bluuebunny/crossref_metadata_2025 huggingface dataset:
Flood risk assessment in the Ganga Basin, India: A multi-criteria geospatial analysis with NASA’s Black Marble Nighttime light Data
Authors: Aggarwal Ekta , de Ruiter Marleen C. , Buijs Sophie , Whittaker Alexander C. , Gupta Sanjeev , Sangwan Kartikeya S. , Shrestha Ranjay
Published: March 2024

Changing climate, intense rainfall, and geomorphological conditions within the Indo-Gangetic Basin (IGB) have led to recurring flooding within the area in the recent past. The devastating August 2022 floods in Pakistan affected 33 million people causing severe loss of life and property. The occurrence of such flooding events has increased the need to understand the complexities of the interplay between flood hazards, exposure, vulnerability, and risk. This study delves into flood risk within India's Ganga Basin, examining the flood-inducing factors, vulnerability, and exposure through an innovative approach using NASA's Black Marble Nighttime Lights Product Suite (VNP46).  The product suite, available globally on daily, monthly, and annual composite scales, corrects extraneous sources of noise in nighttime light (NTL) radiance signals and has proven effective in disaster monitoring, risk assessment and reduction, humanitarian response, preparedness, resilience, and sustainable development.Our work to date has successfully utilized these NTL data to quantify flood exposure and the impact of flooding in both urban and rural areas by analyzing changes in radiance across time and space. However, to improve our understanding of human response to floods, we now focus on a more intricate analysis: incorporating geomorphological and socio-hydrological factors into a risk assessment approach.Our study evaluates flood hazard, exposure, and vulnerability as three separate entities and combines them using a multi-criterion decision tool to assess flood risk within the basin. Flood hazards are studied as a relationship between geomorphological and hydrological parameters, whereas flood vulnerability is studied using land use and land cover data. The novelty of this research is using NASA’s Black Marble nightlights as a proxy to study flood exposure. We argue that the NTL data can more effectively capture the human presence and economic activities compared to some conventional parameters for flood exposure such as population count, household density, and literacy amongst others. By integrating these diverse data layers using the robust Analytical Hierarchical Process (AHP), we generate comprehensive flood risk maps across the Ganga Basin spanning a decade. The accuracy of these maps is validated against historical flood event data from the EM-DAT database. Ultimately, our research culminates in a spatially explicit and data-driven approach to flood risk assessment, which can empower targeted mitigation strategies and proactive planning within the basin.
Assessing the spatial expansion of plants in an Earth System model
Authors: Gurung Khushboo , Mills Benjamin , Zheng Dongyu
Published: March 2024

The emergence of land plants and their expansion across the Earth's surface has helped shape the climate of the Phanerozoic. Land plants are a major contributor to global photosynthetic biomass which in turn influences atmospheric CO2 and O2 levels. They also amplify continental weathering processes, which are a critical component of many global biogeochemical cycles. The inclusion of spatially-resolved vegetation within climate-biogeochemical models that predict paleo-CO2 and O2 levels can create a more accurate picture of the paleo-Earth [Gurung et al., in revision], however these applications have been limited by the availability of climate model simulations at high time resolution, which makes continuous spatial modelling difficult. Here, we use a new machine learning approach [Zheng et al., in revision] to build a 1-Myr climate emulator for the SCION climate-biogeochemcial model, and couple this to a deep-time vegetation model [FLORA; Gurung et al., 2022]. This allows us to re-run the plant colonisation of the land over the Paleozoic in detail and to view the global impact of changes in land occupation and productivity between early and more complex plants. By integrating simplified evolutionary and competition dynamics into the model, we can compare the effects on weathering, carbon burial and climate to help us better understand the dynamics that influence the expansion of plants and the resulting long-term Earth system changes.Gurung et al., Climate windows of opportunity for plant expansion during the Phanerozoic Nat Comms 13 (2022)
Identification and description of fire emission plumes from Sentinel-5p observations   
Authors: Kinalczyk Daniel , Forkel Matthias , de Laat Jos
Published: March 2024

Understanding the dynamics and characteristics of emission plumes from wildfires is of paramount importance for environmental monitoring and policy decisions. These plumes, composed of various greenhouse gases and pollutants, can have far-reaching consequences on global climate, air quality and health. In this study, a data-driven approach to detect and characterise emission plumes from wildfires utilising TROPOMI (Tropospheric Monitoring Instrument) of the Sentinel-5p satellite observations of nitrogen oxides (NOx), carbon monoxide (CO) and aerosols. The analysis leverages VIIRS active fire data to identify locations of fire occurrence, laying the foundation for plume detection. The primary hypothesis states that a plume image consists of three components: a plume body or core, a transitional zone from plume to clear sky, and the clear sky itself. To realise this hypothesis, a data-driven unsupervised algorithm to identify and map plumes is developed, which is based on kernel functions to pre-process the Sentinel-5p images. These kernels effectively highlight plume-related features, allowing for more precise delineation. Subsequently, Gaussian Mixture Models (GMM) are utilised to classify the images into three components of the plume according to the main hypothesis. In instances where multiple plume candidates exist, a Gaussian distance weighting function to identify the likeliest plume is employed. Furthermore, the mapping of the plume-clean air transition zones is further evaluated by employing Monte Carlo simulations to validate and refine the transition zone assessments. To verify the detections, plumes of methane (CH4), carbon monoxide (CO), formaldehyde (HCHO), nitrogen dioxide (NO2) and aerosols for several plumes over the Amazon and Alberta are extracted and the plume properties are related to different landcover types. The findings of this study provide valuable insights into the development of an advanced methodology for plume detection, which has broad implications for the understanding and monitoring of fire emissions and atmospheric research.
Parallel inversion of drone-based electromagnetic data for near-surface geophysical prospecting
Authors: Xiao Longying , Patzer Cedric , Kamm Jochen
Published: March 2024

The rapid development of geophysical systems utilizing drones facilitates mineral exploration with more efficient and economical data collection. To align the progress of hardware advancement and meet the model complexity needs for exploration, we aim to develop an efficient and robust 3D inversion code to interpret the drone-based EM data. Here, we present the framework of the implementation and show some preliminary results of the development.We use a total electric field formulation with curl-conforming Nédélec elements to solve Maxwell equations in the frequency domain. Octree grids are used to accommodate the meshing of even large models at adequate resolution, separately in forward and inverse domains. A direct solver (MUMPS) is applied to solve the linear system of equations of the forward problem. The code is implemented in C++ and allows for easy adaptation for various sources and data types.Currently, to solve the inverse problem, we minimize the misfit using a Gauss-Newton scheme with explicit computation of the Jacobian. The implementation was built on the deal.II library, where the interface wrappers allow to use MUMPS and PETSc for numerically intensive computations, such as system equation solving (MUMPS) and inversion model update (PETSC Conjugate Gradient solver). Currently, the code is parallelized using MPI throughout for both forward and inverse modeling and additionally OpenMP for MUMPS only.The code is planned to be a reliable and competent imaging tool, that can be applied for both commercial and educational use. Currently, the code is under the development and testing stage. The preliminary results will be shown on-site.
Functionally refined model for cracked cylindrical shells repaired with laminated composite materials
Authors: Yang Seungho
Published: March 2024

This study is focused on the performance evaluation of composite laminated shells when the crack initiates and propagates longitudinally or circumferentially. For this purpose, two numerical composite shell models are considered. One is the equivalent single layer model, and the other is discrete-layer model. Both models are based on the p-convergent higher-order theory or called as the functionally refined model. The second model is mainly adopted and compared with the first model to predict the stress intensity factor in the vicinity of a crack tip not only before patch repair, but also after patch repair. The patch reinforcement effect has been analyzed with respect to various experimental parameters in terms of material type of patch, patch size, patch thickness, adhesive shear modulus, adhesive thickness, etc. The present model has a subprarmetric concept that considers linear mapping of geometry fields on a cylindrical coordinate, and hierarchical approximating functions are based on one- and two-dimensional integrals of Legendre polynomials, allowing accurate simulation of three-dimensional behavior. In assumed displacement field, stain-displacement relations and 3-D constitutive equations of one random layer are obtained by product of 1-D and 2-D higher-order shape functions. Thus it allows independent implementation of increasing p-level, order of shape function, for in-plane and out-of-plane displacement. In the proposed elements, the integrals of Legendre polynomials and Gauss-Lobatto technique are applied to interpolate displacement fields and to implement numerical integration. The sensitivity test has been carried out to show the robustness of present p-convergent higher-order element associated with severe element distortions, very high aspect ratios of elements, and very large radius-to-thickness ratios of shells. For verification of the proposed model, some benchmark laminated shell problems have been solved as compared to the numerical results obtained by the conventional h-convergent finite element method and other p-convergent analyses that used the Lagrange type polynomials as a shape function. Numerical results show that the proposed model is capable of prediction in-plane stresses around the crack tip as well as interlaminar stresses at the interface between shell layers.
Modelling and Analysis of Lightning-Induced Wildfires in Australia 
Authors: Zhao Li , Yebra Marta
Published: March 2024

Lightning-induced wildfires lead to significant loss of life and extensive property damage worldwide. This issue is especially critical in southeast Australia, where such wildfires account for 80-90% of the total area burned, emphasising the need for a comprehensive understanding of the contributing factors and mechanisms that drive these events. This study aims to investigate the complex interactions between climate, topography, lightning activity, and fire events in New South Wales (NSW), Australia. By analysing comprehensive datasets from 2017-2021, including ignition records, meteorological data, topographical information, and fuel characteristics, this research seeks to identify the key factors influencing lightning-attributed wildfires and predict the probability of lightning-caused fire occurrence. A Random Forest model is trained and tested to estimate the probability of fires caused by lightning strikes. Model performance was assessed through the Receiver Operating Characteristic, with an Area Under the Curve (AUC) around 0.7 in the validation datasets, indicating a good agreement between the estimated probabilities and the reported lightning-caused fires. The identified key factors that influence lightning fire ignitions include humidity, elevation, temperature, rainfall, soil moisture, and fuel moisture, highlighting the dominant influence of weather variables on wildfire ignitions. The preliminary results demonstrate a potential link between the geographic distribution of lightning-induced fires and the temperate climate zones, possibly due to the presence of dense vegetation and seasonal weather patterns. Our ongoing efforts focus on further refining the predictive model and conducting a more extensive analysis of the data to enhance our understanding of the dynamics of lightning-induced wildfires. Ultimately the study will provide insights for effective risk management and mitigation of lightning-caused wildfires in the regions prone to wildfires.
Tracking real-time impacts of climate variability and trade disruptions on water and food security 
Authors: Gülpen Marijn , Siderius Christian , van der Velde Ype , Cranko Page Jon , Biermann Jan , Hutjes Ronald , Nauta Lisanne , Sutanto Samuel , Biemans Hester
Published: March 2024

Food insecurity results from a complex interplay of climate, socio-economic and political drivers, with local food security being frequently influenced by events elsewhere. Recent unprecedented climate events and economic disruptions such as Covid-19 and the resurgence of large intra- and inter-state conflict, show the diverse and unpredictable nature of risk, which can suddenly impacting food production and supply chains.Here, we present a coupled hydrology-crop production-trade model that is able to simulate, in real time, current and near-future risks to water and food security. The model combines an operational process-based simulation of global crop production and hydrology with an ML-powered trade module, trained on FAOs detailed trade matrix dataset. It is updated monthly with the latest ERA5 climate data from the Copernicus Data Store to assess current risk, and can be forced with seasonal forecasting and long term climate projections up to 2100. The model explains about 50% of yield variability in major growing regions - a critical characteristic for nowcasts or seasonal forecasts – and the majority of food trade and trends therein, but generally still underestimates the variability. As a first step to better reproduce observed crop yield anomalies we improved the simulation of growing seasons in the production model.  By combining production with trade, we are able to estimate the impact of climate-related yield anomalies elsewhere, and to assess risks for water- and food security at the country, regional or global scale. Derived indicators provide a real-time insight into, for example, food production and storage per capita, crop water productivity, or crop or export specific water stress. Through continued evaluation and learning, we expect to be able to better identify emerging stresses in the food system and its drivers, and support early anticipation of potential future food security risks. This should ultimately lead to a better understanding of the complexity of the global food system and eventually result in a more sustainable food system.
Relevance  of Landscape Metrics in Predicting Water-Related Ecosystem Services demonstrated on the Arno River Basin Italy
Authors: El Jeitany Jerome , Nussbaum Madlene , Pacetti Tommaso , Schröder Boris , Caporali Enrica
Published: March 2024

Quantification of the impact of Land Use and Land Cover Change on ecosystem services is crucial for identifying critical areas requiring conservation efforts and sustainable land practices. Landscape metrics, which quantify the spatial arrangement of land cover types within a landscape, have emerged as valuable tools for systematically understanding such impacts and operationalize land use changes. In this study, we explored the contribution of landscape metrics to predicting water-related ecosystem services, mainly water provisioning at the watershed scale represented by runoff. We employed a random forest model to approximate   distributed  maps of runoff  for the Arno River Basin in Italy, obtained from a nationally used gridded hydrological water balance model .   Open access earth observation data were used as environmental predictors, including hydroclimatic variables, land use classes, and of landscape metrics related to runoff. The out of bag error is used to assess model performance along with variance and bias, and a leave one sub-watershed out a time is used for validation.  Our results demonstrated that despite a relatively low feature importance compared to other direct hydrological predictors like precipitation and temperature, landscape metrics, especially the core area index of forest and agricultural land use, captured significant interactions between forest and agricultural land use and their influence on water provision. In wet and normal conditions where precipitation is the predominant factor, the significance of these metrics intensifies, whereas in dry conditions characterized by dominant groundwater recharge processes, their relevance diminishes.  Leveraging land use data and earth observations, this approach clarifies the complex LULCC-ecosystem service relationships, informing strategies that balance ecosystem multifunctionality with environmental sustainability despite limitations in comparison to process based models.
Estimating the impact of mobility scenarios on urban air quality - a regional scale analysis
Authors: Lugon Lya , Kemgne Chloé , Le Vot Valentine , Mauchard Nicolas , Vu Quang Bérénice , Wang Chaopeng , Vigneron Jérémy , Dugay Fabrice , Sanchez Olivier , Sartelet Karine
Published: March 2024

Atmospheric pollution is pointed out by the World Health Organization as the responsible for approximately 7 million premature deaths per year, and different approaches are investigated worldwide to reduce the high concentrations observed in urban areas. Regional-scale concentrations are influenced by different sources of pollutants, such as residences, industries and road traffic. Particularly road traffic is one of the important sources of regulated and emerging pollutants, including fine and ultra-fine particles, nitrogen dioxide and black carbon. Nevertheless, the traffic emission rate of each pollutant depends on the vehicle characteristics: the vehicle type, fuel and the vehicle manufacturing year. Urban mobility is, then, a key aspect to determine the total amount of traffic emissions, and choices related to the available modes of transport in a city may have an important role in urban air quality. This study investigates the influence of five extreme mobility scenarios on pollutant emissions and concentrations in urban air quality. In each scenario very strong limitations on road traffic are adopted: (i) a limited electrification of private and commercial vehicles and a shift to soft mobility, (ii) a significant increase in the number of users per car and reduced use of private cars car, (iii) a total electrification of the fleet (Paris-region target for 2030), (iv) limits on private vehicles circulation in specific areas, and (v) the implementation of all these measures simultaneously. For this, the regional-scale model CHIMERE is employed to calculate the concentrations of multi-pollutants with a 1 km x 1 km spatial resolution. A special focus is given to the emerging pollutants black carbon and ultra-fine particles. In this study CHIMERE is coupled with the chemical module SSH-aerosol, which enables the representation of aerosol dynamics with the state-of-art modules available in the literature. Simulations are performed in Paris during summer 2022. This study shows the potentialities of an air-quality modeling approach to understand trends in concentrations according to scenarios aiming to reduce population exposure to atmospheric pollution. 
Parent material modulated effects of soil degradation on fertility and organic carbon of tropical cropland soils in Eastern Africa
Authors: Summerauer Laura , Bamba Fernando , Akoraebirungi Bendicto , Wobusobozi Ahurra , Drake Travis W. , Kabaseke Clovis , Muhindo Daniel , Cizungu Ntaboba Landry , Ramirez-Lopez Leonardo , Six Johan , Wasner Daniel , Doetterl Sebastian
Published: March 2024

Deforestation for cropland expansion in the sloping landscapes along the East African Rift system causes severe soil erosion and thus the loss of fertile, organic rich topsoil. However, the varying effect of land degradation in the region on soils developed from different parent material - which may influence soil fertility and carbon stabilization - are still largely unknown. To examine these factors, we compared soil organic carbon (SOC) and soil fertility indicators in undisturbed forest topsoils with cropland hillslope topsoils along a chronosequence after deforestation (2–7, 10–20, 20–40, > 60 years of cropping, land abandonment) on mafic (South Kivu, Democratic Republic of Congo) and felsic parent material (western Uganda). From previous studies, we expected higher soil fertility and SOC contents and therefore slower degradation on mafic soils due to the higher amounts of clay and pedogenic metal phases which stabilize SOM and thus further maintain soil fertility. However, we found similar SOC contents on both parent materials and a consistent decrease with time after deforestation. SOC values were significantly lower in soils that were cleared more than 60 years ago, compared to cropland which was cleared 2–7 years ago and nearby undisturbed forest topsoils (0–10 cm soil depth). While the effective cation exchange capacity (ECEC) positively correlated with SOC in soils on felsic parent material, this was not observed in soils with mafic parent material, where it correlated with mineralogical proxies (total reserves in bases). In both regions, SOC did not correlate with clay content. Mid-Holocene carbonate volcanism appears to have offset soil degradation in the felsic region, contributing to higher pH and ECEC and impeding land abandonment due to the maintenance of acceptable soil fertility levels. Surprisingly, abandoned cropland sites in the mafic region still had an average SOC content of 14–29 g kg-1 in topsoils, likely due to strong fixation of SOC with reactive metal phases; however, they were characterized by extremely low pH values and high Al3+ mobility, combined with low available nutrient status. Our results emphasize that soil fertility and carbon stabilization are reliant on the mineral composition of the underlying parent material, even in deeply weathered soils of the humid tropics. Soil organic matter in degraded tropical cropland soils does not appear to be a reliable indicator of soil fertility.
In situ grapevine hydraulic response to drought is soil-texture specific
Authors: Delval Louis , Javaux Mathieu
Published: March 2024

Climate change will exacerbate drought events in many regions, increasing the demand on freshwater resources and creating major challenges for viticulture. The knowledge on grapevine drought stress physiology has increased significantly in recent years, but a holistic comprehension on how soil-grapevine hydraulic conductances develop and are regulated in the soil-grapevine-atmosphere continuum (SPAC) remains poorly understood. In particular, how soil type affects the grapevine hydraulic response to drought is still an open question.The aim of this work is to understand how the hydraulic conductances in the SPAC continuously evolve according to soil type, during drought.The continuous, concomitant and automatic monitoring of soil and collar water potentials, as well as sap flow, made it possible to characterize the evolution of the soil-grapevine hydraulics in situ in real-time. To investigate the impact of the soil type, two vineyards planted with Vitis vinifera cv. Chardonnay were selected due to their intra-field heterogeneity of soil properties (two subplots per vineyard). In a first vineyard, soil-grapevine hydraulics were measured on a sandy subplot and on a loamy subplot. In a second vineyard, we worked on a loamy subplot and on a silty-clay subplot.We found that grapevine hydraulic response to soil drying is soil texture specific. Stomatal closure was observed for grapevines planted on coarse-textured soils, but not, or little, on fine-textured soils. This stomatal response was triggered by a decrease in belowground hydraulic conductance and not xylem cavitation in the trunk. This suggests that the interaction between the grapevine and the soil hydraulic environment plays a crucial role in shaping hydraulic behaviour of Chardonnay during drought periods.While soil dries out, the decline in soil hydraulic conductivity led to a steep and nonlinear reduction in soil matric potential at the soil-root interface, with greater reduction in sandy soils compared to loamy soils. This rapid decline in soil hydraulic conductivity implies that the soil is more rapidly limiting (at less negative soil water potential), triggering earlier stomatal closure in coarse-textured soils. Stomatal regulation is amplified in sandy profile as compared to fine textured profile within the same grape variety.
Swiss Alps 3D: building a large-scale 3D underground model of the Central European Alps
Authors: Musso Piantelli Ferdinando , Baland Pauline Baland , Ursprung Anina , Baumberger Roland
Published: March 2024

The Swiss Geological Survey (SGS) is the competence centre for the subsurface and georesources of the Swiss Confederation. It provides up-to-date, high-quality spatial reference data for the whole of Switzerland in the form of nationwide geological datasets and 3D geological models. Between 2024 and 2030, the SGS is funding the Swiss Alps 3D project, which consists of eight research projects involving multiple universities and aims to develop a consistent large-scale 3D geological model of the main contacts and structures of the Swiss Alps.In this poster we present the complete workflow that will be used for the construction of this 3D model and the project plan for the next 7 years. The main challenge for 3D modelling in Alpine regions is the lack of subsurface data (seismic, boreholes, etc.). However, the high relief, the sparse vegetation and the large number of scientific studies make these regions an excellent site for advanced surface-based 3D modelling. Based on the new Tectonic Map of Switzerland 1:500'000 (2024, in prep.), the area is divided into eight 3D modelling projects according to their paleogeographic origin and structural evolution. The resulting models will then be merged into a single large-scale 3D model.At the beginning of each modelling project, a 1:25’000 scale geological map of the main structural and lithostratigraphic contacts will be produced by verifying and harmonising a 2D geological dataset compiled for the study (published maps, strike and dip data, tunnel and seismic data). 3D modelling software packages (e.g., Move™, SKUA-Gocad) will be then used to generate a network of regularly spaced (1000 m) geological cross sections throughout the area. By applying explicit or implicit 3D interpolation and meshing techniques between the cross sections and the surface outcrop lines (i.e., spline curve method), lithological and structural boundaries will be then interpolated to generate 3D surfaces of each horizon of the model. The workflow presented here offers the chance to gain validation approaches for domains only weakly constrained or with no subsurface data available, by generating a 3D model that integrates all accessible geological information and background knowledge.Swiss Alps 3D will generate key knowledge by establishing an experienced modelling community and 3D visualization of the main structures and lithostratigraphic boundaries of the Central European Alps. The development of such a model will provide a framework model of the area as a basis for higher resolution 3D models to be used for infrastructure planning, groundwater studies, natural hazard assessment, education and research purposes. In addition, such models will provide access to strategic subsurface knowledge for geo-resource and geo-energy management and exploration.
A practical approach to link lysimeter and large-scale measurement systems.
Authors: Liebhard Gunther , Strauss Peter , Cepuder Peter , Nolz Reinhard
Published: March 2024

An accurate and reliable measurement system is essential for analysing transport processes within the soil-plant-atmosphere continuum and for calibrating and validating ecosystem or hydrological models. Weighing lysimeters are very suitable tools for these purposes, as they are the most direct tools to reliably and precisely measure water mass balance components such as rainfall and non-rainfall water inputs, evapotranspiration, and percolation at the system boundaries. Investigating the ecosystem by use of lysimeters is more or less limited to point measurements, though. Approaches are therefore required to link lysimeter mesurements to the landscape scale. We present our experimental approach to link point and large-scale parameter assessment at an experimental station in Groß-Enzersdorf, Austria. In particular, we use soil water content data across the soil profiles from capacitance sensors and t-test statistics to check the representativeness of the conditions in the lysimeter body with the surrounding field and to assess soil hydraulic properties for numerical modeling of water fluxes. Based on this, we transfer measurement data with high measurement accuracy and temporal resolution from the lysimeter scale to the large-scale measurement systems such as eddy covariance, scintillometry, or isotope hydrology. On the other hand, we are able to incorporate parameters from areal measurements and from measurements using disturbed and undisturbed soil samples into the lysimeter measurement system.
The Role of Rainfall in Humid Heat Extremes across the Global Tropics
Authors: Jackson Lawrence , Birch Cathryn , Chagnoud Guillaume , Marsham John , Taylor Christopher
Published: March 2024

Extreme humid heat poses a serious risk to human health, reducing the body’s ability to cool itself through sweating. The impact on humans will increase under climate change, particularly in tropical regions, such as the Indian subcontinent, that are highly populated and already hot and humid. Whilst there is a growing body of research on dry-bulb temperature extremes, there is limited understanding of the meteorological drivers of humid heat extremes, particularly the role of moisture transport, rainfall, and evaporation of moisture from the Earth’s surface.In this study, we use ERA5 data to identify and analyse extreme humid heat events in the global tropics during 1993-2022. In particular, we focus on the relationship between rainfall and the occurrence of humid heat and use extremes in wet-bulb temperatures to define the humid heat events.We find that rainfall is a key driver of humid heat extremes across much of the global tropics. In monsoon regions, dry-bulb temperature extremes typically occur in the pre-monsoon period whereas wet-bulb extremes occur more frequently during the monsoon season. The role of rainfall varies between humid heat events characterised by extremes in dry-bulb temperature versus those characterised by extremes in humidity. In much of the global tropics, rainfall followed by a few days of dry clear weather primes the surface and boundary layer climates for the initiation of humid heat events. These events typically have extremes in dry-bulb temperatures accompanied by what we characterise as a sufficiently high level of humidity. In arid regions, away from irrigated areas, rainfall is critical for the initiation of humid heat and frequently occurs locally on the first day of humid heat events. These events typically have extremes in humidity whereas dry-bulb temperatures are less likely to be extreme.These findings are a step towards greater understanding of the meteorological drivers of humid heat extremes at the regional scale. They will be valuable in the evaluation of weather and climate models, will aid the use and interpretation of climate model projections, and ultimately inform the design of much needed early warning systems for humid heat extremes.
Youth education and empowerment through outdoor experiential learning and peer-to-peer communication
Authors: Walden Jane , Rodari Léa , Naegeli Kathrin ,   Girls on Ice Switzerland Team
Published: March 2024

Anthropogenic climate change is a daunting issue facing today’s society. In recent years, youth have shown a growing interest in preserving the planet by becoming involved in political demonstrations and school strikes. It is thus of paramount importance that youth are well-informed on the topic and equipped with the necessary skills to share information with their communities. We seek to educate youth, particularly those from traditionally underrepresented genders in the sciences, about geosciences, art, and mountaineering, especially in the context of ongoing climate change. At Girls on Ice Switzerland, we believe that first-hand experience is the key to both learning and motivating scientific concepts. We offer tuition-free glacier expeditions for teenage girls*, where the selection process is independent of academic performance, giving equal opportunities to all interested youth, and ensuring socio-cultural diversity within the team. During the week-long expedition, participants conduct artistic and scientific modules with professionals, learn new techniques and carry out an experiment in small groups, and finally present their work to the public. Following the expedition, school workshops led by participant-scientist tandems build upon the scientific content of the expedition, allowing participants to share their knowledge with peers and distribute scientific information to a broader audience. This fosters self-confidence in the participants, helping them to become scientific ambassadors for their peers, and also provides them with invaluable networking and mentoring opportunities through their interaction with female scientists. Through these steps, participants are exposed to the scientific process: experimental design and performance, resiliency in the face of unforeseen challenges, and analyzing and communicating findings. The expedition experience has been shown to be empowering for participants: it boosts their confidence, motivates them at a critical stage in their lives, and provides them the opportunity to learn from female role models. School workshops and expeditions allow former expedition participants to be leaders amongst their peers and further deepen their understanding of the topics. In this way, we prepare future generations of scientists and members of society to think critically, and this experience gives them the knowledge and power to dispense information within their communities as scientific ambassadors.*cisgender girls and transgender, agender, nonbinary, intersex, and genderqueer youth
Analysis of Monsoon Characteristics in China based on GNSS Precipitable Water Vapor (PWV)
Authors: Zhang Zhixuan , Lou Yidong , Zhang Weixing , Cao Yunchang , Liang Hong
Published: March 2024

In the context of the global warming, we experience increasing extreme weather events, in particular extreme precipitation which may cause natural disasters. As monsoon climate is dominant in China bringing frequent and intense convective precipitations, adequate knowledge of monsoon characteristics is necessary for understanding of extreme weather events. Considering that the monsoon is usually accompanied by distinct variations in water vapor between dry and wet seasons and rapid transitions between dry and wet states, understanding of the distribution and variability of water vapor can play a certain role in indicating monsoon characteristics. Compared with other traditional water vapor acquisition methods, ground-based Global Navigation Satellite System (GNSS) observations have big advantages for monsoon studies due to its high accuracy, high temporal availability, and long-term homogeneity. In this work, GNSS data from nearly 1000 stations densely distributed in China were used to obtain Precipitable Water Vapor (PWV) during 2016. We first utilized the bimodality of PWV statistical distribution and selected a suitable metric to quantify the impact of monsoon in different regions. Results indicate that the strongest bimodality occurs in Southwest China with the metrics below 1.75. Eastern China is also part of the monsoon regions with metrics between 1.75 and 2.25. For the less affected regions such as Northwest China, the bimodality is weak with metrics above 2.25. Subsequently, the normalized precipitable water indexes (NPWI) were constructed using temporal variations in PWV to describe the monsoon onset and retreat. The monsoon reached the south-eastern coastal regions in early/mid May (Day of year 120-140) and advanced to the north-eastern regions at the end of July (Day of year 210). In general, the monsoon advances from the south-east to the north-west with an uneven speed over China.
Land-use scenarios for assessing climate risk as a tool for spatial planning: a case study of the Stuttgart Region, Germany
Authors: McMillan Joanna M. , Göttsche Franziska , Janssen Hendrik , Hoppe Holger , Birkmann Jörn
Published: March 2024

Spatial development, particularly the rapid expansion of urban areas, is increasing disaster risk in city-regions around the world. The planning region of Stuttgart is a growing polycentric region with a high demand for housing and commercial space, and at the same time faced with increasing risk of pluvial flooding and heatwaves. Spatial planning that controls and coordinates urban development is an important tool for ex-ante disaster risk reduction. However, planners face a complex task to weigh up a myriad of development goals of which risk reduction is just one. Decision-making tools for planning practitioners and the public that quantify resilience factors spatially can support the integration of resilience and risk considerations into planning processes. In our research, we investigate the use of land-use scenarios as a way to measure the relevance of land to the hazards of pluvial flooding and the urban heat island effect and thus to risk reduction. We do so with a particular focus on operationalizing such a quantitative assessment for the regional planning level, whose task it is to coordinate the spatial development of the municipalities. Such coordination is particularly important in the context of disaster resilience in urban regions such as Stuttgart, because, for example, the development of land in one municipality can increase water runoff or decrease cooling airflows in a neighboring municipality.In our contribution to this session, we share our insights from a combined effort by research, modelling and planning practitioners to operationalize land-use scenarios as a way to quantify the effect of urban development on risk. A central aim of our approach was relevance to regional and local planning processes. The land that we considered as potential for urban development was thus based on the current planning law. We constructed two land-use scenarios, in which all land in the region with potential for development was fictitiously used for building housing but in two different ways – one with a building density and height and level of soil sealing typical to the local setting, and the second with a more compact urban form with more green and less impervious surfaces. The aim was, firstly, to measure the effect of urban expansion on hazard exposure and, secondly, to determine if through a compact and climate-sensitive urban form the needs for more housing could be met without increasing hazard exposure. The pluvial flood hazard model and an urban climate model of the two scenarios provided useful results for the first aim, but less so for the second. In our contribution, we will share the methodological challenges of translating the scenarios for two different types of models, and discuss the results and their potential as a tool for use in spatial planning processes.
Assessing the 20-Year Changes in Leaf Phenology of Temperate Deciduous Forests in Japan Using in-situ and Satellite-GRVI
Authors: Noda Hibiki , Takeuchi Yayoi , Muraoka Hiroyuki
Published: March 2024

In the temperate region, inter-annual variation of air temperature affects leaf phenology, i.e., timings of leaf emergence and growth in spring and defoliation in autumn. These changes have significant impacts not only on the canopy of dominant trees of forest ecosystems, but also on the seasonal light environment within the forest understory which further influences the growth and survival of tree seedlings, shrubs, and herbaceous species. Consequently, global warming is expected to influence biodiversity by altering species-specific growth responses to the environmental shifts, affecting primary production and hence the progress of vegetation succession. Therefore, in order to comprehensively monitor and assess the state and changes in forest ecosystems across wide geographical and decadal scales, it is important to observe leaf phenology at both the species and ecosystem scales, which is considered one of Essential Biodiversity Variables (EBVs).The objective of this study is to investigate the decadal-scale change of the leaf phenology in deciduous forest in Japan. We examined 20-year changes of the dates of leaf emergence, leaf area index (LAI) reached its maximum, and defoliation by using in-situ and satellite data. The in-situ remote sensing has been conducted by a spectroradiometer and automated digital cameras on a canopy tower since 2003 at a deciduous forest in Takayama site, located in the cool-temperate region in the central Japan. The system is part of the Phenological Eyes Network (PEN). We estimated the dates of leaf emergence, maximum LAI, and defoliation based on the seasonal pattern on the Green-Red Vegetation Index (GRVI). These dates exhibit notable inter-annual variations, and notably, the date of maximum LAI occurrence tended to shift earlier over the 20-years period from 2004 to 2023. Those inter-annual variations in the leaf phenology were strongly related to the air temperature. Based on the knowledge gained at the Takayama site, we then examined the spatial distribution and annual changes of phenology of the deciduous forests in Honshu Island with satellite-GRVI. We will discuss the spatial and temporal changes in phenology along the environmental gradient and rising air temperature due to global warming, and evaluate the sensitivity or tolerance of these forests by focusing on species composition and geographical characteristics.The authors thank PEN for sharing the data of spectral reflectance and canopy images.
Labile substrate availability affects interactions and function in degrader communities: Insights from a combined experimental and modelling approach
Authors: Mohrlok Moritz , Guseva Ksenia , Alteio Lauren , Berger Julia , Kaufmann Lilian , Mor Galvez Julia , Sirbu Dave , Kaiser Christina
Published: March 2024

Bacterial communities that degrade chitin in soils often exhibit “social” behavior, where different strains fulfill different functional roles. “Degraders” produce extracellular enzymes that attack and cleave the complex biopolymer, releasing the monomer N-acetylglucosamine (NAG) as a public good. This compound can be readily taken up by both degraders and “exploiters”. The latter do not contribute directly to the degradation process but might in turn produce different substances that can be utilized by other members. “Scavengers” do not utilize NAG themselves but live mostly off metabolites secreted by the other strains. Our work aimed to investigate what effect the addition of a readily available C compound, like NAG, has on these interactions in such a system. Based on the results of a wet-lab experiment using a model bacterial consortium, we hypothesized that adding labile C leads to domination of the exploiter-strain though competitive exclusion. This in turn results in the breakdown of positive interactions, and a loss of diversity and functionality of the community. To further investigate this, we designed an ordinary differential equation (ODE) consumer-resource model, consisting of different linked pools representing the experiment. By parametrizing this model based on our respiration measurements and simulating the system over time, we were able to reproduce most of the observed experimental patterns in silico. When there was no NAG added to the system, the model matched the measured respiration when we included several positive interactions (such as crossfeeding or division of labor). This resulted in a more diverse community that degraded chitin more efficiently than the degrader-strain in monoculture. When NAG was added, the exploiter-strain outcompeted the other strains quickly, resulting in a loss of their potential function for the community. Through this combined experimental and modelling approach, our work shows that the addition of excess labile C to degrader communities in soil can alter interactions between bacteria, possibly leading to a loss of biodiversity and function.
Imaging the Electrical Resistivity Structure of a Locked Fault Segment: The Ganos Fault example
Authors: Tank Bülent , Yazıcı Ruken , Doğukan Esra , Demir Tunç , Taşseten Gözde , Duran Pınar , Assar Tannaz
Published: March 2024

The Ganos Fault, in the westernmost part of the North Anatolian Fault Zone (NAFZ), stayed quiet for approximately 146 years before two catastrophic events shook the area in the summer of 1912. The historical records point out that two devastating activities shook both sides of the Marmara Sea in 1766, too. Following the 1766 events, on August 9th, 1912, two blocks of the dextral Ganos Fault shifted one more time to create an Mw = 7.4 event near Mürefte in Tekirdağ. Nearly a month later, further to the west, the fault zone moved on September 13th, forcing another disastrous Mw= 6.8 earthquake. Almost 112 years have passed since then (leaving approximately 34 more years to complete the recurrence), and the Ganos Fault is again acting as a seismic gap. In brief, the Ganos Fault tends to generate another series of earthquakes in the region, and the fault zone characteristics of this locked segment are poorly known. In this study, magnetotellurics (MT) method is utilized to image the crustal electrical resistivity structure for deciphering the fault zone geometry. With this object in mind, simultaneous electric and magnetic observations were made at nearly 40 sites in two campaigns. For each observation point, the collected data were transferred to the frequency domain where the electromagnetic impedance tensor elements were calculated with robust processing algorithms (Birrp) for wideband frequencies. Following the dimensionality analyses performed with various tools such as Groom and Bailey decomposition, phase tensor analysis, etc., which eventually pointed out a geo-electric strike angle of nearly ~N60oE, numerical models based on two- and three-dimensional algorithms (such as MT2D and ModEM) were developed to image the fault zone properties of the Ganos Fault. Several numerical models were calculated to realize the influence of the coast-effect caused by the Marmara Sea. Pre-modeling analysis results and the final models suggest that (i) the geo-electric strike angle of ~N60oE agrees well with the earlier results, the geology and the fault’s geometry, (ii) the Ganos Fault acts as a geological boundary between the Eocene-aged Keşan Formation in the north and Miocene-aged Çengelli Formation in the south, (iii) while the Keşan Formation defines a continuous tubular highly resistive zone (~500- 800 Ωm) that may be acting as the seismogenic zone along the Ganos Fault, the Çengelli Formation appears to be less resistive in coherent with the ages of the formations highlighted earlier, (iv) the aforementioned resistive block reaches to a depth of nearly 15 - 18 km and this feature may mark the bottom of the seismogenic zone.          