bluuebunny/crossref_metadata_2025 huggingface dataset:
What does Net Zero mean for reactive gases?
Authors: Collins William
Published: March 2024

The decrease in carbon dioxide concentrations following a zeroing of emissions leads to a cooling that approximately balances the hidden warming from past emissions, due to the similarity of the timescales of climate response and carbon cycle response. But what are the climate implications of zero emissions of chemically-reactive gases such as nitrous oxide, halocarbons and methane with response timescales that don’t align with those of the climate system?In this work we invert the analytical formulae used by the IPCC to represent the evolution of climate, to derive the time evolution of radiative forcing needed to stabilise temperatures. We find that stabilising the warming attributable to any gas requires decreases in radiative forcing that depend on the past history of that gas (more rapid historical ramp-up requires stronger future mitigation). We show that for reactive gases the analytically-derived radiative forcing decreases are most closely matched by step-like cuts in emissions, but that even for long-lived gasses such as nitrous oxide the emissions cuts do not need to be 100%. N2O emission cuts of 60-80% are sufficient to stabilise its temperature contribution - depending on the previous emission history.It has been suggested that a more ambitious goal is to mitigate reactive gases sufficiently that their contribution to temperatures reduces rather than stabilises. We show that the above methodology can equally be applied to a declining temperature profile and so were are able to quantify the cuts in reactive gas emissions consistent with achieving desired cooling goals.
A boreal summer warming in the subsurface of the Bay of Bengal and its dynamics
Authors: Chen Tuyi
Published: March 2024

A pronounced subsurface warming occurs in the southern Bay of Bengal (BOB) during the summer monsoon (from July to September), as revealed by the data from Array for Real-time Geostrophic Oceanography (Argo). This subsurface warming can be attributed to the deepened thermocline, which plays a crucial role in regulating the ocean subsurface temperature. The variations of thermocline in the southern BOB are primarily influenced by local and remote forcing, with local forcing dominating and remote forcing being a secondary contributor. To better understand the individual effects of each forcing mechanism, a 1.5-layer reduced gravity model is employed in this study. The model shows that the equatorial zonal wind stress reaches its first peak in May, inciting downwelling Rossby waves from the eastern boundary of BOB. These equatorial waveguides rapidly deepen the thermocline of the entire southern BOB in June. From July to September, the southwest monsoon intensifies and prevails, forcing the annual Rossby wave and local Ekman pumping that sustains the thermocline in the southwestern BOB. Simultaneously, the remote forcing causes negative effect by shoaling the thermocline in the eastern region, thus accentuating the observed warming trend in the west. This study discusses the complex air-sea interaction in the BOB, contributing to a deeper understanding of the upper thermal structure within BOB. In addition, the findings provide valuable insights to enhance weather forecasting capabilities in the surrounding countries.
Examining the Spatial-Temporal Evolution of the Chongzhen Drought (1627-1644) in China and Its Impact on Famine
Authors: Chen Siying , Su Yun , Chen Xudong , Yang Liang Emlyn
Published: March 2024

Climate change is a critical context for the development of human civilization. Case studies on the societal impacts of climate change contribute to the understanding of the mechanisms of interactions between natural forces, ecosystems, and human societies. This study investigates the Chongzhen Drought occurring in 1627-1644 in China, which was very likely the worst drought in eastern China in the past 1500 years. Its duration, scope, and number of people affected are rare in history. At the same time, a large-scale famine broke out, which is argued as a main trigger of the peasant uprisings that led to the fall of the Ming Dynasty. This paper extracted 1,802 drought records and 1,977 famine records from Chinese historical documents (mainly local chronicles and history books) and reconstructed the spatio-temporal evolution of drought from 1627 to 1644 in eastern China as well as its impact on famine. First, we classified the drought events into four levels according to the duration and severity, based on the semantic differences. Then the kernel density estimation was used to reconstruct the spatial pattern of drought at annual resolution, as well as a series of Drought Kernel Density Index (DKDI) in different regions. The main drought area in 1627-1644 was located north of 29°N and shifted from Northwest China to North China and then expanded to the south. The development of drought in different regions was not synchronized. The DKDI series of North China approximated a single-peaked curve, with the drought gradually worsening from 1633-1640; the peak of DKDI in Northwest China also appeared in 1640. However, the DKDI series of the Yangtze-Huai Region showed a multi-peaked curve, constantly experiencing a cycle of drought aggravation-reduction in the early period and reaching its peak in 1641. Second, the spatio-temporal evolution of famine was also reconstructed and compared with drought. It showed that the range of drought and famine largely overlapped and their developing trends were generally similar.  However, the movement of the Famine Kernel Density Index (FKDI) series tended to be 1-2 years later than that of DKDI, suggesting a lag and continuation of transmission of drought impacts to the human system. Finally, the regression analysis showed that drought was the most critical factor triggering famine in this case with a contribution weight of 67.3%. The weight is higher at 73.4% in North China in comparison with other subnational regions. The study identified the transmission pathway from climate change to social consequences through “persistent drought → declining agricultural harvests → food shortage → famine”. While socioeconomic factors and human behaviours also played various roles in regulating the transmission process.
Scale Size Estimation of Magnetosheath Jets
Authors: Pöppelwerth Adrian , Glebe Georg , Mieth Johannes Z. D. , Koller Florian , Karlsson Tomas , Vörös Zoltan , Plaschke Ferdinand
Published: March 2024

Transient enhancements in the dynamic pressure, so-called magnetosheath jets or simply jets, are abundant in the magnetosheath.They propagate from the bow shock towards the magnetopause. On their way through the magnetosheath, jets interact with theambient plasma. The scale size of jets is determined almost exclusively with statistical studies, but not for individual jet events.We use multipoint measurements from the Time History of Events and Macroscale Interactions during Substorms (THEMIS) missionto study the passage of a single jet and obtain its size. We observe an evasive motion of the plasma on the jet path. Using thisflow pattern we can reconstruct the position of the central axis of this jet along its propagation direction. This allows us toestimate the spatial distribution of the dynamic pressure within the jet. Furthermore, the size perpendicular to thepropagation direction can be estimated for different cross sections. Using this method, the scale size of individual jet eventscan be determined with multiple spacecraft. In principle, only two spacecraft are needed if we assume a simplified geometry.In the case we investigated, both the dynamic pressure and the perpendicular size increase along the propagation axis fromthe front part towards the center of the jet and decrease again towards the rear part.
A probabilistic model for slope stability analysis including the root reinforcement effects
Authors: Galeazzi Sara , Ciabatta Luca , Brocca Luca , Salciarini Diana
Published: March 2024

The presence of vegetation plays an important role in slope stability, especially in triggering of shallow landslides. It influences the mechanical and hydrological behaviour of soils, generating both stabilizing and destabilizing actions [1,2]. Variation in vegetation related to land use change can affect slope stability and can be evidenced in terms of variation of probability of failure.In this study we implement a module for the calculation of root reinforcement in the slope stability physically-based probabilistic model PG_TRIGRS (Probabilistic, Geostatistic-based, TranSient Rainfall Infiltration and Grid-based Slope stability, [3]). Such model allows the wide-area assessment of the probability of rainfall-induced failure, considering the spatial variability of the soil properties treated as random variables. In this work, we apply the model to an area prone to landslides in Central Italy assuming the spatial variability of vegetation.To investigate the influence of the spatial layout of plant roots on slope stability, the root reinforcement is implemented in the PG_TRIGRS probabilistic model. The considered root cohesion values  were derived from literature and were determined according to vegetation maps available for the study area. In addition, root cohesion variation is also considered along the vertical profile as a function of rooting depth. Finally, the resulting probability of failure distribution is compared to the results obtained for the bare soil with the absence of roots.[1] Pollen-Bankhead, N., & Simon, A. (2010). Hydrologic and hydraulic effects of riparian root networks on streambank stability: Is mechanical root-reinforcement the whole story?. Geomorphology, 116(3-4), 353-362.[2] Masi, E. B., Segoni, S., & Tofani, V. (2021). Root reinforcement in slope stability models: a review. Geosciences, 11(5), 212.[3] Salciarini, D., Fanelli, G., & Tamagnini, C. (2017). A probabilistic model for rainfall—induced shallow landslide prediction at the regional scale. Landslides, 14, 1731-1746.
Quantifying the effects of rainfall temporal variability on landscape evolution processes
Authors: Lian Taiqi , Peleg Nadav , Bonetti Sara
Published: March 2024

Rainfall characteristics such as intensity, duration, and frequency are key determinants of the hydro-geomorphological response of a catchment. The presence of non-linear and threshold effects makes the relationship between rainfall variability and geomorphological dynamics difficult to quantify. This is particularly relevant under predicted exacerbated erosion induced by an intensification of hydroclimatic extremes. In this study, we quantify the effects of changes in rainfall temporal variability on catchment morphology and sediment erosion, transport, and deposition across a broad spectrum of grain size distributions and climatic conditions. To this purpose, multiple rainfall realizations are simulated using a numerical rainfall generator, while geomorphic response and soil erosion dynamics are assessed through a landscape evolution model (CAESAR-Lisflood). Virtual catchments are used for the numerical experiments and simulations are conducted over centennial time scales. Simulation results show that higher rainfall temporal variability increases net sediment discharge, domain erosion and deposition volumes, and secondary channel development. Particularly, dry regions respond more actively to rainfall variations and finer grain size configurations amplify the hydro-geomorphological response. We find that changes in erosion rates due to rainfall variations can be expressed as a power-law function of the ratio of rainfall temporal variabilities (quantified here through the Gini index). Results are further supported by long-term observational data and simulations over real catchments. Such quantification of the effects of predicted changes in rainfall patterns on catchment hydro-geomorphic response, as mediated by local soil properties, is crucial to forecasting modifications in sediment dynamics due to climate change.
Advances and Prospects of Deep Learning for Medium-Range Extreme Weather Forecasting
Authors: Olivetti Leonardo , Messori Gabriele
Published: March 2024

In recent years, deep learning models have rapidly emerged as a standalone alternative to physics-based numerical models for medium-range weather forecasting. Several independent research groups claim to have developed deep learning weather forecasts which outperform those from state-of-the-art physics-basics models, and operational implementation of data-driven forecasts appears to be drawing near. Yet, questions remain about the capabilities of deep learning models to provide robust forecasts of extreme weather.Our current work aims to provide an overview of recent developments in the field of deep learning weather forecasting, and highlight the challenges that extreme weather events pose to leading deep learning models. Specifically, we problematise the fact that predictions generated by many deep learning models appear to be oversmooth, tending to underestimate the magnitude of wind and temperature extremes. To address these challenges, we argue for the need to tailor data-driven models to forecast extreme events, and develop models aiming to maximise the skill in the tails rather than in the mean of the distribution. Lastly, we propose a foundational workflow to develop robust models for extreme weather, which may function as a blueprint for future research on the topic.
Empowering Human-Water System Analysis through ABSESpy: An Agent-Based Modeling Framework of SES
Authors: Song Shuang , Wang Shuai , Jiao Chentai , José Mantilla Elías
Published: March 2024

ABSESpy emerges as an agent-based modeling (ABM) framework for socio-ecological systems (SES) research. By adeptly addressing pivotal needs in SES studies, such as decision-making complexity and data integration, ABSESpy sets a new tool for integrating human and natural subsystems, ensuring replicability and effective model coupling. Here, we demonstrate ABSESpy’s prowess in human-water systems analysis through two real-world application cases. The first delves into the impact of water management policy changes over the past fifty years on river basin water usage. This case underscores ABSESpy's proficiency in modeling policy effects and capturing human responses within water management. The second case takes a deep dive into the millennia-long evolution of human livelihood patterns, influenced by dynamic shifts in the water environment. This exploration showcases ABSESpy's capability to simulate extensive, temporal, socio-hydrological phenomena, providing profound insights into enduring human-water interplays. Our belief is firm: socio-hydrological systems, as quintessential SESs, can be effectively studied through data-driven agent-based modeling. ABSESpy is a testament to this approach, enhancing efficiency and depth in SES research. 
Sensor-based Multi-Level Analysis of Ferronickel Furnace Slag: Exploring Economic Opportunities   
Authors: Desta Feven , Kamps Oscar , Buxton Mike
Published: March 2024

The ever-growing demand for mining products has led to the extraction and processing of large volumes of materials, resulting in the production of significant amounts of mine waste. While the composition of mine waste materials can vary and may cause environmental impacts, they can also be a valuable source of raw materials to meet the current and future mineral demand. The efficient re-mining of minerals of economic interest from mine waste materials (such as slag) requires accurate and reliable estimation. This can be achieved using state-of-the-art sensor technologies coupled with advanced data analytics. Such technologies include laser-induced breakdown spectroscopy (LIBS), x-ray fluorescence (XRF), short-wave infrared (SWIR) and Fourier transform infrared spectroscopy (FTIR). This study evaluates the usability of LIBS, FTIR, SWIR, and XRF technologies for the characterization of Ferronickel slag materials at a multi-level. Methodological approaches were developed to assess the usability of each technique for the identification, classification, or semi-quantification of the target elements (such as Ni, Ti, Pb, and Cr) in the analyzed samples. The results demonstrate that the use of the techniques enabled a comprehensive compositional analysis of slag materials. Moreover, the findings suggest that such an approach could promote sustainable mining practices by providing valuable insights into the potential economic benefits of reusing slag materials for secondary recovery. Such an approach could contribute to reducing the possible environmental impact of waste and could enable achieving a circular economy.
Seismicity, Segmentation and Structure of the Blanco Transform Fault System in the Northeast Pacific
Authors: Lange Dietrich , Ren Yu Ren , Grevemeyer Ingo
Published: March 2024

The Blanco transform fault system (BTFS) in the northwest off the coast of Oregon is highly segmented and one of the newly evolving transform faults. While for most transform systems, no high-resolution seismological data is available, the BTFS was instrumented with a dense network of 54 ocean-bottom-seismometer stations in 2012-2013.  We use one year of ocean-bottom-seismometer data from the Blanco Transform OBS Experiment (network code X9) to compare the seismicity with high-resolution multibeam bathymetry, aeromagnetic, and gravity datasets to study the seismotectonics of the BTFS. We determine P and S-phase arrivals using a new machine learning picker trained on OBS data to create a high-resolution local seismicity catalogue. We compare seismicity catalogues based on different picking algorithms and event associators, including an automated phase picker for OBS data (PICKBLUE) using the hydrophone and seismometer channels. In total, we locate ~9.000 local events, which reveal lateral deformation along the BTFS in very high detail, including smaller step-overs, transtensional structures, and focused seismicity along the fault trace and several ~15 km long aseismic segments along the BTFS. At segments where the BTFS is linear, most seismicity is very concentrated to the transform fault, suggesting that the deformation is within +/-7 km of the fault trace and, hence, very focused. Furthermore, we will present vp and vp/vs velocity models, which reveal the three-dimensional structure of the BTFS and compare the seismicity with seismic velocities.  The local seismicity indicates substantial along-strike variations, indicating different slip modes in the eastern and western BTFS. Seismic slip vectors suggest that the eastern BTFS is a mature transform fault system accommodating the plate motion. At the same time, the western BTFS is immature as its re-organization is still ongoing.The available datasets provide no evidence of either transform faults or fracture zones around the BTFS before 2 Ma, supporting that there were no pre-existing transform faults before the initiation of the BTFS. Therefore, we suggest that the BTFS developed from two broad transfer zones instead of pre-existing transform faults. Furthermore, we applied the deep learning phase picker, to analyse an extensive OBS dataset over three years, including a total of 225 OBS deployments (network codes: 7D, X9, and Z5) deployed offshore the south-central Cascadia subduction zone, south of the BTFS. As a result, ~7000 well-constrained local events were derived, providing new insights into offshore fault dynamics and the segmentation of the Gorda ridge  South of the BTFS. 
Sun-as-a-star Spectroscopic Observations of the Line-of-sight Velocities of Solar Eruptions
Authors: Xu Yu , Lu Hongpeng , Tian Hui
Published: March 2024

The propagation direction and true velocity of a solar coronal mass ejection, which are among the most decisive factors for its geo-effectiveness, are difficult to determine through single-perspective imaging observations. Here we show that Sun-as-a-star spectroscopic observations, together with imaging observations, could allow us to solve this problem. Using observations of the Extreme Ultraviolet Variability Experiment (EVE) onboard the Solar Dynamics Observatory (SDO), we found clear blueshifted secondary emission components in extreme-ultraviolet spectral lines during a solar eruption on 2021 October 28. From simultaneous imaging observations, we found that the secondary components are caused by a mass ejection from the flare site. We estimated the line-of-sight (LOS) velocity of the ejecta from both the double Gaussian fitting method and the red-blue asymmetry analysis. The results of both methods agree well with each other, giving an average LOS velocity of the plasma of ∼423 km s−1. From the 304 Å image series taken by the Extreme ultraviolet Imager onboard the Solar Terrestrial Relation Observatory-A (STEREO-A) spacecraft, we estimated the plane-of-sky velocity from the STEREO-A viewpoint to be around 587 km s−1. The full velocity of the bulk motion of the ejecta was then computed by combining the imaging and spectroscopic observations, which turns out to be around 596 km s−1 with an angle of 42.4 degrees to the west of the Sun–Earth line and 16.0 degrees south to the ecliptic plane.Similar technics were applied to other eight events after systematically searching Sun-as-a-star spectra observed by the EVE/SDO from 2010 May to 2022 May. We identified eight CMEs associated with flares and filament eruptions by analyzing the blue-wing asymmetry of the O III 52.58 nm line profiles and estimated their full velocivites as well as propagation directions. We find a strong correlation between geomagnetic indices (Kp and Dst) and the angle between the CME propagation direction and the Sun–Earth line, suggesting that Sun-as-a-star spectroscopic observations at extreme-ultraviolet wavelengths can potentially help to improve the prediction accuracy of the geoeffectiveness of CMEs. Moreover, an analysis of synthesized long-exposure Sun-as-a-star spectra implies that it is possible to detect CMEs from other stars through blue-wing asymmetries or blueshifts of spectral lines.
Coupling hydrological and geotechnical models for enhanced flood–landslide cascading disaster modelling
Authors: Asurza Véliz Flavio Alexander , Hürlimann Marcel , Medina Vicente
Published: March 2024

Flash floods, fluvial floods and shallow landslides triggered by intense rainfall present substantial threats to both human lives and infrastructure. Furthermore, floods and landslides often manifest in a cascading sequence, where an initially lower-consequence event like heavy rainfall can lead to more severe floods and/or landslides, intensifying the impact to affected communities. Losses resulting from these combined hazards may be significantly greater than the sum of losses from individual hazards. Therefore, there is a crucial need to integrate hydrological and geotechnical modelling into an integrated flood–landslide cascading preparedness and hazard management. This research introduces a coupled flood and landslide initiation modelling system, integrating a temperature index-based snowmelt model (SNOW-17), the Coupled Routing and Excess STorage (CREST) model, and the Fast-Shallow Landslide Assessment Model (FSLAM). The proposed approach is evaluated in the Val d’Aran region that experienced multiple landslides and important flooding due to a combination of heavy rainfall and snowmelt in June 2013. The coupled-model involves three main steps: i) The SNOW-17 model is applied to quantify the snow melting process which is further included in ii) the hydrological model CREST in order to estimate soil water content conditions, discharge and flood extent. Later, iii) the FSLAM model generates landslide susceptibility maps based on the hydrological model outputs, and finally iv) a random walk runout model will determine the landslides trajectories and the amount of sediment that may reach the river network. Preliminary results, related to snow, hydrological and landslide model calibration, have shown good statistical performance when comparing modelled daily soil water equivalent and daily hydrographs with observations from 2012-2020. Landslide predictions also showed a good accuracy (72%). Further steps will try to include the cascading effect of sediments being delivered to drainage network during landslides episodes. This study highlights the importance of the physical connection among snow melting, hydrological processes and slope stability, and aims to provide a prototype model system for operational forecasting of floods and landslides.
The Ouarmdaz region: A new copper-silver potential of the Igherm inlier (Western Anti-Atlas, Morocco).
Authors: Ayoub Abouttarouk , Saida Alikouss , Yousra Morsli , Mohamed Ennabir , Mohamed Abidi , Lhoussayn Ouhoussa , Rachid Tahar , Youssef Zerhouni , Mohamed Samir , Zouhir Baroudi
Published: March 2024

The Western Anti-Atlas belt is globally renowned for hosting metallic ore deposits, including large copper-silver deposits. The Ouarmdaz-Chikh Imi Nrfi area is located southwest of the Precambrian Ighrem inlier, approximately 168 km east of the city of Agadir. This area is known for its stratiform copper-silver mineralization along the contact between the Precambrian basement and the infracambrian cover. This level is of particular interest on a regional scale because of its spatial extension.The Igherm inlier comprises Precambrian basement formations, including polygenic conglomerates, red sandstones, and andesitic lava. The cover consists of a siltstone-sandstone series capped by Tamjout dolomites and lower limestones. These terrains are cross-cut by the Ighrem doleritic dyke and are affected by extremely discrete brittle deformation and very pronounced ductile deformation, indicating highly mineralized zones.This area is characterized by polymetallic mineralization with copper, silver, lead sulfides, and iron oxides. These mineralizations are hosted in the infracambrian cover. Paragenesis is stratiform, vein-type, or in geodic cavities. The mineralized structures are mainly oriented NE–SW, with a dip of 30° to 50° toward the southwest.The paragenetic study of mineralization has enabled us to identify the different metallic phases and propose a paragenetic succession. The primary paragenesis comprises pyrite, chalcopyrite, bornite, and galena. The primary mineral phases underwent metasomatism, giving rise to secondary parageneses represented by chalcocite, covellite, malachite, azurite, and iron oxides, including hematite and goethite. This mineralization features complex textures (myrmekitic, collomorphic, carrie, and continent).The analytical data by (ICP) indicated relatively high levels of copper and copper oxide (
Methane Flux Heterogeneity and Driving Mechanisms in Wetland Ecosystems
Authors: Okiti Isaac , Arias-Ortiz Ariane , Shortt Robert , Gamez Eduardo , Delwiche Kyle , Wang Carlos , Ahmadi Arman , Yi Koong , Yildiz Kadir , Baldocchi Dennis , Tizabi Daniela , Oikawa Patty , Szutu Daphne , Verfaillie Joseph , Pindus Mihkel , Kasak Kuno
Published: March 2024

Wetlands are significant contributors to global methane (CH4) emissions, a critical driver of climate change. However, the spatial heterogeneity of CH4 fluxes and the underlying mechanisms within these wetland ecosystems remains largely unexplored. This study examines the heterogeneity of CH4 emissions from different types of wetlands in Estonia and California, USA. The studied wetlands include free surface water treatment wetlands, recently restored peatlands in Estonia and three different restored wetlands in California that differ from each other in salinity level, tidal influence, vegetation, and restoration year. All studied sites except the free surface treatment wetlands are equipped with eddy covariance stations for continuous CO2, H2O, and CH4 measurements (open path LI-7500 and LI-7700 analyzers, LICOR Biosciences). Spatial heterogeneity in methane flux was assessed through static chamber measurements using a LI-7810 trace gas analyzer (LICOR Biosciences). Chamber measurement surveys revealed significant variations among gas measurement points within the eddy tower footprint. Additional parameters such as LAI, water pH, electrical conductivity, dissolved oxygen concentration, temperature, turbidity, salinity, water level, and dissolved gas concentration (dCO2 and dCH4; analyzed in the lab with GC-2014, Shimadzu) were measured from each sampling spot. After measurements, we collected surface sediment samples for soil TN, TOC, TIC, DOC, DIC, and DN analyses. Our results indicate significant variation in CH4 fluxes and soil C and N content within different sampling points and in different ecosystems. In the constructed wetland in Estonia, biweekly measurements from twelve distinct points over two years revealed significant heterogeneity in CH4 fluxes, with peak emissions ranging from 144 mg m-2 d-1 to 254.4 mg m-2 d-1 observed from specific chamber measurement plots. In contrast, the restored peatland showed a lower range of CH4 emissions (0.096 mg m-2 d-1 to 34.6 mg m-2 d-1) observed from six measurement plots. The preliminary measurements conducted in California wetlands also showed a large variation within and between the sites. These findings highlight the complex nature of CH4 flux heterogeneity in wetlands and the critical need for site-specific management strategies. Accurately quantifying and understanding these variations is essential for refining CH4 budgets and developing effective mitigation strategies for greenhouse gas emissions from wetland ecosystems.
Arctic puzzle: pioneering a shrimp habitat model in topographically complex Disko Bay (West Greenland)
Authors: Krawczyk Diana , Vonnahme Tobias , Burmeister Ann-Dorte , Maier Sandra , Blicher Martin , Meire Lorenz , Nygaard Rasmus
Published: March 2024

Our study focuses on the geologically, topographically, and oceanographically complex region of Disko Bay in West Greenland. Disko Bay is also considered a marine biodiversity hotspot in Greenland. Given the impact of commercial fishing on seafloor integrity in the area, seafloor habitats studies are crucial for sustainable use of marine resources. One of the key fishery resources in Greenland, as well as in the North Atlantic Ocean, is northern shrimp.In this study we analyzed multiple (1) monitoring datasets from 2010 to 2019, including data from shrimp and fish surveys, commercial shrimp fishery catches, satellite chlorophyll data, and (2) seafloor models, encompassing high-resolution (25 x 25 m) multibeam data with a low-resolution (200 x 200 m) IBCAO grid. Using multivariate regression analysis and spatial linear mixed-effect model we assessed the impact of physical (water depth, bottom water temperature, sediment type), biological (chlorophyll a, Greenland halibut predation), and anthropogenic factors (shrimp fishery catch and effort) on shrimp density in the area. The resulting high-resolution predictive model of northern shrimp distribution in Disko Bay is the first model of this kind developed for an Arctic area.Our findings reveal that shrimp density is significantly associated with static habitat factors, namely sediment type and water depth, explaining 34% of the variation. The optimal shrimp habitat is characterized by medium-deep water (approximately 150-350 m) and mixed sediments, primarily in the north-eastern, south-eastern, and north-western Disko Bay. This pioneering study highlights the importance of seafloor habitat mapping and modeling, providing fundamental geophysical knowledge necessary for long-term sustainable use of marine resources in Greenland.The developed high-resolution model contributes to a better understanding of detailed patterns in northern shrimp distribution in the Arctic, offering valuable insights for stock assessments and sustainable fishery management. This novel approach to seafloor habitat mapping supports the broader goal of ensuring the responsible utilization of marine resources, aligning with principles of environmental conservation and fisheries management. Our work serves as a foundation for ongoing efforts to balance economic interests with the preservation of marine ecosystems, fostering a harmonious coexistence between human activities and the fragile Arctic environment.
Harnessing Soil Moisture Data for Enhanced Eco-Hydrological Modeling Precision in Snow-Dominated Catchment in Finland
Authors: Panchanathan Anandharuban , Ghag Kedar , Ahrari Amir Hossein , Klöve Björn , Oussalah Mourad
Published: March 2024

Eco-hydrological modeling in water resources management has a pivotal role in the assessment of physical processes at various spatial-temporal scales. However, modeling the hydrological processes intrinsically contains uncertainties. Such uncertainties need to be addressed to develop a reliable hydrological model. In this study, in-situ and remotely sensed soil moisture data are used to enhance the precision of hydrological modeling using the Soil and Water Assessment Tool (SWAT). The objectives of this study are, (i) to assess the uncertainty and their propagation in hydrological modeling using the conventional and multi-source data set, and (ii) to simulate the hydrologic parameters using soil moisture as an indicator to evaluate uncertainties in hydrological forecasting. This study is carried out in the Temmesjoki basin of northern Finland with a basin area of 1190 km2. This region’s land cover is dominated by forest (61%), agricultural lands (18%), and shrubs (13%). The average annual rainfall and annual average temperature in this region are 406.21 mm, and 2.60°C respectively. The mean daily discharge ranges from 0.17 to 34.15 m3/s. The in-situ soil moisture data and Soil Water Index from the Copernicus Global Land Service are used to test the hypotheses. The Sequential Fitting Algorithm (SUFI-2) in R-SWAT was used for sensitivity and uncertainty analysis and calibration of the streamflow and ET. Two conceptual models are built to compare conventional data sources and multi-source data sets for the assessment of uncertainties in the simulation of the hydrological process. Preliminary analysis of hydrologic parameters of the basin reveals higher and non-uniform distribution of rainfall, ET, and discharge during summer months. Furthermore, the application of soil moisture data for the calibration of the SWAT model reveals higher fitness score, and, at the same time, the in-situ soil moisture data are found to reflect more accurately the soil moisture conditions in SWAT model, which results in the reduction of uncertainties. Consequently, the model conceptualized with the multi-source data sets provides a better water budget for the catchment. 
Estimates of human influence on North Sea sedimentary carbon - Current impacts and future scenarios 
Authors: Porz Lucas , Zhang Wenyan
Published: March 2024

There is ongoing debate on the influence of human activities on the marine carbon cycle, their potential impacts on climate and resulting implications for marine spatial management. In order to gauge the efficacy of different management options, we estimate the contributions of three direct human impacts on particulate organic carbon in the North Sea: material dumping, marine aggregate mining and bottom trawling. While dumping and mining are considered in a budgetary manner based on existing data, the impacts of bottom trawling are simulated using a high-resolution 3D ocean and sediment models. Several future scenarios of fishing closures and redistribution of effort are considered and their potential climate impacts discussed. Our results indicate that the impacts of sand mining are negligible, while both material dumping and bottom trawling can alter the sequestration capacity of carbon in the North Sea significantly. In the case of bottom trawling, we show that through targeted design of fishing closure zones, the impacts could be greatly reduced without the need to change the overall trawling effort.
Asphalt Volcanism versus Asphalt Seepage - Examples from the Campeche-Sigsbee Salt Province, Southern Gulf of Mexico
Authors: Bohrmann Gerhard , Roemer Miriam , Marcon Yann , Pape Thomas , Hsu Chieh-Wei , Smrzka Daniel , MacDonald Ian
Published: March 2024

Asphalt deposits have been described from several places of the ocean floor, like the Gulf of Mexico, the Santa Barabra Basin, the Angolan margin and the southwest Atlantic Ocean offshore Brazil. The term asphalt volcanism has been introduced as a novel type of hydrocarbon seepage after an area of approximately 1 km2 solidified asphalt was found on top of one of the Campeche Knolls in the southern Gulf of Mexico named Chapopote. Visual seafloor surveys revealed extensive surface deposits of solidified asphalt and light crude oil, emanating from sites along the rim of a crater-like structure in 2.900 m water depth. Large areas of the asphalt deposits were colonized by vestimentiferan tubeworms, bacterial mats, and other biological communities. Also discovered alongside the asphalt were locations of sediment/gas hydrate interlayering associated with emanating gas and oil bubbles from the seafloor. Seafloor mapping in the Southern Gulf of Mexico revealed various morphological elevations like knolls and ridges which all are related to salt diapirism of the underlying sediment sequences. Most of those features show crater like areas associated with seepage. During recent expeditions, the crater structures of Mictlan Knoll and Tsanyao Yang Knoll were measured in high resolution with an AUV and sampled in detail and visually examined with MARUM ROV QUEST4000. Although large areas are also covered with lava-like asphalt sheets, the asphalt seems not to be flown at higher temperatures. Extrusion of heavy liquid oil in form of whips or sheets were observed at several locations which indicate a slow consolidation of the liquid oil to form firm asphalt. After extrusion, chemical and physical changes in the asphalt generate increasing viscosity gradients both along the flow path and between the flow’s surface and core. This allows the asphalt to form pāhoehoe lava-like shapes and to support dense chemosynthetic communities over timescales of hundreds of years.
Improving forest disturbance labels through Sentinel-1 change detection validation
Authors: Müller Franziska , Eifler Laura , Cremer Felix , Benson Vitus , Camps-Valls Gustau , Bastos Ana
Published: March 2024

Global forest ecosystems face unprecedented challenges, such as fire, wind, drought, and insect outbreaks, resulting in rapid forest decline. Analyzing these disturbances on a large scale requires the use of remote sensing techniques, but the spatial and temporal uncertainty in forest disturbance reference data poses a significant obstacle.In this study, we validate and refine existing disturbance labels of the U.S. Forest Service Forest Health Protection [1] Dataset USDA by using a change detection algorithm [2] based on radar data from Sentinel-1. To this end, we analyze the spatio-temporal overlap of disturbed areas from Sentinel-1 with the USDA labels and further explore spatio-temporal fingerprints of remote sensing indices commonly used for disturbance detection. As the analysis of the remote sensing indices shows, this refinement of the accuracy of disturbance labels provides a more reliable basis for ecological research and land management practice. References:[1] Coleman, T. W., Graves, A. D., Heath, Z., Flowers, R. W., Hanavan, R. P., Cluck, D. R., & Ryerson, D. (2018). Accuracy of aerial detection surveys for mapping insect and disease disturbances in the United States. Forest Ecology and Management, 430, 321–336. https://doi.org/10.1016/j.foreco.2018.08.020[2] Cremer, F., Gans, F., Cortes, J. & Thiel, C. (2023). Mapping Forest Loss in Europe with Sentinel-1. In European Commission, Joint Research Centre, Soille, P., Lumnitz, S., Albani, S., Proceedings of the 2023 conference on Big Data from Space (BiDS’23) – From foresight to impact – 6-9 November 2023, Austrian Center, Vienna, Soille, P.(editor), Lumnitz, S.(editor), Albani, S.(editor), (pp. 361 - 364) Publications Office of the European Union, 2023, https://data.europa.eu/doi/10.2760/46796 
Unveiling Hydrological Dynamics in Data-Scarce Regions:A Comprehensive Integrated Approach
Authors: Ayalew Ayenew Desalegn , Wagner Paul D. , Sahlu Dejene , Fohrer Nicola
Published: March 2024

The hydrological system of Rift Valley Lakes in Ethiopia has recently experienced changes since the past two decades. Potential causes for these changes include anthropogenic, hydro-climatic and geological factors. The main objective of this study was to utilize an integrated methodology to gain a comprehensive understanding of the hydrological systems and potential driving factors within a complex and data-scarce region. To this end, we integrated a hydrologic model, change point analysis, indicators of hydrological alteration (IHA), and bathymetry survey to investigate hydrological dynamics and potential causes. A hydrologic model (SWAT+) was parameterized for the gauged watersheds and extended to the ungauged watersheds using multisite regionalization techniques. The SWAT+ model performed very good to satisfactory for daily streamflow in all watersheds with respect to the objective functions, Kling–Gupta efﬁciency (KGE), the Nash–Sutcliffe efﬁciency (NSE), Percent bias (PBIAS). The findings reveal notable changes of lake inflows and lake levels over the past two decades. Chamo Lake experienced an increase in area by 11.86 km², in depth by 4.4 m, and in volume by 7.8 x 108 m³. In contrast, Lake Abijata witnessed an extraordinary 68% decrease in area and a depth decrease of 1.6 m. During the impact period, the mean annual rainfall experienced a decrease of 6.5% and 2.7% over the Abijata Lake and the Chamo Lake, respectively. Actual evapotranspiration decreased by 2.9% in Abijata Lake but increased by up to 0.5% in Chamo Lake. Surface inflow to Abijata Lake decreased by 12.5%, while Lake Chamo experienced an 80.5% increase in surface inflow. Sediment depth in Chamo Lake also increased by 0.6 m. The results highlight that the changing hydrological regime in Chamo Lake is driven by increased surface runoff and sediment intrusion associated with anthropogenic influences. The hydrological regime of Abijata Lake is affected by water abstraction from feeding rivers and lakes for industrial and irrigation purposes. This integrated methodology provides a holistic understanding of complex data-scarce hydrological systems and potential driving factors in the Rift Valley Lakes in Ethiopia, which could have global applicability.
Structure and geometry of the Chilean subduction zone near Copiapó (~27°S) based on an amphibious seismic refraction experiment
Authors: Warwel Arne , Lange Dietrich , Dannowski Anke , Wirp Sara Aniko , Contreras-Reyes Eduardo , Klaucke Ingo , Moreno Marcos , Diaz-Naveas Juan , Kopp Heidrun
Published: March 2024

The subduction of the oceanic Nazca plate beneath the continental South American plate shapes the Chilean margin and is known to generate large megathrust earthquakes. Our study focuses on the region defined by the pre-collision and subduction of the Copiapó Ridge with the Chilean margin at ~27°S. This area has been a seismic gap since 1922, and little is known about the geometry and deep structures of the incoming plate, the overriding plate, and the processes related to the subduction of the Copiapó Ridge. We model the seismic structure in the region by using wide angle seismic data from a recent amphibious seismic refraction experiment. Thereby, we utilize seismic signals from both offshore airgun-shots and onshore mining blasts. Overall, we use 36 Ocean-Bottom-Seismometers and 10 temporal seismic land stations along an approximately 420 km long profile ranging from more than 300 km offshore up to more than 100 km landwards.Our P-wave velocity model images the geometry and velocity structure of the incoming oceanic plate, including three seamounts belonging to the Copiapó Ridge, the marine and continental forearc, and the upper part of the downgoing slab. The model shows an oceanic crust with hardly any sediment cover (generally less than 10 m) and an average oceanic Moho depth of about 6.2 – 6.9 km below the seafloor, which increases to over 10 km below the seamounts of the Copiapó Ridge. The velocities beneath the seamounts are similar or slightly slower compared to the adjacent upper oceanic crust (Vp ranging from 3.5 to 6 km/s). This suggests that the Copiapó Ridge was predominantly formed by extrusive processes. In addition, the velocity model reveals a significant thinning (to less than 4 km) of the oceanic crust landwards of the trench axis.Together with recently acquired bathymetry data, we will compare our findings to other studies north and south of the Copiapó region and discuss the structural and geometric along-strike variations of the northern Chilean subduction zone.   
Denser microplastics migrate deeper? Effect of particle density on microplastics transport in artificial and natural porous media
Authors: Li Wang , Brunetti Giuseppe , Bolshakova Annastasiia , Stumpp Christine
Published: March 2024

Predicting the fate of microplastics (MPs) in porous media has been challenging and previous research mainly focused on the transport of MP considering plastic size and shape effects, media size effects, and solution chemistry effects. However, few studies examined the plastic density impact on the transport behavior of MPs in porous media. This is significantly important to gain insight into how the MP density influences its fate in the environment. Therefore, column experiments under saturated conditions were conducted to explore the MP transport in columns packed with glass beads and gravel and using polyethylene microspheres with different densities within the same size range together with a conservative tracer. Experimental results were fitted well (R2 > 82.3-98.7 %, and low RMSE value) with a two-site transport model with a depth-dependent blocking function in HYDRUS-1D. The results showed that particle density influences the transport of MPs, and the deposition rate varied with particle density in the following order: 1.12 g/cm3 > 0.995 g/cm3 > 1 g/cm3. This suggests that compared to neutrally buoyant and buoyant MP, denser MPs tend to deposit in the selected material under the tested flow rate. The coupled experimental and simulated results indicate that denser MPs may be retained but neutrally buoyant MPs can be potentially migrated with infiltrated water into subsurface systems, thus posing groundwater contamination risk. Hence, further studies are needed with viable densities and diverse conditions to advance the understanding the impact of plastic density on its transport fate.Keywords: Microplastics, density, transport, sediments, glass beads