bluuebunny/crossref_metadata_2025 huggingface dataset:
The massive weathering of the Central Atlantic Magmatic Provinces reconstructed from marine osmium isotopic ratio records
Authors: Murai Ryota , Kuroda Junichiro , Mukai Kazumasa , O. Ogawa Nanako , Suzuki Katsuhiko , Ohkouchi Naohiko , S. Hori Rie
Published: March 2024

It is widely recognized that one of the main cause of the end-Triassic Mass Extinction (~201.4 Ma) was the formation of one of the Large Igneous Provinces (LIPs), the Central Atlantic Magmatic Province (CAMP). CAMP consists of extrusive and intrusive rocks, mainly basalt, but most of the extrusive rocks is not present today. This is interpreted as a result of the rapid weathering of the extrusive rocks. However, temporal constraints of the weathering events have not been well-established yet, leaving the linkage with paleoenvironmental changes unclear. Osmium isotopic ratio (187Os/188Os) in the ocean is one of the geochemical proxies to reconstruct the past activities of LIPs. The osmium isotopic ratio reflects the relative contribution from three sources: upper continental crust (187Os/188Os=~1.3), extraterrestrial material (~0.13), and mantle (~0.13). Therefore, the rapid weathering of the CAMP extrusive rocks, which are mantle-derived, is expected to have decreased the marine osmium isotopic ratio. In this study, we aimed to clarify the relationship between the igneous activity caused by the CAMP formation and the fluctuations in the marine osmium isotopic ratio by examining the changes in osmium isotopic ratio of Panthalassa at the end-Triassic. In this study, we investigated the Miyanoura Section located in Shikoku, southwest Japan. This section is a bedded cherts sequence in the southern Chichibu Belt. The age of sediment was roughly estimated as Upper Triassic based on radiolarian biostratigraphy, although the radiolarian tests are poorly preserved. Measurements of osmium concentration, rhenium (Re) concentration, and Os isotopic ratio were performed. The initial osmium isotopic ratio (187Os/188Osi) was determined by age correction of 200 Ma for the bedded chert in the Miyanoura section. The results revealed a significant decrease in the marine Os isotopic ratio over approximately 100,000 years at the end-Triassic. The onset of this decrease coincides with a negative isotopic excursion of total organic carbon, which is correlated to the widely recognized Initial Carbon Isotope Excursion (ICIE), one of the characteristic changes in the end-Triassic, and also overlaps with the formation period of the CAMP. This suggests that the decrease in the marine Os isotopic ratio during this period was caused by the massive and rapid weathering of the CAMP extrusive rocks. In this presentation, I will introduce a quantitative evaluation using a simple box model and further discuss the paleoenvironmental changes that triggered this weathering event.
Rapid detection of elements' radial translocation and mobility in tree rings by iTrax core scanner
Authors: Wei Hsin-Lin , Shen Chuan-Chou , Löwemark Ludvig , Liao Chien-Yi , Chen Shu-Li , Hsieh Chun-Kuang
Published: March 2024

Dendrochemistry has been developed as a new environmental indicator in recent decades. Elements, such as Hg, Pb, and Cd, in tree rings were considered as new tracers for industrialization, air pollution, and soil contamination. However, the movement and diffusion of elements across the rings, called radial translocation, intensifies when the sapwood transforms into heartwood, which blurs the elemental records. Detecting the translocation of elements and their mobility in tree rings due to heartwood formation is crucial for the availability and confidence of applying dendrochemistry. We developed methods to evaluate radial translocation. 1. The iTrax core scanner was used to scan tree ring core slices of four conifers in Taiwan to evaluate the feasibility of applying the iTrax core scanner to analyze the elemental trends in tree ring cores and the scanning parameters. 2. The elemental distributions in tree ring cores of different species were measured. 3. The mobilities of elements were evaluated. Forty-second exposure was successful and reproducibly scanned K, Ca, V, Cr, Mn, Fe, Cu, Sr, and Pb contents. Results show that the levels of Ca and K in the tree ring of all four species and the levels of Mn of three species significantly differ between the heartwood and sapwood phases. For the remaining elements, including V, Cr, Fe, Cu, Sr, and Pb, there is no significant difference between phases. After treating with an extraction solution to remove soluble or mobile elements, the different levels of Ca, K, and Mn between phases were not observed, indicating the mobility of these elements. The effect of radial translocation should be considered when applying the three elements as environmental tracers.
Optimizing Groundwater Forecasting: Comparative Analysis of MLP Models Using Global and Regional Precipitation Data
Authors: Soni Akanksha , Barma Surajit Deb , Mahesha Amai
Published: March 2024

This study investigates the efficacy of Multi-Layer Perceptron (MLP) models in groundwater level modeling, specifically emphasizing the pivotal role of input data quality, particularly precipitation data. Unlike prior research that primarily focused on regional datasets like those from the India Meteorological Department (IMD), our research explores the integration of global precipitation data, specifically leveraging the Integrated Multi-satellitE Retrievals for Global Precipitation Measurement (IMERG) dataset for MLP-based modeling. The assessment was conducted using two wells in Dakshina Kannada, evaluating four MLP models (GA-MLP, EFO-MLP, PSO-MLP, AAEO-MLP) with IMERG and IMD precipitation data. Performance metrics were employed, including mean absolute error, root mean square error, normalized Nash-Sutcliffe efficiency, and Pearson's correlation index. The study also includes convergence analysis and stability assessments, revealing the significant impact of the precipitation dataset on model performance. Noteworthy findings include the superior performance of the AAEO-MLP model in training with IMD data and the GA-MLP model's outperformance in testing at the Bajpe well with both datasets. The stability of the GA-MLP model, indicated by the lowest standard deviation values in convergence analysis, underscores its reliability. Moreover, transitioning to the IMERG dataset improved model performance and reduced variability, providing valuable insights into the strengths and limitations of MLP models in groundwater-level modeling. These results advance the precision and dependability of groundwater level forecasts, thereby supporting more effective strategies for international groundwater resource management.
Current and future blue water availability for agriculture in the Mediterranean
Authors: Bianucci Sandra Paola , Sordo-Ward Álvaro , Garrote Luis
Published: March 2024

The current and future water availability for Mediterranean basins was assessed under different climate and policy scenarios. The high-resolution GIS-based WAPA model (Water Availability and Adaptation Policy Analysis) was used to obtain potential water availability under a set of realistic hypotheses. Diverse data sets were compiled on meteorological variables, water resources, runoff, land cover, and population density to create a geospatial database that covers river basins that drain into the Mediterranean Sea. The model was forced with the results of the global hydrological models H08 and CWatM for ISIMIP (Inter-Sectoral Impact Model Intercomparison Project) scenarios. These two hydrological models were forced with climate drivers for three historical scenarios (obsclim, picontrol, and historical), which define a baseline, and three future scenarios (ssp126, ssp370 and ssp585) provided by the sixth assessment report of IPCC (2023). A high-resolution map of the potential availability of water for irrigation was developed in Mediterranean basins. The allocation of water for irrigation is subordinated to the urban supply (drinking water) and for the conservation of river ecosystems. The results indicate that changes in hydrological regimes across the region are expected to have a significant impact on future water availability. The proposed approach provides a valuable tool for decision makers and stakeholders for the identification of areas vulnerable to changes in water availability. The information generated in this study, high-resolution spatial outputs and detailed water availability estimates, could work as a relevant input for integrated water resource management and climate change adaptation planning. This research offers a robust framework for assessing water resources under changing climate, applicable to other regions facing similar challenges. In summary, our study provides useful information to policymakers and stakeholders, helping them to make informed decisions to develop adaptive measures for sustainable water management under uncertain future climate conditions.
Refining exposure-age estimates of 40- to 800-ka surfaces with 10Be, 21Ne, and additional geologic constraints
Authors: Schildgen Taylor , Orr Elizabeth , Niedermann Samuel
Published: March 2024

Dating alluvial-fan or river-terrace surfaces that are more than several tens of kyr old is challenging in many environments. Depth profiles of samples can be difficult to extract in the field, time consuming to process in the lab, and expensive to analyze. Even under idealized sampling conditions, the difficulty of constraining possible surface erosion or inflation can lead to large uncertainties in the surface exposure age. Alternatively, sampling individual boulder surfaces or cobbles may be logistically simpler, but large scatter in ages can be difficult to explain, given the possibility that the boulders/cobbles have rotated from their original position, surfaces experienced erosion, or the clasts may have some inherited concentration of cosmogenic nuclides. All of these problems are exacerbated in surfaces that have been exposed for hundreds of kyr.In the Toro Basin of NW Argentina, a set of alluvial-fan surfaces has recently been interpreted to comprise two generations, one likely spanning from ca. 500 to 800 ka, and another less than 100 ka, based on 10Be exposure ages of individual boulder surfaces and one depth profile. Here, we report 21Ne data from a subset of the boulder surfaces with the aim of better constraining the ages.Despite the apparently simple geomorphic setting of the fans, dual-nuclide (“banana”) plots of 21Ne and 10Be data reveal that most of the boulders have a complex burial history, with inferred burial times up to ca. 750 kyr. This finding implies that the boulders were not simply transported from nearby bedrock hillslopes and exposed on the fan surfaces. Instead, the boulders must represent exhumed rocks from an earlier generation of basin filling, which is constrained to between 4.5 and 0.85 Ma in the vicinity of the fans from U-Pb zircon dating of intercalated ashes (Pingel et al., 2020). We use a Monte Carlo approach to explore what possible range of initial exposure times, burial times, and final exposure times are consistent with the 10Be and 21Ne data on any given surface. For several surfaces, parameters trade off such that a wide range of exposure ages is possible. However, if we also take into account the stratigraphic relationships among the surfaces (higher surfaces must be older), and we consider that boulders exposed in the highest surface must have burial times that are shorter than boulders exhumed from lower elevations, relatively tight constraints on exposure ages, inherited nuclide concentrations, and boulder-surface erosion rates are possible on some of the surfaces.
Observing auroras with dynamic vision sensors
Authors: Stokholm Andreas , Gulbrandsen Njål , Pedersen Nicolas , Kucik Andrzej , Olesen Daniel , Willer Anna Naemi , Hivdegaard Sine Munk , Chanrion Olivier
Published: March 2024

Auroras are a faint space weather light phenomenon caused by the interaction between the solar wind and the Earth’s magnetic field. This interaction can lead to processes that increase the energy of charged particles in the magnetosphere, enabling the particles to enter the ionosphere and cause diffuse or discrete auroras. Often, the images of auroras are captured using exposure times of 1-2 seconds to collect sufficient light. However, prolonged exposure times also intensify other light sources, such as urban- or moonlight, thus, dark night conditions are preferred. Long exposure times are also incapable of capturing fast dynamics, though some studies have carried out high-speed imaging with up to 160 frames per second (160Hz). Instead of traditional cameras, we propose to utilise the emerging optical technology, Dynamic Vision Sensors (DVS), that possess high dynamic ranges (110 - 120 dB) and sampling rates. DVS is a biologically-inspired silicon retina that detects negative or positive brightness change on a logarithmic scale similar to human eyes. In addition, pixels can independently adjust to lighting scenarios with an adaptable brightness threshold and without a static upper limit or constant frame rate. If no change occurs, no information is registered, providing a variable data rate and low power consumption.Here, we present the first DVS observations of auroras in 5kHz, captured in March 2023 in Tromsø, Norway. We extract and interpret information based on reconstructed brightness and event frames. Further, we derive the incoming photon flux by mimicking a photometer. In all, we show that DVS is capable of observing auroras in challenging urban- and moonlight conditions while preserving the high temporal resolution that could enable a paradigm shift for aurora monitoring.
Modelling ISR plasma line frequency using ALPS dispersion relation solver 
Authors: Gupta Mini , Guio Patrick
Published: March 2024

In the Incoherent Scatter Radar (ISR) spectrum, we observe a large amount of scattered power at frequencies corresponding to plasma electrostatic modes with wavenumber imposed by the radar. The commonly occurring resonant frequencies are ion and plasma lines. Ion lines are signatures of ion-acoustic waves travelling towards and away from the radar and are observable all the time. Plasma lines are signatures of high-frequency electrostatic waves and are observable when enhanced above the thermal level by a suprathermal electron population. In this work, we assume a Maxwellian thermal population together with a suprathermal population derived from the electron transport code Aeroplanets that calculates the angular electron flux. We provide the numerical electron velocity distribution function as an input to the Arbitrary Linear Plasma Solver (ALPS) to numerically solve the linear Vlasov-Maxwell dispersion relation and estimate the resonance frequency at angles to the magnetic field. The linear resonance frequency calculated from ALPS is then compared to the resonance frequency estimated from ISR plasma line measurements.  
How climate and soil properties limit mineral-associated organic carbon (MAOC) accrual under afforestation. Findings from a climate gradient study in warm drylands.
Authors: Yalin David , Mlelwa William , Rotenberg Eyal , Yakir Dan , Grünzweig José M.
Published: March 2024

How climate and soil properties limit mineral-associated organic carbon (MAOC) accrual under afforestation. Findings from a climate gradient study in warm drylands.David Yalin, William Mlelwa, Eyal Rotenberg, Dan Yakir and José M. GrünzweigThe efficiency of afforestation in climate mitigation has been a matter of debate in recent years. Specifically, there have been doubts about whether afforestation in drylands can be climate-positive. If afforestation can contribute to accumulation of soil organic carbon (SOC) and to the buildup of the mineral-associated organic C (MAOC) pools this may be a significant contribution to long-term C capturing in dry environments. However, there are still gaps in our understanding of how the interactions between vegetation type and climate affect MAOC storage. Furthermore, studies of MAOC dynamics have often disregarded the finite capacity of soils to store MAOC. In this work, we aimed at bridging these gaps by examining SOC and its partitioning between different soil size fractions in sites planted with Aleppo pine over 50 years ago (PF) as compared to neighboring fallow sites which were not actively forested (NF). This was performed at 16 sites along a climate gradient in Israel (ranging from 250-800 mm in annual precipitation) and differing in soil properties. MAOC in the 0-10 cm and 10-20 cm showed a general trend of increase with precipitation (more statistically significant in PF sites). Calcareous sites (>10% CaCO3 equivalent) showed lower MAOC concentrations, which may arise from smaller fine-grain soil fraction but also from reduced input from vegetation due to poor nutrient availability. MAOC composed between 37-83% of total SOC with a weak decreasing trend with increasing SOC (regardless of afforestation). The decrease in MAOC/SOC points to possible MAOC saturation at~40 g C kg-1 soil, a value previously suggested for saturation in European soils. To investigate whether saturation could be limiting MAOC accrual, we examined the saturation limit using topsoil samples (collected at the 0-2 cm depth) selected for high total SOC. In the topsoil fine fraction SOC reached 95 g C kg-1 soil-fine-fraction, slightly above global reports for soils with high activity clays. Based on these topsoil measurements, MAOC even in the high SOC soils (at 0-10 cm depth), reached less than 70% of its capacity, suggesting that saturation was not a limiting factor. However, density fractionation of the topsoil samples raised questions about whether they truly represent soil capacity to associate organic carbon. In the presentation we will discuss the concept of MAOC capacity in light of these findings and its implications for afforestation in dry climates. 
How Did Sediments Disperse and Accumulate in the Oceanic Basin, South China Sea 
Authors: Wang Fei , Ding Weiwei
Published: March 2024

As one of the largest marginal sea basins in the Western Pacific, the South China Sea (SCS) is an important part on the “source-to-sink” process in East Asia. The SCS oceanic basin was not only the crucial pathway for transporting terrigenous materials from Eurasia to the Western Pacific Ocean since the Oligocene, but also the dominant accumulation place because of limited material exchange between the semi-closed oceanic basin and the open ocean since the Middle Miocene. This semi-closed basin can help establishing a systematic connection between the infilling process and tectonic events, climate change, sea level changes, etc. Based on 32 multichannel seismic profiles covering the whole oceanic basin and the drilling results from the IODP Expeditions, we got the sedimentary budget on a million-year geological scale. Sediment isopach maps in different geological times were reconstructed to understand the regional and local controlling factors dominating the Cenozoic sedimentary infilling process, as well as the possible provenances.
Results showed that the sedimentary budgets of the SCS oceanic basin and the East Subbasin (ESB) increased gradually with time, especially since the Pleistocene, the whole sedimentary budget increased significantly (increnment 39.32×103 km3/my). Regional factors superimposed on local factors jointly controlled the sedimentation process. In the Middle Miocene, the uplift and denudation of the Tibetan Plateau and the intensification of the summer monsoon led to the increased terrigenous sediments entering the SCS through the widely developed canyon systems. Submarine channel/canyon systems developed in the continental margin acted as the major conduits for terrestrial sediments discharging into the oceanic basin. During this period, the sedimentary budgets in most of the marginal basins and oceanic basin increased significantly. The three sedimentary centers on the northern flank were located at the mouth of the canyon systems.
Sediment isopach maps indicate that the sediment accumulation was dominantly in the northern flank of the SCS oceanic basin before the Late Miocene, with the depocenters generally distributed at the mouth of the channel/canyon systems and slope foot area near basement highs; the main depocenters gradually migrated to the southern flank of the basin since the Pliocene. This is likely due to an increase sediment from the Mekong River and the high sea level. An exception is the development of a new depocenter in the northeast related with the Taiwan orogeny. The primary sediment provenances include the South China, Tibet Plateau, Indo-China Peninsula, and Taiwan Island, with minor contributions from the Hainan Island, Palawan, Luzon Islands, as well as local basement highs developed on the continental margin.
Investigating Large-Scale Variation in Plant Water Uptake Across European Climates and Vegetation Types – a WATSON Cost Action Initiative
Authors: Meusburger Katrin , Geris Josie , Penna Daniele , Rothfuss Youri , van Meerveld Ilja , Lehmann Marco
Published: March 2024

The COST Action WATer isotopeS in the critical zONe (WATSON; https://watson-cost.eu/) aims to elucidate the interactions between groundwater recharge, soil water storage, and vegetation transpiration across various climatic settings. Within this framework, root water uptake by trees is crucial for understanding water partitioning and forest resilience to drought. While isotopic approaches have successfully revealed root water uptake strategies for different species, a comprehensive assessment across different climates and vegetation types is still missing (Beyer and Penna, 2021).To address this research gap, we executed a synchronized, participatory sampling campaign by WATSON Action members in late spring and summer of 2023. Soil and vegetation samples were taken across 39 well-distributed forest sites encompassing 17 European countries. The samples were analyzed for the stable isotopes of oxygen and hydrogen at the WSL laboratory in Switzerland. The data enable us to investigate the spatial and temporal (spring vs summer) variability of root water uptake of the shallower-rooted spruce (Picea abies) and deeper-rooted beech (Fagus sylvatica) trees. We expect beech to exhibit a more pronounced shift to deeper water sources during summer than spruce due to its deeper rooting system. We also expect that the dominant root water uptake depth is influenced by site-specific factors (climate, elevation, latitude, soil type, level of understory cover) and tree characteristics (tree height, stem diameter). This presentation will describe the sampling campaign and the preliminary results on root water uptake for both species across Europe.
Solar Wind Periodic Density Structures: Size Scales and Geo-effectiveness
Authors: Di Matteo Simone , Katsavrias Christos , Kepko Larry , Viall Nicholeen
Published: March 2024

Mesoscale transient structures affecting the solar wind-magnetosphere coupling can be either generated in the near-Earth environment or already present in the pristine solar wind. Among the solar wind mesoscale structures, in recent years, there has been a growing attention to Periodic Density Structures (PDSs), that are quasi-periodic enhancements of solar wind density ranging from a few minutes to a few hours. These structures have been extensively observed in remote sensing observations of the solar corona, and in in situ observations up to 1 AU where they manifest radial length scales (Lx) greater than or equal to the size of the Earth’s dayside magnetosphere, i.e., from tens to hundreds Earth’s radii (RE). The PDSs have significant impact on the dynamics of the Earth’s magnetosphere and space weather for example driving Ultra-Low-Frequency (ULF) waves and affecting the dynamics and precipitation of electrons in the outer radiation belt. One key aspect to understand the PDSs role in the dynamics of space weather is to characterize their 3D size scales. Current interplanetary multi-spacecraft observations mostly occur at spatial separations unable to measure the 3D size scale of PDSs. Here, we focused on high density slow solar wind intervals observed by the Wind and ARTEMIS-P1 spacecraft.  We classified solar wind parcels based on the occurrence or not of quasi periodic density enhancements. When both spacecraft observe PDSs, we further classify each interval based on the level of coherence of the relative periodicities. Combining our results with a simulation of PDSs transit, we provide, for the first time, an estimate of the PDSs azimuthal size scale, that is their extent in the direction perpendicular to the Sun-Earth direction. For two PDSs groups with radial length scales of Lx1≈86 RE and Lx2≈35 RE, we obtained azimuthal scales of Ly1≈340 RE and Ly2≈187 RE. After discussing the consequence of these findings in the context of solar wind-magnetosphere coupling, we remark that the magnetosphere response to PDS become even more relevant when these structures are compressed in Stream Interaction Regions (SIRs) creating larger fluctuations in solar wind density/dynamic-pressure. Finally, we select time intervals of PDSs in SIRs and, using GOES and RBSP constellations, we investigate the PDSs geo-effectiveness in term of ULF waves and outer belt/GEO electron response.
Challenges and Solutions: Selecting Suitable Species for Vegetation Restoration in Arid Mining Areas
Authors: chengzhi li
Published: March 2024

Mining resources are essential natural resources for economic development. Arid regions possess abundant mineral resources, and the development of these resources is crucial for local economic growth. However, the fragile ecological environment in arid areas often suffers damage during the mining process, leading to severe ecological problems and impacting regional sustainability. Ecological restoration of mining areas is a pressing issue in arid regions. Restoring surface vegetation is key to repairing the damaged ecological environment in mining areas. In arid mining regions with sparse precipitation, poor soil quality, and scant vegetation, the selection of suitable species for vegetation restoration is a critical challenge. In the case of the Shuixigou Coal Mine Fire Restoration Area in Jimsar County, Xinjiang, China, we conducted experiments involving the planting of 10 types of seeds (including Caragana korshinskii, Calligonum mongolicum, Hedysarum laeve, Corethrodendron scoparium, Caragana roborovskyi, Haloxylon ammodendron, Nitraria tangutorum, Kalidium foliatum, Peganum harmala, and Krascheninnikovia ceratoides). We observed the germination rate of the seeds, the height of seedlings, aboveground biomass, and conducted statistical analysis on the observational data.  The experimental results indicated that in arid restoration areas, where the climate is dry and the soil is poor, the germination rate of plant seeds is extremely low, generally below 10%. Therefore, a large quantity of indigenous species seeds is required for vegetation restoration. There are significant differences in the germination rates of plant seeds in arid regions, with germination rates ranging from highest to lowest as follows: Nitraria tangutorum (8.59%) > Krascheninnikovia ceratoides (7.25%) > Peganum harmala (5.79%) > Caragana korshinskii (5.03%) > Caragana roborovskyi (4.80%) > Haloxylon ammodendron (3.96%) > Kalidium foliatum (3.93%) > Corethrodendron scoparium (2.41%) > Calligonum mongolicum (1.08%). Significant differences also exist in the growth of plant seedlings in arid regions. In the first year, Haloxylon ammodendron exhibited the fastest growth, with individual biomass reaching 65.76 g. This was followed by Kalidium foliatum, with individual biomass reaching 53.86g, and then Peganum harmala, with individual biomass reaching 3.76 g. Caragana roborovskyi exhibited the slowest growth, with only 0.41g. Considering both the germination rate and first-year biomass, Haloxylon ammodendron and Kalidium foliatum are suitable pioneer species for rapid restoration in the Shuixigou Coal Mine Fire Restoration Area in Jimsar County, Xinjiang, China, while the remaining species are suitable as accompanying species.
Losing water through evaporation from water reservoirs in water-stressed regions: The case of Iran-Afghanistan
Authors: Shokri Nima , Nevermann Hannes , Madani Kaveh
Published: March 2024

The rising demand for water in the transboundary Helmand basin is causing heightened tensions between Afghanistan and Iran concerning the Helmand River with serious environmental, socio-economics and political implications. This intensifies the long-existing transboundary water conflicts between the two countries. To overcome water shortages during dry spells, water reservoirs and storage infrastructure have been constructed in a region experiencing extremely hot and dry climate conditions. Water evaporation from these reservoirs diminishes their storage efficiency. This makes quantification and prediction of water evaporation from these reservoirs a crucial step for water management, accountability and transboundary cooperation in the river basin. In this study, we used satellite remote sensing information of the large water reservoirs in the Helmand basin combined with physically-based modelling approaches (Aminzadeh et al., 2024) to obtain reliable estimates of evaporative losses from the main storage infrastructures. Our results suggest that a considerable amount of water loss in the region stems from the evaporation of water in major water storage infrastructure within the basin, particularly from the man-made reservoirs located on the Iranian side of the basin in a very water-deprived region. Our results indicate 491 million cubic meters of water was evaporated from the reservoirs in 2020 accounting for 11% of their total storage capacity and 8.2% of the water demands in the basin. Our findings improve water accounting and management in the Helmand basin. Additionally, they underscore the key role of effective water storage infrastructures in managing limited freshwater resources which could improve water security. Aminzadeh, M., Friedrich, N., Narayanaswamy, S.G., Madani, M. Shokri, N. (2024). Evaporation loss from small agricultural reservoirs: An overlooked component of water accounting, Earth’s Future (Accepted).
Modeling pressure-dependent seismic anisotropy in the lower mantle reveals anisotropic discontinuity at 1000 km
Authors: Magali John Keith , Thomas Christine , Gay Jeffrey , Pisconti Angelo , Merkel Sebastien
Published: March 2024

There is growing evidence, both from a modelling perspective and seismic observations, that seismic anisotropy in the lower mantle is localized around penetrating slabs where large straining is anticipated. It is believed that the high stresses experienced near the slab activate dislocation creep mechanisms that drive the crystallographic preferred orientation (CPO) of bridgmanite aggregates. Still, deformation mechanisms in bridgmanite remain enigmatic. In recent years, deformation experiments in bridgmanite subjected to mantle temperatures and pressures suggest that its microstructures evolve with pressure, providing another perspective on the debated structure and deformation in the lower mantle. Using this information, we develop a numerical technique that calculates pressure-dependent large-scale seismic anisotropy in a pyrolitic mantle with variable velocity gradients. As a first test, we use the method to predict seismic anisotropy by calculating anisotropic reflection coefficients of underside reflections off a depth corresponding to 50 GPa where pressure-induced slip transitions in bridgmanite are expected. For this, we consider two simple deformation styles: (1) uni-axial compression, akin to vertically penetrating slabs, and (2) simple shear associated with corner-type flows. Finally, we demonstrate a multiscale approach that calculates large-scale seismic anisotropy from a fully time-dependent thermo-chemical model of free subduction with latent heating and phase transitions. The result is a long-wavelength equivalent azimuthal and radial anisotropy maps that are actually comparable to a seismic tomography model. We demonstrate how such an approach can create discontinuities in anisotropy at ~1000 km and provide insights as to how it relates to the heterogeneous distribution of the 1000-km discontinuity.
Compound events drowned in climate noise? The benefits of employing a regional SMILE in compound hot and dry summer assessment 
Authors: Böhnisch Andrea , Felsche Elizaveta , Mittermeier Magdalena , Poschlod Benjamin , Ludwig Ralf
Published: March 2024

Compound hot and dry extremes like the recent summers of 2015, 2018, and 2022 have an impact on a wide range of sectors in Europe, including health, transport, energy production, ecology, agriculture, and forestry. Current research suggests that climate change will increase the intensity, frequency, and duration of joint hot and dry extreme summers in Europe.However, how robust and skilful are assessments of these compound events?Here, we understand compound hot and dry extreme summers as the joint exceedance of temperature and (negative) precipitation thresholds (thresholds: 2001-2020 summer 95th percentiles). Since this definition results in particularly rare events, a robust climatology of these extreme events can hardly be obtained from observational time series alone. To investigate these events and their variability, larger sample sizes are required. Some studies so far focus on temporally limited observational records and regional multi-model ensembles that both do not allow for robust climate variability assessment. Others address internal climate variability by using single-model initial condition large ensembles (SMILEs), but based on global models and thus truncating spatial heterogeneity. In an attempt to meet these limitations, we exploit a 50-member SMILE of the Canadian Regional Climate Model, version 5, at 12 km resolution (CRCM5-LE, RCP 8.5 from 2006 onwards, driven by the Canadian Earth System Model Version 2 large ensemble, CanESM2-LE) in this study. Owing to its large size and high spatial resolution, the CRCM5-LE is a yet unique source for analyzing compound events on a regional scale.We consider detrended ERA5-Land data during 1955-2023 for evaluation purposes. In general, comparing single observational time series to SMILEs remains challenging due to internal climate variability. By using, among others, a bootstrapping approach, we find a very good agreement of the local compound event frequency distribution in the CRCM5-LE and ERA5-Land. Also, regional hotspots of event frequencies agree in the SMILE and reanalysis data. Going one step further, we also statistically disentangle climate change signals and internal variability in event frequencies at two global warming levels (+2 °C, + 3°C) by means of, e.g., signal-to-noise ratios.  In general, the regional model (re)produces fine-scale spatial patterns of hot and dry compound events (e.g., mountains, land-sea contrast). These are found in event frequencies and change signals at impact-relevant scales. Furthermore, the application of a SMILE provides an extensive database of events. The latter is crucial for assessing trends and climatologies of highly variable events like compound hot and dry extremes. In combining a regional climate model and the SMILE approach, we thus show the benefits of a regional SMILE for addressing the uncertainty in compound event assessment.
A Study of Rainfall-Runoff Process considering two uncertainties in Basin with multiple dams
Authors: Furuoka Ojiro , Yamada Tomohito
Published: March 2024

Forecasting of natural phenomena is generally based on observation data, but it is impossible to measure everything perfectly, and there are uncertainties in the limits of observation and human perception. In runoff forecasting, there is also uncertainty in the rainfall information that uses as input data, and it is important for flood control to estimate the effect of this uncertainty on the output data, the runoff data.Currently, rainfall in Japan is monitored by ground rain gauges and meteorological radar. Ground rain gauges measure rainfall on the ground, but they are installed at intervals of 10 to 20 km, and not all locations are measured seamlessly. Ground-based rain gauges have spatial uncertainties because they may miss cumulonimbus clouds with a horizontal scale of about 10 km that bring heavy rainfall, and because rainfall in mountainous areas is considered to be highly spatially variable due to the topography. On the other hand, radar observations use radio waves to measure the shape of raindrops in the sky and estimate rainfall on a 250 m mesh or 1 km mesh. There are limitations in accuracy, such as indirect rainfall estimation and rainfall attenuation behind strong rainfall areas. There are discrepancies in comparison with ground rain gauges at the same location, and radar must also accept uncertainties due to observation limitations. Uncertainty in rainfall data is not limited to observational uncertainty.Uncertainty also exists in the process of rainfall retention by soil until it flows into the river. In particular, while the degree of soil wetness prior to a rainfall event is considered to have a significant impact on the process of water retention, it is impossible to observe the wetness of the entire watershed, and there is inherent uncertainty as to how much rainfall will contribute to direct runoff. Against this background, it is necessary to convert the conventional deterministic model, which uniquely provides rainfall data and uniquely determines the runoff height, to a stochastic model that accounts for uncertainty.For studies that consider uncertainty, a rainfall-runoff model that takes into account uncertainties due to observation limitations was proposed by Yamada et al. and a rainfall-runoff model that takes into account uncertainties due to observation limitations and initial soil moisture uncertainty was proposed by Intan and Yamada.In this study, the theoretical development is described and a rainfall-runoff model with two uncertainties is applied to Kinugawa river basin to quantify the inflow.
Development of the Atmosphere-Ocean-Wave Coupled Model in the Korean Integrated Model (KIM)
Authors: Han Yong-Jae , Lee Eunjeong , Koo Myung-Seo
Published: March 2024

The Korea Institute of Atmospheric Prediction Systems (KIAPS) has been developing an integrated model with predictive performance in an extended range (14 to 30 days) since 2020. To enhanced the performance of coupled model, it is necessary to examine the interaction and feedback among the components of the Earth system. This study introduces the current status and future plan of a KIAPS-developing coupled modeling system with a focus on atmosphere-ocean-wave coupling. The Korea Integrated Model (KIM), the operational atmospheric model of the Korea Meteorological Administration, was coupled with the Nucleus for European Modeling of the Ocean (NEMO) and the WAVEWATCH III (WW3) through a Model Coupling Toolkit, and the predicted variables are exchanged between the model components. The WW3 model receives the wind component from the first layer of the atmospheric model, and the surface currents and sea surface height are obtained from the ocean model. The Charnock coefficient and wave energy flux calculated by WW3 are sent to the ocean model. The Charnock coefficient impacts the air-side through a roughness length that is calculated using the bulk formula at the sea surface. Meanwhile, the wave energy flux into the ocean is applied as a surface boundary condition in the turbulent kinetic energy (TKE) model, which results in determining the ocean deepening. The presentation will focus on explaining the effects of the surface energy flux obtained from the wave model on the wave breaking in the TKE scheme of the coupled KIM in the medium-range forecasts and seasonal simulations. Furthermore, we plan to discuss strategies for improving the Coupled KIM based on preliminary results.Acknowledgements. This work was carried out through the R&D project “Development of a Next-Generation Numerical Weather Prediction Model by the Korea Institute of Atmospheric Prediction Systems (KIAPS)”, funded by the Korea Meteorological Administration (KMA2020-02212).
Exploring satellite soil moisture products for irrigation. A case study: Braila County, Romania
Authors: Chitu Zenaida , Trifan Daniela , Ghiorghe Alin , Stroia Cristian , Popescu Nicolae , Ontel Irina , Angearu Claudiu-Valeriu , Irasoc Adrian , Luftner Giorgiana
Published: March 2024

Irrigated agriculture will be impacted by climate change as average temperatures and rainfall variability increase. This trend will continue in the future, according to numerical experiments with climate models, but how it develops will be strongly influenced by the anthropogenic emission levels of greenhouse gases. However, the effects of climate change have not been, and will not be, uniform across regions or over time because human-induced warming is superimposed on natural climate variability (IPCC, 2021).Recent studies (Caian et al., 2023) focused on the projected changes in extreme agro-climatic indicators reveal that Southern Romania appears as a regional hot-spot of climate change because the projected changes are higher and more accelerated than other regions of the country. In this context farmers will need to improve crop water allocation for sustainable irrigation as a measure of climate change adaptation.Irrigation is the largest consumer in the agriculture sector and the efficient use of water is crucial in the next decades. Monitoring soil moisture will improve water allocation in space and time in irrigated agriculture. Braila County has the largest irrigated areas in Romania and efficient water allocation will mitigate the environmental issues related to water scarcity and soil degradation by salinization and erosion. According to the Koeppen-Geiger classification, the climate of this area is warm temperate humid with hot summers (Cfa) (Cheval et al., 2023). The mean annual precipitation is 450 mm, while the mean annual potential evapotranspiration exceeds 800 mm. The agro-climatic conditions require the use of irrigation in order to avoid crop losses and to ensure high crop productivity.In this study, we focus on investigating the feasibility of satellite soil moisture products (AMSR-2, ASCAT, SMOS and SMAP) to derive amount of water applied for irrigation and the applicability of this approach to climatic and irrigation conditions specific to Braila County, Romania. This study has received funding from the European Union Agency for the Space Programme under the European Union’s Horizon Europe research and innovation programme under grant agreement No. 101082189 (MAGDA project).
Changes in Hydrological Extremes for Sub-Arctic catchment in Finland
Authors: Nakigudde Christine Kaggwa , Patro Ritesh , Haghighi Ali Torabi
Published: March 2024

Climate change has been associated with increased frequency in the occurrence of extreme precipitation. These extreme events are in turn linked to peak discharges and flood events. In the Nordic region, peak discharges in unregulated rivers occur during spring snowmelt thereby posing a challenge in attributing extreme precipitation events to peak discharges. This study aims to assess the effect of extreme events on hydrological river flows by analysing the timing and intensity of extreme precipitation events (highest 1-day precipitation RX1day, highest 5-day precipitation RX5day and maximum consecutive wet days (CWD)) with river discharges using a sub-Arctic catchment. Using a calibrated Hydrologiska Byråns Vattenbalansavdelning (HBV) model, we analyse changes in discharge occurring as a result of these extremes. By analysing the relationship between extreme precipitation, and the resulting river discharges, findings from the study provide a valuable insights and basis to predict the effect of extreme precipitation events on river flows.
Variability of Total Column CO2, CH4 and CO in the Eastern Mediterranean And Middle East (EMME) Region: Insights from the TCCON Nicosia and AirCore
Authors: Rousogenous Constantina , Petri Christof , Warneke Thorsten , Quéhé Pierre-Yves , Laemmel Thomas , Ramonet Michel , Notholt Justus , Paris Jean-Daniel , Vrekousis Michail , Sciare Jean
Published: March 2024

At the crossroads of Europe, Africa, and Asia, the island of Cyprus receives long-range and regional pollution from various anthropogenic and natural sources. To assess the variability and amounts of greenhouse gases (GHG) in the region, we have set up, in 2019, a new Total Carbon Column Observing Network (TCCON) site, the TCCON Nicosia, at The Cyprus Institute. Herewith, we present the first time series of columnar amounts of the main GHGs in the region (Xgas; X stands for total column average dry-air mole fractions), namely carbon dioxide (XCO2), methane (XCH4), nitrous oxide (XN2O), carbon monoxide (XCO) and hydrogen fluoride (XHF). To evaluate the performance of TCCON, an AirCore campaign was conducted in Cyprus in June 2020, providing independent in-situ vertical profiles of CO2, CH4 and CO extending up to the stratosphere. The recent observations of XGHG data, together with the results of the AirCore, are presented. The observed variability in the columnar time series and its possible drivers are discussed.
Detrital Garnet Petrology: Inclusions as a main source of information
Authors: Schönig Jan
Published: March 2024

Documenting metamorphic conditions through the geologic record is a key for understanding the evolution of plate tectonics on Earth. Minerals characteristic for deep subduction processes (i.e. modern-style plate tectonics) like glaucophane, coesite, and diamond are commonly replaced by their low-pressure polymorphs during exhumation. However, when entrapped as inclusions in resistant host minerals like garnet, these mineral phases are shielded from external metamorphic fluids and may be preserved. Finding evidence for deep subduction processes in host garnets of large volumes of (partially) re-equilibrated crystalline rocks is challenging, time consuming, and often hampered by poor outcrop conditions due to weathering and soil formation. In contrast, by analyzing detrital garnet, natural processes such as erosion and sedimentary transport can sample garnet grains sourced from fresh as well as altered crystalline rocks located in the drainage area, enabling large crustal volumes to be screened using a comparatively low number of samples. Case-studies from Norway (Schönig et al. 2018, Sci. Rep.), Germany (Schönig et al. 2019, Geology; Schönig et al. 2020 Gondwana Res.), Austria, Papua New Guinea (Baldwin et al. 2021, PNAS), and Greenland (Schönig et al. 2023, Eur. J. Mineral.) demonstrate mineral inclusion analysis of detrital garnet integrated with major-element chemistry (Schönig et al. 2021, Contrib. Mineral. Petrol.) to be an efficient tool for screening tectonometamorphic units on the presence or absence of rocks related to modern-style plate tectonic processes (Schönig et al. 2022, Earth-Sci. Rev.). This contribution gives a synopsis of the main findings from the five spatially, chronologically, and tectonically distinct localities.