bluuebunny/crossref_metadata_2025 huggingface dataset:
RANS simulations of surf zone hydrodynamics using Reynolds stress transport equations
Authors: Kuan Yi-Hsuan , Wang Chi-Hung , Lee Cheng-Hsien
Published: March 2024

The surf zone, situated at the beach where waves break, hosts various hydrodynamic phenomena, including waves, surface rollers (recirculating flow on the wave's front), and undertows. These phenomena have a substantial impact on beach evolution.  In this study, a Reynolds-averaged Navier-Stokes numerical model with Reynolds stress equations is applied to simulate the hydrodynamics of the surf zone. The air-water interface is captured using the volume of fluid method. To validate the numerical model, comparisons are made between the simulated results and measured ones from prototype experiments. The study extends to the analysis of wave energy, surface roller energy, and undertow dynamics. Furthermore, the numerical results are used to assess the effectiveness of a surf zone model based on the wave action equation, roller energy equation, and shallow water equation. This comprehensive approach enhances our understanding of the complex interactions within the surf zone and provides valuable insights for coastal engineering.
Understanding socioeconomic, climatic, and physical factors on 311 flooding and raw sewage reports in Norfolk, VA
Authors: Lerma Natalie , Goodall Jonathan
Published: March 2024

Urban stormwater poses significant challenges related to flooding and water quality. Cities utilize 311 service request platforms for residents to report incidents, enabling governmental attention. Existing studies have explored socioeconomic and climatic factors' impact on the submission of requests, but a comprehensive understanding of how socioeconomic, climatic, and physical parameters collectively influence flooding and sanitation reporting remains unexplored. This study analyzes four years of 311 service requests for flooding stoppages and raw sewage concerns in Norfolk, VA, employing two Zero-Inflation Negative Binomial mixed effects models. These models identify statistically significant predictors for flooding stoppage and raw sewage concern request counts. The 311 service request data was geo-aggregated to the census tract level and temporally aggregated into weekly sums to account for possible lags in event occurrence and reporting of flooding stoppage or raw sewage. Duplicate service requests were also removed from the dataset. This study incorporates a wide range of explanatory variables, including socioeconomic factors (race, income, gender, education level), climatic factors (precipitation, tide level, groundwater level), and physical factors (topographic wetness index, impervious cover, distance from water bodies). All explanatory variables were aggregated to census tract level and weekly values where appropriate. Results reveal precipitation as a robust predictor in both flooding stoppages and raw sewage concerns. The conditional model for flooding stoppages identifies additional predictors such as educational attainment, race, and groundwater level. For raw sewage concerns, tide emerges as a significant predictor in the conditional and zero-inflation models, with the zero-inflation model identifying precipitation and groundwater level as well. Models were tested through nested cross-validation to validate their robustness. The study underscores the importance of climatic scenarios in predicting service requests, emphasizing their reliability in directing municipal funds for addressing community-identified flooding and sewage problems. Physical parameters like the topographic wetness index show weak predictability in low-relief coastal plains, such as Norfolk, VA. Moreover, the study sheds light on the limited relationship between flooding stoppages and raw sewage service requests, where the combined presence of these reports may indicate potential water quality and health concerns. This research contributes to a nuanced understanding of the multifaceted influences on urban stormwater reporting, facilitating targeted strategies for effective stormwater management.
Indicator-based measurement of resilience and analysis of spatial trend in resilience to forest fire in Uttarakhand, India
Authors: Madhukumar Aryalakshmi , Indu Jayaluxmi , Karthikeyan Lanka
Published: March 2024

Wildfires are becoming increasingly frequent and devastating in many tropical forests. In India, nearly 6% of forest cover is highly fire-prone, and 36% is prone to frequent fires. These frequent wildfires have compound impacts on forests, which include changes in biodiversity and, forest functionality. In the short term, the burnt ecosystem cannot have the same functionality as that of a pre-fire situation. Understanding forest ecosystem health status after a fire event can help increase our ability to manage the fire seasons. In the current study, time series data from optical remote sensing is used to assess the forest ecosystem resilience. The study area chosen is the forest region in Uttarakhand, India, including Jim Corbett National Park, that witnessed a severe forest fire in 2016. The active fire pixels during the 2016 fire event in the area were identified, and resilience over the identified pixels was measured based on the concept of engineering resilience.  Results are presented as resilience quantified for all burnt pixels based on three different indices which represent resistance and recovery namely, time taken for recovery, maximum impact of fire event, and cumulative impact. Further, we identified how resilience differs with the type of forest cover in the study area and how well each type of forest recovers from the fire event. The findings suggest that in the Indian scenario, deciduous broadleaf forests have a longer recovery followed by evergreen broadleaf and evergreen needleleaf, while grasslands and broadleaf cropland have shorter recovery times and impacts. From this work, we aim to study forest resilience in the Indian scenario and how well this can be compared with other areas where similar climatic conditions exist. The current work has potential applications in risk governance, ecosystem management, etc. and in evaluating the post-fire processes and primary factors driving the processes. Extensive data feeds available from current satellite platforms enable the post-fire dynamics study to be more accurate, thus more informed, and faster choices by stakeholders.
Impacts of climate extremes on agricultural water scarcity under historical and future periods and the spatial scale effect
Authors: Liu Jiongjiong , Liu Wenfeng
Published: March 2024

BackgroundBoth blue water and green water contribute to agricultural water scarcity, which is subjected to impacts of escalating climate extremes, e.g., precipitation and temperature extremes. However, an explicit quantification of the possible effects of compound climate extremes on agricultural water scarcity index (AWSI) under historical and future climate is absent and current research often overlooks how different spatial scales influence agricultural water scarcity.MethodsWe applied an integrated AWSI, which incorporates blue water and green water, to estimate agricultural water scarcity in provincial and basin scales in China, and to determine the association of AWSI with compound climate extremes over the historical period 1971–2010 and for future period 2031–2070.ConclusionsOur results indicate a marked escalation in AWSI during dry years and periods of elevated temperatures, and precipitation significantly impacts AWSI more than temperature variations. In secondary basins, AWSI was about 25.7% higher than the long-term average during dry years, increasing to nearly 49% in exceptionally dry conditions. Comparatively, in tertiary basins, the increases were 27.7% and 55%, respectively. In years characterized by high temperatures, AWSI rose by approximately 6.8% (7.3% for tertiary basins) from the average, surging to around 19.1% (15.5% for tertiary basins) during extremely hot periods. Future climate change would further intensify AWSI and amplify the effects of climate extremes, particularly in Inner Mongolia with changes of AWSI over 200%. Southwestern China could also experience expanding agricultural water scarcity under future climate scenarios. Improving irrigation efficiency has potential to alleviate water scarcity by up to 30%. Moreover, it illustrates that AWSI assessment at the tertiary basin level could better capture the influence of climate extremes on AWSI compared to assessments at the secondary basin level. As a whole, the investigation offers an in-depth evaluation of the influence of compound precipitation and temperature extremes and research scale on water scarcity.
Evolution of the covered glaciers in the Cordillera Blanca during the period 1962 - 202
Authors: Curo Yadira , Fernandez Juan de Dios , Celmi Gladis , Robles Danny , Mejia Mayra
Published: March 2024

Glacier dynamics and the effects of climate change accelerate bedrock erosion and instability of the surrounding topography, causing clean glaciers to be gradually covered by debris, particularly in the ablation zones. While the area of glaciers covered worldwide is increasing, there are few studies on this phenomenon in tropical glaciers and its possible significant effects on glacier melt. In this context, this study analyzes the spatio-temporal evolution of the area of glaciers covered by debris in the Cordillera Blanca from 1962 to 2020. To achieve this aim, we used data from the Peruvian National Glacier Inventory for 1962 and 2020. We also identify the covered glaciers through the photo-interpretation of geomorphological features, such as the color and texture of the ground surface, the presence of thermokarst zones, and the formation of small lakes/lagoons observed in the satellite images. In addition, we got the topographic features from the ALOS PALSAR digital elevation model.The outcomes of this investigation reveal an increase in the number and surface area of glaciers covered, from 33 units (15.41 km2) in 1962 to 173 units (23.06 km2) in 2020. This shows an increase of 49.64% from the glacier area covered by debris. The increase in covered glaciers in the Cordillera Blanca could be because many glaciers identified as debris-free in 1962 were partially or totally covered in 2020; 17.13 km2 of the glacier debris-free area was covered by debris during this period. It has been observed that 93% of the area covered by debris is on slopes greater than 8°. Of these, 25% were in the 24° - 33° range, and 23% were on steeper slopes than 33°. The orientation analysis indicates a predominance of surface covered towards the southwest and south.Likewise, the areas of glacier retreat covered between 1962 and 2020 were analyzed, identifying 9.45 km2 of glacier surface loss. 18% of the loss areas are on slopes steeper than 8º, mainly from 8º to 17º slope, where 28% of the loss area is located. Meanwhile, a clear retreat trend is observed in those areas with a north orientation of 95% and a northeast orientation of 5%.These findings suggest a possible association between the higher magnitude slope conditions and the formation of covered glaciers, while the orientation influences the retreat of these glaciers.
Digital Twin Ocean for China Coastal Seas
Authors: Chai Fei
Published: March 2024

With over 2 billion people relying on the marine resources, the East Asian seas have nourished rapid economic growth over the past decades. But this comes at the expense of ocean health. Coastal-SOS - “Coastal Zones Under Intensifying Human Activities and Changing Climate: A Regional Programme Integrating Science, Management and Society to Support Ocean Sustainability”, a UN Ocean Decade endorsed project aims to provide solutions for the sustainable development of coastal ocean through effective integration of science, governance, and society. Numerical modelling is a key programmatic effort, serving synthesis analysis, mechanistic studies, and most importantly, predictions, which will contribute to construct the next generation of product: the data-model fully integrated Digital Twin Ocean. One of the expected outcomes of this project is a decision-making support system and toolbox aided by numerical modelling and the Digital Twin Ocean initiative that will result in integrated coastal management and development of marine spatial planning and ecosystem conservation practices. I will review the existing observational data and modelling work in Xiamen Bay and Changjiang Estuary which are two pilot sites and discuss plan of constructing a Digital Twin Ocean in these regions.
New insights on the structural configuration and evolution of the deepwater offshore margin of Sabah, Borneo
Authors: Domzig Anne , Lee Mei Lu , Shah Jaiswal Jyoti , Ismail M Hisham , MacGregor Lucy , Saleh Ahmad Shahir
Published: March 2024

Offshore Borneo in the South China Sea has a complicated structural setting resulting from complex regional geodynamics, marginal basins subductions and openings. Here we present a model for the tectonic evolution of the deepwater offshore Sabah region, North-West Borneo, based on recent observations on seismic and integration of multiphysics data in the Sabah trough (also called Nansha trough) and the Dangerous Grounds. In this work we look at the basin architecture, structural style, and evolution of the margin and well as discussing the nature of the crust in the study area.The area of interest experienced rifting from Palaeocene-early Eocene to the Oligocene when the South China Sea starts opening. We look at the early configuration of the basin, the rifting style and fault systems involved in the rifting stages. At the end of the rifting there is evidence of volcanic activity across the margin, then starts a sag phase and the buildup of carbonate mounds on topographic highs. Subsidence continues in the Sabah trough during the Miocene, which causes carbonate mounds, which are at the edge of the trough, to be drowned and a more siliciclastic sedimentation takes the relay. A fold-and-thrust belt starts forming to the South-East and puts the trough in a position of foreland basin.The reason and modalities for the presence of compressional structures West of Borneo are still debated and various tectonic models exist. Nonetheless, recent paleomagnetic studies have proposed that Borneo started to rotate anticlockwise since the late Eocene and this results in compressional features on the west margin of Borneo. We investigate the possible scenarios of crustal configurations associated with the structures visible on seismic. The integration of magnetotelluric (MT) data to seismic, gravity and magnetic data allows us to draw a new picture of this part of the margin, showing crustal thickness variations and nature, and the implications for the regional tectonics.
Hydrochemical characteristics and genesis analysis of typical aquifer system in Karst Critical Zone of central Yunnan Platea
Authors: Xu Mo , Huang Jingyu
Published: March 2024

The study of hydrogeochemical processes in Karst Critical Zone (KCZ) is of great significance for scientific understanding of their internal evolutionary environment and structural characteristics. Karst groundwater is the main information carrier after water-rock interaction. Quantitative analysis of its hydrochemical characteristics and causes is an effective means to reveal the medium environment and hydrodynamic conditions of aquifer system in KCZ. In this paper, three typical karst aquifer systems in the KCZ of central Yunnan Plateau are taken as the research objects. Through field sampling and laboratory testing of karst springs exposed by different aquifer systems, mathematical statistics analysis, hydrochemical diagram, ion ratio coefficient and hydrogeochemical simulation are comprehensively used to deeply analyze the characteristics of hydrochemical components, genesis and aquifer medium of karst groundwater in each aquifer system, and the internal relationship and law between water cycle and hydrochemistry in the key belt are discussed. The results show that : (1)  HCO3− and Ca2+ are the highest and stable ion components in regional karst groundwater, and Mg2+ is the key factor to control the alienation of hydrochemical types in each aquifer system ; (2)  The rock weathering and mineral dissolution of carbonate rocks are the main causes of the chemical composition characteristics of karst water in each aquifer system, and the karst groundwater dissolution on the aquifer of Huaning aquifer system is still occurring. The alternation of cation adsorption and the weathering and dissolution of silicate rocks are the main sources of Na+ and K+ in regional karst groundwater. (3)  The development intensity of regional karst, the exposed condition of karst aquifer and the lithology and connectivity of aquifer medium jointly shape the groundwater chemical characteristics of different aquifer systems in the KCZ of central Yunnan Plateau.
3-D Numerical Simulation of Island Arc Deformation based on the Dislocation Model for Plate Subduction and its Insight into Topographic Evolution of Island Arcs
Authors: Fukahata Yukitoshi , Mori Yutaro
Published: March 2024

Elastic/viscoelastic dislocation theory is a fundamental tool in computing crustal deformation due to fault motion, not only for instantaneous coseismic deformation but also for gradual postseismic and interseismic deformation. Expressing the kinematic interaction between the subducting and overriding plates by dislocation along the plate interface, our group has developed a crustal deformation model due to plate subduction, named "dislocation model for plate subduction" (Matsu'ura & Sato 1989, GJI), which is a generalization of Savage's back slip model (Savage, 1983, JGR), including the effect of deformation due to steady plate subduction. Hashimoto et al. (2004, PAGEOPH) demonstrated that the pattern of uplift rates in and around Japan computed by this model shows excellent coincidence to the observed free-air gravity anomalies. Fukahata and Matsu‘ura (2016, GJI), using the 2D model, explained the physical mechanism of island-arc uplift, trench subsidence, and outer rise uplift by combining the effects of lithospheric rotation and gravity.   In this study, we develop a 3D numerical model and compute vertical displacement rates in a subduction zone caused by steady slip along a plate interface, in which the trench axis has a bend convex toward the island arc. Computation results show that the island arc lithosphere significantly subsides around the bend, and that the subsidence is larger for a larger bend angle.   This subsidence can be physically understood by mass deficit in the island arc lithosphere, as explained below. When a plate subducts along a trench with a bend convex toward the island arc, mass excess inevitably occurs in the subducting slab, which can be understood from an analogy of a tablecloth draped at a corner of a table. In the dislocation model, the motion of plate subduction is expressed by displacement discontinuity along the plate interface. The displacement discontinuity, which is equivalent to a force system of a double couple, requires two surfaces that sandwich a fault to move in exactly opposite directions each other, which results in mass deficit in the island arc, because mass excess occurs in the subducting slab.   Along the main Japanese islands, we observe significant invasions of negative free-air gravity anomalies into the forearc around the Hidaka Trough, the Kanto Plain, and the Bungo Channel, which correspond to the junctions of the trench axes. In brief, these forearc negative free-air gravity anomalies can commonly be understood by the above mechanism. We also observe similar invasions of negative free-air gravity anomalies around the Arica bend, South America, and Cascadia, though the signals of negative gravity anomalies are smaller in these regions, reflecting gentler changes of the strikes of the trench axes.
Primary production and dinitrogen fixation in a subtropical inland saline environment
Authors: Rathi Ajayeta , Sarkar Siddhartha , Rahman Abdur , Kumar Sanjeev
Published: March 2024

For over half a century, scientists have endeavoured to measure the rates of primary production (PP) and dinitrogen (N2) fixation in a diverse range of inland waters, spanning from freshwater to saline. There is nearly an equivalent portion of the saline as well as fresh in the world's inland waters, emphasizing their significance within our continental landscapes. Lakes play crucial role in global biogeochemical processes and are fundamental for essential ecosystem functions and services. Nonetheless, swift alterations in lakes have been recognized (i.e., salinization of freshwater ecosystems) on a global scale due to shifts in climate and increasing human interventions, posing risks to the valuable services these habitats offer. While considerable research on saline lakes has occurred in the past years across Africa, Australia, and North America, there remains a substantial amount to explore in Asian lakes and beyond, necessitating investigation into these unique ecosystems worldwide.            The current study explores rates of PP and N2 fixation within a subtropical saline lake (Sambhar, India) along with its neighbouring brine reservoir and salt pans. Incubation experiments were performed to estimate the PP and N2 fixation rates using 13C and 15N tracer techniques. The study reveals that PP and N2 fixation rates were higher in the lake than the adjacent brine reservoir. Concentrations of particulate and dissolved forms of carbon and nitrogen were also higher in the lake than the brine reservoir. However, salt pans showed huge variation in PP, but N2 fixation rates were quite low. The highest concentration of particulate and dissolved forms of carbon and nitrogen were also found in the salt pans. The high uptake rates in the lake and salt pan may be attributed to high biomass and high nutrient concentrations than the brine reservoir. The difference in the rates is possibly due to variation in salinity, temperature, nutrient concentrations, and runoff to the lake, which can affect primary producers and potentially leading to shifts in community structure and biodiversity in different systems. This study provides insights into the complex interactions of PP and N2 fixation rates with environmental parameters in a subtropical saline environment.
Experimental Investigation of Lithium Partitioning among Plagioclase, Rhyolitic Melt, and H2O Vapor
Authors: Dupont de Dinechin Maylis , Martel Caroline , Balcone-Boissard Hélène , Rusiecka Monika , Champallier Remi , Deloule Etienne
Published: March 2024

Volcanic eruptions are unpredictable and present a significant challenge for volcanic crisis management, primarily due to the variety of eruptive styles, ranging from effusive to explosive. By elucidating the dynamics of magma ascent, with a focus on degassing, we can better understand of the interconnections between petrological characteristics, geochemical and geophysical signals, volcanic hazards, and volcano monitoring. To this aim, lithium (Li), which has a high mobility in both silicate melts and crystals, has been used as a geospeedometer to monitor short-time processes, such as syn-eruptive magma ascent and degassing and post-eruptive processes (cooling). Yet, to appropriately interpret Li data in crystals from volcanic deposits, a clear understanding of the Li behavior and partitioning between the crystal-melt-fluid phases during an eruption is essential. Most of the Li partitioning data rely on glass inclusions and their host minerals, which do not always guarantee equilibrium conditions. Experimental data are largely missing, especially in the case of silica-rich hydrated magmas. Therefore, we provide Li contents and partitioning via phase-equilibrium experiments for analyzable-sized plagioclases crystallized from Li-bearing H2O-saturated rhyolitic melts at pressures from 50 to 150 MPa and temperatures of 800 and 875 °C. In addition to its applications in volcanology, this research could yield valuable information for assessing the economic viability of lithium in felsic deposits, specifically those with rhyolitic/granitic compositions (as highlighted by Benson et al., 2017), and in magmatic fluids. Moreover, it holds futuristic potential for extracting lithium directly from these fluids.
An alternative mode of slab deformation in the mantle transition zone: segmentation and stacking
Authors: Li Keqing , Hu Jiashun , Li Yida , Zhou Hao , Zhang HaiJiang
Published: March 2024

The contradiction of high subducting plate speed (ranging from 4-9 cm/yr on Earth’s surface) and slow slab sinking rate (about 1-2 cm/yr in lower mantle) is intimately related to the subduction dichotomy of strong plates and weak slabs. The significant difference in the two rates indicates significant slab deformation in the mantle transition zone. However, the way and mechanism by which this deformation occurs have not been fully understood. Slab buckling has been frequently invoked to explain the deformation, but it is insufficient to accommodate the large difference in slab sinking rates across the mantle transition zone, even if an extremely low yield stress  100 MPa is applied.Using 2-D numerical models that incorporate composite viscosity and grain size evolution, we propose a new mode of slab evolution, slab segmentation and stacking, to accommodate the differential slab sinking rates between the upper and lower mantle. The segmentation of slab is facilitated by the serpentinization of the normal faults at the outer rise and the grain size evolution, confirming the results of earlier studies (Gerya et al., 2020). More interestingly, we find periodic tearing and stacking of slab when it encounters the high viscosity lower mantle. Stacked slabs slowly sink in the lower mantle, while periodic slab tearing hinders stress transimission upward, allowing shallow plates to subduct at a higher rate. This model not only explains the high plate subduction rate observed at present day, but also the thickening of slab in the lower mantle. In addition, it provides a mechanism for slab to tear in the mantle transition zone, and thus may explain the enigmatic slab geometry beneath the Izu-Bonin-Mariana subduction zone.
CoFI - Linking geoscience inference problems with tools for their solution
Authors: He Jiawen , Hauser Juerg , Sambridge Malcolm , Magrini Fabrizio , Valentine Andrew , Marignier Augustin
Published: March 2024

Inference problems within the geosciences vary significantly in size and scope, ranging from the detection of data trends through simple linear regressions, to the construction of complex 3D models representing the Earth’s interior structure. Successfully solving an inverse problem typically requires combining various types of data sets, each associated with its own forward solver. In the absence of established software, many researchers and practitioners resort to developing bespoke inversion and parameter estimation algorithms tailored to their specific needs. However, this practice does not promote reproducibility and necessitates a substantial amount of work that is frequently beyond the primary objectives of the research.Our aim with CoFI (pronounced: coffee), the Common Framework for Inference, is to capture inherent commonalities present in all types of inverse problems, independent of the specific methods employed to solve them. CoFI is an open-source Python package that provides a link to reliable and sophisticated third-party packages, such as SciPy and PyTorch, to tackle inverse problems of a broad range. The modular and object-oriented design of CoFI, supplemented by our comprehensive suite of tutorials and practical examples, ensures its accessibility to users of all skill levels, from experts to novices. This not only has the potential to streamline research but also to support education and STEM training.This poster presentation aims to give an overview of CoFI’s main features and usage through practical examples. Moreover, we hope to foster collaboration and invite contributions on inference algorithms and domain-relevant examples.
Water stagnancy and wastewater input enhance primary productivity in an engineered river system
Authors: Sarkar Siddhartha , Kumar Sanjeev
Published: March 2024

Rivers play a crucial role in the global carbon cycle, acting as active conduits of CO2 and CH4 and efficient burial sites for carbon. The behaviour of rivers as source or sink of CO2 depends on the dominance of respiration vs primary production which is ultimately governed by the supply of organic matter and nutrients. Under warming conditions and with increasing human perturbations, rivers across the globe are facing drastic shifts in their hydrological regime resulting in fragmentation and disconnection from the catchment. Subsequently, a dependency on in situ primary productivity as the source of organic matter increases and warrants detailed investigation of the nature of primary production in urbanised river systems. In this study, primary productivity was estimated at multiple locations along the continuum of an engineered (Sabarmati) and a free flowing (Mahi) river system using 13C tracer incubation method. Enhanced primary productivity in the riverfront (engineered construction along Sabarmati that holds water supplied by the Narmada Canal) and polluted downstream of Sabarmati was observed. It was observed that water stagnancy, temperature, and nutrient availability are the key factors regulating the rates of primary productivity in rivers.
Impact of subducting slabs on the mantle transition zone
Authors: Zhang Xiaoqing , Thybo Hans , Artemieva Irina M. , Xu Tao
Published: March 2024

The mantle transition zone (MTZ) bounded by the 410-km discontinuity (d410) and 660-km discontinuity (d660), controls material and heat exchange between the upper and lower mantle. The phase transformations in MTZ are affected by subducting slabs that reach the transition zone by the exothermic phase transitions from olivine to wadsleyite around d410 and from wadsleyite to ringwoodite around 520 km depth (d520), as well as the endothermic phase transition from ringwoodite to post-spinel phases around 660 km depth which has long been considered as a likely cause of a viscosity increase below d660. However, how subducting slabs impact the mantle transition zone (MTZ) is debated. The Pacific-Asia subduction system is ideal for studying slab impact on the MTZ. It includes multi-stage subduction of the modern Pacific plate and the earlier Izanagi plate, and seismic tomographic models image flattening of the Izu-Bonin and Japan-southern Kurile slabs at the base of the MTZ. We calculate receiver function images of the MTZ based on data recorded by 322 broadband seismic stations in Northeastern China. We image the area of the flattened slab inside the MTZ but not the effects where the slab interacts with d410. Our results show that the d410 is flat and 5-10 km deeper than the global average within the area covered by our data and the average depth of d660 is about 670 km, which is consistent with previous results and may be explained by temperature-chemical effects. A complex d520 is clearly observed which we interpret as the top boundary of the flattened slab although it may also be caused by unstable temperature conditions.
Subglacial Water Pressure Reshapes projected Antarctic Sea-Level Rise
Authors: Zhao Chen , Gladstone Rupert , Zwinger Thomas , Gillet-Chaulet Fabien , Wang Yu , Caillet Justine , Mathiot Pierre , Saraste Leopekka , Galton-Fenzi Ben , Christoffersen Poul , King Matt
Published: March 2024

Subglaical hydrology significantly influences the basal sliding that controls how fast ice sheets transport ice from land to oceans. The absence of hydrologic systems in ice sheet models is therefore a notable source of uncertainty in projected ice-mass loss and its subsequent impact on sea-level rise. Specifically, the uncertainty associated with the representation of effective pressure (the difference between subglacial water pressure and ice overburden pressure) in basal sliding lacks comprehensive investigation in Antarctic sea-level rise projections. Here we use Elmer/Ice ice-sheet model setups to examine how different approaches to determining effective pressure in the regularised Coulomb sliding law impact the projected ice mass loss pre-2300 under both continental and basin scales. Our results reveal basin-specific responses to the representation of effective pressure in basal sliding, significantly influencing projected ice-mass loss and the timing of the passing of tipping points. We find that the ongoing interactions between ice dynamics and the hydrologic system render the grounding line much more mobile than in models with no such interaction. Notably, for the entire Antarctic Ice Sheet, grounding line flux is more than doubled by 2300 when employing a smoothly decreasing effective pressure near the grounding line, compared to constant pressure. Remarkably, Thwaites Glacier shows a tenfold increase in its grounding line flux by 2300. These findings underscore the critical need to better understand the interactions between ice dynamic evolution and the subglacial hydrologic system. Explicitly modelling the hydrologic system in a coupled ice sheet-subglacial hydrology models is crucial to make more robust predictions of Antarctica's future ice-mass loss, thereby reducing uncertainty in sea-level rise projections. 
Assessment of Landslide Susceptibility Map in the Jaintia Hill District Using Remote Sensing and GIS
Authors: Kumar Sachin , Choudhary Mahendra kumar , Thomas Thomas , Umare Shubhangi
Published: March 2024

Landslides, a naturally occurring geological phenomenon, significantly threaten public safety, infrastructure, and the environment. Identifying the landslide-prone areas is essential for efficient risk mitigation and land-use planning. The main reason for concern about landslides is their potential to have disastrous effects, including property damage and casualties. Usually, landslides happen when a slope's stability fails due to natural or man-made causes like intense rain, earthquakes, etc. An area which are susceptible to landslide must be identified to prepare for disasters and take proactive mitigation measures. This study aims to use a Geographic Information System (GIS) and the weighted overlay method to create a landslip susceptibility map for the Jaintia Hills district. The main issue regarding landslide susceptibility involves three key factors: firstly, the inadequate knowledge of the geographic layout of areas vulnerable to landslides; secondly, the lack of a uniform strategy for evaluating landslide susceptibility; and thirdly, the immediate need for reliable resources to assist in land-use planning and development, to minimising the risk associated with landslides. The present study uses remote sensing and GIS techniques to address this challenge. It applies the Analytic Hierarchy Process (AHP) weighted overlay technique in GIS, incorporating eight thematic layers: elevation layer, drainage density (DD), land use/land cover (LULC), soil type, slope layer, aspect layer, geography, lineament density (LD), and geomorphology. The thematic layers are carefully selected to capture various factors influencing landslide occurrence, ensuring a robust and accurate susceptibility assessment. The AHP incorporates expert knowledge to allocate weights to each thematic layer using pairwise comparison. The overlay process combines these layers to generate a comprehensive map reflecting the potential zones of landslides in the Jaintia Hills district. The results reveal a detailed landslide susceptibility map for the Jaintia districts, highlighting areas prone to landslides. It reveals that approximately 11634 hectares are in the high landslide occurrence zone, and 52849 hectares are in the medium zone. The map compared with locations where the landslides occurred in the past and found that most of the points lie in the high-prone zone for landslides, which shows the significant accuracy of the prepared map. However, prepared map will provide valuable insights for land-use planning and risk mitigation strategies, aiding decision-makers in developing sustainable policies to safeguard both human lives and the environment in the Jaintia Hills region.Keywords – Landslide Susceptibility, GIS, Remote sensing, Natural Hazards, AHP weighted overlay method
A web-based platform to assess water supply resilience under climate extremes in irrigated agriculture in the western US: A case study approach for the San Joaquin Valley in California, the Cache Valley in Utah and the Mesilla Valley in New Mexico.
Authors: Medellin-Azuara Josue , Escriva-Bou Alvar , Null Sarah , Sabie Robert , Heerema Richard , Santos Nicholas , Viers Joshua
Published: March 2024

Irrigated agriculture in semi-arid regions such as the western United States will likely face increased volatility in access to water under climate extremes. Competing water uses including community, tribal, urban and environmental, along with higher-temperature driven increases in irrigation requirements will further the gap between available water and overall system demands. This research explores case studies in three regions of the western United States namely, the southern San Joaquin Valley in California, the Cache Valley in Utah an the Mesilla Valley in New Mexico in terms of their future ability to fulfill agricultural water demands while supporting communities and ecosystems using a web platform. The San Joaquin Valley, chronically affected for decades by groundwater overdraft and demand hardening from permanent crops and livestock wet forages, will necesitate substantial reductions in consumptive use via permanent irrigated land idling to meet sustainable groundwater regulation. We present a wide range of scenarios including trading, deficit irrigation and water supply augmentation along with their economic impacts to explore tradeoffs among alternatives. For the Cache Valley in Utah, environmental flow requirements to regulate levels in the Great Salt Lake may require upstream diversion reductions that will likely affect irrigated forages the most. We present varios crop choice scenarios and water exchange to find least cost alternatives considering downstream sectors such as livestock. The Mesilla Valley in New Mexico, supplied by sufarce water from the Rio Grande and supplemental pumping from the underliying aquifer system in dry years, may see an overall allocation reduction presenting challenges for their high value vegetable and tree crops. We examine the impact of potential groundwater regulation and markets to secure future water access for agriculture and competing sectors. 
Automatic identification of systematic model failures in ensemble precipitation forecasts
Authors: Kazachkova Yuliya , Miltenberger Annette
Published: March 2024

Quantiative precipitation forecasting remains a major challenge even for kilometre-scale ensemble forecasating systems. However, operational high-resolution ensemble systems provide a large data-set from which - if combined with observational data - insight into systematic issues in the model physics can be gained. Here, we explore statistical methods to automatically identify systematic error patterns and their relation to the larger-scale conditions at example problem of precipitation at the Harz mountain range in northern Germany. For the analysis COSMO-D2-EPS forecasts for the years 2011-2018 are combined radar-derived and station-calibrated surface precipitation estimates provided by the German Weather Service (DWD). For the identification of common precipitation error patterns, empirical orthogonal function (EOF) analysis has been employed. For the winter season the leading order principal components show error features located on the elevated topography in the Harz region. Analysis of large-scale conditions (derived from ERA5) for each principal component shows systematic differences in upstream wind direction and speed, temperature, and specific humidity. In the summer seasons patterns are less localised, but some regional structure is maintained especially for the first principal component. Also the differentiation in large-scale conditions between EOFs is less. The challenges in summer are presumably related to a large contribution of convective precipitation. Overall, the leading 5 principal components explain 70,4% (48,2%) of the variance in winter (summer). To gain a better understanding of the relationship of error models to larger-scale conditions, as well as the physical mechanisms of model errors, simulations of precipitation at representative dates for principal components 1 and 2 were performed using the ICON-D2 model.
Statistics of the extreme events with extreme value theory
Authors: Chen Si , Yuan Hong , Wei Yong
Published: March 2024

Measuring the probability of extreme space weather events poses a challenge due to their infrequency. However, these rare events significantly and extensively impact various facilities in modern society. Extreme space weather events from the Sun have the potential to push the magnetosphere into an extreme state, where electromagnetic fields and particle environments behave differently than predicted by conventional theory, potentially causing more severe impacts than anticipated. In this study, we applied Extreme Value Theory to geomagnetic indices (such as the AE index, Aa index) derived from ground-based magnetometer observations spanning various solar cycles. We obtained the return levels of the indices with different return periods and identified an upper bound for the time series. Diligent precautions are necessary to mitigate the consequences of such extreme events, and surpassing the upper limit becomes increasingly challenging over time.
The age and extent of the late Maastrichtian calcification stress at Bidart, France
Authors: Patra Subham , Kesen Kebenle , Keller Gerta , Font Eric , Adatte Thierry , Punekar Jahnavi
Published: March 2024

The final 0.5 m of the Cretaceous-Paleogene (K/Pg) boundary at Bidart (France) is characterized by geochemical, taphonomic, and biotic vestiges of an ocean acidification event linked with Deccan volcanism. The larger (>150 μm) planktic foraminifera morphogroups show varying populations (absolute abundance), with lowered abundances within the Deccan benchmark (final 0.5 m) and a demographic collapse at the K/Pg boundary. Additionally, the Deccan benchmark exhibits diminished test size (p:
CFD simulations on Vertical Forest’s Effects in a Step-up Street Canyon
Authors: Kim Dong-Hyeon , Rho Ju-Hwan , Kang Geon , Moon Woo-Sok , Kim Jea-Jin
Published: March 2024

The expansion of urban areas has heightened air pollution and exacerbated the urban heat island effect, giving rise to urgent environmental and health challenges. In dense urban landscapes where traditional urban greening solutions prove insufficient, the adoption of vertical forests, incorporating vegetation on building facades, balconies, and rooftops, has emerged as a critical strategy. These innovative green spaces plays a particularly vital role in street canyons, where they have possess the potential to significantly impact air quality and thermal comfort. We conducted an investigation into the effects of vertical forests on airflow and pollutant dispersion in step-up street canyons, utilizing dry deposition in a computational fluid dynamics (CFD) model. For validation, we compared the performance of the dry deposition effect in the CFD model with a wind tunnel experiment. Despite a substantial reduction in fine particles through dry deposition, there was an observed increase of 20-25% in fine particle concentrations within lower layer of the street canyon. This increase was attributed to a 14-20% reduction in wind speed in the street canyon.AcknowledgmentsThis research was supported by Particulate Matter Management Specialized Graduate Program through the Korea Environmental Industry & Technology Institute(KEITI) funded by the Ministry of Environment(MOE)
Status and Plan of Standard Verification System for the NWP model in Korea Meteorological Administration
Authors: Park Sora , Park Hyeja , Lee Haejin , Song Saem , Ha Jong-Chul , Kwon Young Cheol
Published: March 2024

The Korea Meteorological Administration (KMA) has established and operated a standard verification system of the operational NWP models to evaluate the predictive performance of NWP model and compare them with other NWP models operated by domestic and foreign organization. This secures the objectivity of the verification results by applying the verification standards (WMO-No.485) presented by World Meteorological Organization (WMO), and being able to compare the performance with the numerical forecasting models of other institutions under the same conditions. The NWP models to be verified is a global, a regional, very short-range, and an ensemble prediction system and verification against analyses and observations are performed twice a day (00 UTC, 12 UTC). In addition to standard verification, precipitation, typhoon and various verification indexes (CBS index, KMA index, jumpiness index) are verified and used to evaluate the utilization of NWP models. The Korea Integrated Model (KIM), which is developed for Korea’s own NWP model, has been in operation since April 2020. Since the start of operation, the RMSE of 500hPa geopotential height (in Northern Hemisphere) has decreased every year, showing that forecast performance is improving. In addition, it can be seen that the 72-hour prediction accuracy for 12-hour accumulated precipitation (1.0 mm or more) in the Korean Peninsula area (75 ASOS stations) is also improving. As such, this study intends to discuss the predictive performance of the numerical forecast model based on the standard verification system and plans to improve the verification system in the future. 
Intensified floods after mega forest fires in southeast Australia 
Authors: Xu Zhenwu , Zhang Yongqiang , Blöschl Günter
Published: March 2024

Forest fires are commonly expected to exacerbate local flood hazards. Yet, it's not well-established if such an effect is evident across broader geographic regions concurrently, particularly when considering the compounded influences of forest fires and climate variability on floods. Here, we show that recent 2019–2020 mega forest fires in southeast Australia, characterized by unprecedented burned areas, have significantly increased the flood peak discharges in the ensuing two years. The impact varied regionally, being more pronounced in areas with winter-dominated and uniform rainfall patterns, while it was insignificant in regions with summer-dominated rainfall. This regional divergence in fire impacts can be attributed to the differences in burned areas and dominant flood generating mechanisms. Given the increasing influence of climate change on fire activities, people living in these fire-prone regions might face escalating risks of cascading flood hazards following fires in the future.