bluuebunny/crossref_metadata_2025 huggingface dataset:
Gravity Wave Lateral Propagation Prominence in the Extratropical Stratosphere
Authors: Gupta Aman , Sheshadri Aditi , Alexander M. Joan
Published: March 2024

Internal gravity waves (GWs) exhibit both vertical and horizontal (lateral) propagation in the atmosphere, influenced by the background shear of the flow that supports them. GW model parameterizations, however, represent them in climate models assuming strict vertical propagation. This modeling assumption can have implications for modeled large-scale stratospheric circulation and variability. We use ERA5 reanalysis to produce the climatological distribution of resolved GW momentum fluxes and forcing in the stratosphere, and their composite evolution around prominent modes of extratropical stratospheric variability like sudden stratospheric warmings (SSWs) and springtime final warmings (FWs). The climatology reveals that lateral propagation leads to the formation of a belt of rich GW activity in the upper winter stratosphere, which is otherwise localized over orographic hotspots in the lower stratosphere. The resolved forcing due to lateral GW propagation is found to be roughly the same order of magnitude as resolved forcing due to vertical fluxes, underlining the importance of lateral propagation for future GW parameterizations. Strikingly different GW forcing profiles before vs. after SSWs and FWs, highlighting the strong two-way connection between GWs and the stratospheric mean flow.
Vegetation drought monitoring in the Huang-Huai-Hai Plain of China using solar-inducedfluorescence and near-infrared reflectance
Authors: Zeng Yelu , Gao Yongyuan
Published: March 2024

Drought is a complex and pervasive natural disaster that frequently exerts adverse effects onvegetation dynamics. Recent advancements in satellite-based solar-induced chlorophyllfluorescence (SIF) remote sensing offer unprecedented opportunities to monitor and understandvegetation responses to drought on a large scale. In this study, we utilized high-resolutionTROPOspheric Monitoring Instrument (TROPOMI) SIF data, Bidirectional Reflectance DistributionFunction and Albedo (BRDF/Albedo) Model Parameters dataset (MODIS MCD43C1), MODIS landcover data, and meteorological information to investigate the physiological responses of crops inthe Huang-Huai-Hai Plain of China during the drought period of 2019. Our results demonstratethat NIRv, SIF, and BRDF-adjusted SIF/PAR (SIFn) exhibited significant dynamic changes during thedrought period, outperforming traditional vegetation indices such as NDVI in sensitivity.Furthermore, a high correlation was observed between anomalies in precipitation and SIFn,elucidating the substantial impact of moisture availability on crop physiology. These findingsprovide essential insights into our understanding of plant responses to drought conditions atlarge spatial scales and underscore the unique value of high-resolution remote sensing SIFobservations in tracking the physiological responses of vegetation to water stress.
Controls on the growth of wave-influenced river deltas: The roles of fluvial sediment composition and basin depth
Authors: Broaddus Connor , Foufoula-Georgiou Efi
Published: March 2024

Deltas are among Earth’s most important depositional landforms. They host megacities, serve as ecological hotspots, and control fluxes of water, sediment, and nutrients between terrestrial and marine domains. Nearly all river deltas are subject to some degree of wave-influence, and most river mouths are wave-dominated. These systems exhibit strong spatiotemporal variability across a range of scales and form under hydrodynamic conditions that are highly nonlinear. As a result, the processes involved in the formation and evolution of wave-influenced deltas are poorly understood, limiting our ability to predict how they will respond to future changes.Here we explore the factors governing wave-influenced delta evolution using a coupled flow-wave-transport model (Delft3D-SWAN). We present the first physics-based simulations to correctly reproduce the morphological attributes commonly observed in wave-influenced deltas (smooth cuspate shorelines, simple distributary networks, systems of barriers and lagoons) and capture the emergent processes that govern their evolution.We show that wave-influenced deltas grow through a combination of shoreface accretion, crevasse splays, and distributary channel avulsions. Shoreface accretion occurs when fluvial sediment is deposited in the nearshore faster than it can be removed by wave-driven currents, and manifests as spit / barrier growth and migrating sand waves. Splays and avulsions lead to aggradation on the delta top, but also increase the area over which fluvial sediment is distributed, effectively decreasing the deposition rate at each channel mouth and in turn limiting shoreface accretion. We show that for a given wave climate, the relative importance of these processes determines a delta’s morphology and is controlled by the fluvial sediment composition and the receiving basin depth via the distributary channel network. In systems with shallow receiving basins or high sand loads, distributary channels are shallow, wide, and unstable. Network reorganization is frequent, creating deltas with smooth shorelines, many distributaries, and few barrier features. By contrast, a deep receiving basin or an abundance of cohesive fluvial sediment leads to enhanced levee formation, stabilizing distributary channels and reducing network complexity. Simpler networks deliver proportionally more water and sediment to individual distributary mouths, favoring shoreface accretion and leading to deltas with high protrusion angles and an abundance of barrier features.Our results provide insight into the processes involved in wave-influenced delta growth and the factors governing those processes. This information can be used to improve stratigraphic interpretation of delta deposits and helps inform sediment management practices for improving delta resilience in the face of anthropogenic pressures, such as land use and climate change.
Use-case specific performance assessment of sub-seasonal to seasonal drought predictions for local-scale applications in the Netherlands, Spain, and Italy
Authors: van Andel Schalk Jan , Bertini Claudia , Ramos Sánchez Celia , Ficchì Andrea , Giuliani Matteo , Pezij Michiel , Lugt Dorien , De Stefano Lucia , Pechlivanidis Ilias , Werner Micha , Castelletti Andrea
Published: March 2024

Sub-seasonal to seasonal (S2S) hydrometeorological ensemble predictions are being put to the test, given their potential to increase preparedness for, and improve management of, extreme events. Whereas forecast skill at the global, continental, and regional scales of S2S hydrometeorological predictions is relatively well-documented and regularly updated in the scientific literature for generic definitions of events, assessments of forecast skill at the catchment and local scale for local use-case definition of events have been reported to a relatively limited extent.In this research, the forecast skill of S2S predictions is analysed for local preparedness and management of droughts. In case studies in the Netherlands, Spain and Italy; potential end users have been consulted on their definition of drought, warning thresholds, decision-making process, and potential mitigation actions. The result is a variety of meteorological, hydrological and agricultural use-case-specific drought event definitions.For each of these case studies, a state-of-the-art multi-year (re-)forecast hydrometeorological dataset is downloaded or developed (e.g. for sub-seasonal and seasonal meteorological forecasts from ECMWF Extended Range and SEAS5 prediction systems, respectively, and for hydrological forecasts from the E-HYPE and GLOFAS hydrological systems), and its performance analysed for the user-driven drought definitions.The results contribute to an improved understanding of the potential of state-of-the-art S2S predictions for local-scale drought preparedness and management, and identify aspects to focus on in further enhancing this potential.
Spatially-distributed Intensity-Duration-Frequency (IDF) curves for Chile using sub-daily gridded datasets
Authors: Zambrano-Bigiarini Mauricio , Soto Cristóbal , Tolorza Violeta
Published: March 2024

In this work, we computed IDF curves for the climatically and topographically diverse Chilean territory (17-56ºS) using both stationary and non-stationary approaches based on three state-of-the-art gridded datasets: i) the Integrated Multi-Satellite Retrievals for GPM (IMERGv06B), ii) the fifth generation ECMWF ERA5 reanalysis, and iii) ERA5-Land, the high-resolution reanalysis from ECMWF. The three gridded datasets were used to compute the annual maximum intensities for 12 durations (1, 2, 4, 6, 8, 10, 12, 18, 24, 48, and 72 h) and six return periods (T=2, 5, 10, 25, 50, and 100 years), for the period 2001-2021, using a common spatial resolution of 0.10° and hourly temporal resolution. Data from 161 quality-checked hourly rain gauges are used to calculate IDF curves that serve as a benchmark for the curves derived from the gridded datasets.First, we calculated a bias correction factor for the annual maximum intensities for each duration, based on the comparison of the gridded value with the point one. Second, the previous correction factors were applied to the annual maximum intensities derived from each gridded dataset, using splines over the entire spatial domain. Third, the bias-corrected annual maximum intensities were calculated for each duration and return period using the Gumbel probability distribution, assuming stationary conditions. Then, the same annual maximum intensities were calculated for each duration and return period using a non-stationary Gumbel probability distribution with a varying mean. Fifth, we used the non-parametric Mann-Kendall test to assess the existence of trends in annual maximum intensities. Finally, 41 (1981-2021) and 21 (2001-2021) years of hourly precipitation data from ERA5 and ERA5-Land were used to test the effects of data length on the resulting stationary and non-stationary IDF curves.Our results reveal how the bias of annual maximum intensities changes in space, with generally smaller biases for longer periods. In addition, minor differences were found between the maximum annual intensities calculated using the stationary and non-stationary approaches for 2001-2021. Unexpectedly, we found some significant decreasing trends (p-value < 0.05) in Central-Southern Chile (32-43ºS) for the annual maximum intensities derived from ERA5 and ERA5-Land, while these trends were more localised and divergent (increasing and decreasing) for IMERG. Finally, there were only minor differences between the annual maximum intensities derived from ERA5 and ERA5-Land when using 21 years compared to 41 years of hourly records, for both the stationary and non-stationary approaches.We gratefully acknowledge the financial support of ANID-Fondecyt Regular 1212071,  ANID-PCI NSFC 190018, and ANID-Fondecyt Iniciación 111908064.
Alternative grass and shrub states emerge in paleo-climatic cellular-automaton ecohydrology model simulations for central New Mexico
Authors: Istanbulluoglu Erkan , Nudurupati Sai , Collins Scott
Published: March 2024

During last glacial cycle that peaked ~18,000 years (B.P.), the southwestern United States was much wetter and cooler than in the Holocene (last 11,000 years) and today. Since the Last Glacial Maximum (LGM), wetter and cooler climate in most arid and semiarid regions has generally transitioned to drier and warmer conditions, establishing their characteristic (i.e., today’s native) ecosystems and fire regimes 3,000 - 5,000 years B.P. We use the Landlab earth surface modeling toolkit to explore the implications of the climate since the late Pleistocene on ecosystem patterns, driven by a reconstructed climate. Alternative grass and shrubs states emerged as the modern climate established due to randomness in fire arrivals. The role of topography is explored. Our findings offer an explanation for observed shrub and grass ecotones under similar environmental conditions in central New Mexico. 
Stochastic LSTM network for flood hazard map forecast
Authors: Vemula Sreenath , Gatti Filippo , Jehel Pierre
Published: March 2024

Flood hazard has gained importance worldwide in recent decades owing to its impact on human lives, socio-economic, and infrastructure and is one of the most destructive in natural disasters. Consequently, several flood prediction models are developed either using physical modeling, statistical approaches, or data-driven machine learning (ML) approaches. While developing physical models would provide the desired insights, it is often challenging to obtain extensive information regarding the river basin and hydrological parameters and requires expertise. Additionally, often, they fail to predict short-term accurately. ML approaches have the advantage of mimicking any complex function when trained with sufficient data, and the data requirements drastically reduce with the incorporation of appropriate physical constraints. Hence, over the years, ML approaches contributed significantly to the advancement of flood forecasting and reducing hazards.
 
A recent study estimated €581 million in damage annually to the EU railways. In regards to the French railway network it is 28,000 km long and, therefore, exposed to various natural hazards. There is, therefore, a dire need to estimate the flood hazard to railway infrastructure accurately. Initially, data is curated about the frequency of occurrence and the flood intensity that can impact railways. From the collected data, feature engineering is performed to understand parameters (e.g., corresponding to hydrological, geology, and topography) that cause significant hazards. The obtained parameters are used to develop an LSTM-based forecasting model for short-term and long-term predictions and consequently develop hazard maps along the regions of railway infrastructure that are significantly prone to risk. Finally, we conclude the work with a few mitigation strategies to reduce the risk.
Safe and just Earth system boundaries
Authors: Lade Steven ,   Earth Commission
Published: March 2024

We present our paper published in Nature last year: https://www.nature.com/articles/s41586-023-06083-8. The work can be viewed as a "deep dive" into a subset of the planetary boundaries on dimensions of justice and operational spatial scales.Abstract from the paper: The stability and resilience of the Earth system and human well-being are inseparably linked, yet their interdependencies are generally under-recognized; consequently, they are often treated independently. Here, we use modelling and literature assessment to quantify safe and just Earth system boundaries (ESBs) for climate, the biosphere, water and nutrient cycles, and aerosols at global and subglobal scales. We propose ESBs for maintaining the resilience and stability of the Earth system (safe ESBs) and minimizing exposure to significant harm to humans from Earth system change (a necessary but not sufficient condition for justice). The stricter of the safe or just boundaries sets the integrated safe and just ESB. Our findings show that justice considerations constrain the integrated ESBs more than safety considerations for climate and atmospheric aerosol loading. Seven of eight globally quantified safe and just ESBs and at least two regional safe and just ESBs in over half of global land area are already exceeded. We propose that our assessment provides a quantitative foundation for safeguarding the global commons for all people now and into the future.This work is an output of the Earth Commission, an independent international scientific assessment initiative hosted by Future Earth. The Earth Commission is the scientific cornerstone of the Global Commons Alliance.
Mapping a Gondwana suture zone integrating magnetic methods and geology at the SE Brazilian continental margin
Authors: de Andrade Silva Raphaela Lopes , da Silva Schmitt Renata , Santos Gomes Stanton Natasha , Gonçalves Martins Guilherme
Published: March 2024

According to previous reconstructions, the South Atlantic Ocean is the biggest gap ofGondwana, with important crustal limits that controls convergent and divergent tectonicevents since the Paleoproterozoic. In the SE Brazilian continental margin, a Cambrian NE-SWsuture zone is marked by an expressive magnetic anomaly onshore that extends offshore tothe proximal Santos basin (Rio de Janeiro). This suture separates two contrasting geologicalterranes: a Neoproterozoic magmatic domain (Oriental Terrane), to the west, and aPaleoproterozoic gneissic terrane, to the east (Cabo Frio Tectonic Domain). The focus is todetermine how this suture extends offshore, hence determining the nature of the basementthat constitutes the continental margin, and how it continues in depth, determining theorientation of the Ediacaran paleo subduction zone. We made a geological and geophysicalintegration aiming to characterize the magnetic pattern of terranes and structures in order todeterminate the geometry and dip direction of the suture in depth. The methodology includedthe generation and interpretation of aeromagnetic images combined with geological mapping.Also, two magnetic sections were made on field along the suture zone and modeled on GMSYSadopting magnetic susceptibility values obtained both on field and laboratory. The studiedarea comprises mainly two geological units separated by a thrust fault (suture zone): dioritic togranitic Paleoproterozoic rocks with metabasite layers (Região dos Lagos Complex - RLC) andEdiacaran aluminous paragneisses with calcsilicate layers (Palmital Succession). Based on theamplitude (intensity), geometry, magnetic signal’s texture and lineament pattern, in map view,two domains were defined: A1 and A2. The A1 is correlated with the Paleoproterozoicgneisses, with high amplitude, long wavelength (55 km) with numerous magnetic rectilinearand curvilinear lineaments. Amplitude ranges between -100 and 452 nT, mostly higher than150 nT. A2 coincides with the Palmital paragneisses, defined by a low frequency, longwavelength (55 km) magnetic domain, with amplitudes
Regional Information for Society within the World Climate Research Programme
Authors: Goldenson Naomi , Hewitson Bruce , Pryor Sara , Solman Silvina , Alves Lincoln , Block Paul , Bojovic Dragana , Caron Louis-Philippe , Dosio Alessandro , Harrington Luke , Horsburgh Kevin , Larsen Morten , Maina Jemimah
Published: March 2024

The World Climate Research Programme (WCRP) has created a new core project: Regional Information for Society (RIfS), which has begun to plan its inaugural activities. Recognizing a gap between core disciplinary projects of WCRP and societal impact, RIfS seeks to foster community exchange around the practices of creating and utilizing climate information. The members of the Scientific Steering Group and International Project Office see this as a collaborative process with stakeholders from various sectors of society. Rather than reproducing more climate services, we are focused on identifying best-practices, building worldwide capacity and equity, and contributing to existing projects at the regional scale, particularly in regions where there are limited resources for such services. This RIfS presentation will focus on the identification of best-practices, particularly in the assessment of climate information. Currently there is no systematic, consistent, or accepted approach to assessing which climate information is robust and actionable, at regional or global scales. This recognizes the multiplicity of non-congruent data and information sources that may be used, the choice of which depends often on subjective selections that can lead to different decision outcomes and the commensurate consequences. At the same time, the volumes of data and demand for information are only growing, and new organizations are emerging offering products to decision-makers with varying levels of transparency about methods. Decisions are being made that affect the global distribution of resources, for example in finance and the insurance sectors. No professional organization has so far managed to establish widely accepted standards and guidelines for what constitutes robust information appropriate for various types of decision-making. This is the central challenge of the moment for the community of climate researchers interested in societal applications. RIfS will begin a process of consensus-building with an expert meeting on robustness of climate information just after the EGU meeting this year, to be followed by additional opportunities to come together around these questions.
Characterization of soil aggregates in green bioswales in relation to carbon sequestration, aggregate stability, and microbial activity
Authors: Deeb Maha , Groffman Peter M. , Amato Matthew , Cheng Zhongqi , Giménez Daniel
Published: March 2024

Green Infrastructure (GI) plays a crucial role in reducing stormwater runoff and providing ecological benefits in urban areas. Aggregation is a key process in many soil functions as it influences carbon storage, greenhouse gas emissions, nutrient cycling, hydraulic properties, and biotic activity. In this study, we investigated soil aggregation processes and stability in GI.Soil samples were collected from six bioswale sites in New York City that had two different designs - streetside infiltration swales and enhanced tree pits. The soil samples were taken from the inlet, center, and outlet positions (relative to stormwater input) of each site. These samples were then tested for 1) macro and micro aggregate sizes; 2) distribution of soil organic carbon (SOC) and nitrogen; 3) aggregate stability; and 4) microbial biomass and activity relevant to carbon and nitrogen cycles in macroaggregates.Our results showed that 60% g/g of the soil aggregates at these GI sites were smaller than 2 mm and had high structural stability. Microaggregates between 1-2 mm had the highest SOC and accounted for 60% g/g of all microaggregate size classes. GI aggregates are formed from the breakdown of macroaggregates into intermediate microaggregates. The newly formed microaggregates contained more stable SOC than macroaggregates and bonds within microaggregates were stronger than bonds grouping microaggregates, which is not consistent with a classical model of aggregate formation in natural soils. Microbial biomass and activity were correlated with the carbon and nitrogen content of aggregates and with GI type, allowing for the identification of microbial hot spots. These results suggest that aggregation processes in human-engineered soils included in GI play an important role in sustaining carbon and nitrogen cycles.
Attributing methane and carbon dioxide plumes by emission sector with the EMIT and AVIRIS-3 imaging spectrometers
Authors: Thorpe Andrew , Green Robert , Thompson David , Brodrick Philip , Chlus Adam , Fahlen Jay , Coleman Red Willow , Chadwick Katherine Dana , Eastwood Michael
Published: March 2024

Imaging spectrometers like NASA’s Earth Surface Mineral Dust Source Investigation (EMIT) and the Airborne Visible/Infrared Imaging Spectrometer 3 (AVIRIS-3) have similar instrument parameters and methane and CO2 mapping capability that enables direct attribution of observed plumes to the oil and gas, waste, and agriculture sectors. Onboard the International Space Station, EMIT can constrain methane and CO2 emissions over a significant portion of the Earth’s surface. With improved spatial resolution, the airborne AVIRIS-3 instrument enables quantification of smaller emissions sources that compliment EMIT observations from space.We provide an update of EMIT methane and CO2 observations to date and highlight examples from the oil and gas, waste, and agriculture sectors. For the first time, we present AVIRIS-3 methane and CO2 results. The fine spatial resolution of these instruments allows pinpointing of multiple emission sources in close proximity from different sectors, which is not possible with coarser spatial resolution instruments. These instruments offer the potential to improve understanding of greenhouse gas budgets, inform mitigation strategies, and in some cases lead to voluntary mitigation.In support of NASA’s Open Source Science Initiative, all EMIT data and greenhouse gas data products are available through the Land Processes Distributed Active Archive Center (LP DAAC) and code is open source. EMIT results are also available through the greenhouse gas applications online mapping tool (https://earth.jpl.nasa.gov/emit/data/data-portal/Greenhouse-Gfases/) and U.S. Greenhouse Gas Center (https://earth.gov/ghgcenter/).Figure 1: Over 900 methane plume complexes observed by NASA’s Earth Surface Mineral Dust Source Investigation (EMIT) are available through the EMIT greenhouse gas applications online mapping tool (https://earth.jpl.nasa.gov/emit/data/data-portal/Greenhouse-Gfases/) and U.S. Greenhouse Gas Center (https://earth.gov/ghgcenter/).
Application of innovative technologies for increasing gold production in Kyzylkum province of Uzbekistan
Authors: Antonov Alexander , Tsoy Vladimir , Nurtaev Bakhtiyar
Published: March 2024

The Kyzylkum province in Southern Tien Shan, Uzbekistan, which includes the world's largest gold deposit Muruntau, is among the world's major gold provinces. Analysis of all available geological and geophysical data has revealed ten linear trends controlled by regional strike-slip shear zones in the ore-bearing sand-shale sediments O₂-S₁. Analogies were made with gold trends in North-Eastern Nevada (Carlin trend and others). Gold is present predominantly as microinclusions in pyrite and arsenopyrite in both provinces. A significant part of inclusions is represented by invisible nano-sized gold particles.Opportunities of increasing gold output in the Kyzylkum province are connected with the reduction of losses of "invisible" gold in the process of ore concentration and processing. Innovative technologies and modern laboratory equipment were used to determine nano-sized gold concentration. Another source of increasing gold production is exploration and development of ore-controlling structures overlapped by younger sediments. Remote sensing methods are widely used to identify promising parts of the structures. 
Analytical Propagation of Emission Uncertainties into CAMS Policy Products
Authors: Blake Lewis , Wind Peter , Fagerli Hilde , Valdebenito Alvaro , Super Ingrid , Kuenen Jeroen
Published: March 2024

We present a methodology and first results for analytical propagation of emissions uncertaintiesthrough the EMEP MSC-W chemical transport model (CTM) and an application of these uncertaintyestimates to policy products provided by the Copernicus Atmosphere Monitoring Service(CAMS) for European cities. CTMs are widely employed in atmospheric modeling to simulatethe transport and transformation of pollutants, but uncertainties in emission estimates cansignificantly impact the accuracy of air quality predictions. Our study systematically analyzesthe propagation of uncertainties arising from emissions. The emissions’ uncertainties are consistentwith the CAMS regional emissions product and are calculated using detailed, countryspecificuncertainty estimates in activity data and generic emission factor uncertainties. Theuncertainties are calculated per source sector and country. The Local Fractions/Sensibilities [1]methodology available in the EMEP MSC-W model is a tool that allows computation of sourcereceptorrelationships more efficiently. In conjunction with analytical methods for uncertaintypropagation, we deliver air quality predictions with uncertainty estimates at a fraction of thecomputational cost and with increased traceability compared to modern surrogate modelingtechniques. In our study we focus on PM2.5 and PM10, and first results will be presented for theimpact of emission uncertainties on forecasted PM concentrations in European cities, as well asuncertainties in contributions from different source sectors and countries. By integrating emissionuncertainty propagation, our study aims to provide decision-makers with a more accurateassessment of the reliability of CAMS policy products under various atmospheric conditionsand in the future provide these estimates as part of their operational delivery.
 
 
References
[1] P. Wind, B. Rolstad Denby, and M. Gauss, “Local fractions – a method for the calculationof local source contributions to air pollution, illustrated by examples using the emepmsc-w model (rv4 33),” Geoscientific Model Development, vol. 13, no. 3, pp. 1623–1634,2020. [Online]. Available: https://gmd.copernicus.org/articles/13/1623/2020/
Addressing the Dynamic Energetic Particle Environment for Space Radiation Operations at NASA
Authors: Whitman Kathryn
Published: March 2024

NASA's Artemis missions are taking astronauts back to the Moon with a view towards Mars. The dynamic space climate and space weather environment is a concern for space radiation operations and the protection of astronauts. The NASA Space Radiation Analysis Group (SRAG) at Johnson Space Center is developing the requirements and tools needed for quick operational response to space weather events during mission operations. To estimate long-timescale changes in the galactic cosmic ray (GCR) background due to solar modulation, SRAG maintains and develops NASA's Badhwar-O'Neill galactic cosmic ray (GCR) model. On short timescales, SRAG provides measurements, tools, expertise, and console support to keep crew safe during explosive solar energetic particle (SEP) events. In the past few years, SRAG, in collaboration with NASA Community Coordinated Modeling Center (CCMC) and the Moon to Mars Space Weather Analysis Office (M2M), has been working directly with the research community to onboard SEP models into real time operations. Real time forecasts are visualized in the SEP Scoreboards developed by CCMC and currently under evaluation by SRAG for radiation operations. An intensive validation effort has been ongoing to develop the infrastructure and standards for the validation of SEP model performance. This effort has broadly engaged the US, European, and worldwide scientific community through community challenges as well as focused on the evaluation of model performance in a real time operational environment. These efforts and preliminary outcomes will be described.
Potential fields characterization of inaccessible areas: multiscale analysis of the West Antarctic Rift System
Authors: Ferrara Giuseppe , Ferraccioli Fauso , Fedi Maurizio
Published: March 2024

We used potential field data to help unravel the geological characteristics of the West Antarctic rift system, one of the largest and least known rift systems on our planet. A comprehensive understanding of this region is lacking, as it is covered by the West Antarctic Ice Sheet (WAIS), which reaches thicknesses of over 3 km. Aeromagnetic and aerogravity datasets collected by the British Antarctic Survey (Ferraccioli et al., 2007) were analyzed via a multiscale analysis (Fedi et al., 2015) useful for identifying the main structural lineaments, i.e., contacts, dykes, sills, volcanic bodies and intrusions in the Pine Island Glacier catchment of WAIS. Our results reveal that several regions are characterized by contact-type sources associated to fault systems bordering major magma-rich rift basins, like the Pine Island Rift, Byrd Subglacial Basin, and Bentley Subglacial Trench, as well as those associated with Pine Island glacier tributaries, which lie at high angle wrt to the glacier trunk and rift basins. Furthermore, we identified magmatic sources near or off-rift zones, such as the edges of the Bentley Subglacial Basin, which allow a better understanding of the sub-ice depth of the magmatic sources. In addition, our results provide new information about the main magmatism trends and their average depths. We thus showcase that potential field anomalies allow a better comprehension of the West Antarctic Rift System regional geology, tectonic architecture and magmatic patterns. This research opens interesting scenarios about the extent and position of magmatic sources and on how they contribute towards shaping the sub-ice topography within this sector of the rift system, which in turn is a primary control on ice sheet flow in this highly dynamic and potentially unstable sector of WAIS. In conclusion, potential field analysis with a multiscale approach emerges as a pivotal tool and provides valuable insights into continental rifting processes, especially in inaccessible areas such as West Antarctica, where there are only very few geological outcrops.
Constraining the tsunami initiation area associated with the 2010 M7.7 Mentawai and 2024 M7.5 Noto peninsula earthquakes from first-arrival measurements on TEC data
Authors: Twardzik Cédric , Rolland Lucie , Munaibari Edhah , Mikesell Thomas Dylan
Published: March 2024

Forecasting the impact of a tsunami on coastal areas requires accurate location of the source of the tsunami. This is particularly challenging because tsunamis often originate far from seismological and geodetic networks. However, tsunami waves often induce total electron content (TEC) perturbations in the ionosphere, which can be detected using Global Navigation Satellite Systems (GNSS). Tracking the source of these perturbations makes it possible to determine the tsunami source area. Previous studies have confirmed this approach. However, this is usually done by (1) using a "quasi-homogeneous" model to propagate the disturbances in the atmosphere and (2) arbitrarily fixing the height of the ionosphere. These approximations lead to relatively large uncertainties in the location of the tsunami source. Therefore, in this study we try to reduce these uncertainties by using a 1D model of the atmospheric structure and by including the search for the optimal height of the ionosp here in the inverse problem. To do this, we use a Bayesian approach to invert the onset times of the TEC disturbances. First, we test our method on synthetic data to determine the potential gain in accuracy between using a "quasi-homogeneous" and a 1D model of the atmosphere. We then apply our approach to study the 2010 M7.7 Mentawai tsunami earthquake and discuss the strength and limitations of the method as well as its usability for tsunami warning. We finally show preliminary results for the 2024 M7.5 Noto peninsula earthquake, and related tsunami offshore Japan.
Impluvium and multifunctional tree planting pits for clean-water sponge cities
Authors: Deeb Maha , Palman Marie , Boivin Pascal
Published: March 2024

Soil artificialization goes together with increasing impermeable surface areas. The increased surface runoff and flood hazard is as a major threat in large cities. Moreover, runoff waters transport pollutants to downstream surface waters. A key strategy for sponge cities is to design permeable soils allowing for rain water infiltration, which should go together with runoff water depuration. High quality permeable soils are also necessary to secure and increase the tree cover in cities, which is highly recommended both to fight against heat waves, to provide a comfortable environment and contribute to urban biodiversity. We present a combined solution to these different goals.To this end, a highly permeable and fertile growing media was designed based on recycled manure and partly pyrolyzed organic matter. The depuration properties of this substrate were quantified for road runoff pollutants (soluble and micro particle forms) and commonly used pesticides. About 100% removal of these pollutants were observed based on breakthrough experiments on Technosol columns, with outflow quality matching the Swiss Water Protection Agency requirements. The fertility of the substrate was assessed in greenhouse pot experiments. Faster plant growth than with conventional horticulture production methods was observed, though no fertilizer was applied to the growing media.The growing media, named TP70, was then mixed with 70% stones (100-150 mm size) to obtain a Technosol (TP-P) with high bearing capacity such as required for urban use. An experimental 1m large tree plantation pit was built in Lausanne city using a 60 cm layer of the Technosol, covered with 20 cm of stone ballast. The pit was installed under the walkway of a 4% slope street. Runoff water was injected into the ballast via collectors and infiltrated into the Technosol porosity before drainage at the low-end of the pit.The volume of the pit was designed to comply with the local regulation on runoff water regulation, namely offering a fast-drainage porosity volume larger than the amount 10-year return-time rainfall on the corresponding watershed, with full drainage in less than 4 hours. It was planted with trees and offered an available water volume corresponding to 9 days of maximum evapotranspiration in the experimented case. Both tree growth and hydrological functions of the pit offered high performance. Based on this first experiment, an eco-district was fully equipped with these impluvium pits, thus infiltrating all the rain waters on the district, and Lausanne city is now extending the technology to the city.
Late Neogene terrestrial climate reconstruction of the central Namib Desert derived by the combination of U–Pb silcrete and terrestrial cosmogenic nuclide exposure dating
Authors: Albert Richard , Ritter Benedikt , Rakipov Aleksandr , van der Wateren Frederik M. , Dunai Tibor J. , Gerdes Axel
Published: March 2024

The Cenozoic “Namib Group” of the Namib Desert relies on relative chronology and lacks direct radiometric dating. Therefore, the landscape evolution and paleoclimate of the central Namib Desert remains imprecise, hindering the detailed search for global and/or local forcing factors for the aridification of the Namib. The broad presence of silcretes and calcretes in the Namib Desert allows the application of the of the U–Pb laser ablation dating technique on silcretes and calcretes to date important phases of landscape stability and to retrieve crucial paleoclimatic and environmental information on desertification and its paleoclimatic variability. Microscale silcrete formation (maximum of 8 mm), as a result of pressure solution by expanding calcrete cementation, grants the opportunity to date multiple phases (multiple generations of silcrete as growing layers) of silcrete formation. Groundwater silcrete and calcrete formation took place at our study site during the Pliocene, an epoch of relatively stable climate and landscape evolution under semi-arid to arid conditions. Terrestrial cosmogenic nuclide (TCN) exposure dates from flat canyon rim surfaces show the remission of groundwater calcrete formation due to river incision during Late Pliocene–Early Pleistocene. This incision is a consequence of a large-scale landscape rejuvenation caused by a climate shift towards more arid conditions in the Pleistocene, which can be connected to global climate patterns. This study shows the feasibility of applying U–Pb laser ablation to groundwater calcretes and silcretes, discusses important issues associated with this technique, and opens up the possibility of dating numerous sedimentary sequences with silcretes and calcretes in arid environments. Our study redefines and improves the generally accepted Late Cenozoic chronostratigraphy of the Namib Desert (Miller, 2008).
Developing a practical approach to assessing the drivers of multi-hazard risk in the Alpine space
Authors: Hoffmann Amelie , Frimberger Theresa , Krautblatter Michael , Straub Daniel
Published: March 2024

Unprecedented weather extremes have affected the Alpine space in recent years, significantly impacting human populations, the economy, and the environment. Extreme weather events can trigger a multitude of alpine hazards that, due to the distinct characteristics of the Alpine natural and built environment, have the potential to induce severe compound and cascading impacts. Despite recent scientific evidence that climate change will contribute to more intense and more frequent weather extremes, our understanding of local implications on multi-hazards, compound and cascading effects, and future risks remains insufficient. Consequently, risk managers and decision-makers lack a systematic approach to assess future changes in multi-hazard risk.We are developing a practical approach that aims to help local risk managers answer fundamental questions about the drivers of multi-hazard risk in their respective Alpine regions. To that end, we combine a questionnaire about the current risk situation with a systematic basis for propagating the effects of future changes, covering all aspects of the risk chain, namely hazard, exposure, vulnerability, and capacity. Ultimately, the method aims to help (1) identify important drivers of (future) risk, (2) assess their contribution to the (future) risk landscape, and (3) identify relevant risk pathways for targeting (future) risk management practice.The approach relies on detailed knowledge of local conditions that can only be provided by local stakeholders as well as more general input on the future trends in climate and anthropogenic developments that must be provided by higher authorities and the scientific community. This work is part of the X-RISK-CC project, funded by the Interreg Alpine Space Program 2021-27. The approach will be applied to some of the project's pilot regions to help generate insights that will assist risk managers in the evaluation and management of newly emerging risks associated with weather extremes in their respective regions.
Automatic detection of river bankfull parameters from high density lidar data
Authors: Rétat Alexandre , Thommeret Nathalie , Gob Frédéric , Depret Thomas , Bailly Jean-Stéphane , Lespez Laurent , Kreutzenberger Karl
Published: March 2024

The European Water Framework Directive (WFD), adopted in 2000, set out requirements for abetter understanding of aquatic environments and ecosystems. In 2006, following the transposition ofthe WFD into French law (LEMA), France began work on a field protocol for the geomorphologicalcharacterization of watercourses, as part of a partnership between the Centre National de la RechercheScientifique (CNRS) and the Office Français de la Biodiversité (OFB). This protocol, known as "Carhyce"(For « River Hydromorphological Caracterisation »), has been tested, strengthened and approved overthe last 15 years at more than 2500 reaches. It consists of collecting standardised qualitative andquantitative data in the field, essential for the caracterisation of a watercourse: channel geometry,substrate, riparian vegetation... However, certain rivers that are difficult to survey (too deep or toowide) pose problems for data collection.To address these issues, and to extend the analysis to a wider scale (full river section), usingremote sensing, and in particular LiDAR data, was considered. The major advantages of LiDAR overpassive optical sensors are better geometric accuracy and especially under vegetation. For a long time,LiDAR data rarely exists at national scale with data density similar to passive imagery. Today, the FrenchLiDAR HD dataset (10 pulses per meter square) program run by the French mapping agency offers anunprecedented amount of data at this scale. Thanks to them, a national 3D coverage of the ground canbe used, and numerous geomorphological measurements can be carried out on a more or less largescale. This is the case for hydromorphological parameters such as water level and width.The aim of this study is therefore to use this high-density lidar to automatically determine thehydromorphological parameters sought in the Carhyce protocol. In particular, we have developed alidar-based algorithm to reconstruct the topography from point cloud and automatically identify thebankfull level at reach scale. Designed to be applicable to every French river, the method must berobust to all river features such as longitudinal slope, width, sinuosity, multi-channel etc... Forvalidation purposes, the bankfull geometry calculated by the algorithm has been compared with fieldmeasurements at some twenty Carhyce stations across France. To determine the test stations, welooked for the diversity of situations in terms of river characteristics describe above to observed theinfluence of this features on the results.
A method to collect clear profile with Ground Penetrating Radar in tunnel
Authors: Deng Xinsheng
Published: March 2024

At present, we are using commercial ground penetrating radar (GPR) to inspect tunnel walls, conduct an underground geological structure assessment and anticipate geology behind the tunnel face. A variety of metal objects, include portal frame, forklift, and excavator, can cause back reflection in the GPR profile during the test in the tunnel. Typically end users of GPR are unable to appropriately interpret the GPR profile because they are unware of what is actually coming from back reflection in the air and projection into the ground penetrating radar profile or from subsurface. They really need some method to identify real reflection signals from underground sources.
The GPR antenna transmits electromagnetic (EM) waves that can travel all space, including the air, the interface between the ground and the air, and the subsurface. During EM travel in the air, there is some back reflection from the air object to be recorded in the GPR profile during data collection in the field. We need to measure and recognize and elimate this back reflection interference noise. We have made electromagnetic waves absorbent block configuration for the GPR antenna that can complete cover the GPR antenna. We have done the comparative experiments tests with and without electromagnetic waves absorbent block have been conducted in the field, the results show that, without this block, GPR profile recorded many back reflection from the air objects, while the GPR antenna with covering electromagnetic waves absorbent block can only record the refection from surbsurface during data collection in the field, and it is clear GPR profile. This allows the GPR end user direct interpret the GPR profile only with reflection from surbsurface as it may completely eliminate back reflection from the air object.
Reconstruction of ENSO variability using the standardized growth index of a Tridacna shell from Yongshu Reef, South China Sea
Authors: Geng Jun , Yan Hong , Liu Chengcheng , Han Tao , Liu Shan , Zhao Nanyu , Wen Hanfeng , Yang Haotian , Zhou Pengchao , Wang Guozhen , Dodson John
Published: March 2024

El Niño-Southern Oscillation (ENSO) is the strongest signal of global interannual climate anomaly and reconstructing past ENSO variations using high-resolution paleoclimate archives can improve our understanding of ENSO variability, as well as improve our ability to predict future climate changes. Here, a daily resolution standardized growth index (SGI) was established using a giant clam (Tridacna spp.) shell specimen MD2 (life span: AD 1994-2013), collected from the Yongshu Reef, southern South China Sea (SCS). The cross-spectral and correlation analysis indicated that the SGI variation of MD2 was strongly influenced by ENSO variability on an interannual timescale. Tridacna spp. is in symbiosis with zooxanthellae, and its growth index is usually modulated by the photosynthetic efficiency of zooxanthellae. During the El Niño (La Niña) period, the convective anomalies stimulated in western Pacific would increase (decrease) the effective solar radiation on Yongshu Reef, and in turn influence the photosynthesis rate of zooxanthellae and enzyme activity for the calcification site and thus the SGI of giant clam MD2. The SGI can explain 54.7% of ENSO variance, demonstrating the potential for Tridacna SGI in ENSO reconstruction. Compared with conventional ENSO reconstruction using high-resolution geochemical proxies, the method of giant clam SGI is rapid and economical.