bluuebunny/crossref_metadata_2025 huggingface dataset:
Recent advances in developing high-resolution flood forecasting systems in Germany
Authors: Najafi Husain , Rakovec Oldrich , Kumar Shrestha Pallav , Kumar Rohini , Vorogushyn Sergiy , Apel Heiko , Thober Stephan , Merz Bruno , Samaniego Luis
Published: March 2024

This presentation aims to offer valuable insights into the state-of-the-art technologies and methodologies employed to enhance Real-time Flood Forecasting (RTFF) systems by highlighting recent progress in the development of high-resolution RTFF systems. Given the existing uncertainties associated with RTFF and the documented increasing trends in flood peaks in the western and central regions of Europe [1], continuous improvement of RTFF systems is essential for better disaster risk preparedness.Recurrent and severe flooding events have impacted Germany in recent years. The predictability of two recent flooding events, including the extensive flooding from December 2023 to January 2024 across the entire country, and the 2021 summer flood in Ahrtal [5] will be explored by introducing an experimental RTFF chain. This chain utilizes high-resolution weather forecasts from Germany's National Meteorological Service, Deutscher Wetterdienst (DWD). The chain incorporates high-resolution streamflow and water level forecasts at 1 km using the mesoscale Hydrologic Model (mHM) [2,3]. Additionally, it features a fast hydrodynamic model (RIM2D) at 10 m resolution [4] with an extended component for impact forecasting tailored to the scale of individual buildings. We showcase how the newly developed RTFF system enables tailored decision-making compared to the common practices currently used by local authorities.References[1] Blöschl, G., Hall, J., Viglione, A., Perdigão, R. A., Parajka, J., Merz, B., ... & Živković, N. (2019). Changing climate both increases and decreases European river floods. Nature, 573(7772), 108-111. DOI: 10.1038/s41586-019-1495-6[2] Samaniego, L., Kumar, R., & Attinger, S. (2010). Multiscale parameter regionalization of a grid‐based hydrologic model at the mesoscale. Water Resources Research, 46(5).[3] Samaniego, L., Kumar, R., Thober, S., Rakovec, O., Zink, M., Wanders, N., ... & Attinger, S. (2017). Toward seamless hydrologic predictions across spatial scales. Hydrology and Earth System Sciences, 21(9), 4323-4346.[4] Apel, H., Vorogushyn, S., & Merz, B. (2022). Brief communication: Impact forecasting could substantially improve the emergency management of deadly floods: case study July 2021 floods in Germany. Nat. Hazards Earth Syst. Sci., 22(9), 3005-3014. doi:10.5194/nhess-22-3005-2022.[5] Najafi, H., Shrestha, PK., Rakove, O.,  Apel, H., Thober, S., Kumar, R., Vorogushyn, S., & Merz, B., Samaniego, L. (in review). Advancing a High-Resolution Impact-based Early Warning System for Riverine Flooding. Nature communications.
Integrated water scarcity index reveals increased exposures of populations and areas to water scarcity
Authors: Fu Zhonghao , Liu Wenfeng , Bai Yawei , van Vliet Michelle T. H. , Ciais Philippe , Davis Kyle Frankel , Wada Yoshihide
Published: March 2024

Freshwater resources are fundamental to supporting humanity, and measures of water scarcity have been critical for identifying where human water requirements and water availability are imbalanced. Traditional metrics for water scarcity primarily focus on actual blue water withdrawal, while the contribution of rain-fed water requirements (RWR) and water quality – dimensions with important implications for multiple societal sectors – to overall water scarcity remains unclear. Here we address this gap by explicitly merging the three dimensions of water scarcity into an integrated index (iWSI). Specifically, combining a process-based crop water model with spatially detailed information on water pollution and sector-specific withdrawals, we first develop global gridded (30 arcminute) estimates of iWSI and its individual dimensions (blue water, RWR, and water quality) averaged over the period 2001–2010. We then perform a quantitative comparison of water scarcity indices that consider different combinations of the three water scarcity dimensions, together or in isolation, and estimate their water withdrawals and associated global land area and population under conditions of monthly and annual water scarcity. We find that the global land area and population under water scarcity increases by 126% (119–133%) and 53% (49–57%) using this integrated index relative to assessments focusing only on blue water. These effects are most pronounced for populations in Africa and Asia. Examining seasonal water scarcity, we estimate that 4.4 billion people are exposed to integrated water scarcity at least one month per year – 31% more people than under blue water scarcity alone. Our research highlights that water scarcity challenges are more widespread than previously understood. As such, our findings underscore the need for actions to bring human pressure on freshwater resources into balance with both water quantity and quality, addressing previously overlooked blindspots in global water sustainability.
Study on the Outgoing longwave radiation changes of earthquakes based on the China Fengyun Satellite - taking the Luxian earthquake in Sichuan Province in 2021 and the Turkey earthquake in 2023 as examples
Authors: Cui Jing , Sun Xuexia , Liu Jun , Ma Weiyu , Jiang Wenliang
Published: March 2024

An earthquake is a process during which the Earth’s tectonic stress accumulates to a certain intensity, breaking through the critical value of rock elastic rupture and releasing energy quickly. Previous studies have shown that thermal infrared radiation (TIR) changes relative to stress in loaded rocks. The results of mechanical rock loading and fracture tests show that the infrared radiation generated during rock failure exhibits a time series phase change with respect to microintensification–intensification–attenuation–intensification–quietness synchronization, which provides a physical basis, monitoring content, and abnormal evaluation criteria for infrared remote sensing earthquake monitoring and prediction. Tidal force (TF) is an essential external mechanical factor that triggers earthquakes when crustal stress reaches a critical state. It is also the only physical parameter of earth deformations that can be calculated in advance and has an indicative advantage over time. Therefore, the extraction of seismic thermal anomalies based on tidal forces is helpful for obtaining infrared anomalies that conform to the radiation variation law of rock stress rupture as it can improve the recognition level of seismic infrared anomalies in time and space. In this study, the relationship between OLR and earthquake was studied by combining the celestial tide generating force with the OLR data of China Fengyun satellite, and the breeding and occurrence process of earthquake was discussed. The results show that the tidal force of celestial bodies has an induced effect on the earthquake, and the anomaly of long-wave radiation may be the radiation characterization of stress and strain in the process of earthquake incubation. After that, the abnormal period was tracked and verified by using NOAA satellite OLR product data, and it was found that the characteristics of the two results were relatively consistent, which further demonstrated that the FY satellite OLR data can be better applied to seismic anomaly monitoring.
 
Late Quaternary glacier-climate reconstruction in the Ahuriri River valley, Southern Alps of New Zealand
Authors: Tielidze Levan , Eaves Shaun , Norton Kevin , Mackintosh Andrew , Hidy Alan
Published: March 2024

I present the first dataset of Late Quaternary glacial maximum extent and deglaciation along with quantitative paleoclimate reconstructions from the Ahuriri River valley, Southern Alps, New Zealand. The new constraints based on geomorphological mapping and sixty-six cosmogenic 10Be surface exposure ages offer the opportunity to test hypotheses about the climate system, to better understand the processes that drove ice retreat and readvance during the Last Glacial Maximum and the subsequent glacial termination.Reconstructions of past glacier geometries indicate that the local ELA was depressed by ~880 m and climate was 5±1 °C colder than present (1981–2010) at 19.8±0.3 ka, while ELA was depressed by ~770 m and climate was 4.4±0.9 °C colder at 16.7±0.3 ka. Subsequent estimations suggest ELA elevations at 14.5±0.3 ka, 13.6±0.3 ka, and 12.6±0.2 ka were ≤700 m, ≤630 m, and ~360 m lower than today. This equates to air temperatures of ≤3.9 °C, ≤3.5 °C, and 2.3±0.7 °C colder than today, assuming no changes in past precipitation.The small amount of warming estimated in this study between 19.8±0.3 and 16.7±0.3 ka differs somewhat from glacial reconstructions in other major valleys in the Southern Alps, specifically from Rakaia River valley. Robust constraints of glacier changes in the Ahuriri valley between 14.5±0.3 and 12.6±0.2 ka confirm that an early glacier readvance occurred in New Zealand at this time, which has been previously recognised with only limited evidence. The reconstructed ELA suggests that the coldest part of the Late Glacial reversal occurred at 14.5±0.3 ka. 
Assessment of Rice Yield Potential changes over Korean Peninsula under climate change with 1-km high resolution SSP-RCP scenarios 
Authors: Jo Sera , Kim Yong-Seok , Hur Jina , Shim Kyo-moon , Hong Seung Gil , Kang Min-gu , Kim Eung-sup
Published: March 2024

The changes in rice climatic yield potential (CYP) across the Korean Peninsula are evaluated based on the new climate change scenario produced by the National Institute of Agricultural Sciences with 18 ensemble members at 1 km resolution under a Shared Socioeconomic Pathway (SSP) and Representative Concentration Pathways (RCP) emission scenarios. To overcome the data availability, we utilize solar radiation for CYP instead of sunshine duration which is relatively uncommon in the climate prediction field. The result show that maximum CYP(CYPmax) decreased, and the optimal heading date is progressively delayed under warmer temperature conditions compared to the current climate. This trend is particularly pronounced in the SSP5-85 scenario, indicating faster warming, except for the northeastern mountainous regions of North Korea. This shows the benefits of lower emission scenarios and pursuing more efforts to limit greenhouse gas emissions. On the other hand, the CYPmax shows a wide range of feasible futures, which shows inherent uncertainties in future climate projections and the risks when analyzing a single model or a small number of model results, highlighting the importance of the ensemble approach. This work was supported by a grant (no. RS-2021-RD009055) from the Rural Development Administration, Republic of Korea
NGFS scenarios: Scope, design limitations and gaps
Authors: Werner Sebastian , Pui Alex , Tomita Motoshi
Published: March 2024

There has been increasing focus on climate risk disclosure within the industry, evidenced by a shift from guidance (TCFD) to standards (ISSB) based approach.  However, surveys show that climate scenario modelling remains challenging, with high complexity and lack of expertise cited as key reasons.While there are global scenarios such as NGFS to support practitioners by providing key analytical foundations and parameters, concerns have been raised regarding the robustness of physical and transition risk assessment methodologies, and hence the fitness for such scenarios.  Given that the primary aim of climate scenario analysis at an entity level is to inform prudent risk management and business strategy, it is instructive to explore fundamental questions and context around the design of these scenarios, leading to an improved interpretation of end results.To this end, we aim to critically review the fourth iteration of NGFS scenarios that have recently been released, with a particular focus on 3 areas: First, the evolution of scenarios since the first vintage in 2020. Secondly, the design limitations of IAMs which do not feature frictions that could allow for misprinting and price bubbles. Thirdly, we discuss how the scenario design could benefit from incorporating uncertainty into its variable projections.
Laser absorption spectroscopy-based ultraportable analyzer for δ18O and δ2H in water.
Authors: Nataraj Akshay , Fortson Susan , Despagne Frederic , Lobo Neto Julio , Baer Doug
Published: March 2024

Stable isotope analysis of water 2H2O and H218O are powerful tracers to understand the different hydrological processes like ecohydrological processes, and hydroclimatic processes [1]. The measurement of δ2H and δ18O in water samples using laser-based absorption techniques is adopted increasingly in hydrologic and environmental studies. In contrast to the conventional Isotope ratio mass spectrometry (IRMS) technique, optical absorption spectroscopic techniques allow the realization of isotopologue-specific, non-destructive, and compact spectrometers with short analysis times with high-precision capabilities.ABB’s ultraportable water analyzers are compact, portable field-deployable laser spectrometers capable of making continuous, high-frequency measurements of δ18O and δ2H from multiple water sources. The instrument is based on Off-Axis Integrated Cavity Output Spectroscopy (OA-ICOS) technique [2]. These analyzers are capable of measuring liquid water (GLA132-LWIA) or vapor (GLA132-WVIA).  They are rugged and designed to handle both natural and isotopically enriched water samples.  Users can leverage the precision and speed of the GLA132-LWIA by coupling it with a portable auto-injector to perform automated, unattended injection patterns on multiple samples.An important asset of this innovative approach based on OA-ICOS technology coupled with the portable auto-injector technology is its sample throughput, which allows one to measure approximately 90 samples a day corresponding to 720 injections each with a sample volume of 0.5 µL per injection per day. The precision (1σ) achieved corresponds to 0.6 ‰ for δ2H and 0.2 ‰ for δ18O. The analyzer’s ease of use, field portability, durability, and high throughput make it an excellent choice for reliable, high-performance measurement of freshly collected samples in the field, thereby opening a plethora of applications to understand the different processing governing the earth’s climate.[1] Tian, C.,et al., Sci Rep 8, 6712 (2018). https://doi.org/10.1038/s41598-018-25102-7[2] A. O’Keefe, et al., Chemical Physics Letters, vol. 307, no. 5, pp. 343–349, Jul. 1999, doi: 10.1016/S0009-2614(99)00547-3.
The effect of correcting the projection error in Digital Terrain Models on Earth surface processes
Authors: Voigtländer Anne , Rheinwalt Aljoscha , Tofelde Stefanie
Published: March 2024

Hiking up a steep mountain, in comparison to walking on a flat beach, is unarguably different. But the horizontal distance made, estimated using a Digital Terrain Model (DTM), might be the same. The projection of 3D landscapes onto 2D grids in DTMs leads to a slope-dependent, inhomogeneous sampling of the surfaces, and a first-order error in topographic metrics. Using the slope dependency of this error, we can quantify and revert it. Foremost, correcting the projection error allows for more accurate estimates of area and volume, e.g., to quantify natural hazards; and enables the use of the full slope distribution to define the physical space of surface processes at any scale.We quantify the projection error using synthetic landscapes for which analytical solutions of slope angles and surface area are known. In applying the correction to DTM data of a real landscapes, we can address geomorphological processes in physically more meaningful ways. The corrected extracted topographic proxies, here exemplary, the erosional response to uplift in the Mendocino Triple Junction (MTJ) area, California, USA, provide two aspects for interpretation of geomorphic processes. First, as all slope angles are now represented equally, the variations in slope distribution by region of uplift rate is more pronounced. Second, the erosional response causes not only a steepening but narrow slope distribution in the regions of high uplift. The transient response is visible in a broadening of the distribution towards the lower slope angles, as deposition becomes more prevalent. In this example, we also find that the surface area ratio, enables determining the effectiveness of Earth surface processes, by increasing or decreasing the differential between the standard-planform and the surface area. Earth surface processes, that involve transport and volume along the surfaces, if not referenced in time, the ratio between the planform and surface area can provide a spatial reference and could be explored further. Correcting topographic metrics also allows addressing additional questions, like, which slope angles characterize which process domains, which processes create steepening, which lowering of slopes, where, and to what extent? Or, which parts of landscapes, maybe not the steepest, correlate to the highest potential to erode? 
Recent patterns of crop yield growth, stagnation and their drivers in China’s dryland
Authors: Zi Shuangshuang
Published: March 2024

Continued population growth, changing climate and increased pressure on water resources will dramatically increase the pressure on Chinese agriculture in the coming decades. Although there have been some reports of yield stagnation in the world’s major cereal crops, including maize, rice and wheat, the reasons for stagnation have not been quantified thoroughly. Here, we use statistical data to examine the trends in crop yields for two key Chinese crops: maize and wheat and their drivers in China’s drylands. Results showed that although yields continue to increase in many areas, we found that across 70.2% of maize- and 51.9% of wheat- growing prefectures or provinces, yields either never improved, stagnated or collapsed. The reasons for the decline and stagnation of crop yield were mainly caused by the change of growing season precipitation and irrigation fraction. New investments such as increased irrigation fraction in underperforming regions, as well as strategies to continue increasing yields in the high-performing areas, are required.
Interactions of Soil-plant Hydraulic Resistances under Drought Stress
Authors: Lei Guoqing , Zeng Wenzhi , Cai Gaochao
Published: March 2024

Plant transpiration is a critical hydrological process that regulates the water, carbon, and energy fluxes in the terrestrial system. However, there is significant uncertainty in the transpiration estimation due to a limited understanding of the hydro-physiological responses of plants to drought stress. In recent years, there has been increasing attention to exploring the primary component of hydraulic resistance that restricts soil-water water transport under drought stress. The impact of specific soil-plant hydraulic resistances on water transport is the preferred focus over their interactive way. We utilized a soil-plant water transport model to illustrate the interactions of stomatal sensitivity, plant hydraulic resistance, and soil planting conditions under drought stress. Results show soil drought almost simultaneously triggers hydraulic resistance variations in multiple components, including stomata, stem xylem, roots, and soil. These variations have distinct influences on water transport and interact with each other. Stomata-sensitive plants can slow down the increase in plant hydraulic resistance and water potential gradient between soil and leaf by promptly closing their stomata. Soil texture and its distribution in the rhizosphere are critical factors affecting transpiration, root water uptake distribution, and plant hydraulic conductance. Stomatal behavior, plant hydraulic resistance, and soil planting conditions all contribute to iso/anisohydric behaviors. Thus, we advocate adopting a systematic view to examine the process of soil-plant water transport.
Combustion Efficiency and Methane Emission Rate of Flares Subjected to Crosswind
Authors: Mohammadikharkeshi Milad , Burtt Damon , Tanner Alexis D. , Crosland Brian , Kopp Gregory A. , Johnson Matthew R.
Published: March 2024

An estimated 139 billion m3 of gas are burned globally each year in flares at upstream oil and gas production sites.  However, data and models to reliably predict emissions from flares are notably lacking.  Especially concerning are the impacts of strong crosswinds, which can reduce the overall combustion efficiency and strip unburned methane from the flare, although the specific mechanisms behind these emissions are not well understood.
Building on a methodology developed by Burt et. al, this study reports quantitative measurements of carbon conversion efficiencies and methane emission rates of 25-100 mm diameter flares subjected to turbulent crosswind in a large closed-loop wind tunnel.  Experiments considered multicomponent flare gas mixtures and operating conditions representative of flares at upstream oil and gas production sites which generally operate as simple non-premixed flames without supplementary air or steam injection.  Emission rates and combustion efficiencies were found to be influenced by wind speed, burner diameter, exit velocity, and particularly composition of the flared gas.  Comprehensive Monte Carlo uncertainty and sensitivity analysis was used to assess the uncertainties associated with such experiments.
Attempting to propose a practically implementable model capable of encapsulating known affecting factors, good correlation was observed between carbon conversion inefficiency and both burner diameter and exit velocity for a single fuel mixture over a range of wind speeds.  However, in different flare gas mixtures, minor changes in the composition dramatically affected the overall efficiency and emission rates.  To capture the effect of fuel chemistry in a general model, different correlating factors (such as stoichiometric molar air-fuel ratio, volumetric hating value, carbon number, etc.) were considered and introduced to the model.  The final semi empirical model was shown to be capable of predicting combustion efficiency with reasonable accuracy (less than 1% absolute error for conversion inefficiency at a 95% confidence interval) over a wide range of flaring conditions. 
Permafrost hydrology in an Arctic tundra ecosystem: quantifying water sources using stable water isotopes
Authors: Jung Hyejung , Ahn Jinho , Iwahana Go , Lee Jeonghoon
Published: March 2024

Global warming in the Arctic can lead to the alteration of the hydrological cycle and the thawing of permafrost. In this study, we utilized stable water isotope techniques (δ2H and δ18O) to infer the sources mixing of stream water at two sites (HV and PS) along the Sag River on the North Slope, Alaska (USA) during August 2022. The isotopes of snow and rain samples were plotted above the LMWL and reflected the isotopic characteristics of seasonal precipitation in Alaska. The porewater collected within the active layer showed enriched isotope values than other samples, indicating summer precipitation. Using δ18O and deuterium excess in a Bayesian mixing model, we estimated the contribution rates of summer precipitation, seasonal ice, and ice wedge. The results indicated a substantial contribution from melted seasonal ice (HV: 96.8% and PS: 74.1%), formed by frozen precipitation from the previous year, to surface water in August. Additionally, it was observed that the contribution of ice wedge was relatively greater in the downstream (PS: 21.8%) compared to the upstream (HV: 2.1%). Furthermore, we observed that the isotopic compositions of surface water in the PS site revealed evidence of evaporation, as indicated by a characteristic isotopic fractionation slope. Summer precipitation (HV: 1.1% and PS:4.1%) did not contribute substantially to surface waters. This research provides insight into fundamental processes related to sources and mixing of waters in permafrost hydrology.
Understanding the role of vegetation responses to drought in regulating autumn senescence
Authors: Choi Eunhye , Gray Josh
Published: March 2024

Vegetation phenology is the recurring of plant growth, including the cessation and resumption of growth, and plays a significant role in shaping terrestrial water, nutrient, and carbon cycles. Changes in temperature and precipitation have already induced phenological changes around the globe, and these trends are likely to continue or even accelerate. While warming has advanced spring arrival in many places, the effects on autumn phenology are less clear-cut, with evidence for earlier, delayed, or even unchanged end of the growing season (EOS). Meteorological droughts are intensifying in duration and frequency because of climate change. Droughts intricately impact changes in vegetation, contingent upon whether the ecosystem is limited by water or energy. These droughts have the potential to influence EOS changes. Despite this, the influence of drought on EOS remains largely unexplored. This study examined moisture’s role in controlling EOS by understanding the relationship between precipitation anomalies, vegetation’s sensitivity to precipitation (SPPT), and EOS. We also assess regional variations in responses to the impact of SPPT on EOS.The study utilized multiple vegetation and water satellite products to examine the patterns of SPPT in drought and its impact on EOS across aridity gradients and vegetation types. By collectively evaluating diverse SPPTs from various satellite datasets, this work offers a comprehensive understanding and critical basis for assessing the impact of drought on EOS. We focused on the Northern Hemisphere from 2000 to 2020, employing robust statistical methods. This work found that, in many places, there was a stronger relationship between EOS and drought in areas with higher SPPT. Additionally, a non-linear negative relationship was identified between EOS and SPPT in drier regions, contracting with a non-linear positive relationship observed in wetter regions. These findings were consistent across a range of satellite-derived vegetation products. Our findings provide valuable insights into the effects of SPPT on EOS during drought, enhancing our understanding of vegetation responses to drought and its consequences on EOS and aiding in identifying drought-vulnerable areas.
Assessment of climate change impacts on Brazilian catchments using a regional deep learning approach
Authors: Almagro André , Zamboni Pedro , Oliveira Paulo Tarso
Published: March 2024

The potential impacts of climate change in catchment hydrology are still unknown in most of the world and it is not different in Brazil. Conducting an integrated analysis of catchments based on similarity groups allows us to extract conclusions and observations about the overall controls of hydrological behavior, but also considering the specific and distinctive characteristics of each of these groups. This approach enables us to identify and comprehend the primary features influencing hydrological behavior within each distinct group, increasing hydrologic predictability and knowledge of catchments’ functioning, which is essential to better understand the impacts of climate change. In this study, we investigate the possible shifts in Brazilian catchment hydrology behavior in response to a changing climate. Employing a regional approach of the Long Short-Term Memory (LSTM) to understand and predict streamflow across 735 catchments of six hydrologically similar groups in Brazil, we simulated streamflow throughout the 21st century. This simulation utilized a multi-model ensemble comprising 19 bias-corrected Global Climate Models (GCMs) from the sixth phase of the Coupled Model Intercomparison Project (CMIP6), driven by intermediate and high-emission scenarios (SSP245 and SSP585). Our results show that the regional LSTM outperforms the conventional hydrological modeling (NSE≈0.60), underscoring the reliability of deep learning to estimate streamflow with simplified input. Interestingly, we found that substantial variations in projected temperatures across scenarios do not necessarily correspond to significant differences in projected streamflow. Moreover, changes in precipitation and temperature may not exert proportional impacts on streamflow. Further, we will investigate the dynamics of transitions between catchment groups. This innovative approach to assess the impacts of climate change enhances the reliability of projected streamflow trajectories, a critical consideration given the uncertainties associated with CMIP6 models. Furthermore, this study holds potential utility in developing strategies to mitigate the impacts of climate change on Brazilian water resources.
Predicting Future Suitability of Ski Resorts in China by MaxEnt Model
Authors: Wang Shijin , Zhao Rongfang
Published: March 2024

Abstract: Investigating the scientific site for ski resorts has significant implications for the sustainable development of ski resorts and regional economic development. This paper aims to analyze the sustainable distribution of ski resorts toward achieving the sustainable development of ski resorts. To achieve this, a maximum entropy (MaxEnt) model optimized with parameter adjustments was utilized to simulate the suitability distribution and to explore the affecting factors of ski resorts based on distribution sample points of ski resorts and the natural and socio-economic factors influencing ski resorts selection. Additionally, the ski industry is extremely sensitive to climate change. Hence, we predict the suitability distribution of ski resorts under the Shared Socioeconomic Pathways SSP126, SSP245, and SSP585 for the years 2040 and 2060. The results indicate that the highly suitable areas for ski resorts in China are mainly distributed in low-altitude regions such as the North China Plain, the Loess Plateau, and the Northeast Plain in northern China. Population density, average temperature in January, altitude, and total annual snowfall days are the main factors affecting the suitability distribution of ski resorts. Between 2030 and 2050, the suitable areas for ski resorts in China will gradually decrease. The warming climate during the snow season leads to a shift in the suitability of ski resorts towards higher latitudes and altitudes. The unsuitable areas in the south are gradually expanding northward. Based on these findings, this study suggests that the future development of ski resorts should fully consider the impact of climate change. The MaxEnt model offers a novel approach for investigating the sustainable areas of ski resorts, bearing significance in promoting the sustainable development of ski industry and regional economic development.
Physics-Informed Diffusion Model and Sampling for Global Weather Forecasting
Authors: Choi Sanghoon , Topping David
Published: March 2024

Recent advancements in weather forecasting have shown that generative probabilistic models, particularly diffusion models, exhibit significant promise in spatiotemporal forecasting. These models demonstrate enhanced accuracy, surpassing both machine learning-based deterministic models and traditional Numerical Weather Prediction (NWP) models, especially in short-range forecasting. However, a key challenge in utilising diffusion models for long lead time predictions is the increased variance in samples, which complicates the identification of the most accurate predictions. Specifically, ensemble means from samples at longer lead times often lack the necessary granularity to provide detailed and accurate predictions. This study addresses these challenges by introducing a novel approach: a physics-informed diffusion model coupled with physics-based sampling strategies. We incorporate physical information into the diffusion model as guiding constraints, and apply additional knowledge-based control to reduce the diversity in predictions, aiming for more consistent and reliable forecasts. The effectiveness of various types of physical information and the methods used to integrate this physics into the diffusion model are evaluated on WeatherBench2. Furthermore, we propose a unique physics-based sampling technique that utilises conservation laws. This methodology is designed to enable the selection of predictions that are most consistent with physical principles, potentially enhancing the model's capability in accurately forecasting extreme weather events. By integrating physical laws and principles into both the diffusion model and the sampling process, this approach aims to improve the overall accuracy and reliability of long-range weather predictions. The combination of physics-informed modelling and physics-based sampling offers a new strategy in generative model for weather forecasting.
GDAS-Powered Machine Learning Weather Prediction: A Comparative Study on GraphCast initialized with GDAS States for Global Weather Forecasting
Authors: Tabas Sadegh , Wang Jun , Yang Fanglin , Levit Jason , Stajner Ivanka , Montuoro Raffaele , Tallapragada Vijay , Gross Brian
Published: March 2024

The medium-range forecasting of global weather plays a pivotal role in decision-making processes across various societal and economic sectors. Recent years have witnessed a rapid evolution in machine learning (ML) models applications in weather prediction, demonstrating notably superior performance compared to traditional numerical weather prediction (NWP) models. These cutting-edge models leverage diverse ML architectures, such as Graph Neural Networks (GNNs), Convolutional Neural Networks (CNNs), Fourier Neural Operators (FNOs), and Transformers. Notably, Google DeepMind has pioneered a novel ML-based approach known as GraphCast, enabling direct training from reanalysis data and facilitating global predictions for numerous weather variables in less than a minute. Impressively, GraphCast forecasts show improved accuracy in predicting severe weather events, including phenomena like tropical cyclones, atmospheric rivers, and extreme heat. However, the efficiency of GraphCast relies on high-quality historical weather data for training, typically sourced from ECMWF's ERA5 reanalysis. Concurrently, the National Centers for Environmental Prediction (NCEP) has initiated efforts in collaboration with the research community, focusing on developing Machine Learning Weather Prediction (MLWP). This study assesses the pre-trained GraphCast model, leveraging Global Data Assimilation System (GDAS) data from the operational GFSv16 model as initial states. Additionally, we explore the potential use of GDAS data as an alternative training source for GraphCast. Notably, GDAS data is available at a 0.25-degree latitude-longitude resolution and with a temporal resolution of 6 hours. Our investigation involves a comparative analysis of GraphCast's performance when initiated on GDAS data versus ERA5 and HRES data. Alongside this comparative analysis, we investigate the advantages and limitations of utilizing GDAS data for GraphCast while proposing potential approaches for enhancing future iterations of this study.
A SLAM-based high-resolution full-character debris-flow channel morphological mapping system
Authors: Shen Ping , Wang Tengfei , Lu Fucheng , Kong Hui
Published: March 2024

Enhancing the study of channelized debris flow necessitates precise and high-resolution mapping of channel topography and deposit conditions. Existing mapping technologies like satellite imaging and drone photogrammetry face challenges in accurately observing the interiors of extensive mountainous gullies, particularly in regions affected by events like the Wenchuan Earthquake. Despite the emergence of Simultaneous Localization and Mapping (SLAM) as a 3D mapping technology, its efficacy is hampered in rugged gullies due to two primary challenges: (1) Unusual terrain features and (2) Severe sensor swaying and oscillation, causing significant deviations and noise in SLAM-generated results. Addressing these challenges, we propose an innovative SLAM-based debris-flow channel detection and mapping system. It incorporates three key enhancements to refine SLAM outcomes: (1) A deviation correction algorithm assisted by digital orthophoto maps effectively mitigates systematic errors; (2) A point cloud smoothing algorithm significantly reduces noise levels; and (3) A cross-section extraction algorithm enables quantitative assessment of channel deposits and alterations. Conducting field experiments in Chutou Gully, Wenchuan County, China, in February and November 2023—representing pre and post-rainy season observations—validated the system's capabilities in markedly improving SLAM results. This advancement facilitates SLAM's efficacy in mapping challenging terrains, compensating for existing technology limitations in detecting debris flow channel interiors. The system aids in delineating detailed channel morphology, erosion patterns, deposit differentiation, volume estimation, and change detection. By rectifying the shortcomings of current methodologies, this methodological approach serves to augment the understanding of full-scale debris flow mechanisms, long-term post-seismic evolution, and hazard assessment in affected regions.
Stochastic Strong-Motion Simulation of Valparaiso 1985 Mw 8.0 Chile Earthquake
Authors: Torres Rogelio , Ruiz Sergio
Published: March 2024

In recent years, several historical earthquakes have been studied in Chile to understand the seismotectonic context and anticipate the ground motion of these natural phenomena. One of the first great earthquakes documented by the Global Digital Seismographic Network (GDSN) occurred on March 3, 1985, off the coast of Valparaiso, with a moment magnitude (Mw) 8.0.Several researchers have modeled the slip distribution at the seismic source, obtaining satisfactory results and fits, mainly at low frequencies and in far field. However, a discrepancy has been observed between the areas of maximum slip and the accelerations recorded in the near field.In this study, the code proposed by Ruiz and Otarola (2016) was employed to stochastically generate synthetic accelerograms capable of accurately replicating the accelerations observed during near-field ground motion. This approach provides a realistic simulation of earthquake characteristics, source, path, and site.The importance of generating synthetic accelerograms extends to critical sectors such as civil engineering, geophysics, construction, and urban planning. These simulations play a critical role in understanding ground behavior, predicting large seismic movements, and improving the development of earthquake-resistant structures. Furthermore, in the fields of construction and urban planning, synthetic accelerograms are essential for assessing the vulnerability of specific areas, diversifying applications in industry, and facilitating a more resilient design approach for future seismic events.The results obtained by generating synthetic accelerograms can replicate the spectral and temporal shape, in agreement with the records provided by the National Seismological Center (CSN) network. Stochastic simulations have been run both in rocky environments and in areas with site effects.
Middle-late Mesozoic tectonic evolution of the NE China—corresponding to westward subduction of the paleo-Pacific plate
Authors: Zhou Liyun , Wang Yu
Published: March 2024

How did the continent-oceanic plate interact, and when did the initial west paleo-Pacific plate subduction beneath Eurasian continent occur, are still unknown. NE China deformation, volcanic eruptions and magmatic intrusions can give some constraints. Muling located in the Dunhua-Mishan fault zone in NE China, is a key area where the E-W-trending Eurasian domain changed to NE-trending west Pacific Plate domain in NE China. During the Mesozoic time, at least three stages of deformation occurred, including: (1) E-W-trending structures with extensive ductile shear deformation and south-verging folds which result from thrusting towards the south, followed the emplacement of granitic rocks. (2) NE- or NNE-trending thrust faults and strike-slip movement, accompanied by the formation of west-verging inclined and recumbent folds. This phase deformation changed the whole tectonic framework of eastern China from an E-W-trending Eurasian domain to a NE-trending west Pacific Plate domain. (3) NE-trending strike-slip faults and E-W-trending strike-slip motion. Field investigations of Mesozoic ductile shear zone and faults, granitic intrusions and dykes, combined with zircon U-Pb dating and muscovite 40Ar/39Ar plateau ages, reveal the age of the E-W-trending structures as ~254-209Ma, and NE–SW-trending tectonic belts as ~182–170 Ma. The tectonic transformation of the eastern China continent involved a change from E-W to NE-SW-trending structures was a response to the initial subduction of paleo-Pacific plate.
Seismic Silence Speaks Loud: No extensive magmatic underplating found in recent seismic studies of the Hawaiian Ridge
Authors: Dunn Robert , Fujimoto Megumi , Xu Chong , Watts Anthony , Boston Brian , Shillington Donna
Published: March 2024

Some prior active-source seismic studies beneath oceanic seamount chains indicate a sub-crustal layer of what is considered to be underplated magmatic material. The classic example is the Hawaiian Ridge, where a seismic study in the early 1980s first proposed the existence of such a layer. Since then, Hawaii has been considered one end-member in a range of possible scenarios, extending from underplating to no underplating, but with possible magmatic intrusion into the lower oceanic crust. Magmatic underplating affects mass flux and lithospheric loading calculations. All else being equal, underplating would be expected to lower the amplitude of the gravity anomaly over the crest of the edifice and provide a positive buoyancy force that makes the plate appear more rigid than it actually is. One hypothesis put forward to explain variations in the style of magmatic emplacement at intraplate volcanoes hinges on the age of the lithosphere at the time of volcano formation. In this model, shallow intrusion into the oceanic crust and overlying edifice is favored for seamounts growing on younger lithosphere, while magmatic underplating is favored for seamounts growing on older lithosphere such as Hawaii. However, recent seismic, gravity, and plate flexure studies conducted along the Hawaiian-Emperor Seamount Chain collectively provide clear evidence for shallow magmatic emplacement and contradict the notion of significant magmatic underplating for ages at the time of loading of ~57 Ma (Emperor Seamounts) and ~90 Ma (Hawaiian Ridge). Additionally, reprocessed legacy seismic data has not revealed evidence for underplating beneath the Hawaiian Ridge. In this presentation, results from these recent studies will be shown, compared, and the evidence for a simple mantle structure without underplating will be presented along with seismic synthetic tests that explore the degree of underplating that may be 'hidden' in the data.
New slow slip events along the Hikurangi margin detected using wavelet analysis
Authors: Perez-Silva Andrea , Wang Ting , Wallace Laura
Published: March 2024

Along the Hikurangi margin, where the Pacific plate subducts beneath the Australian plate, slow slip events (SSEs) have been detected at both shallow and deep depths. With the aim of improving the SSE catalog along the Hikurangi margin, we use a wavelet-based method developed by Ducellier et al. (2022) to detect SSEs recorded by the GPS sites operated by the GeoNet network. We apply wavelet decomposition to the east component of the GPS stations along Hikurangi. To do so, we consider two transects, transect 1 and transect 2 that target the shallow and deep SSE regions, respectively.We take equally spaced points along the transects and group stations within a 50-km radius of a given point. Then we apply wavelet decomposition to each station within the radius. We then stack each detail over all stations within the radius and sum the stacked details at each level of decomposition. We find that SSEs are best distinguishable in levels 5, 6 and 7 for shallow SSEs and levels 7, 8 and 9 for deep SSEs. We then define a displacement threshold of one standard deviation of the stacked details. To define an SSE, we consider the stacked details below the displacement threshold that are followed by stacked details above the displacement threshold, following Ducellier et al. 2022. Considering the stacked details along transect 1, which targets shallow SSEs, we find 54 SSE detections from 2005 to 2023. Of those, 20 have been reported in previous work, which leaves 34 potential new SSE detections. The stacked details along transect 2, which runs close to the deep SSE region, indicate 15 SSE detections over the same period; six of which were previously reported and nine potential new detections. We then geodetically model the new SSE detections using the software TDEFNODE (McCaffrey 2009) to study their spatial and temporal distribution along the margin.
Grotifer: a Profound Change in the Double-Probe Instrument Design to Provide Highly Accurate Three-Component Electric Field Measurements throughout the Heliosphere
Authors: Lejosne Solène , Auslander David , Bonnell John , Candey Scott , Klumpar Dave , Kurumiya Tatsuyoshi , Montalvo Neli , Pankow David , Sample John , Vu Van
Published: March 2024

No instrument is currently capable of consistently measuring all three components of the DC and low frequency electric field (E-field) throughout the heliosphere with sufficient accuracy to determine the smallest, and most geophysically relevant component: the E-field component parallel to the background magnetic field. E-field measurements in the heliosphere are usually made on spinning spacecraft equipped with two disparate types of double probe antennas: (1) long wire booms in the spin plane, and (2) ~10 times shorter rigid booms along the spin axis. On such systems, the potential difference (signal + noise) is divided by the boom length to produce a resultant E-field component. Because the spacecraft-associated errors are larger nearer the spacecraft, the spin plane components of the E-field are well measured while the spin axis component are poorly measured. As a result, uncertainty in the parallel E-field is usually greater than its measured value. The new design proposed by the Grotifer team is a way to overcome this difficulty. It consists of mounting detectors on two rotating plates, oriented at 90 degrees with respect to each other, on a non-rotating central body. Each rotating plate has two component measurements of the E-field such that the Twin Orthogonal Rotating Platforms provide four instantaneous measurements of the E-field, and the three E-field components are well-measured by the rotating detectors. Grotifer marks a profound change in E-field instrument design that represents the best path forward to close the observational gap that currently hampers resolution of significant science questions at the forefront of space plasma physics research. Here, we present recent advances in the development of the Grotifer design and we demonstrate the feasibility of its implementation in a 27-U CubeSat designed for a Low Earth Orbit mission.