bluuebunny/crossref_metadata_2025 huggingface dataset:
Benchmarking remote sensing-based forest recovery indicators for predicting long-term recovery success
Authors: Mandl Lisa , Viana-Soto Alba , Stritih Ana , Seidl Rupert , Senf Cornelius
Published: March 2024

Natural disturbances and post-disturbance recovery are principal drivers of forest ecosystem dynamics. While disturbances and their causes and consequences have received considerable attention from the scientific community in recent years, there is – however – a substantial lack of knowledge on post-disturbance recovery, despite its importance for forest resilience, carbon storage and developing effective conservation and management strategies. This is particularly pertinent in mountain landscapes, such as the Alps, where steep topography and frequent climate extremes could hamper natural tree regeneration but closed canopy forests are needed for protecting infrastructure from natural hazards. In our study, we aim to close this knowledge gap by the means of Earth Observation. Specifically, we mapped land cover fractions (treed vegetation, non-treed vegetation and bare soil) annually at 30 m spatial grain and over the period 1990-2021 across the Alps. To do so, we employed a temporally generalized regression-based spectral unmixing approach to dense time series of Landsat and Sentinel-2 data, including more than 73,000 individual scenes. From this dataset, we characterized post-disturbance recovery intervals, that is the time it takes to reach a similar canopy closure than pre-disturbance, across 1.76*106 disturbance patches, including both natural and human disturbances. Results show that disturbed sites close their canopy on average after 10.6 years, with 60% of the disturbances reaching closed canopy after 10 years. We then compared recovery intervals derived from spectral unmixing to existing recovery indicators based on simple vegetation indices (NDVI, NBR), showing that those recovery indicators underestimate post-disturbance canopy closure time by a factor of 1.5 – 2. Finally, we tested whether post-disturbance bare soil fractions and disturbance characteristics (i.e., pre-disturbance tree cover and relative severity) can be used to predict long-term recovery success.  Results show that long-term recovery success (defined as canopy closure at 10 years post-disturbance) could be predicted with > 80% accuracy. From our results we conclude that (i) recovery indicators based on spectral indices are not well suited to characterize post-disturbance recovery in complex landscapes such as mountain forests and (ii) that disturbance characteristics and post-disturbance bare soil fractions are largely sufficient to predict whether a pixel will recover in the future or not. Our approach thus overcomes a major limitation of past remote sensing-based recovery assessments, which required long time series (>10 years) to assess recovery and thus were limited in understanding changes in post-disturbance forest recovery over time.
The outstanding European and Mediterranean heatwave activity during summer 2022
Authors: Trigo Ricardo , Barriopedro David , Garrido-Pérez José , Simon Amelie , Plecha Sandra , Teles-Machado Ana , Russo Ana , García-Herrera Ricardo
Published: March 2024

The European summer of 2022 has been widely recognized as the warmest since mid-19th century. Our updated analyses of instrumental and reconstructed temperature series since 1500 indicate that the European summer (June-to-August) of 2022 was the warmest on record, exceeding the previous hottest summer of 2021 by a large margin. In fact, the past three summers of 2021–2023 have been among the hottest ones of the last five centuries.By applying a heatwave (HW) detection algorithm to reanalysis data, we identify three large European HW events that affected ample regions of the continent in mid-June, mid-July and August/early September 2022. These episodes were triggered by high-pressure systems with noticeable differences in their characteristics. Additional analyses confirm that high-latitude blocks were largely responsible for the August 2022 HW, whereas subtropical ridges dominated during the June and July 2022 HWs. These HW events were also accompanied by dry soils and warm Sea Surface Temperatures (SSTs) over the Mediterranean. Indeed, summer 2022 displayed the largest marine heatwave activity of the 1982–2023 period due to an unusually high frequency of long-lasting and intense events, particularly over western Mediterranean.Taking the June 2022 HW over Iberia as an example, we address the role of dynamical (atmospheric circulation) and thermodynamical (regional soil moisture and western Mediterranean SSTs) drivers in the severity of the event. Flow analogues of the June 2022 heatwave are used to reconstruct the expected temperatures under different combinations of these thermodynamical drivers and assess their separate and combined influences on the intensity of the event. Results show a measurable intensification of the heatwave event (of ~1 °C) by both dry land and warm sea conditions. Although these two drivers are significantly correlated, southwestern European HWs are aggravated if dry soils concur with warm SSTs over western Mediterranean. The magnitude of the Mediterranean SST influence could depend on the soil moisture state, being larger for dry than wet conditions, as well as on the atmospheric circulation.R.M.T., A.R., S.P. and A.T.M. thank Fundação para a Ciência e a Tecnologia (FCT) I.P./MCTES through national funds (PIDDAC) – UIDB/50019/2020 (https://doi.org/10.54499/UIDP/50019/2020) and LA/P/0068/2020 (https://doi.org/10.54499/LA/P/0068/2020). A.R. and R.M.T. thank also FCT (https://doi.org/10.54499/2022.09185.PTDC, (http://doi.org/10.54499/JPIOCEANS/0001/2019). A.R. was supported by FCT through https://doi.org/10.54499/2022.01167.CEECIND/CP1722/CT0006.
Understanding of CMIP6 surface temperature cold bias over the westerly and monsoon regions of the Tibetan Plateau
Authors: Wu Fangying , You Qinglong
Published: March 2024

The Tibetan Plateau (TP) directly heats the middle tropospheric atmosphere, and accurate simulation of its surface temperature is of great concern for improving climatic prediction and projection capabilities, but climate models always exhibit a cold bias. Based on the Coupled Model Intercomparison Project Phase 6 (CMIP6) models and in-situ observations during 1981-2014, this study elucidates the impact of the snow overestimation on the temperature simulation over the TP in CMIP6 from the perspective of local radiation processes and atmospheric circulation. On the one hand, more snow in the CMIP6 models not only directly cools the surface more, but also makes the surface receive less shortwave radiation due to the higher surface albedo, and thus has lower ground surface temperature (GST), and the more snow/albedo-low temperature process is particularly evident in the westerly region due to more uncertainty at high elevations. This process contributes 87% to the annual GST cold bias. Lower GST corresponds to less latent heat transfer and thereby lower surface air temperature (SAT). In addition, the more snow in the CMIP6 models leads to the weaker the South Asian summer monsoon and the westerlies, and brings less warm and moist air (less integrated water vapor flux), as well as less clear-sky downward longwave radiation (less water vapor amount and lower tropospheric air temperature) to the TP (contributing 58% to the annual GST cold bias). These processes will result in less both precipitation and surface latent heat loss, which offsets a 35% annual GST cold bias. Besides, the physical mechanism of snow on GST and SAT differs with season over the westerly and monsoon regions of the TP. The research highlights the importance of topography and snow parameterization schemes for optimizing CMIP6 models.
Short-term Antarctic ice-sheet dynamics during the late Oligocene: Multi-proxy records from ODP Site 689
Authors: Creac'h Layla , Brzelinski Swaantje , Friedrich Oliver , Frank Martin , Gutjahr Marcus , Lippold Jörg
Published: March 2024

Paleoceanographic records spanning the Oligocene (33.9–23.03 Ma) provide insights into Antarctic ice-sheet (AIS) dynamics in a world warmer-than-today, allowing to improve future projections linked to current global warming. While the long-term evolution of Oligocene glaciations is relatively well-known, current knowledge about the short-term (i.e., orbital to suborbital scale) AIS dynamics is still limited. Here, we investigate short-term dynamics of the AIS during the late Oligocene (spanning ~26–25 Ma), using a high-resolution multi-proxy record from Ocean Drilling Program Site 689 (Maud Rise, Southern Ocean). Variations in ice volume were quantified using the stable oxygen isotope composition of seawater (δ18OSW) inferred from benthic foraminiferal δ18O and Mg/Ca-based bottom-water temperatures. Changes in sediment provenance and weathering inputs were characterised using detrital neodymium isotopic compositions (εNd) of the sediments. The δ18OSW record reflects a highly dynamic AIS during the late Oligocene, with glacial conditions characterised by an AIS volume larger than the modern one (up to +14%) and interglacial conditions characterised by a much smaller AIS volume (up to -29%) than today. Detrital εNd varies from -12 to -9, with less radiogenic εNd signatures generally matching higher δ18OSW values (i.e., glacials) and vice-versa. This co-variation between an ice-volume proxy and a tracer of sediment provenance characterises crustal sequences exposure to weathering as the ice-sheet retreated. The detrital εNd record thus supports recent interpretations of a highly dynamic AIS during the late Oligocene, which is mirrored by large changes in the provenance of weathering products induced by the waning and waxing of the AIS.
Landslide Inventory Mapping in Densely Populated and Forested Environments using UAV LiDAR Data: A Case Study in Zindisi, Surami District, Georgia
Authors: Bakhsoliani David , Magalashvili Archil , Gaprindashvili George
Published: March 2024

In the country of Georgia, the administrative territories of Surami (Khashuri municipality, Shida Kartli region) are particularly susceptible to the development of landslide processes. Among these areas, the Zindisi district stands out as a focal point for our research due to the occurrence of a significant landslide process in 2007, which remains active and poses periodic threats to residential houses and infrastructure. Zindisi district is characterized by dense forest cover and a high population density. Conducting a detailed landslide survey in such a challenging terrain using standard methods is difficult. Therefore, our research aims to overcome these challenges by employing lidar technology in a similar environment.The research initiative commenced with the acquisition of high-density point cloud data utilizing UAV lidar surveys. A UAV (DJI- The Matrix 300 RTK) equipped with a lidar camera (DJI Zenmuse L-1), was deployed to scan the study area. This approach allowed for the capture of detailed topographical information crucial for understanding the landslide processes. The obtained dataset serves as the foundation for creating a precise Digital Elevation Model (DEM) with a spatial resolution of 1 meter. This DEM enabled the identification of landslide boundaries by leveraging lidar-derived high-resolution topographic information. Linear structures were mapped based on hillshade, aspect, slope, and other thematic maps, providing a comprehensive understanding of the terrain.To validate the accuracy of our results, both aerial photos and on-site field investigations were utilized. The combination of lidar technology, high-resolution topographic data, and thorough validation techniques enhances the reliability of our landslide inventory in the Zindisi district. This research contributes valuable insights for effective land management and mitigation strategies in landslide-prone areas. Furthermore, the approach outlined in this research provides a method for landslide mapping in similar environments and demonstrate the potential of UAV LiDAR technology in enhancing landslide risk management in densely populated and forested regions.
Exploring the deposition mechanism in saturated porous media for polydisperse composites of XG and nZVI@rGO
Authors: Ren Liming , Qin Bing , Cao Fengyi
Published: March 2024

Engineered nanomaterials (ENMs) have shown promise for remediation of groundwater contaminants and the potential application relies on the delivery of aqueous solutions of ENMs to a targeted subsurface location or region. Thus, the ability to accurately predict nanoparticle transport and retention in saturated porous media is one of the most technical challenges faced by the design and assessment of potential field-scale environmental applications. Here, a prior prediction model was presented by coupling the effect of Derjaguine-Landaue-Verweye-Overbeek (DLVO) interaction, Brownian diffusion, hydrodynamics and interception. Characteristics used in the model were medium size, porosity, injection velocity, size distribution of particles, attachment efficiency, single-collector contact efficiency. The direct comparison of parameterized prior model predictions to experimental measurements was proposed to thoroughly understand deposition mechanism of polydisperse ENM. The model predicted deposition rate coefficient quantitatively very close to measured rates. When the particle diameter (dp) of ENM excessed 1.2080 mm, it was retained in the porous medium by interception; When dp < 0.1737 mm, ENM would deposite in the porous medium if the kinetic energy (Ek) it possessed is less than the depth of the secondary energy minimum; When 0.1737 mm < dp < 1.2080 mm, deposition occurred where adhesive torques (TA) was in excess of hydrodynamic drag torgues (TH) particles subject to. Further, deposition rate was positive correlated with injection concentrations among the range of 0.34 g/L~1.70 g/L. Besides, low deposition rates were observed with injection velocities around 0.69 cm/min.
TC-induced Increases in Extreme Rainfall over the Northeast United States 
Authors: Jong Bor-Ting , Murakami Hiroyuki , Delworth Thomas
Published: March 2024

The Northeast US has faced the most rapidly increasing occurrences of extreme rainfall within the US in the past few decades. The latest fully-coupled 25-km GFDL SPEAR simulation, possessing 10 ensemble members, presents a good opportunity to study changes in regional extreme rainfall and relevant physical processes in both current and future climates. The surge in extreme rainfall over the Northeast US since the 1990s is primarily linked to events associated with tropical cyclones (TCs). In a future warming climate, the 25-km GFDL SPEAR SSP5-8.5 simulations project unprecedented rainfall events over the Northeast US, driven by increasing anthropogenic radiative forcing and distinguishable from natural variability, by the mid-21st century. Also, the occurrences of extreme rainfall related to both atmospheric rivers and TCs are projected to increase, even though the number of TC in the North Atlantic is projected to decrease in the 25-km GFDL SPEAR SSP5-8.5 simulations. Factors such as enhancing TC intensity, strengthening TC-related rainfall, or/and westward shift in TC tracks may offset the influence of declining TC numbers in the model projections, leading to more frequent TC-related extreme rainfall over the Northeast US in the future. On the other hand, the increase in extreme rainfall linked to atmospheric rivers is projected to outpace that associated with TCs. Given the distinct spatial patterns of rainfall resulting from atmospheric rivers and TCs, shifts in their relative contributions carry profound implications for risk prevention and mitigation strategies.
Combining citizen science and Earth observation data to produce global maps of 31 plant traits
Authors: Lusk Daniel , Wolf Sophie , Moreno Martínez Álvaro , Kattge Jens , Maria Sabatini Francesco , Kattenborn Teja
Published: March 2024

The acceleration of global environmental change underscores the pressing need for a comprehensive understanding of how the biosphere interacts with its environment. To reliably examine these connections across diverse ecosystems, having extensive and spatially comprehensive data on plant functional traits is imperative. The TRY database boasts an extensive repository of plant trait measurements for thousands of species, and, while previous approaches have attempted to spatially extrapolate these traits using environmental predictors and remote sensing data, the scarcity of the original data leads to significant uncertainty in the extrapolations. Meanwhile, citizen scientists have been actively gathering dense observations of species occurrences worldwide, and when matched with trait data, can adequately represent global trait patterns. Here, we explore the use of citizen science and Earth observation data to generate global maps of 31 ecologically relevant plant functional traits. The study utilizes sparse spatial grids created by linking species occurrences from the Global Biodiversity Information Facility (GBIF) with the TRY gap-filled database to generate continuous global trait maps as a function of climate, soil, and remote sensing data. We first evaluated model performance using spatial cross-validation, and they demonstrated up to R2 = 0.53 with a normalized RMSE = 0.21. We then compared mean trait values from the GBIF-based extrapolations to community-weighted mean traits from sPlotOpen, a global, environmentally balanced dataset of vegetation plot data. Our results show correlations between the two datasets of up to r = 0.73 with particular resilience to decreasing map resolution. When compared to similar extrapolations based on sPlotOpen alone, we found that GBIF-based extrapolations increased global spatial applicability for all maps by up to 12%. Additionally, we show that GBIF-based extrapolations have higher correlations to sPlotOpen-derived maps than the majority of previously published trait maps. Despite the inherent noise and biases of their crowd-sourced origins, GBIF-based models are remarkably capable of producing even closer approximations of the trait distributions of scientifically controlled vegetation plots than their own sparse reference data. Considering the rapid growth and availability of crowd-sourced data, the capacity of models to overcome their noisy and opportunistic nature further affirms the potential of databases such as GBIF to complement more scientifically rigorous data collections.
Integration of Ocean Alkalinity Enhancement Processes with Coastal Industries: Ecotoxicity Assessment for Local Environmental Impacts
Authors: Buceta Juan , Sdez Nicolas
Published: March 2024

Bringing carbon dioxide (CO2) removal approaches from the laboratory to the industrial scale in the following years is imperative to reaching Net Zero goals. Ocean Alkalinity Enhancement (OAE) is a promising approach that introduces alkalinity into surface waters, slightly modifying the carbonate equilibrium and thus increasing the seawater’s CO2 removal capacity. The co-location of OAE with existing coastal industries (e.g., desalination plants) is a way to accelerate their deployment.Recognizing the importance of balancing climate mitigation strategies with environmental stewardship, our study focuses on the outcomes of comprehensive ecotoxicity tests conducted to discern the effects of return flows from desalination plants (concentrated seawater or brine) enriched with alkalinity (carbonates). To simulate real conditions, we investigated three scenarios: (i) brine alone, (ii) alkalinity alone, and (iii) brine with added alkalinity. The ecotoxicity tests were designed to capture the responses of key marine organisms across various trophic levels. Bacterial assays illuminated the microbial community's sensitivity to different scenarios, while diatom assessments provided insights into primary producers' adaptive capacity. Copepod and crustacean tests explored the cascading effects on higher trophic levels, elucidating potential ramifications for marine food webs.Our findings shed light on the intricate interplay between alkalinity-enhanced brines and local ecosystems, providing valuable insights into potential stressors and their implications for marine biota. The ecotoxicity results at different dilutions are combined with the knowledge of mixing zones for ocean outfall technologies, putting forward the environmental impact at different distances from the alkalinity addition.By addressing the specific challenges posed by integrating OAE with desalination, this research contributes to the ongoing dialogue on responsible and sustainable climate mitigation strategies. It offers a nuanced understanding of the potential trade-offs and synergies between addressing climate change and preserving or benefitting local marine environments. At a time when environmental testing at scale is needed, this study assesses the potential risks of such research. Ultimately, this work facilitates dialogue among OAE companies, desalination experts, policymakers, and organisms for environmental control and protection.  
Investigating the Complex Heliosheath of our Heliospheric Shield
Authors: Kornbleuth Marc , Opher Merav , Powell Erick , Onubogu Chika , Ma Xiaohan , Richardson John
Published: March 2024

The solar wind travels supersonically in the solar system until it reaches the termination shock, where itis slowed down due to the interplay between the interstellar medium (ISM) and heliosphere. The regionof slowed down solar wind is referred to as the heliosheath, where a great number of mysteries remainunsolved. Within the SHIELD NASA Drive Center, investigating the physical processes within theheliosheath and their consequences is a fundamental goal in understanding both the shape of theheliosphere and also how it protects the solar system from harmful galactic cosmic rays. Here, wehighlight some of the findings of SHIELD: (1) a Rayleigh-Taylor like instability develops in theheliosheath due to charge exchange, which in turn allows for mixing between the solar wind and ISMplasma yielding a short, “croissant-like” heliotail; (2) via magnetohydrodynamic modeling, we cancapture this mixing region, which has potential implications for particle acceleration; (3) currentenergetic neutral atom (ENA) observations appear to be insufficient for distinguishing the true shape ofthe heliotail, but future ENA-focused missions, such as IMAP, will have the capability to determine theshape of the heliotail; (4) ENA observations of the heliotail and Lyman-alpha observations may also beable to reveal the properties of the interstellar magnetic field
Observations and Analysis of MeV Electrons from REPT PHA Data and REPTile-2 data 
Authors: Li Xinlin , O'Brien Declan , Mei Yang , Xiang Zheng , Baker Daniel
Published: March 2024

The Relativistic Electron-Proton Telescope (REPT) Pulse Height Analysis (PHA) data captures individual particle event for each of REPT’s nine silicon detectors onboard the Van Allen Probes. The PHA data set was taken every 12 milliseconds (ms), including the pulse height that is proportional to the energy deposit of each individual particle from all nine detectors. Geant4 simulations are used to extend and improve the electron detecting capabilities of REPT (beyond its nominal data) using the PHA data. After replicating the nominal characteristics of REPT in the Geant4 toolbox, new channels for REPT, going from 12 nominal electron channels to 47 and lowering the minimum energy to ~1 MeV, have been formulated. By applying these newly simulated electron channels to PHA data and combining with the detector singles rates, an estimated count rate data product for finer-resolution, lower-energy channels is created. This method enables higher resolution observations of electrons of 1.1 – 12 MeV, revealing more detailed characteristics of these high energy electrons in the magnetosphere, especially in the inner edge of the outer belt, slot region, and inner belt. Similarly, Relativistic Electron and Proton Telescope integrated little experiment -2 (REPTile-2) onboard Colorado Inner Radiation Belt Experiment (CIRBE), launched on 15 April 2023 into a low Earth orbit (LEO), has implemented PHA processing onboard, measuring 0.25 – 6 MeV electrons in 60 channels and protons in 60 channels and revealing detailed structures of the energetic electrons and protons, especially in the inner belt.
Enabling Subglacial Geodesy Through High-Precision Radar Sounding and GNSS Time Series Observations
Authors: Schroeder Dustin , Falconer Jasmin , Siegfried Matthew
Published: March 2024

Our capacity to estimate vertical motion of the solid Earth with high precision has transformed our understanding of a variety of Earth processes, including mantle dynamics, plate tectonics, volcanic hazards, earthquake rupture, and surface-water balance. Geodetic observations of solid Earth deformation were first achieved on land with conventional surveying techniques, global navigation satellite system (GNSS) deployment, and satellite remote sensing, then expanded to the global ocean with seafloor geodesy techniques like GNSS-Acoustic (GNSS-A) experiments and fiber-optic sensing. Although we can now assess solid Earth deformation nearly everywhere on Earth, we still have not achieved subglacial geodesy: directly observing uplift or subsidence beneath glaciers and ice sheets. Due to decreasing ice mass, we expect high rates of uplift beneath Earth’s ice masses (i.e., glacial isostatic adjustment, or GIA), but available GNSS observations from exposed rock on the periphery of the Greenland and Antarctic ice sheets suggest uplift rates can be highly variable on 10s of km length scales. Recent observational and modeling studies have suggested that GIA could provide a critical stabilizing feedback for ice-sheet mass loss on decadal and centennial timescales, therefore developing and deploying the technology needed for subglacial geodesy is critical for accurate projections of sea level change, particularly in Antarctica where areas of exposed bedrock are rare. To address this challenge, we present a suite of combined radar sounding / GNSS experiments and systems under development to constrain uplift rates beneath both slow-flowing (< 10 m/yr) and fast-flowing ( > 10 m/yr) ice. We also discuss a range of related systems and experiments under development to constrain and correct for potentially confounding firn compaction signals.
Vertical mixing and horizontal transport determine bloom dynamics in a large riverine reservoir
Authors: Gai Bo , Sun Jian , Lin Binliang , Li Yuanyi , Mi Chenxi , Shatwell Tom
Published: March 2024

Phytoplankton blooms in lakes and reservoirs are sensitive to hydrodynamics. Bulk metrics of hydrodynamics are often used to investigate bloom formation, but they may not adequately represent the synergistic hydrodynamic processes in large riverine reservoirs caused by dam operation. Here we examine how complex three-dimensional hydrodynamic processes trigger blooms in Xiangxi Bay, a typical tributary bay of the Three Gorges Reservoir, China, which has suffered phytoplankton blooms of different scales in recent years. We used a 3D ecological-hydrodynamic model, which integrated hydrodynamics with the abiotic factors that limit phytoplankton growth to simulate one whole year (2010). By implementing a scaling criterion, we quantified the contribution of local phytoplankton growth and hydrodynamic processes, including advection transport and vertical mixing, on bloom dynamics. Results indicated vertical mixing was the main process inhibiting blooms in colder months (from October to February) but horizontal advection, which flushed and diluted blooms, was dominant in warmer months (from May to July) when stratification was intense and nutrients were replete. Accordingly, blooms occurred when both vertical mixing and horizontal advection were low. We suggested a potential dam operation strategy to mitigate blooms during stratification, which involves withdrawing the warm surface water from upstream reservoirs to increase horizontal flows in the surface layer. Extending the critical turbulence model, our study shows that not only the rate of vertical mixing, but also horizontal advection controls blooms in highly dynamic riverine systems.
Paleogeographic affinity of Northern China block clusters in Archean-Paleoproterozoic supercraton solution
Authors: Zhang Qiao , Yao Jinlong
Published: March 2024

An Archean ancestral landmass of Columbia supercontinent is a matter of concern to geologists. A single supercontinent called “Kenorland” or several supercratons have been mainly proposed, but more evidence from geological records and palaeomagnetism argue for the latter supercraton solution, in which two long-lived supercratons Sclavia and Superior were recently reconstructed. Studies has shown that the Northern China blocks, including the North China and Tarim cratons, the Alxa, Quanji blocks, were involved in the reconstruction of Columbia. However, their affinity in Archean supercratons remained little constrained. Owe to the lack of reliable palaeomagnetic data old than 1.8 Ga, the geological piercing points in these blocks could allow us to figure out the question. Then, compilation and comparison of Neoarchean–early Paleoproterozoic magmatism, metamorphism, and sedimentary records, have been conducted among these blocks. As a result, 2.4-2.2 Ga magmatism and khondalite-like sedimentary sequence may be used as indicators of the affinity of these blocks in northern China. Consequently, the Kuruktag Block, Quanji Block, Alxa Block, TNCO, Khondalite Belt have similar evolutionary history during the Neoarchean-Paleoproterozoic, suggesting their close affinity at that period. Besides, the North China craton and Dharwar craton of India shield were proved to be connected during the Archean-Proterozoic. And latest study indicate the Dharwar craton was one of the Sclavia supercraton. Therefore, we speculate that during the Neoarchean–early Paleoproterozoic, the Kuruktag-Quanji-Alxa-TNCO-Khondalite Belt link was close to the Dharwar craton in Sclavia supercraton. The absence of Siderian glacial event (ca. 2.4 Ga) in the Alxa, Quanji, Kuruktag blocks and TNCO, Khondalite Belt of the North China craton rule out the link with Superia, which is common in Superia supercraton. Further geological and paleomagnetic studies are required to constrain the above hypothesis, the relation between these blocks clusters and other cratons, which is crucial to understand the origins of blocks in northern China.
Permafrost degradation increases risk and large future costs of infrastructure on the Qinghai-Tibet Plateau
Authors: Ran Youhua , Li Xin , Cheng Guodong
Published: March 2024

Qinghai-Tibet Plateau (QTP) is the largest permafrost region among middle- and low-latitude regions in the world. Permafrost in QTP is dominated by unstable and climate-driven. It is especially vulnerable to climate change and ecosystem disturbances (both natural and human). Currently, more than 9389 km of roads, 580 km of railways, 2631 km of power lines, and 1064590 m2 of buildings are located in the QTP permafrost area. Depending on altitude, the warming rate of the QTP has been twice the global average in recent decades and in the foreseeable future. Climate change-induced permafrost degradation can seriously threaten the stability of infrastructure and thus increase the infrastructure repair and replacement frequency. The consequence can be expressed as the shortening of useful life and increases maintenance costs, leading to diverse financial risks. The damage to infrastructure caused by near-surface permafrost degradation is directly related to the well-being of 10 million people and the sustainable development on the Qinghai-Tibet Plateau, the Third Pole of the Earth. Here we identify the economic damage caused by permafrost degradation to infrastructure on the Qinghai-Tibet Plateau by integrating data-driven projection, multihazard index, and lifespan replacement model. We found that additional cost of approximately $6.31 billion will be needed to maintain the service function of current infrastructure under the historical scenario (SSP245) by 2090. While 20.9% of these potential costs can be saved with strategic adaptations. Controlling global warming to below 1.5 °C will reduce the costs by $1.32 billion relative to the 2 °C target of Paris Agreement. These findings highlight the importance of mitigating global warming and of investment in the adaptation and maintenance of infrastructure on the Qinghai-Tibet Plateau, which has a sparse population but is a climate hotspot.
Relative importance of groundwater and sediment-produced methane in stream emissions of two boreal catchments 
Authors: Balathandayuthabani Sivakiruthika , Panneer Selvam Balathandayuthabani , Gålfalk Magnus , Saetre Peter , Peura Sari , Kautsky Ulrik , Klemedtsson Leif , Arunachalam Lakshmanan , Vellingiri Geethalakshmi , Bastviken David
Published: March 2024

Inland waters are important sources of methane (CH4) to the atmosphere. Significant quantities of CH4 are shown to be emitted from stream networks, despite their small areal coverage. Considerable gaps and uncertainties exist in the knowledge on the regulation of stream CH4 emissions, and their contribution to landscape scale C emissions. When the CH4 input from groundwater/surface runoff or from sediment production reaches the discharge areas, CH4 can either be microbially oxidised to carbon dioxide or emitted to the atmosphere. The relative importance of these sources and fates has implications for modelling and assessing long-term ecosystem CH4 balances. In the existing body of literature, there is a clear lack of data on the share of groundwater CH4 and sediment-produced CH4 to the total CH4 input in streams, the extent of CH4 oxidation or emission of these sources and the spatial variability over whole-catchment scales. Here we present a study on the fates of ground water and sediment-produced CH4 reaching stream environments in two different boreal catchments in Sweden. A combination of measurements, including CH4 concentration gradients below stream beds, stable carbon isotope gradient measurements, high resolution stream flux and discharge assessments, were used to follow the transport of CH4 below the stream bed to the stream water surface using inverse mass-balance modelling. The measurements covered all parts of the stream network in both catchments to include spatial variability. We show that around half of the total CH4 entering the streams were from groundwater. Almost all the groundwater and sediment-produced CH4 were oxidised (> 97%) before reaching atmosphere. Emissions to the atmosphere only represented a small fraction of the groundwater and sediment-produced CH4 reaching the stream (< 3%), indicating that CH4 oxidation is a major sink in the studied streams. Our data also reveals large spatial variability in surface water CH4 concentrations, concentration gradients below the stream beds, CH4 inputs, oxidation, and emission related to morphometry and presumably soil characteristics. We emphasize the importance of including spatial variability in stream networks to constrain the uncertainties in stream CH4 budget studies.
Risk-based multi-objective optimization model for the inter-basin water diversion system under multiple uncertainties and water-use constraints
Authors: Mo Ran , Xu Bin
Published: March 2024

Inter-basin water diversion has emerged as a critical measure for achieving a balanced distribution of water resources across basins. This process requires careful planning and implementation of an effective water supply operation scheme. However, an observed decrease in prediction accuracy with extended time periods reduces the effectiveness of long-term water resource management, presenting a dilemma between the risk of water scarcity due to insufficient water diversion and water wastage resulting from excessive diversion. Moreover, stringent regulations on water resources management are critical to achieving intensive water use. Setting limits on the dynamic spatial-temporal allocation of water resources poses a persistent scientific issue requiring immediate attention. Therefore, this study proposed a multi-objective risk-based optimization model for the inter-basin water diversion system under multiple uncertainties and water-use constraints. Backed by probabilistic predictions of local streamflow and water demand via scenario tree method, the water shortages and wastage risks along with costs associated with water diversion were identified. Simultaneously, a dynamic decomposition method for the total water-use constraints, considering changes in various streamflow scenarios, was proposed. Real-time water supply operations under severe constraints and heightened uncertainty were investigated in this study, while the eastern route of the South-to-North Water Diversion Project in Jiangsu Province, China was selected as the case study. The principal findings were as follows: (a) Conflicting relationships exists in this complex system, with the loss of water shortage and the cost of water diversion being the main contradictions. By utilizing high-prediction information, the water diversion was reduced by 41.9%, spilled water by 72.0%, and the water deficit by 10.6%, contributing to achieving an equilibrium in terms of cost, loss, and risk of water diversion and provision; (b) The total water-use constraint effectively controlled inter-basin water diversion and spillage, thus promoting the optimal exploitation of local water supply potential. The core of the water-use constraint is to promote the utilization of water resources through the compression of inter-basin water diversion; (c) By applying the dynamic decomposition of total water-use constraint, the water supply and consumption in a typical dry year increased by 15.46 × 108 m3, theoretically reducing the water deficit by 18.0% compared to the rigid constraint condition, meeting essential agricultural needs during severe drought conditions; (d) The incorporation of chance-constraint functions allowed for a more aggressive water diversion strategy (increasing additional water diversion by 0.574 × 108 m3) while mitigating risks associated with operational decision-making, thereby enhancing reliable water resources management.
Analyzing the Impact of Typhoon MINDULLE (2116) on South Korea's Extreme Temperatures Using WRF
Authors: Yun Semin , Wie Jieun , Kim Hak-Sung , Cho Jae-Hee , Moon Byung-Kwon
Published: March 2024

During October 2021, South Korea experienced an unprecedented heatwave, yet the factors behind it remained elusive. Simultaneously, Typhoon MINDULLE (2116), originating in the Northwest Pacific, approached the Korean Peninsula. The aim of this study was to analyze the influence of Typhoon MINDULLE on the extreme warming in October. Using the Weather Research and Forecasting (WRF) model, we conducted two experiments for comparison: one considering the presence of typhoon (TC) and the other eliminating typhoon (TC-removed). The results showed that temperatures on the Korean Peninsula in the first half of October were 1.35°C higher with TC than with TC-removed. Additionally, the typhoon contributed to enhanced moisture and stronger southerly winds. It intensified warm air advection, leading to the amplified temperatures experienced in South Korea. This study suggests that it is essential to consider typhoons as a significant factor when studying autumn heatwaves.
Sedimentary numerical simulation of the development mechanism in sandy braided-meandeing transitional river
Authors: Li Rongyu , Zhang Xianguo
Published: March 2024

Braided river and meandering river are possible to form a braided-meandering transitional river, which has been concerned by scholars from sedimentology, geomorphology and hydrology. Traditional studies based on satellite data, field outcrop and drilling data while lacking understanding of its formation process and mechanism. In this study, sedimentary numerical simulation based on hydrodynamics is adopted to reproduce the development process of braided-meandering transitional river and compare it with modern river sedimentary data for verification. Through analyzing different sedimentary elements such as bar, channel and bank, The development process of sandy braided-meandering transitional river is revealed as follows: 1) Due to the extension and lateral accretion of the tail of the unite bar, a large number of secondary braided channels are filled, forming a compound bar, and the main channel gradually emerges, controlling the morphology development and evolution of the river bed; 2) The sediment and discharge of the channel on both sides of the compound bar are asymmetrical, and the sediment of the main channel is carried by denudation to the secondary channel near the bank and then unloaded and filled. Finally, the compound bar is connected with the embankment, and the main channel gradually presents a curved shape. 3) The main channel constantly adjusts and transforms the banks and bars. The concave bank is eroded and the sediments are transferred to the convex bank due to tranverse circulation. At this time, the compound bars develop multi-stage lateral deposits and the main channel migrated laterally. This understanding is of significance to the characterization of palaeochannel sediments.
Carbonate U-Pb ages constrain Paleocene initiation along the Altyn Tagh fault in response to the India-Asia collision
Authors: Yi Kexin , Cheng Feng , Jolivet Marc , Li Jiaming , Guo Zhaojie
Published: March 2024

The formation of the Tibetan Plateau as a result of the Cenozoic India-Asia collision had a profound impact on the Asian tectonics configuration and climate dynamics. The kinematics and deformation pattern along the Altyn Tagh fault (ATF), marking the Plateau’s northern boundary, is of great significance for resolving the dispute on the deformation mechanisms of the Tibetan Plateau. However, the timing and configuration of the initial rupture along the ATF remains debated given the limited constraints on the depositional age of associated Cenozoic syntectonic strata.Here we investigated the syntectonic Cenozoic strata in the Xorkol Basin, the pull-apart basin of the ATF. New uranium-lead analyses of the carbonate deposits yield dates of 58.9 ± 1.29 Ma. Therefore, we propose that the initiation of strike-slip motion along the ATF occurred no later than 58.9 Ma, leading to the formation of the Xorkol Basin as a composite pull-apart basin. This finding clarifies the timing and location of the initial ATF activity, indicating that the modern configuration of the ATF was established as early as the early Cenozoic.This research provides the first yet oldest radioisotopic age along the ATF and surrounding area. This age estimate is also indicative of the depositional age of the Lulehe Formation in the Qaidam Basin, suggesting that the syntectonic sedimentation in the northern Tibetan Plateau initiated during the Paleogene. This timing coincides with the ca. 60 Ma onset timing of India-Asia collision, highlighting its far-field effect. We infer stress triggered by the India-Asia collision has propagated across the entire plateau in ca. 1-2 Ma, resulting in Paleocene strike-slip faulting along the ATF and other deformation in North Tibet.
Rice cultivation under continuous flooding vs alternate wetting and drying: implications for biomass, nitrogen cycling and greenhouse gas flux
Authors: Ullah Sami , Kaviraj Megha , Guo Yafei , Micucci Gianni , Sgouridis Fotis
Published: March 2024

Rice uses 34-43% of the global irrigation water and is responsible for the usage of 24-30% of the world's total freshwater. More than 75% of rice produced in India is cultivated using the traditional continuous flooding (CF) irrigation method, which is a labour-intensive, time, water and energy-consuming process and a key source of global methane emissions. Alternate Wetting and Drying (AWD) is a popular water-saving approach trailed in Asia including India to reduce water use and methane emissions, whilst sustaining rice production. AWD is a method of periodic soil saturation followed by drying compared to CF. The objective of this research was to evaluate greenhouse gas (GHG) fluxes and internal and external nitrogen cycling processes as influenced by AWD and CF management regimes. A mesocosm experiment was set up in the laboratory using imported Indian paddy soil where Jasmine rice (var KDML 105) was grown. Our results depicted that plant biomass (52.57%), root biomass (28.57%), height (24.77%), effective tiller number (45.15%), stem sheath diameter (53.38%) and stomatal conductance (66.49%) were significantly (p
Reactivity of a marly-limestone caprock in contact with an alkaline HS--rich solution: application to hydrogen storage in a saline aquifer
Authors: Ceballos Elina , Cama Jordi , Soler Josep M.
Published: March 2024

Underground hydrogen storage (UHS) is proposed as a carbon-free energy source derived from renewable solar and wind energies. Deep saline aquifers are proposed for UHS since can potentially contribute to large-scale renewable energy storage, providing high storage capacities required to buffer seasonal energy demands. The caprock plays an important role in the sealing capacity for safe and effective UHS. The geochemical reactions involved in H2-saline groundwater-rock interaction are significant for the integrity of the caprock as these processes directly determine the sealing capacity during UHS.Aqueous H2 could react with minerals and trigger redox and dissolution/precipitation reactions, which may affect the permeability and porosity of the caprock. The resulting changes reactivate or propagate microfractures and, consequently, affect the integrity of the caprock and the long-term storage stability. UHS in formations with sulfate-rich groundwater can induce an increase in pH due to sulfate reduction (i.e., SO42- + 4H2 = HS- + 3H2O + OH-). The main goal of this work is to study the effect of the increase in pH (HS--rich water) on a marly limestone caprock.The PHREEQC code and the phreeqc.dat database were used to simulate equilibrium of H2 (at any pressure in a range between 1 and 100 bar) with a saline solution in equilibrium with calcite and gypsum at 60 °C. The thermodynamic calculations show that H2 reduces sulfate and that the pH increases from 8.2 to 11.1. This high alkaline water could, therefore, affect the integrity of the caprock. We tried to prove the model results (sulfate reduction and pH increase) in a batch experiment. A saline water rich in sulfate was put in equilibrium with H2 at 3 bars. After a week, however, the pH did not increase, suggesting that the short-term sulfate reduction does not occur in the absence of sulfate-reducing microorganisms.A column experiment was carried out to observe potential changes in the marly limestone in contact with an alkaline (pH ≈ 12), HS--rich solution at 60 °C. Circulation of the solution led to a release of Si and Al, i.e., dissolution of quartz and aluminosilicates. After 380 h, an increase in the flow rate (from 0.01 to 0.03 mL min-1) resulted in a decrease in the concentrations of Si and Al, suggesting a far-from-equilibrium dissolution of the silicates (SIquartz = -2.8; SIalbite = -5.9 and SIillite = -10.6) although the solution was supersaturated with respect to chlorite (SIchlorite = 5-12). The dissolution of silicates at highly alkaline (pH ≈ 12) may result in a variation of the initial properties of the UHS caprock (e.g. porosity, permeability). Numerical and experimental results of ongoing column experiments will help reveal the extent of the rock alteration.