landslide mechanism changes through time, and how hazard translates into physical exposure through the use of metrics such as landslide proximity to roads and buildings.
Impact of multiscale heterogeneities on the nucleation of earthquakes
Authors: Lebihain Mathias , Roch Thibault , Violay Marie , Molinari Jean-François
Published: March 2024

Earthquake nucleation is traditionally described using cascading or slow pre-slip models. In the latter, nucleation occurs as the sudden transition from quasi-static slip growth to dynamic rupture propagation. This typically occurs when a region of the fault of critical size Lc, often called nucleation length, is sliding. This transition is relatively well-understood in the context of homogeneous faults. Yet, faults exhibit multiple scales of heterogeneities that may emerge from local changes in lithologies or from its self-affine roughness. How these multiscale heterogeneities impact the overall fault stability is still an open question.Combining the nucleation theory of [Uenishi and Rice, JGR, 2003] and concepts borrowed from statistical physics, we propose a theoretical framework to predict the influence of brittle/ductile asperities on the nucleation length Lc for simple linear slip-dependent friction laws. Model predictions are benchmarked on two-dimensional dynamic simulations of rupture nucleation along planar heterogeneous faults. Our results show that the interplay between frictional properties and the asperity size gives birth to three (in)stability regimes: (i) a local regime, where fault stability is controlled by the local frictional properties, (ii) an extremal regime, where it is governed by the most brittle asperities, and (iii) a homogenized regime, in which the fault behaves at the macroscale as if it was homogeneous and the influence of small-scale asperities can be averaged.  Using this model, we explore the overall stability of rough faults, featuring multiscale distributions of frictional properties. We also investigate the stability of velocity-neutral faults that features brittle asperities. Overall, our model provides a theoretical basis to discriminate which heterogeneity scales should be explicitly described in a comprehensive modelling of earthquake nucleation, and which scales can be averaged.
Drought stress vulnerability for mature versus young trees in a mixed temperate forest stand
Authors: Hoch Guenter , Dups Raphael , Peters Richard , Steger David , Zhorzel Tobias , Kahmen Ansgar
Published: March 2024

Drought can affect mature and young trees differently, and many studies suggested that large trees might be more prone to drought-related damage and mortality than conspecific smaller individuals. A higher drought vulnerability for tall trees is generally assigned to increasing constraints to water transport with tree height, but a multitude of other biotic and abiotic factors can additionally contribute and modulate their drought resistance. The interrelation of these factors and its consequences for the different drought vulnerabilities between small and dominant trees is so far not well understood and awanting exploration.Within our study, we took advantage of the Swiss Canopy Crane II (SCC II) site to simultaneously measure critical physiological parameters related to drought stress, namely, pre-dawn and mid-day leaf water potentials (LWP) and stomatal conductance, of mature, ca. 30 m tall individuals and small saplings of 9 common temperate European tree species. These measurements took place throughout the growing season 2023 that was characterized by high temperatures and extended dry periods in late summer and early autumn. Independent of tree size, the increasingly drier conditions caused pre-dawn and mid-day LWP to decrease significantly along the season, with mature trees of some species showing values close or at the species-specific P50 threshold (i.e. the LWP where 50 % loss of xylem conductivity is expected). Our results show that mature trees experienced overall more negative LWP than saplings. Most of these differences could be explained by increasing hydrostatic constraints with increasing tree height. However, even after accounting for this hydrostatic effects (-0.01 MPa per meter tree height), there remained significant differences in pre-dawn and mid-day LWP between mature trees and sapling in some of the investigated species, that were likely caused by either 1) microclimatic effects (especially VPD differences between the upper canopy and the understory), 2) different abilities to refill tree-internal water stores during the night, or 3) differences in soil water access due to rooting differences. Following this first assessment, we are planning to expand our investigations in the next years to better disentangle these different factors that significantly contribute to differences in drought vulnerability with tree size in different tree species, with important implications for the future state and population dynamics of temperate forests.
Transforming public spaces towards user-friendly, climate resilient and energy producing spaces - the BARTLETT
Authors: Tötzer Tanja , Bügelmayer-Blaschek Marianne , Jung Martin , Schneider Martin , Berg Romana , Berger Karl , Tillner Silja , Willinger Alfred , Grimm Karl , Zluwa Irene , Stefan Elia
Published: March 2024

Urban areas are severely affected by climate change, as the associated increase in temperature and precipitation intensity are further exacerbated by the prevailing morphology of densely built areas and the prevalence of sealed surfaces. Especially heat has been recognised as an increasing risk and therefore, appropriate adaptation measures such as nature-based solutions (NbS) have been studied extensively.Space is scarce and valuable in cities and the usability of urban spaces has gained a growing attention in the last years – not only in the sense of climate adaptation but also for climate protection, as the energy transition calls for the implementation of renewable energy sources, where public spaces offer great potential for PV-suitable areas. In addition, an increasing number of people living in cities demand more living space and put even more pressure on available public spaces.These three aspects form the basis of the presented study, where a highly frequented public space, the Volkertplatz in Vienna is chosen to be transformed into a climate-resilient, user-friendly and energy-generating space. To achieve this, the following steps are necessary: (i) analysis of the current and future local climate conditions, (ii) incorporating and understanding the needs of the local users, (iii) design of the BARTLETT (Blue-green energy-generating canopied seating and communication facility) and (iv) implementation of an appropriate process of involvement of the local authorities.The analyses show that the current design of the space prevents the infiltration of rainwater, intensifies the prevailing heat load in summer and mainly meets the needs of male users. Therefore, the transformed space needs to reduce the identified barriers in order to improve the quality of the Volkertplatz.  A key element is the BARTLETT, a construction that improves the local microclimate, collects rainwater for irrigation of the plants and produces energy through the installed PV collectors. Furthermore, the design enhances the usability of the square by different groups, providing both open and more hidden spaces. To ensure the acceptance of local citizens, their needs have been identified, their behaviour observed, and their opinions incorporated through workshops. As important as the local support, is the timely involvement of relevant political stakeholders, which is ensured by the project partners and collected in a handbook to allow transferability to other public spaces.