bluuebunny/crossref_metadata_2025 huggingface dataset:
A spatio-temporal analysis of the risks of flooding and landslides in Greater Abidjan, Ivory Coast, by applying a multi-risk framework.
Authors: Traore Habal Kassoum , De Angeli Silvia , Lebaut Sébastien , Drogue Gilles , Konan Kouadio Eugène
Published: March 2024

Most scientific research acknowledges the overall complexity of the interaction mechanisms between different natural hazards, as well as complex interdependencies with societal drivers such as exposure and vulnerability. Comprehensive understanding of multi-risk dynamics remains crucial for sustainable development in many parts of the world. Moreover, the integration of multi-risk approaches into the planning and implementation of adaptation, resilience and disaster risk reduction measures remain a priority, specifically in developing countries.Located in West Africa, Ivory Coast faces recurring floods and landslides, mainly due to heavy rainfall during the rainy season. These hazardous events have significant consequences, particularly in coastal urban areas such as Greater Abidjan, where continued and uncontrolled urbanization increases disaster risk, as highlighted in the Disaster risk profile of Ivory Coast by UNDRR in 2019. In this context, a multi-risk approach is essential to deal with the complexity of these interacting threats and their interdependencies with dynamic social and demographical conditions. The limited availability of open disaster risk data, such as the ‘Desinventar’ database endorsed by the UNDP and UNDRR, hinders a comprehensive assessment of risks in the country, particularly in Greater Abidjan, the most populated area. In addition to this gap, there is minimal research focused on conducting a multi-risk analysis on the scale of Greater Abidjan.By applying the multi-hazard impact framework developed by De Angeli et al. (2022), we seek on the one hand to carry out a multi-hazard assessment with an emphasis on the causal dependencies between heavy rains, floods and landslides. In a second part, we carry out an assessment of the impact of these hazards, focusing on their spatial and temporal evolution, by including an assessment of the physical vulnerability of the built environment and the socio-economic vulnerability of affected populations. Our research draws on various georeferenced data sources, including historical meteorological data, satellite images, digital elevation models, as well as field surveys. These sources enable an in-depth understanding of the spatial and temporal dynamics of flood and landslide risk in the region.Our research will make it possible to establish a multi-risk framework across Greater Abidjan, emphasizing the importance of considering flood and landslide risks in an integrated manner in the region. All the research falls within the scope of the national action plan of the Sendai framework for capacity building for disaster risk reduction in Ivory Coast (2016-2020).
Methods for geoid determination in regions with challenging data quality and coverage
Authors: Liu Qing , Schmidt Michael , Sánchez Laura
Published: March 2024

The combination of satellite positioning techniques (e.g., GPS) and high-resolution geoid or quasi-geoid models provides an alternative to the expensive and time-consuming spirit leveling for the determination of physical heights. The reliability of the physical heights thus undergoes the same accuracy limitations of the (quasi-) geoid models. However, in many regions, especially developing or newly industrializing countries, there is no reliable regional gravity model, due to the low availability or quality of surface gravity data. This study tackles such challenges in a case study in the northwestern part of South America and provides the first up-to-date high-resolution Colombian quasi-geoid model.This region is a challenging study area with coastlines on both the Pacific and the Atlantic Ocean and rugged topography with high elevation reaching more than 5,000 m. Available terrestrial and airborne data were collected during the last eight decades, which frequently contain systematic errors and biases and the corresponding metadata is missing. We develop approaches to validate and improve the quality of old gravity datasets. They are then combined with a global gravity model (GGM) and topography models, which play an important role in mountainous areas, within the remove-compute-restore (RCR) procedure. In the offshore area, satellite altimetry-derived gravity data are additionally incorporated, which are obtained from the latest release of the DTU (Technical University of Denmark) gravity anomaly grid, DTU21GRA.The computed quasi-geoid model is thoroughly validated with independent GPS/leveling data. It delivers an STD of 15.76 cm in comparison to the GPS/leveling data, which is 36% smaller than that obtained from the latest South American quasi-geoid model QGEIOD2021 (24.51 cm). Five recent high-resolution GGMs, namely EGM2008, EIGEN6C4, GECO, SGG-UGM-1, and XGM2019 are also validated using the same GPS/leveling data. They deliver STD values of 28.09 cm, 21.10 cm, 20.39 cm, 20.93 cm, and 17.86 cm, respectively, which are averagely 38% larger than that of our computation.
Diverse P-T-t paths within the Neoarchean sagduction regime of North China Craton: insights from field data and numerical modeling
Authors: Yu Chenying , Yang Ting , Zhang* Jian , Zhao Guochun , Cawood Peter A. , Yin Changqing , Qian Jiahui , Gao Peng , Zhao Chen
Published: March 2024

The Neoarchean greenstone-granite rock association preserved in the Eastern Block of the North China Craton exhibits distinctive dome-and-keel structures. Although the metamorphic data from these rock assemblages provide valuable insights into the tectonic evolution of this region, the interpretation of the clockwise paths with nearly isothermal decompression (ITD) and the anticlockwise P–T paths involving near-isobaric cooling (IBC) remain inconsistent and controversial. By conducting 2D numerical models with the initial and boundary conditions similar to those of the Neoarchean Eastern Block, we investigated the coexistence of diverse P-T paths and determined their possible geodynamic regime. The model results demonstrate that the combination of crustal density inversion and heat from the high-temperature lower boundary initiates a crustal-scale sagduction process, leading to the formation of dome-and-keel structures. Additionally, we identified four primary types of P-T-t paths. Firstly, an anticlockwise IBC-type P-T-t path reveals the supracrustal rocks gradually subside to a deep crustal level, where they experience a prolonged residence period characterized by ambient mantle cooling without significant exhumation. Secondly, a clockwise ITD-type P-T-t path suggests the supracrustal rocks descend to the deep crust and are partly entrained by upwelling TTG magmas, leading to their rapid ascent to a middle crustal level. Thirdly, a newly identified crescent-type P-T-t path indicates an integrated burial-exhumation cycle, consisting of an initial burial stage with high dT/dP, followed by a rapid exhumation stage and a subsequent cooling stage exhibiting low dT/dP. Lastly, a hairpin-type P-T-t path highlights the slow exhumation rate experienced by deeply buried supracrustal rocks. The dome-and-keel structure and P-T-t paths observed in the numerical model are consistent with the geochronological, metamorphic and structural data of the Eastern Block. Based on these observations, we propose that the crustal-scale sagduction involving a mantle plume could responsible for the geological complexity of eastern China.This work was financially supported by the National Natural Science Foundation of China (42025204) and National Key Research and Development Program of China (No. 2023YFF0803804).
BITS: BluePrints for the Integration of Terminology Services in Earth System Sciences
Authors: Wolodkin Alexander , Ganske Anette , Kraft Angelina , Lammer Andrea , Martens Claudia , Salhi Ichrak , Stocker Markus , Thiemann Hannes , Weiland Claus
Published: March 2024

The BITS project is building a Terminology Service (TS) for Earth System Sciences (ESS TS). As a first step it will develop this service for the subfields of climate science (results from climate simulations) and geodiversity collections (representing Earth’s diversity of i.a. rocks, fossils, soils, sediments). The project will use the existing Terminology Service of the TIB – Leibniz Information Centre for Science and Technology, which currently contains  190 ontologies, more than 1.2 million terms and over 26,000 properties from a range of domains such as architecture, chemistry, computer science, mathematics and physics. It has implemented the ESS collection within the TIB TS by now, which already contains relevant terminologies for the ESS and to which further relevant terminologies will be added. The ESS TS will be integrated into the two different data repositories of the German Climate Computing Center (DKRZ) and the Senckenberg - Leibniz Institution for Biodiversity and Earth System Research (SGN):DKRZ will use the TS to develop a more user-friendly search for its World Data Center for Climate (WDCC) repository. The terminologies will be used to suggest additional and more relevant search terms to users. This will help users who are unfamiliar with the terminology used by the climate community to find the right keywords for their data search and to get accurate and high quality search results.
SGN will use the TS to add standardised structured metadata to geothematic Digital Specimens in their digital collections. This will increase the FAIRness of collection data, i.e. foster self-contained discovery and processing of Digital Specimens by software agents or, in short, machines (machine actionability).  
The experience gained in building the ESS TS and integrating it into the repositories at DKRZ and SGN will be used to create blueprints to connect later on other Earth System Science repositories to the TS. We also aim to work closely with NFDI4Earth and the wider ESS community, and with TS4NFDI as the NFDI base service project for terminology services.As BITS evolves, ESS TS will be supplemented by additional components e.g. to support FAIR semantic mappings (leveraging on SGN’s mapping.bio service). However, feedback from the wider ESS community about expectations for such a service and their needs is welcome and required for the project. Our aim is a Terminology Service, which serves as a valuable resource for researchers, students, professionals and developers in ESS, providing them with accurate and consistent terminology to enhance their work, improve communication and data sharing and advance knowledge in their respective fields.
Impact of waxing and waning of Northern Ice sheets on Pleistocene climate 
Authors: Bauch Henning
Published: March 2024

Pleistocene temperatures correlate well with glacial-interglacial changes in global ice volume. While a discharge of ice-rafter debris (IRD) into the ocean directly reflects the rates of growth and decay (deglaciations) of glacial ice sheet margins at sea level, it is also the result of a rapidly changing global environment which affected both the meridional overturning in the ocean and the patterns in ocean-atmosphere circulation on a regional scale.  Circum-arctic land regions and adjacent ocean basins hold clues of varying ice sheet sizes through time. Understanding these records correctly is therefore an important asset to better appreciate Quaternary climate change also within a much broader global context. Marine sediment core data from the Nordic Seas show a stepwise trend of decreasing fluxes of IRD during major glaciations of the last 500 ka, i.e., marine isotope stages (MIS) 12, 6, and 2. Strongest IRD deposition occurred in MIS 12 (Elsterian), while it was lower in MIS 6 (Saalian) and 2 (Weichselian). These marine results of iceberg discharge rates from the western European margins, in particular, point to significant temporal changes in the ice-sheet coverage over northern Eurasia. Indeed, field data provide evidence for several major pre-Weichselian glaciations. Although their maximum limits were likely asynchronous in certain places, it seems evident that these ice sheets not only pre-date the Saalian time, they also extended much farther south (and east) than at any time later. The stepwise decreases in Eurasian ice-sheet extents during glacial maxima terminated in quite contrasting deglaciations and subsequent interglacial developments. It appears evident that such a systematic change in ice-sheet sizes were the result of specific ocean heat circulation, which influenced the pathways of atmospheric moisture transfer across northern Eurasia.
Improving high-resolution spatial information on agricultural land use management in Europe for economic land use modelling and the assessment of policy impacts
Authors: See Linda , Yashchun Orysia , Romanchuk Zoriana , Balkovič Juraj , Skalsky Rastislav , Malek Žiga , Schepaschenko Dmitry , Deppermann Andre , Kriztin Tamás , Havlík Petr
Published: March 2024

There is currently a lack of high-resolution pan-European information on land use management, especially in terms of how intensively and extensively cropland and grassland are managed. This is partly due to the lack of ground-based information, which is needed to downscale these types of management practices (some of which are captured in different types of agricultural censuses and surveys) as well as the inability of remote sensing to capture different kinds of land use. This type of information is needed for economic land use modelling and for assessing policy impacts, such as the latest reforms from the Common Agricultural Policy (CAP) and other European Union (EU) Green Deal targets. These types of analyses are undertaken using economic land use models such as GLOBIOM and CAPRI, which is one of the main aims of the Horizon Europe funded LAMASUS project (https://www.lamasus.eu/).  This presentation will provide an overview of the ongoing developments in creating high-resolution spatially explicit layers on agricultural and grassland management for Europe to support the LAMASUS project. The proposed cropland and grassland management classes will be outlined along with the methodology for how they have been implemented using existing data layers from remote sensing, statistical data from Eurostat, the Joint Research Centre of the EU, agricultural ministries, and other sources. One of the key challenges is ensuring that the high-resolution data matches official statistics at the national (and NUTS2 level where available) so that they can be used by the economic land use models in LAMASUS. A method will be presented for how this is achieved using priors in the form of integrated layers of cropland and grassland probability created from existing high-resolution remotely sensed input layers. 
Impact of basaltic intrusion on organic-rich clays: organic geochemistry and rock magnetic perspective
Authors: Marynowski Leszek , Staneczek Dorota , Szaniawski Rafał
Published: March 2024

We studied the impact of the basaltic intrusion on the Miocene organic-rich clay level found in the Grabiszyce quarry, Lower Silesia, Poland. The clays were deposited under terrestrial conditions, and fragments of fossil wood and small plant debris are often present within them. The total organic carbon (TOC) values range from 4 to 12% depending on the distance from the intrusion and the organic debris content. The vitrinite reflectance values increase gradually from 0.15% to 1.4% close to the intrusion. Gas chromatography–mass spectrometry (GC-MS) results show significant changes with distance from the intrusion. Carbon preference index (CPI) values change from c.a. 1 for samples near the basalt to > 2 for samples about 0.5 m and more from the intrusion. As the distance from the basalt decreases, some biomarker groups disappear, including tricyclic and tetracyclic diterpanes, des-lupanes and des-oleananes, hopenes, ββ-hopanes, oleanenes and sterenes. Moreover, such polar compounds as sitosterol, stigmastanol, α- and β-amirin and fridelan-3-one are only present in samples far from the basalt. In contrast, there is an increase in the content of unsubstituted and methyl derivatives of PAHs as well as stable derivatives of hopanes and steranes near the intrusion. Notable differences caused by the intrusion are documented also by rock magnetic methods. Both in-phase and out-of-phase magnetic susceptibility decreases with the distance from the basalt and with the measured vitrinite reflectance. In addition, magnetic susceptibility values correspond very well with the second applied maturity parameter based on the benzo[e]pyrene/(benzo[e]pyrene +perylene) ratio. Moreover, the elevated temperatures resulted in the formation of fine-grained superparamagnetic magnetite, which is documented by frequency-dependent susceptibility, hysteresis curves and their parameters. The thermal impact of the intrusion on the magnetic mineralogy diminishes at around 20 cm distance from the basalt.
Abrupt ending of MJO by CCKW precipitation leaves swath of flooding across Indonesia
Authors: Senior Natasha , Matthews Adrian , Webber Ben , Paski Jaka , Nuriyanto Danang , Permana Donaldi , Jones Richard
Published: March 2024

Convectively coupled equatorial Kelvin waves (CCKWs) are eastward propagating weather systems that locally organise convection and have been linked to precipitation extremes across the Maritime Continent (MC). They are often embedded in convectively active phases of the Madden-Julian Oscillation (MJO) which too propagates eastwards but influences convection in the MC over longer timescales and larger areas. Previous high impact weather case studies have linked CCKWs to local precipitation extremes. In this study, we examine a case study during July 2021 of multiple CCKWs embedded within an active MJO. The final CCKW traversed the western MC causing precipitation extremes across equatorial Indonesia that lead to numerous reports of flooding and landslides, with the West Kalimantan region the worst affected. The MJO event itself was abruptly terminated following the passage of this CCKW. Through analysis of the moisture budget we find that the rainfall exceeded the convergence of moisture to produce the pronounced drying. Prior to the local MJO termination, we find there was enhanced westward propagating diurnal activity across the equatorial MC coinciding with a steady increase of total column water. We also examine observations of the extreme rainfall event in the West Kalimantan province. Comparing different deterministic model configurations, we find that the convection permitting models generally perform better when there are not multiple CCKWs present within the initial conditions. This research highlights how CCKWs should not simply be viewed as convective systems that locally affect weather but have the potential to have devastating impacts over the entire equatorial MC especially when involved in multiscale interactions both with the diurnal cycle and with the MJO.
Synthetic Seismic Waveform Analysis for Constraining Anisotropy in the D'' Layer Using the PcSdiff Phase
Authors: Karakostas Foivos , Song Teh-Ru Alex , Deng Kai
Published: March 2024

The D'' layer, at the base of Earth's mantle above the core-mantle boundary (CMB), is a region of profound interest due to its complex seismic characteristics and structural heterogeneity. Varying from 100 to 400 km in thickness, it features anomalous seismic velocity gradients, large-scale lateral variations, and ultra-low velocity zones, hinting at dynamic interactions with the core and potential origins for mantle plumes and subducting slabs.
The PcSdiff waves, extending beyond the core-reflected PcS wave's ray theoretical limit (~63°), feature a P-wave diffracting along the CMB before being converted into an S wave. The observation of PcSdiff waves offers a novel method for examining the lowermost mantle, particularly the D'' layer, as they enable enhanced resolution in this complex region not readily available from nominal diffracted waves such as P/S diffracted waves. Their unique path can be highly sensitive to the anisotropic properties of the lowermost mantle, allowing for a detailed analysis of both isotropic and anisotropic structures, which help elucidate the dynamics and composition of this enigmatic region.
This study focuses on an in-depth exploration of the D'' layer's anisotropic properties, and performs seismic forward modeling against the novel PcSdiff phase. By simulating seismic wave propagation through this region, we aim to provide a novel methodological approach to decode the intricate seismic interactions within the D'' layer. In the first step, we use an extensive synthetic waveform dataset to understand the responses of the PcSdiff phase to the geometry of the D'' layer and its anisotropic features. This process is pivotal in isolating and understanding the PcSdiff phase's nuanced responses to radial and lateral velocity variations due to anisotropy within the D'' layer. We aim to dissect these responses in systematic detail, looking for subtle signatures and patterns that might be indicative of specific anisotropic features. Then, our approach integrates seismic data from the USArray with synthetics produced for 3D models of the internal structure. In pursuing this detailed characterization, our objective is to provide a more nuanced and comprehensive understanding of how the novel PcSdiff wave can be used to probe the anisotropic properties of the D'' layer.
Sulphur reactions on interstellar water ice grains 
Authors: Di Genova Gabriella , Perrero Jessica , Balucani Nadia , Ceccarelli Cecilia , Rosi Marzio , Rimola Albert
Published: March 2024

Introduction:  Astrochemistry is a multidisciplinary subject that allows us to investigate formation and destruction routes of molecules found in extraterrestrial environments, such as planetary atmospheres, comets or the interstellar medium (ISM) [1].To this day, there is still a lack of knowledge concerning the chemistry of minor species, for example, there are important issues related to the presence of sulphur in the ISM, like the sulphur depletion problem [2]. Many sulphur species (H2S, OCS, SO, S2, SO2 and CS2) have been identified in the coma of the comet 67P/Churyumov-Grasimenko [3] and some have been proposed as the main carriers of S, such as H2S and OCS, condensed in the icy mantles of interstellar dust grains.In this contribution, we present a theoretical investigation of the reactions involving atomic sulphur, in the first electronically excited state 1D, with water.S(1D) is produced by UV-induced photodissociation of precursor molecules, such as OCS [4] and CS2 [5], which are relatively abundant in extraterrestrial environments. In. particular, OCS is among the few molecules for which a secure identification in interstellar ice has been provided [6-7].S(1D) + H2O: The presence S(1D) precursors, like OCS, on interstellar ice is documented. Therefore, if formed on the ice surface, S(1D) will be able to react with water. According to our calculations, the reaction proceeds either by S(1D) addition to one of the lone pairs of O or via insertion into one of the two O-H bonds. Two different intermediates can be formed: H2OS and HOSH.Theoretical method:  We first characterized the gas-phase potential energy surface (PES) of the reaction S(1D) + H2O. We then optimized the geometry of an 18-H2O cluster ice surface at DFT level of theory. We identified several surface binding sites on the grain, based on the amount of available hydrogen bonds that engage the sulfur atom with the surface. For each identified site, we computed the binding energies of the sulfur atom in order to select the best configuration with which to investigate the catalytic effect of water molecules.Conclusions: In this contribution we show the catalytic effect of the water ice: water molecules actively participate to the H-transfer process, reducing the energy barriers compared to the analogous gas-phase steps.References:[1] Caselli P. and Ceccarelli C. (2012) Astron. Astro- phys. Rev., 56, 20[2] Vidal T. H. G. and Wakelam V. (2018) Mon. Not. R. Astron. Soc., 5575–5587, 474[3] Hänni N. et al. (2022) Nat. Commun., 3639, 13[4] Kim, M. H. et al. (2004) Can. J. Chem. 880-884, 82[5] Black, G. and Jusinski, L.E. (1986) Chem. Phys. Lett., 90–92, 124[6] Gibb E. L., et al. (2000) Astrophys. J., 347, 536[7] Gibb E. L., et al. (2004) Astrophys. J. S. S., 35, 15
Scattered wave and coda reliability in 3D elastic seismic simulation: new insights for the advancement of inversion studies.
Authors: Bracale Mirko , Margerin Ludovic , Brossier Romain , Campillo Michel
Published: March 2024

In this study we investigate the behavior of seismic waves in a high-scattering medium using numerical simulations of the full wavefied based on the Spectral Element Method solutions of the wave equation. The simulated 3D elastic medium was designed to have Laplacian correlated heterogeneity, creating a realistic representation of the complexities present in natural seismic environments. We conducted analyses on three distinct cases, each characterized by increasing levels of heterogeneity fluctuation, ranging from 10% to 25% standard deviation.We checked the consistency between theoretical results and simulations with regard to the value of the mean free path, the asymptotic behavior at long times and the partitioning of energy between compressional and shear modes. Excellent agreements were obtained, indicating the reliability of the numerical models of coda waves used here.  Our analyses are made both at depth and at the free surface, allowing us to compare the behavior of seismic waves under varying conditions. Additionally, we validated our findings by conducting independent numerical simulations of wave energy densities that used Monte Carlo methods to solve the Radiative Transfer Equation, thus corroborating the robustness and accuracy of our results for long lapse times.We show that under specific conditions, existing simulation codes can effectively replicate wave propagation in a highly scattered medium. This implies that a greater part of the waveform, namely the late envelops, could be employed in inversion processes, thus opening up new possibilities in the realm of inversion studies. Furthermore, we used these simulations to investigate the behavior of the wavefield and its gradient, exploring the information that can be extracted from their evolution over time to improve characterization of environmental heterogeneity.
The Holocene precipitation dipole pattern in the Asian drylands: mechanisms and processes from PMIP4 simulations and paleo-proxy evidence
Authors: Ma Shuai , Chen Shengqian , Chen Jianhui , Xoplaki Elena , Luterbacher Jürg , Chen Fahu , Huang Wei
Published: March 2024

Asian drylands consist of arid Central Asia (ACA) and West Asia (WA), in which climatological water vapor transport is constantly controlled by the westerlies. Recent research has revealed the presence of dipole pattern in the hydroclimate changes during the Holocene between the ACA and WA, challenging prior notions of consistent hydroclimate changes in the westerlies-dominated mid-latitude of the Northern Hemisphere. However, the mechanisms behind the dipole pattern remain largely unknown. Here we show that PMIP4 models faithfully replicated the dipole pattern, attributing it primarily to opposing spring precipitation variations. From the mid-to-late Holocene, intensified westerlies resulted in increased precipitation in ACA. Conversely, increasing spring solar insolation strengthened the subtropical high, resulting in decreased water vapor and descending motion in WA, which resulted in decreased precipitation in WA. Our study suggest that WA is a unique region within the westerlies-dominated mid-latitude, and the low-latitude process caused inconsistent Holocene precipitation variations.
The effect of seismic swarms on short-term seismic hazard and Gutenberg-Richter b-value temporal variation. Examples from Central Italy seismic activity durign October-November 2023.
Authors: Spassiani Ilaria , Taroni Matteo
Published: March 2024

Seismic hazard can be quantified by using probabilities. Modern seismic forecasting models, such as Operational Earthquake Forecasting (OEF) systems, allow us to quantify short-term variations of such probabilities. These probabilities change indeed with time and space, in particular after strong seismic events. However, the short-term seismic hazard could also change during seismic swarms, e.g. sequences with several small/medium size events. The goal of this work is to quantify these changes by both using the Italian OEF system, and estimating the variations of the b-value parameter in Gutenberg-Richter frequency-magnitude distribution. We focus our attention on three seismic swarms that occurred in Central Italy during October-November 2023. Our results indicate that the short-term variations of seismic hazard are limited, less than an order of magnitude. The b-value variations are also not significant. Our conclusion is then that, with the currently available models and catalogs, occurrence of seismic swarms does not significantly affect the short-term seismic hazard.
Developing Long-term Satellite Based Chlorophyll Estimates via Multiple Machine Learning Methods 
Authors: Zhao Minyan , O 'Loughlin Fiachra
Published: March 2024

Chlorophyll is widely used to assess the level of eutrophication, which is recognized as one of the major causes of deterioration in water quality, especially across Irish inland waters. The use of optical remote sensing for chlorophyll monitoring has already been shown to be able to complement existing in-situ chlorophyll. However, as cloud cover impacts all optical sensors this limits the usefulness in many locations to develop long term records. A potential solution is to combine information from multiple satellites using a machine learning approach. In this study, we develop long-term time series of chlorophyll concentrations for lakes in Ireland using four different remote sensing platforms: Landsat-8, MODIS, Sentinel-2, and Sentinel-3. Several machine learning approaches have been tested, including K-nearest neighbourhood, random forest (RF), XGBoost (Extreme Gradient Boosting), artificial neutral network (ANN), and support vector regression (SVR).Initial result indicate that a machine learning model utilising all four platforms and in-situ observation is effective in developing long-term chlorophyll concentrations. While the methods are tested and validated for Irish lakes, the methodology has the potential to be applied in a global context.
Estimating Basin Recharge and Pumping Rates Using Hydrological-Groundwater Coupled Model (SWAT-MODFLOW) - A Case Study of the Zhuoshui River Alluvial Fan in Taiwan
Authors: Chiang Li-Chi , Li Min-Jing , Lu Chih-Mei
Published: March 2024

The interaction between surface water and groundwater is a crucial factor in assessing regional water resource utilization. As population growth and urban development escalate, the effective allocation of surface and groundwater sources has become a pressing concern. This study employs a coupled model that combines surface water and groundwater simulations, SWAT-MODFLOW, for estimating groundwater recharge and pumping rates in the expansive alluvial fan of the Zhuoshui River Basin in central Taiwan (4,995.76 km2). Utilizing the SWAT model, we derive key parameters related to groundwater recharge, such as rainfall-runoff, recharge rates, and river water levels. These parameters are integrated into the MODFLOW model for the alluvial fan, facilitating a comprehensive understanding of the complex dynamics. To address uncertainties arising from insufficient well pumping data, further calibration of the MODFLOW model is undertaken. The simulation spans from 2002 to 2021, with 2002-2011 and 2012-2020 designed as calibration and validation periods, respectively. Our daily flow simulations demonstrate the SWAT model's effectiveness in accurately capturing hydrological processes in the basin (R2 = 0.59-0.80, NSE=0.43-0.77, PBIAS=-49-55.9%). Through the linkage of the groundwater model and daily-scale simulations, we estimate monthly groundwater levels, revealing an annual recharge of approximately 214 million m3 and groundwater pumping rates ranging from 127 to 186 million m3 within the basin. These findings provide valuable insights for regional water resource management strategies and serve as a reference for decision-makers grappling with the challenges of regional water resource allocation within the context of the Zhuoshui River Basin.
Geological framework for the origin of life in the early continental crust
Authors: Schreiber Ulrich
Published: March 2024

The development of the first cells on a young Earth presupposes the existence of stable conditions in an environment over an extended period, where unlimited primary gaseous reactants were available. Additional prerequisites include a broad range of physicochemical parameters such as pressure, temperature, states of matter, and pH values. Cyclical processes that enable chemical evolution and a transport system for the supply and removal of substances involved in reactions were also necessary. Corresponding conditions were and still are present in open, water-filled fault zones in the continental crust, where CO2, N2, H2, H2S, NH3, and trace gases ascend. Within these zones, synthesis processes occur that are analogous to Fischer/Tropsch and Haber/Bosch syntheses. Variable pressure/temperature conditions in the upper crust create a unique situation likely crucial for the development of life. Above 1000 meters crustal depth, pressure fluctuations, induced by cold-water geysers, cause CO2 to transition from supercritical to subcritical states. For pure N2, the transition occurs approximately 600 meters higher. The phase transition, which is accompanied by a significant increase in entropy, leads to the localized enrichment of organic molecules in cavities within faults, facilitating a multitude of chemical reactions. The transport of organic molecules from deeper formation areas involves a flotation process through supercritical CO2/N2 bubbles. These bubbles directly capture nonpolar molecules or attach certain amphiphiles to the bubble surface, acting as collector molecules for specific RNA molecules, for example. Flotation results in an initial selection of organic molecules and is complemented by surface effects on fault walls. During ascent, specific molecules adhere to changing mineral surfaces such as lead-zinc or iron-sulfide ores, quartz, or clay minerals. Variations in temperature occurred through adiabatic state changes and the influx of hotter deep-seated water or cooler artesian water, simultaneously influencing the pH value.
References
Schreiber, U. (2023): Storage of Biochemical Information as the Start of Life: A Hypothetical Model for the Development of the First Cell, preprints.org > chemistry and materials science > organic chemistry > doi: 10.20944/preprints202201.0364.v2
Changes in sector-specific climate indices: an extension to HadEX3
Authors: Dunn Robert , Herold Nicholas , Alexander Lisa , Donat Markus
Published: March 2024

Extreme events have widespread impacts across human health, our infrastructure, and the natural environment. So far there has not been a global product which presents climate indices relevant for different sectors of our society, including health, agriculture, and water resources. Here we present an extension to HadEX3, an existing dataset of extremes indices based on in situ observations, by including indices recommended by the World Meteorological Organisation (WMO) which were developed with sector specific applications in mind. We have used the approach and methodology of HadEX3, and where possible the same underlying daily temperature and rainfall observations, to produce quasi-global land fields over 1901-2018.  We will demonstrate the key features of this extension, with temperature indices showing changes consistent with global scale warming, as indicated by heat wave characteristics showing increases in the number, duration, and intensity of these extreme events in most places.
Scalable 3D Semantic Mapping of Coral Reefs with Deep Learning
Authors: Sauder Jonathan , Banc-Prandi Guilhem , Perna Gabriela , Meibom Anders , Tuia Devis
Published: March 2024

Coral reefs, which host more than a third of the ocean’s biodiversity on less than 0.1% of its surface, are existentially threatened by climate change and other human activities. This necessitates methods for evaluating the state of coral reefs that are efficient, scalable, and low-cost. Current digital reef monitoring tools typically rely on conventional Structure-from-Motion photogrammetry, which can limit the scalability, and current datasets for training semantic segmentation systems are either sparsely labeled, domain-specific, or very small. We describe the first deep-learning-based 3D semantic mapping approach, which enables rapid mapping of coral reef transects by leveraging the synergy between self-supervised deep learning SLAM systems and neural network-based semantic segmentation, even when using low-cost underwater cameras. The 3D mapping component learns to tackle the challenging lighting effects of underwater environments from a large dataset of reef videos. The transnational data-collection initiative was carried out in Djibouti, Sudan, Jordan, and Israel, with over 150 hours of collected video footage for training the neural network for 3D reconstruction. The semantic segmentation component is a neural network trained on a dataset of video frames with over 80’000 annotated polygons from 36 benthic classes, down to the resolution of prominent visually identifiable genera found in the shallow reefs of the Red Sea. This research paves the way for affordable and widespread deployment of the method in analysis of video transects in conservation and ecology, highlighting a promising intersection with machine learning for tangible impact in understanding these oceanic ecosystems. 
Connecting remote and in situ observations of shock-accelerated electrons associated with a coronal mass ejection
Authors: Morosan Diana , Pomoell Jens , Palmroos Christian , Dresing Nina , Asvestari Eleanna , Gieseler Jan , Kumari Anshu , Jebaraj Immanuel
Published: March 2024

Energetic particle populations are ubiquitous throughout the Universe and often found to be accelerated by astrophysical shocks. One of the most prominent sources for energetic particles in our solar system are huge eruptions of magnetized plasma from the Sun called coronal mass ejections (CMEs), which usually drive shocks that accelerate charged particles up to relativistic energies. Accelerated electrons can be observed remotely as low-frequency radio bursts or in situ at spacecraft. However, it is currently unknown where electrons accelerated in the early phases of such eruptions propagate and when they escape the solar atmosphere to eventually reach spacecraft. Here, we present a new study that uses a three-dimensional representation of radio emission locations in relation to the overlying coronal magnetic field, shock wave propagation, magneto-hydrodynamic (MHD) models of the solar corona, and radio imaging observations from ground-based observatories. These solar observations are also combined with in situ electron data at spacecraft.  Our results indicate that if the in situ electrons are shock-accelerated, their most likely origin is at or near the acceleration site of electrons beams producing herringbone radio bursts. This is the only region during the early evolution of the CME where there is clear evidence of electron shock acceleration and intersection of the CME shock with open field lines that can connect to the observing spacecraft.
Maximizing limestone dissolution rate and alkalinity enhancement in an open-system benchtop reactor 
Authors: Moran Noga , Goldsmith Yonaton , Wurgaft Eyal
Published: March 2024

Reducing CO2 emissions is crucial for mitigating climate change and its environmental impacts. A promising strategy for CO2 reduction involves enhancing limestone dissolution in seawater by reacting it with industrial CO2 waste gas to form dissolved bicarbonate, which prevents the CO2 from being released into the atmosphere. This process of limestone dissolution and atmospheric CO2 reduction occurs naturally over time-scales of 105 – 106 years and serves as “Earth's thermostat”. Enhancing this natural process could serve as an efficient way to remove man-made atmospheric CO2. To adapt this process to perform at industrial scales and rates suitable for mitigating climate change it is essential to scrutinize limestone dissolution rates and assess the parameters governing this process under controlled laboratory conditions. To assess the potential of limestone dissolution rates and characterize the conditions required to maximize dissolution rates and CO2 removal, we constructed a versatile benchtop reactor that mimics the natural limestone dissolution process and allows for experimenting with different materials and dissolution conditions. This experimental setup affords control over gas and recycled gas flow rates, as well as the mineralogy and grain size of the utilized limestones—parameters known to influence dissolution rates. The reactor is a 22 x 110 (cm) circular tube filled with a limestone medium. A continuous stream of seawater and CO2 gas is introduced into the reactor where it reacts with the limestone. An air pump recycles CO2 gas from the reactor head-space, in order to enhance the efficiency of CO2 dissolution in seawater. Excess gas and seawater are removed continuously from the reactor, creating an open, through-flowing system. The system is monitored online using temperature, pCO2 and pH meters. Total alkalinity (TA), dissolved inorganic carbon (DIC) and Calcium concentrations of the sea water in the reactor are sampled throughout the experiments and measured offline. To identify the parameters that achieve maximum limestone dissolution rates we performed experiments under different grain sizes, gas to seawater flows ratio, and recycled gas flow rate. Comparing our findings with previous studies reveals that a significant amount of limestone dissolution occurred in our system, leading to alkalinity enhancement in the sea water and removal of CO2. In the presentation, we will discuss the effects of the different parameters on the final total dissolution rate and suggest the set of parameters that maximize the limestone dissolution rate.
Contrasting interactions between urban heat islands and heat waves in Seoul, South Korea, and their associations with synoptic patterns
Authors: Park Kyeongjoo , Jin Han-Gyul , Baik Jong-Jin
Published: March 2024

This study investigates the interactions between urban heat islands (UHIs) and heat waves in Seoul, South Korea, using 25-year (1997–2021) observations. Under heat waves, South Korea is under strong influence of an anomalous 500-hPa anticyclonic high and the expanded Tibetan high. The urban heat island intensity (UHII) calculated as the difference between the urban-station average and rural-station average of the daily minimum (maximum) 2-m temperature increases by 0.53 °C (0.20 °C) under heat waves, indicating synergistic interactions in both nighttime and daytime. UHII substantially varies within heat waves. UHII tends to increase under stronger heat waves and has statistically significant negative correlation with relative humidity and cloud fraction. Among heat wave days, strong (weak) UHI days with UHII larger (smaller) than its 90th (10th) percentile are selected, and these days well represent positive (negative) interaction cases. The strong UHI days exhibit relatively hot, calm, dry, and clear weather conditions with relatively strong subsidence compared to the weak UHI days. The dominant synoptic patterns on the strong and weak UHI days are the Pacific-Japan (PJ) pattern and the expanded western North Pacific subtropical high (WNPSH), respectively. The strong UHI days are frequent in recent years.
Stronger early-spring dust outbreaks across the Northern Hemispheric mid-latitudes in a warmer climate
Authors: Wang Yiting , Yu Yan , Nie Ji , Ginoux Paul
Published: March 2024

This research focuses on changes in early-spring dust emissions from Northern Hemispheric mid-latitudes, in the context of global warming. Our study was motivated by the abnormally early and strong dust storms across East Asia in March 2021 and March 2023. These two recent dust extremes opposed the decadal decline of East Asian dust activities. Past studies have attributed this dustiness decline to expanded vegetation cover and resultant weaker near-surface winds in April and May; while in March, dust source regions in the Northern Hemispheric mid-latitudes have been mainly covered by snow or frozen soil instead of vegetation. Inspired by the abnormally warm and snow-free conditions associated with both the 2021 and 2023 early-spring dust extremes, our study examines an alternative hypothesis on dust regimes over the Northern Hemispheric mid-latitudes: in a warmer climate, earlier snow melt may cause stronger early-spring dust outbreaks. Here, using multiple observational datasets and model simulations, we show a 10-35% increase in March dust emission across the East Asian, Central Asian and North American drylands, from the 1980s towards the end of the 21st century, bringing ~20% extra PM10 to Beijing and Denver. This hemispherical enhancement in early-spring dust emission is primarily caused by reduced snow cover in response to warming, and further promoted by dynamical coupling between snow, wind, and soil moisture changes. The increased amount of dust, a light absorbing aerosol, may in turn accelerate larger-scale snow melt when it deposits, thereby triggering positive feedbacks between snow melting, dust emission, and warming. Our findings call for adaptation to the anticipated stronger early-spring dust storms across the North Hemispheric mid-latitudes in the upcoming decades.