bluuebunny/crossref_metadata_2025 huggingface dataset:
Using triple oxygen measurements of lacustrine carbonates to constrain the Miocene topography of the Dinaric Alps
Authors: Sanchez Ortiz Gabriela , Löberbauer Marlene , Banerjee Payal , Tomašević Nevena , Mandic Oleg , Pavelić Davor , Demir Vedad , Sharp Zachary , Meijers Maud , Rugenstein Jeremy
Published: March 2024

The Dinaric Alps formed as a result of the collision between the Adria microplate with Eurasia during ongoing closure of the Tethys Ocean. However, there remain a number of questions regarding the mechanisms that created and sustained the high topography (maximum modern elevation of ~2500 m) of this region. We take advantage of a series of lacustrine basins—known as the Dinaride Lake System (DLS)—that formed in the Early and Middle Miocene to constrain paleo-elevations of the Dinaric Alps using stable isotope paleoaltimetry. We collected authigenic lacustrine carbonate samples from six basins in Croatia and Bosnia and Herzegovina that span the range from sea-level to high-elevation (~1200 m) and measured these samples for δ18O. In addition, we also collected stream samples that span the range to constrain the modern change in δ18O across the Dinaric Alps. Stable-isotope paleoaltimetry is based on the concept that, as moist air parcels are forced upwards by orography, 18O is preferentially removed by the resulting precipitation, resulting in lower δ18O at higher-elevations and in the lee of ranges. Today, meteoric water δ18O is high (~ -6‰) at the coast and is ~5‰ lower at the crest of the range (~ -11‰). However, Middle Miocene lacustrine carbonate δ18O is high (~ -3‰) at the crest of the range and lower (~ -6‰) at the coast. Because lacustrine carbonate δ18O is frequently impacted by evaporation, we analyzed a subset of our samples for Δ17O, which is sensitive to the degree of evaporation. These carbonates have Δ17O values ranging from -68 to -150 per meg. Using our Δ17O data and a model of lake evaporation, we reconstruct the unevaporated meteoric water δ18O. Our preliminary results show a similar trend as in the modern, with higher δ18O values at the coast and lower δ18O at the crest of the range. Reconstructed unevaporated meteoric water δ18O at the crest is lower by 2-5‰ than modern water δ18O at the crest of the Dinaric Alps. That unevaporated meteoric water δ18O might have been lower than today at the crest of the range suggest that the Dinaric Alps were higher in the Middle Miocene that today, assuming that coastal meteoric water δ18O was similar to today. Thus, ongoing extension within the Dinaric Alps due to slab rollback may be responsible for lowering of topography.
Choose Your Model Wisely: Navigating Uncertainties in Future Global Tropical Cyclone Risks
Authors: Meiler Simona , Kropf Chahan , Emanuel Kerry , Bresch David N.
Published: March 2024

Future tropical cyclone risks will evolve depending on climate change and socio-economic development, entailing significant uncertainties. A comprehensive uncertainty and sensitivity analysis of future tropical cyclone risk changes is thus vital for robust decision-making not least in the context of physical climate risk disclosure. However, the outcomes of such uncertainty and sensitivity analyses are closely tied to the chosen model setup, warranting caution in interpretation and extrapolation. Our study investigates how four distinct tropical cyclone hazard models as well as alternate representations of socio-economic development influence future tropical cyclone risks. We find that average tropical cyclone risk increases 1-5% by 2050 across all models and global study region. But the estimated maximum risk increases by the end of the century range from 10-400% depending on the hazard model choice. Such diverging results are critically relevant for climate risk assessment in the financial and insurance sectors where usually model choices are made a priori and uncertainties are not quantified systematically. Additionally, socio-economic factors drive risk increase more strongly across all models, while the uncertainty in these risk drivers is hazard model-specific. For instance, the MIT model-based results are sensitive to the choice of global climate model, while estimates from CHAZ, STORM, and climate-conditioned IBTrACS are mainly influenced by exposure scaling based on Shared Socio-economic Pathways. Finally, we assert that quantitative estimates of uncertainty and sensitivity to model parameters greatly enhance the value and depth of climate risk assessments, which are essential for robust decision-making in the financial and insurance sector.
A shift in the biodiversity fitness of meta-communities assessed from space
Authors: Verstraeten Guido J. M. , Verstraeten Willem W.
Published: March 2024

Land surface temperature obtained from remote sensing is a measure of the Earth’s entropy production hypothesizing that the planet’s absorption and emission budget is governed by the Stefan-Boltzmann law for black body radiation. Based on Penrose’s claim, explaining life as the decelerating force of entropy produced at Earth, changing entropy production over time is an indication of shifting forest biodiversity.In earlier research we have analysed Earth’s entropy production in four regions comprising a subarctic forest in Finland, a deciduous forest in Belgium, a Mediterranean forest in Spain, and a rainforest in Congo. Within the period 2003-2018, the deciduous forest was undergoing a dramatic decay of biodiversity by 5%, the rainforest by 2% while the biodiversity of the subarctic and Mediterranean forest remained pretty stable (Verstraeten & Verstraeten, EGU 2023). The entropy production shift was connected to the Shannon entropy of the lognormal distribution of species amount as claimed by Hubbel in his Unified Neutral Theory of Individual Migration of Life (Hubbel, 2001). The latent heat production, however, was not included in the earth surface energy budget.Here we refine our results by focusing on the deciduous forest as pilot ecosystem for applying the Hubbel’s Unified Theory between three interacting communities in Flanders, Belgium. In this study we have included the Sonian forest (south of Brussels), Meerdal forest (east of Brussels) and the Houwaart area (north-east of Brussels). During the period 2003-2018 the refined local entropy changes by including monthly rainfall data of Sonian and Meerdal forest increased substantially (1.7-1.9%/decade), while the entropy change of the Houwaart area remains stable (0.5%/decade).In addition, we have analysed the shift in biodiversity of the Meerdal forest by considering the Sonian forest and Houwaart area as its meta-community using the method of Hubbel. The Meerdal and Houwaart forests follow Preston’s lognormal distributions of species, while the Sonian forest follows the Fisher’s lognormal distribution due to the mono dominant biodiversity. The shift of the total number of species of the central community follows from the Arrhenius species area power law that connects the total number of species in the central community by its biodiversity number.
Inter- and intra-chamber variability of trace elements in benthic foraminifera – potential and risks of LA-ICP-MS analyses
Authors: Doubrawa Monika , Stassen Peter , Robinson Marci M. , Speijer Robert P. , Vellekoop Johan
Published: March 2024

The Mg/Ca ratio of foraminiferal tests is widely used to reconstruct seawater temperature in past climates. With traditional methods (i.e. Inductively Coupled Plasma Optical Emission Spectrometry or ICP-OES), multiple tests have to be clustered together to attain enough material for analysis. The need for high amounts of carbonate can be problematic for shelf sediments if suitable foraminifera are scarce. As a consequence, grouping of different taxa into one bulk value or ‘sample grouping’ is applied, losing information on interspecific and intra-specimen geochemical variability. Laser Ablation Inductively Coupled Plasma Mass Spectrometry (LA-ICP-MS) solves this problem by targeting extremely small surfaces, e.g., single foraminifer tests or even single chambers.Nevertheless, understanding LA-ICP-MS-generated foraminiferal Mg/Ca records requires in-depth knowledge on the growth and reproductive cycle of extinct foraminiferal taxa, such as Cibicidoides sp. and Anomalinoides acutus from the Paleocene-Eocene transition and early Eocene. These species are commonly used for environmental reconstruction because they are thought to have incorporated the ocean water chemistry in equilibrium with their tests, yet not much is known about their life or precipitation cycle.The reproductive cycle of modern benthic foraminifera ranges from a few weeks to a year, depending on species and size, requiring about a single day to precipitate a new chamber. This implies a potential change in geochemistry from chamber to chamber. Hence, LA-ICP-MS hypothetically allows for an extremely high-resolution, in situ Mg/Ca record across a year, or a precipitation season, if sufficient snapshots of chamber calcification moments are incorporated. As a result, a comparison of cyclic temperature changes on both annual (seasonal variations across individual specimens of a sample) and sub-millennial (variations across closely spaced samples) scale could be feasible. However, the complex growth of the foraminiferal test (e.g. layering due to overgrowth of older chambers) likely also results in geochemical variability within chambers.Here we investigate the inter- and intra-chamber variability in Mg/Ca composition of extinct benthic foraminifera using LA-ICP-MS. We evaluate the resulting potential and risks stemming from inhomogeneous trace-element distribution in the tests. We utilize foraminiferal tests from shelves from the western North Atlantic and the North Sea Basin, covering a paleodepth transect (
A GIS-Based Decision Support System for Multi-Hazard Assessment in Post-Mining Regions
Authors: Bouaziz Moncef , Haske Bejamin , Al Heib Marwan , Benndorf Joerg
Published: March 2024

Abandoned mines are generally exposed to multi-hazard: natural and man-mad hazards. The risk assessment is one of the challenges of the site management. This paper presents first the categories of hazards and potential interactions, then it shows a Geographical Information System (GIS)-based Decision Support System (DSS), as part of the European research project titled "POst-mining Multi-Hazards Multi-Assessment for Land-Planning (POMHAZ)." Utilizing predominantly open-source tools (PostGIS, Geoserver, and Leaflet) and Python Scripts, the DSS aims to tackle the intricate challenges posed by post-mining hazards in European mining regions. The objective is to furnish a functional web-based tool tailored for EU administrative units, ensuring a comprehensive evaluation of various hazards that impact their territories.In the context of post-mining landscapes, conventional environmental policies often encounter challenges due to the lack of operational and accessible tools. The proposed DSS seeks to bridge this gap by catering to a diverse user base, including citizens, scholars, associations, and public bodies.The DSS streamlines the acquisition, management, and processing of both static and dynamic data, providing web-accessible data visualization. Customized for post-mining multi-hazards, this tool contributes to enhanced decision-making by generating data, statistics, reports, and maps for various EU areas of interest. Validation is obtained through a case study of abandoned coal mine (France), this validation demonstrates its capabilities. This paper showcases the practical application of the DSS in North Rhine Westphalia offering valuable insights to address the intricate challenges posed by post-mining hazards.
Remote sensing aerosol observations from AREAD ship campaign in the Mediterranean and Middle East
Authors: Papetta Alkistis , Marenco Franco , Pikridas Michael , Blarel Luc , Dubois Gael , Goloub Philippe , Torres Benjamin , Mohamed Ruqaya , Sciare Jean
Published: March 2024

Atmospheric Research Expedition to Abu Dhabi (AREAD) is a ship campaign that sailed from Vigo, Spain to Abu Dhabi, UAE between 26/11/2022 and 19/12/2022, aimed at the characterization of the atmospheric composition and at identifying pollutants transport over the Mediterranean, Red Sea and Arabian Sea. In this study, we present preliminary results from the remote sensing observations acquired during the cruise. The area of interest, surrounded by deserts and anthropogenic sources, has been recognized as a climate change hotspot due to extreme temperature increases and an important contribution to greenhouse gas emissions. Limited studies focus on the area because of limited and few observational data are available.AREAD’s main objective was to contribute to the knowledge of trace gases and aerosol concentrations in the region and to complement with wintertime observations the AQABA campaign (24/06/2017-03/09/2017) performed in the same region during the summer season. The research vessel’s voyage included observations in the Suez Canal, one of the most heavily used navigational hubs in global trade routes. The on-board instrumentation included in-situ observations for trace gases (NO, NO2, O3, SO2, CO2, CH4) and aerosol optical, physical and chemical properties (PM1, PM10, particle sizes, aerosol spectral absorption and scattering). In addition, remote sensing of aerosol, clouds and boundary layer height (BL) was obtained with a VAISALA CL51 ceilometer and an automatic ship-photometer (CIMEL CE318T, modified for marine applications) included in AERONET.The preliminary results suggest a change of regime between the Mediterranean and the Suez Canal. AOD levels remained below 0.1 for the first part of the cruise and increased to more than 0.2 after the entrance of the ship into the Suez Canal. Even though there was no significant variation in BL height which remained below 1km for most of the cruise, increased particle backscatter is observed within the BL and in elevated layers after the Suez Canal. Desert dust, trade ship emissions and pollution from Middle East fossil energy production plants could be some of the species contributing to the higher aerosol loading observed in the latter leg of the cruise. Acknowledgment: The datasets presented in this research were acquired during the Atmospheric Research Expedition to Abu Dhabi (AREAD) on-board research vessel Jaywun, operated by the Environment Agency of Abu Dhabi (EAD), which is gratefully acknowledged. The ship-photometer is developed in the frame of AGORA-Lab joint laboratory (Laboratoire d’Optique Atmospherique from CNRS/University of Lille and CIMEL Electronique company).
Design, Testing, and Preliminary Data Analysis of the Seafloor Absolute Pressure Gauge
Authors: Lin Ching-Ren , Hsu Ya-Ju , Lin Feng-Sheng , Chang Kun-Hui
Published: March 2024

Taiwan is situated in the collision zone between the Philippine Sea Plate and the Eurasian Plate, where these two plates are converging at an average rate of 8.2 centimeters per year, leading to significant crustal deformation on the island. Utilizing data from GPS (Global Positioning System) measurements processed and analyzed using Bernese software, the average velocity field of crustal movements can be estimated, providing a more comprehensive understanding of crustal deformation. The combination of GPS and seafloor geodesy observations can aid in unraveling the seismic processes along plate boundaries. Due to the inability of GPS signals to penetrate seawater, acoustic methods are employed to make ocean bottom pressure (OBP) measurements, serving as a valuable and unique tool for monitoring integrated ocean currents and observing sea level changes.OBP measurements have been applied for various geophysical purposes, including ocean physics and marine geodesy. Seafloor Absolute Pressure Gauges (SAPG) based on quartz oscillation principles have been employed to record phenomena such as tsunamis, ocean tides and non-tidal sea level variations, as well as seafloor vertical deformations. These instruments play a crucial role in marine physics research.In recent years, the Academia Sinica has also conducted research in the surrounding waters of Taiwan using acoustic positioning methods for seafloor geodetic observations. In conjunction with seafloor geodetic observations, ocean bottom pressure (OBP) measurement is another method employed.The seafloor absolute pressure gauge (SAPG) developed by the Academia Sinica is composed of a Paroscientific Inc. quartz vibrating pressure sensor, integrated with an OEM data logger from RBR-Global Co. (http://www.rbr-global.com/products/bpr) and components such as the BART Boards with Regular Tuning ROUND and Acoustic Transducer that made by EdgeTech Co. The assembly of SAPG has been completed, and it has been deployed in the waters off the eastern coast of Taiwan for long-term observations. This paper will introduce the instrument assembly of SAPG, pre-deployment testing, and preliminary analysis results of the marine data.
Enhanced precipitation events and forests stability: a case study in Emilia-Romagna and Tuscany (Italy).
Authors: Georgiadis Teodoro , Cremonini Letizia , Matteucci Giorgio , Rossi Federica , Giannetti Francesca , Zorzi Ilaria , Collalti Alessio , D'andrea Ettore , Cardoni Simone
Published: March 2024

Climate change is endangering natural and anthropogenic ecosystems, as pointed out by the recent IPCC Reports and the COPs' statements. The impacts of climate change on natural ecosystems can affect their production capacity, particularly in those systems characterized by a high quality of yields, especially in densely populated and industrialized countries. We analyze two recent intense rainfall events that hit the Emilia-Romagna and Tuscany (Italy) regions and the damage caused to the agricultural ecosystems downstream of forests and woodlands. Although the scientific debate on these events' climatic or purely meteorological origin is still open, these occurrences provide a potential direct example of the harm climate change may bring. The topic of forest management for risk reduction is also analyzed on the forest itself and anthropized systems and related economies. The study was conducted within the European OptFor-EU Project. 
Green School Project
Authors: García Lara
Published: March 2024

The fight against climate change is often associated with large-scale actions in urban areas. However, the school serves as an engine for change, where all staff, both teaching and non-teaching, can alter their attitudes, values, and behaviors regarding environmental education.With this project, we aim to raise awareness and promote good environmental practices within our school. The objectives of our project include:1. Promoting awareness among students about their role in the fight against climate change by emphasizing the value of plants as CO2 reducers.2. Involving the families of students in the design and implementation of proposals.3. Encouraging public discourse on utilizing private and public spaces as CO2 sinks. 4. Integrating the fight against climate change into all areas of secondary education.This project comprises some activities, ranging from awareness talks to planting vegetables in the green areas of the school and establishing a compost bin. The main activity of this project involves experimentation.  In this activity, students measure CO2 and temperature values under different conditions, such as the presence or absence of plants. Analyzing the results allows them to become aware of the importance of plants as CO2 sinks, and thus, as tolls in the fight against climate change. 
A quantitative, deglacial reconstruction of bottom-water nitrate in the intermediate Pacific using the pore density of the denitrifying benthic foraminifera 
Authors: Govindankutty Menon Anjaly , Davis Catherine V. , Nürnberg Dirk , Schmiedl Gerhard , Glock Nicolaas
Published: March 2024

The marine nitrogen cycle is being altered on a global scale by increasing anthropogenic production and use of chemical fertilizers. Nitrate (NO3−) is an important macronutrient that is limiting in some marine environments. Modelling studies have predicted increased NO3− concentrations during glacial periods due to reduced water column denitrification as compared to interglacials. The aim of our study is to provide a widespread, quantitative reconstruction of bottom-water NO3− concentrations ([NO3-]BW) in the intermediate Pacific covering the last deglaciation. Downcore samples taken from the Eastern Tropical South Pacific in the Gulf of Guayaquil (M77/2-059-1), and Eastern Tropical North Pacific from the Mexican Margin (MAZ-1E-04), Sea of Okhotsk (MDO1-2415), and Gulf of California (DSDP-480) were utilized. We have utilized the pore density of the denitrifying benthic foraminifera Bolivina spissa and Bolivina subadvena as proxy for deglacial [NO3−] concentrations. These shallow infaunal foraminifera species are abundant in oxygen-depleted environments all around the Pacific. They can denitrify and most likely take up NO3- as an electron acceptor through the pores, making their pore density an empirical proxy for NO3- concentrations. We found that the [NO3-]BW in the Gulf of Guayaquil, Gulf of California, and Mexican Margin were higher during the glacial period than the Holocene. The Gulf of Guayaquil showed a pronounced decrease in [NO3-]BW during the Heinrich Stadial, while the Mexican Margin showed a peak in [NO3-]BW during the entire Younger Dryas. The Sea of Okhotsk core covers only from the Younger Dryas until the middle Holocene, and [NO3-]BW was found to increase from the Younger Dryas to the Holocene. In all cores studied, we also compared past and present [NO3-]BW. Our data shows that both the Gulf of Guayaquil and the Gulf of California had higher [NO3-]BW in the past than today. In contrast, the Mexican Margin and the Sea of Okhotsk had lower [NO3-]BW in the past than today. We speculate that a site-specific balance between reduced water column denitrification, sea-ice retreat, increased nutrient input from continental shelves as a result of sea-level changes, changes in water mass ventilation, a decrease in upwelling productivity, or thermal contrast between land and sea may account for changes in nitrate concentrations during cold-warm periods at the studied sites. A comprehensive understanding about past nutrient cycling under rapidly changing climatic conditions is one prerequisite to predict future changes in marine nutrient budgets in the Eastern Equatorial Pacific.
Effects of topographic coupling at core-mantle boundary in rotation and orientation changes of the Earth.
Authors: Dehant Véronique , Rekier Jeremy , Puica Mihaela , Folgueira Marta , Van Hoolst Tim
Published: March 2024

We study coupling mechanisms at the core-mantle boundary (CMB) of the Earth in the frame of nutations and Length-of-Day (LOD) variations. The CMB is usually considered to have a smooth spherical or elliptical shape inducing a Poincaré flow in the nutation case and a global rotation in the LOD case. However, in reality, the CMB is bumpy and there are mountains and valleys representing local height differences of the order of a kilometer. The existence of a topography induces inertial waves that need to be considered in the flow of the core. This is in addition to the Poincaré fluid motion when the nutations are computed and in addition to a relative rotation of the fluid opposite and of the same amplitude as that of the mantle for LOD variations. The additional pressure and the topographic torque depend on the shape of the CMB and can be related to the spherical harmonic coefficients of the CMB topography. We follow the philosophy of the computation of Wu and Wahr [Geophys. J. Int., 128(1), 18-42, 1997] and determine the coefficients of the velocity field in the core at the CMB in terms of the topography coefficients. We used an analytical approach instead of a numerical one. We confirm that some topography coefficients may enhance length-of-day variations and nutations at selected frequencies, and show that these increased rotation variations and nutations are due to resonance effects with inertial waves in the incremental core flow. While they could be at a detectable level for LOD, they are very small for nutations (except for the flattening of the core), enhancing the importance of the electromagnetic coupling at the CMB.
Predicting future land cover degradation through the integrated use of the Cellular-Automata-Markov chain model and the Trends.Earth model: An application in the Upper Zambezi River Basin in southern Africa
Authors: Zimba Henry , Kawawa Banda , Mbewe Stephen , Imasiku Nyambe
Published: March 2024

Attaining a “land degradation neutral world” by 2030, as envisaged by the United Nations (UN) 2030 agenda for sustainable development, sustainable development goal (SDG) number 15, requires accurate information for the implementation of targeted interventions. The Trends.Earth historical data set to support monitoring and reporting, and to track the impact of sustainable land management is only available up to the year 2021. However, combining the predictive ability of Cellular-Automata-Markov (CA-Markov) model(s) in Idris Selva and the Trends.Earth model could provide an insight into potential future land cover degradation. Therefore, this study assesses the status of the land cover degradation in the Upper Zambezi River Basin (UZB) in southern Africa using the CA-Markov model and the Trends.Earth model. The UZB includes the headwaters of the Zambezi River and is susceptible to land cover degradation with potential negative effects on water resources. High resolution multispectral Landsat data are used in the Land Change Modeler (LCM) and the CA-Markov chain model in Idris Selva 17.0 to assess historical changes and predict future changes in land use and land cover (LULC) for the period 1993-2033. The LULC change maps produced with the LCM and CA-Markov models in Idris Selva are used to assess the land cover degradation status for the period 1993-2033 in the UZB using the Trends.Earth model in QGIS 3.34. Results show that land cover degradation maps produced, at local level, from high spatial resolution multispectral data provides more detail of land cover degradation compared to the Trends.Earth global data set. In terms of land cover degradation, the UZB is largely stable. However, of concern are areas, including wetlands and the headwaters of the Zambezi River, which shows land cover degradation as a result of loss of forest cover to expansions in human settlements and cropland. On the contrary, some areas show improvements in forest cover due to conversion of grassland and cropland into forest cover. For the period 2023 – 2033 the forest cover in the UZB is predicted to have a net reduction of 236258 hectares at a net annual rate of -0.14%. The spatial extent of land cover degradation is projected to build-up on the historical spatial extent. Predicting land cover degradation, as demonstrated in this study, makes available information for instituting targeted interventions which may help in the monitoring and management of water resources, as well as contribute towards a land degradation neutral world. 
Design as a participatory foundation for impactful climate communications
Authors: Angela Morelli , Tom Gabriel Johansen
Published: March 2024

When addressing the intricacies of climate change and its profound impact on humanity and nature, we encounter extraordinary complexity. Whether the goal is to present scientific information to support decision-making processes, create seamless digital stories that capture the imagination of an audience, or produce data visualisations that help us discern, distinguish, learn and understand, Design can offer a systematic tool to tackle this complexity. Design provides the solid foundation of human-centered methodologies that equip us with the tools needed to meet our audience where they are, ensuring the participation of multiple stakeholders and the inclusion of diverse perspectives. This is key to building solutions that resonate with an audience, upholding principles of justice, equality, fairness, and transparency.
Changes in concurrent hot and dry extremes based on convection-permitting projections under the SSP5-8.5 scenario
Authors: Zhou Zixuan , Im Eun-Soon , Kwon Hyun-Han
Published: March 2024

Accelerated global warming is anticipated to intensify the frequency and severity of concurrent extremes, leading to negative impacts that surpass those of individual extreme events. Southeastern China has experienced a rise in the occurrence of concurrent hot and dry extremes in recent years, and the expected amplification of such events is likely to worsen economic losses and endanger human well-being. Due to the significant impacts of such concurrent extremes, there is a strong demand for dependable future projections at the local level. However, most studies have focused on univariate analysis of single extremes using coarse-grid global climate models (GCM), which may not fully capture the region-specific climate impacts of global warming. To address this issue, this study will utilize convection-permitting (CP) regional climate modeling and multivariate statistical analysis to evaluate the future changes in concurrent hot and dry extremes. The Weather Research and Forecasting model (WRF) will be used to downscale the bias-corrected CMIP6 GCM projections under the SSP5-8.5 scenario at the convection-permitting scales (4km) over southeastern China. The study aims to investigate the process-based added value of CP projections when assessing future changes in concurrent hot and dry extremes over densely populated regions in China. The high-resolution simulation is expected to enhance the understanding of compound climate extremes and provide quantified insights into prospective climate risks.[Acknowledgements]This research was supported by project GRF16308722, which was funded by the Research Grants Council (RGC) of Hong Kong. This research was also partly supported by Korea Environmental Industry & Technology Institute (KEITI) through Water Management Program for Drought Project, funded by Korea Ministry of Environment (MOE) (2022003610003)
ENSO Modoki impacts on the Interannual Variations of Spring Antarctic Stratospheric Ozone
Authors: Niu Yingli
Published: March 2024

Using observation and reanalysis data, we investigated the effect of the sea surface temperature anomalies associated with ENSO Modoki from September to October on interannual variations in Antarctic stratospheric ozone from October to November. It was found that the planetary wave anomalies generated by ENSO Modoki in the tropical troposphere propagate to the southern mid- and then high-latitude stratosphere. The planetary wave anomalies have a profound impact on the polar vortex, subsequently affecting the interannual variations in Antarctic stratospheric ozone. Further analysis revealed that the responses of the polar vortex and ozone to ENSO Modoki are mainly modulated by the wave-1 and wave-3 components, and the effect of wave-2 is opposite and offset by those of wave-1 and wave-3. The contribution of the residual waves (after removing waves 1, 2 and 3, and the remaining waves) are relatively small. Furthermore, we evaluated the performance of CMIP6 models in simulating the impacts of ENSO Modoki on the southern stratospheric polar vortex and ozone. We selected seven models, that include stratospheric processes and stratospheric chemical ozone. We found that all of them can capable of distinguishing between eastern Pacific ENSO and ENSO Modoki events. However, only GISS-E2-1-G and MPI-ESM-1-2-HAM can simulate the patterns of ozone, circulation and temperature in the Southern Hemisphere in a manner that closely resembles the reanalysis results. Further analysis indicated that these two models can better simulate the propagation of planetary wave activities in the troposphere forced by ENSO Modoki, whereas the other models produce significantly different results to those obtained from observations.
Water content and species in high-pressure granulite: An evaluation based on μ-XRF, THz-TDS spectroscopy, TG and DCS
Authors: Li Shan-Shan , Qiu Kun-Feng
Published: March 2024

Subduction-related dehydration and exhumation-related rehydration play an important role in water recycling on Earth. Water can be transported to the deep mantle through crustal subduction, whereas the behavior of water in the subducted crust during exhumation remains enigmatic. In subduction and exhumation processes, the oceanic crust is transformed into high-pressure mafic granulites and amphibolite through high and low temperature and pressure metamorphism, respectively. During the metamorphism, water can be transported into the deep mantle via subduction-related dehydration and returned to the surface through exhumation-related rehydration processes. As a result, the anhydrous and hydrous minerals are formed within the high-pressure mafic granulites and amphibolites.In this contribution, we use an integrated micro X-ray fluorescence spectrometry (μ-XRF), transmission terahertz time-domain (THz-TDS), thermogravimetry (TG) and differential scanning calorimetry (DSC) approach on high-pressure mafic granulite and amphibolite to investigate the water species and contents, as well as exhumation rehydration reactions. Our study demonstrates that the high-pressure mafic granulite recorded peak/post peak metamorphism with the formation of Grt + Hbl + Pl + Qtz + Ilm + Ru. Amphibolite experienced retrograde metamorphism with an assemblage of Grt + Hbl + Pl + Qtz. Garnet, hornblende, and ilmenite contain considerable amounts of water as molecular and structural species. Plagioclase contains minor amounts of molecular and structural water. Quartz contains only a minor amount of structural water. Water released from garnet and external fluids from the grain boundary will either migrate into hornblende, plagioclase, ilmenite and quartz, or stored in the mantle wedge, or further subducted into the deep mantle. We suggest that water recycling between the Earth surface and deep mantle is an unequilibrium process, and the lower crust and mantle may store a significant amount of water in deep Earth and can function as a container to feed and maintain the water recycling balance.
Bølling-Allerød warming as a part of orbitally induced climate oscillation 
Authors: Sun Yuchen , Zhang Xu , Knorr Gregor , Werner Martin , Tarasov Lev , Lohmann Gerrit
Published: March 2024

Deglacial abrupt warming event is a ubiquitous feature of deglaciations during the Late Pleistocene. Nevertheless, during the last deglaciation an unusually early onset of abrupt Northern Hemisphere warming event, known as Bølling/Allerød (B/A) warming, complicates our understanding of their underlying dynamics, especially due to the large uncertainty in histories of ice sheet retreat and meltwater distributions. Here applying the latest reconstruction of ice sheet and meltwater flux, we conduct a set of transient climate experiments to investigate the triggering mechanism of the B/A warming. We find that the realistic spatial distribution of meltwater flux can stimulate the warming even under a persistent meltwater background. Our sensitivity experiments further show that its occurrence is associated with an orbitally induced climate self-oscillation under the very deglacial climate background related to atmospheric CO2 level and ice sheet configurations. Furthermore, the continuous atmospheric CO2 rising and ice sheet retreating appear to mute the oscillation by freshening the North Atlantic via modulating moisture transport by the Westerly. 
 Viscosity of Venus' mantle as inferred from its rotational state
Authors: Musseau Yann , Dumoulin Caroline , Tobie Gabriel , Gillmann Cédric , Revol Alexandre , Bolmont Emeline
Published: March 2024

Venus' rotation is the slowest of all planetary objects in the solar system and the only one in the retrograde direction. It is commonly admitted that such a rotation state is the result of the balance between the torques created by the gravitational and atmospheric thermal tides1. The internal viscous friction associated with gravitational tides drive the planet into synchronization (deceleration) while the bulge due to atmospheric thermal tides tend to accelerate the planet out of this synchronization1,6. Other torque components (related to the two first one) also affect the rotation2. This work first provide an estimate of the viscosity of Venus' mantle explaining the current balance with thermal atmospheric forcing. Second, this study quantify the impact of the internal structure and its past evolution on the gravitational tides and thus on the rotation history of Venus. Using atmospheric pressure simulations from the Venus climate database4,5,7, we first estimated the atmospheric thermal torque and showed that topography and interior response to atmospheric loading, usually ignored in previous studies, have a strong influence on the amplitude of thermal atmospheric torque. Computing the viscoelastic response of the interior to gravitational tides and atmospheric loading3, we showed that the current viscosity of Venus' mantle must range between 2.3x1020 Pa.s and 2.4x1021 Pa.s to explain the current rotation rate as an equilibrium between torques. We then evaluated the possible past evolution of the viscosity profile of the mantle considering different simple thermal evolution scenarios.  We showed that in absence of additional dissipation processes, viscous friction in the mantle cannot slowdown the rotation to its current state for an initial period shorter than 2-3 days, even for an initially very hot mantle. Beyond Venus, these results has implications for Earth-size exoplanets indicating that their current rotation state could provide key insights on their atmosphere-interior coupling.1Correia, A. C. M. and J. Laskar (2001), Nature.2Correia, A. C. M. (2003), Journal of Geophysical Research.3Dumoulin, C., G. Tobie, O. Verhoeven, P. Rosenblatt and N. Rambaux (2017), Journal of Geophysical Research.4Lebonnois, S., F. Hourdin, V. Eymet, A. Crespin, R. Fournier and F. Forget (2010),  Journal of Geophysical Research.5Lebonnois, S., N. Sugimoto and G. Gilli (2016), Icarus.6Leconte, J., H. Wu, K. Menou and N. Murray (2015), Science.7Martinez, A., S. Lebonnois, E. Millour, T. Pierron, E. Moisan, G. Gilli and F. Lefèvre (2023), Icarus.
Decadal predictability of seasonal temperature distriubutions
Authors: Düsterhus André , Brune Sebastian
Published: March 2024

Climate predictions focus regularly on the predictability of single values, like means or extremes. While these information offer important insight into the quality of a prediction system, some stakeholders might be interested in the predictability of the full underlying distribution. These allow beside evaluating the amplitude of an extreme also to estimate their frequency. Especially on decadal time scales, where we verify multiple lead years at a time, the prediction quality of full distributions may offer in some applications important additional value.In this study we investigate the predictability of the seasonal daily 2m-temperature on time scales of up to ten lead years within the MPI-ESM decadal prediction system. We compare yearly initialised hindcast simulations from 1960 onwards against estimates for climatology and uninitialised historical simulations. To verify the predictions we demonstrate a novel approach based on the non-parametric comparison of distributions with the integrated quadratic distance (IQD).We show that the initialised prediction system has advantages in particular in the North Atlantic area and allow so to make reliable predictions for the whole temperature distribution for two to ten years ahead. It also demonstrates that the capability of initialised climate predictions to predict the temperature distribution depends on the season. Finally, we will also discuss potential opportunities and pitfalls of such approaches.
Influence of groundwater in compound flooding in UK estuaries. 
Authors: Bhattacharya Ankita , Barkwith Andrew , Robins Peter
Published: March 2024

Low-lying estuaries, deltas, and bays are especially prone to flooding from multiple sources of high river discharge, coastal flooding from waves and storm surges, and pluvial flooding from intense rainfall – with groundwater levels a lesser researched flood driver. When these drivers occur simultaneously or sequentially, they create a greater impact, and are referred to as Compound Flooding. Recent compound events such as Hurricane Katrina (New Orleans in 2005), Cyclone Nargis (Myanmar in 2008) or Storm Xynthia (French Atlantic coast in 2010) have been shown to result in significant loss of lives and properties in coastal lowlands. Globally, 2.15 billion people reside in near-coastal areas, with 898 million in low-elevation coastal zones.The UK has a long history of estuarine flooding from compound events. UK climate projections indicate that there will be hotter and drier summers and prolonged wet winter periods, with an increase in the frequency and intensity of extreme storm surge and rainfall events that are also more likely to co-occur. Climate projections also indicate sea level rise at most locations around the UK which will make the coastal areas increasingly vulnerable. Groundwater is an important and dynamic component of the coastal environment. Coastal aquifers are vital fresh groundwater resources that are frequently subjected to coastal flooding due to increased runoff, storm surge and sea-level rise. Despite its lesser volumetric contribution in comparison with fluvial inputs, recent studies have found the presence and movement of groundwater may be both volumetrically and chemically important in river dominated coastal environments and requires future attention in view of climate change. Through our study we aim to investigate the different drivers influencing compound flooding in UK estuaries.Our focus is on the Conwy estuary in North Wales, which is a flashy catchment that floods several times per season. A serious recent compound flood event was due to Storm Ciara (February 2020) where river gauges hit record levels and combined with intense rainfall and high storm tide, impacting 172 properties. River Conwy drains a catchment of nearly 600 km2 and includes large mountains with high annual precipitation of around 1700mm per year and a baseflow contribution of 27%. Baseflow, which is the contribution of groundwater to surface water components, is notably influenced by topography, geology, vegetation, land use, and climatic factors. In this study we will develop a coupled catchment and groundwater model in Caesar Lisflood to understand how groundwater processes in the form of the baseflow can influence compound flood events in the estuary. Model simulations are calibrated against past fluvial and tidal flows to show how the river discharge, groundwater and associated drivers are likely to influence the magnitude, behaviour, and timings of compound flooding in the future.
Investigating the influence of geological heterogeneity in the advancement of the saltwater wedge: A novel perspective study employing Experimental, DC Sounding and Numerical modeling approach
Authors: Tiwari Prarabdh , Sharma Shashi Prakash
Published: March 2024

The global issue of saltwater intrusion (SWI) is impacting coastal aquifers more prominently due to climate changes and the escalating demand of freshwater for various anthropogenic activities. Consequently, there has been a heightened focus on research in this area to improve predictions regarding the effect of geological media on the advancement of salt water into fresh aquifers. The current study simulated saltwater flow into a freshwater zone for a coastal environment, considering density-dependent effects. Two specific scenarios were considered: one involving homogeneous media and the other involving heterogeneous media. In prior studies, researchers commonly employed homogeneous media exclusively for simulating SWI experiments. However, for the present work, we also incorporated heterogeneous media with a geophysical Direct Current (DC) sounding approach to determine the interface between fresh and saltwater. The experimental responses were numerically modelled to know the behaviour of geological constraints during the flow of saline water. For validation, a field example of the DC resistivity survey was incorporated for a better correlation. The experimental findings suggest that the interface between freshwater and saltwater was influenced when the advancing saltwater wedge encountered the clay layer. For a coastal environment, a clay layer (which is porous but not permeable) is crucial in influencing saltwater intrusion dynamics. The agreement between experimental data, numerical simulations, and DC-sounding outcomes indicates that the proposed integrated approach can be a valuable benchmark for future studies on seawater intrusion, even in environments with more complex geological conditions. Keywords: Aquifers, Saltwater Intrusion (SWI), DC Sounding, Numerical modeling.
Geomorphological and hydrogeological features of submerged coastal sinkholes in the Apulian karst
Authors: Onorato Michele , Onorato Raffaele , Liso Isabella Serena , Orsini Sergio , Palmisano Pino , Parise Mario , Zini Luca
Published: March 2024

Low coastal karst is often characterized by widespread presence of sinkholes flooded by mixing of fresh and salt water. Such a mixture creates peculiar environments and ecosystems, at the same time predisposing the areas to possible hazards, in the form of formation of new sinkholes, or enlargement and coalescence of the existing ones through failures at their rims. This is definitely the situation for the south-western coast of Salento (Apulia, southern Italy), where the local karst setting is dominated at the surface by presence of flooded sinkholes, and by bays and inlets of circular shape along the coast. These latter are typically the result of coalescing processes of original individual sinkholes, which outer rim is eventually broken by the action of sea waves. Such a situation characterizes actually many other sites in the region, not only limited to the Ionian side but also involving the Adriatic coastine of Apulia, to the east (Liso & Parise, 2023).In the coastal stretch extending from Torre Castiglione to Palude del Capitano, we have started a variety of activities, with further more on the way: among these, mapping of the sinkholes and interpretation of their mechanisms of formation, both along the coast and inland; identification of the main structural lineations, and of the likely control they exert on sinkhole development and evolution; monitoring of the physico-chemical parameters of the waters, with particular focus on those where upwelling of sulphureous waters has been observed; evaluation of the dissolution rate of carbonate rocks within the submerged areas; assessment of the sinkhole hazard, also in relation to the widespread presence of tourist sites, highly frequented during the summer season. Comprehension of the main flowpath of groundwater, from the inland areas toward the coast, is one of the main goals of our research, which is part of a wider project addressed also to evaluate the biological aspects in these peculiar, high biodiversity, ecosystems. References Liso I.S. & Parise M., 2023, Sinkhole development at the freshwater-saltwater interface in Apulia (southern Italy). In: Land L., Kromhout C. & Suter S. (Eds.), Proceedings of the 17th Multidisciplinary Conference on Sinkholes and the Engineering and Environmental Impacts of Karst, Tampa (Florida, USA), 27-31 March 2023, NCKRI Symposium no. 9, p. 229-238.Parise M., Palmisano P. & Onorato R., 2017, Contributo alla conoscenza dei fenomeni carsici di collasso in zone costiere del Salento Jonico (Puglia): la Spunnulata della Pajara. Thalassia Salentina, n. 39, p. 99-121. 