bluuebunny/crossref_metadata_2025 huggingface dataset:
Petrogenesis of Neoproterozoic high-K intrusion in the southwestern Yangtze Block, South China: Implication for the recycled subducted-sediment in the mantle source
Authors: Jiang Xiuwei , Lai Shaocong
Published: March 2024

Abstract: The study of K-enriched intrusive rocks is essential for deciphering mantle metasomatism beneath active continental arcs. In this contribution, high-precision zircon U‒Pb‒Hf isotope, whole-rock geochemistry, Sr‒Nd isotope, and mineral chemistry analyses were performed to evaluate the petrogenesis and geodynamic system of the Yunnongfeng intrusion on the southwestern margin of the Yangtze Block. The Yunnongfeng intrusion consists of a high-K to shoshonitic rock assemblage with variable lithology from gabbro-diorite to granite. Zircon U‒Pb dating gives concordant crystallization ages of ca. 782.5 ± 3.8 Ma for gabbro-diorite, ca. 774 ± 4.1 and 776 ± 4.1 Ma for diorite, ca. 770 ± 4.7 Ma for quartz monzonite, ca. 763 ± 3.4 Ma for quartz syenite, and ca. 764 ± 16 Ma for granite. These samples also show similar Sr‒Nd, and Lu‒Hf isotopic compositions, implying a common magma source. The similar crystallization age and regular variation of major and trace element contents suggest that these rocks were formed through fractional crystallization of cogenetic primitive mantle magmas. The enriched εNd(t) (−5.7 to −5.1) and εHf(t) (−6.7 to −1.2) values, high Rb/Y and Th/La ratios, slight Nd‒Hf decoupling, and high-K and Th contents demonstrate that their lithospheric mantle source was enriched by slab-related fluid and sediment-related melt. The samples also exhibit remarkable enrichment in large-ion lithophile elements and depletion in high-field-strength elements, indicative of subduction-related arc magmatism. Taking into account previous studies, we suggest that the western margin of the Yangtze Block experienced a long-term subduction process during the Neoproterozoic, and the Yunnongfeng intrusion formed in an extensional back-arc basin. Based on the K-enriched mafic‒intermediate rocks from the western margin of the Yangtze Block commonly show high K2O/Na2O, Rb/Sr, low Ba/Rb ratios, and enriched εNd(t) values, our study, coupled with numerous previous reports, proposes that the K-enrichment resulted from the breakdown of phlogopite, owing to subduction-related sediment melt reacting with peridotite in the mantle source area.Keywords: Potassium-enriched intrusive rocks; Southwestern Yangtze Block; Fractional crystallization; Lithospheric mantle; Sediment melt
Examination of Land Use Resolution Impact on the Correlation Between Fluvial Catchment Landscapes and Riverine Water Quality
Authors: Wang Yucang , Chen Dingjiang
Published: March 2024

Changes in land use and landscape patterns constitute prominent contributors to the degradation of river water quality. The granularity of land use data resolution plays a pivotal role in delineating the spatial distribution of land use within a catchment area. Despite its significance, scant attention has been devoted to investigating the impact of land use data resolution on the interplay between catchment landscape patterns and river water quality. Employing the Yong'an River Basin in eastern China as a case study, this research leverages land use and water quality change data spanning from 1980 to 2020 to scrutinize the influence of watershed landscape patterns on changes in river water quality across varying land use resolutions (30m, 100m, 300m, 500m, 1000m). The findings reveal that alterations in the landscape pattern of grassland, urban land, rural residential land, and paddy fields significantly shape changes in river water quality within the study area. Moreover, the explanatory power of catchment landscape patterns for variations in river water quality varies under distinct data resolutions, with the highest interpretation rate observed at the 300m resolution (88.2%) and the lowest at the 1000m resolution (87.7%). The interpretation rate exhibits an initial ascent followed by a descent as data resolution decreases. Further analysis elucidates that data resolution influences the responsiveness of the landscape index to river water quality by impacting the fitting accuracy of said index. Notably, the 300m resolution exhibits superior fitting accuracy. The degree of grassland fragmentation and the concentration of construction land, along with the fragmentation and area of paddy fields, emerge as pivotal landscape factors influencing changes in river water quality within the study area. Hence, adopting an appropriate land use resolution can mitigate the impact of data redundancy and facilitate a more nuanced exploration of the driving forces behind variations in river water quality.
Emergence of the Central Atlantic Niño
Authors: Zhang Lei , Wang Chunzai , Han Weiqing , McPhaden Michael , Hu Aixue , Xing Wen
Published: March 2024

The Atlantic Niño is characterized by sea surface warming in the equatorial Atlantic, which can trigger La Niña - the cold phase of El Niño-Southern Oscillation (ENSO). Although observations show that the Atlantic Niño has weakened by approximately 30% since the 1970s, its remote influence on ENSO remains strong. Here we show that this apparent discrepancy is due to the existence of two types of Atlantic Niño with distinct patterns and climatic impacts, which we refer to as the central and eastern Atlantic Niño. Our results show that with equal strength, the central Atlantic Niño has a stronger influence on tropical climate than its eastern counterpart. Meanwhile, the eastern Atlantic Niño has weakened by approximately 50% in recent decades, allowing the central Atlantic Niño to emerge and dominate the remote impact on ENSO. Given the distinct climatic impacts of the two types, it is necessary to distinguish between them and investigate their behaviors and influences on climate in future studies.
Similarities and differences in circulation beneath the Filchner-Ronne and Ross Ice Shelves: Lagrangian point of view
Authors: Maderich Vladimir , Bezhenar Roman , Brovchenko Igor , Fabio Boeira Dias , Äijälä Cecilia , Uotila Petteri
Published: March 2024

The two world’s largest ice shelves, the Filchner-Ronne Ice Shelf (FRIS) and the Ross Ice Shelf (RIS) account for half the area of Antarctic ice shelves. They play a key role in transforming water masses on the shelf and forming Antarctic Bottom Water.The objective of the work was to study the similarities and differences of circulation under the FRIS and RIS using the data of numerical simulation of currents, temperature, and salinity in the Weddell and Ross Seas from the Whole Antarctica Ocean Model (WAOM). The modelling results were used to run the particle-tracking model Parcels for computing Lagrangian particle trajectories. Three Lagrangian characteristics were calculated for FRIS and RIS: (i) Visitation frequency is defined as the percentage of the particles P visited each 2x2 km grid column at least once in a period of modelling (20 y); (2) Representative particle trajectory is the particle trajectory which deviates least from rest of trajectories; (iii) The mean age is the age of particles visited each 2x2 km grid column at least once.The representative particle trajectories show that anticyclonic circulation beneath the FRIS and RIS is caused by the inflow of High Salinity Shelf Water (HSSW) through troughs off the western coast of the Weddell and Ross Seas. Transformed into ISW water, it flows out through the troughs in these seas. Part of the transformed water under the FRIS flows out through the Filchner Trough between Berkner Island, while water under RIS flows into the Ross Sea in the strait between Roosevelt Island and the shore. The eastern part of RIS is not ventilated by water inflowing from Ross Island. It is slowly ventilated by water entering a trough between Roosevelt Island and the eastern coast of the Ross Sea. Visitation frequency and representative trajectories suggest similar paths for water mass entering RIS in all seasons. Except December-February particles in anticyclonic gyre can return under RIS. Meanwhile, for particles released in January-August, outflows from FRIS took place through both the Ronne and Filchner ice fronts. In the October-December release the outflow through the Ronne ice front essentially exceeds flow through the Filchner depression.
What do seismic clusters tell us about fault stability?
Authors: Zaccagnino Davide , Vallianatos Filippos , Michas Giorgios , Telesca Luciano , Doglioni Carlo
Published: March 2024

Seismic activity clusters in space and time due to stress accumulation and static and dynamic triggering. Therefore, both moderate and large magnitude events can be preceded by smaller events and also seismic swarms can occur without being succeeded by major shocks – which represents the vast majority of cases.Unveiling if seismic activity can forewarn mainshocks, being somewhat distinguished by swarms, is an issue of crucial importance for the development of short-term seismic hazard. The analysis of thousand clusters of seismicity before mainshocks in Southern California and Italy highlights that the surface over which selected seismic activity spreads is positively correlated with the magnitude of the impending mainshock, as well as the cumulative seismic moment, the number of earthquakes, the variance of magnitude and its entropy, while no significant difference is observed in the duration, seismic rate, and trends of magnitudes and interevent times between foreshocks and swarms. Our interpretation is that crustal volumes and fault interfaces host more and more correlated seismicity as they become unstable, and some properties of seismic clusters may mark their state of stability. For this reason, large mainshocks tend to occur in more extended correlated regions and because of the scaling of maximum magnitudes with the size of unstable faults. Considering this, the recording of more numerous and energetic cluster activity before mainshocks than during swarms is also reasonable.In recent years, our ability to track seismic clusters has improved outstandingly, so that their structural and statistical characterization can be performed almost in real time. Therefore, it may be possible to compare the current features of the active seismic cluster with the cumulative distribution functions of past seismicity. However, we would like to stress that foreshocks should not be considered as precursors in the sense that neither they forewarn mainshocks, nor they are physically different from swarms: the precursor is not in seismic activity itself, but in the development of mechanical instability within crustal volumes.
From formal errors towards realistic uncertainties
Authors: Petrov Leonid , Hanaba Nlingi
Published: March 2024

    Evaluation of uncertainties of geodetic parameter estimates is the problem that is not yet solved in a satisfactory way. A direct evaluation of the uncertainties derived from a least square solution is labeled "formal" and is usually biased, sometimes up to an order of magnitude. Customary, the use of formal errors for scientific analysis is discouraged. We claim that the root of the problem is neglecting off-diagonal elements in the variance-covariance matrix of the noise in the data. A careful reconstruction of the full variance-covariance matrix, including the off-diagonal terms greatly improves realism of uncertainty estimates derived from least squares. We processed the dataset of VLBI group delays and built the a priori variance-covariance of the atmosphere-driven noise based on analysis of the output of NASA high-resolution numerical weather models. We found that the uncertainties of parameter estimates derived from this least square solution that uses such variance-covariance matrices become much closer to realistic errors. We consider approaches for for implementation of this method in routine data analysis of space geodesy data.
P and S Wave Anisotropic Tomography of the Banda Subduction Zone
Authors: Hua Yuanyuan , Zhao Dapeng , Xu Yi-gang
Published: March 2024

In subduction zones with slab-slab interactions, the pattern of mantle convection is very complex and still unclear. In this study, we jointly invert a large number of P and S wave arrival time data of local earthquakes for 3-D isotropic and anisotropic velocity structures of the Banda subduction zone. Along the curved Banda arc, the subducting Indo-Australian slab is detected clearly as a high-velocity zone, and its azimuthal anisotropy changes along the arc strike, representing fossil anisotropy within the slab and modified anisotropy by the subduction processes. Around the northern edge of the Banda slab, a semi-toroidal pattern of anisotropy appears in low-velocity anomalies, representing mantle flow extruded from the Banda arc and escaped from a gap of the Banda-Molucca slab toward the northeast. Our 3-D anisotropic tomography uncovers the mantle convection pattern induced by the slab-slab interactions, shedding new light on the complex dynamical processes in this curved subduction zone.
Ridge-dual hotspots interaction and potential hotspot-hotspot interaction in the Southeastern Indian Ocean 
Authors: Luo Yiming , Lin Jian , Zhou Zhiyuan , Zhang Fan , Zhang Xubo , Zhang Jinchang
Published: March 2024

We investigated the impacts of the Kerguelen and Amsterdam-St. Paul (ASP) hotspots on mantle evolution and crustal accretion of nearby spreading ridges in the Southeastern Indian Ocean. Gravity analysis revealed enhanced magmatism and thickened crust along the ridge caused by the Kerguelen and ASP hotspots. By employing plate motions derived from the GPlates global plate reconstruction model, along with the ASPECT 3-D mantle convection code, we presented a comprehensive depiction of the ridge-dual hotspot system, which has been relatively underexplored in previous research. Model results indicated that the Kerguelen hotspot had a significantly greater influence on mantle temperature and ridge crustal thickness compared to the ASP hotspot. Furthermore, there is evidence suggesting a potential interaction between the dual hotspots, leading to the migration of ASP plume materials towards the Kerguelen plume.
A framework for surface water and groundwater modeling by multiple satellites.
Authors: Chang Liwei , Cheng Lei , Zhang Lu , Liu Pan
Published: March 2024

A comprehensive understanding of renewable water resources, including surface water and groundwater, is crucial for human sustenance, societal advancement, and ecosystem well-being at both local and global levels. Remote sensing technology offers an opportunity to rapidly and conveniently monitor inland water resources on a large scale. This study presents a framework for modeling water storage changes by integrating data from multiple satellites. Specifically, the GRACE and GRACE-FO gravity satellites are utilized to observe changes in terrestrial water storage (TWS), while the Landsat multispectral and ICESat / ICESat-2 altimetry satellites are employed to simulate changes in surface water storage (SWS). Groundwater changes are calculated by subtracting SWS and soil moisture storage (SM) from TWS, with SM data obtained from GLDAS 2.1. The innovation of this framework lies in the improved simulation of surface water, facilitated by the fine resolution of ICESat-2, enabling the establishment of an area-elevation relationship for very small water bodies (< 1 km2). This framework does not account for variations in river channel storage, making it suitable for regions where river discharge can be disregarded. The framework is applied to four provinces or cities in the North China Plain, where water scarcity constrains the demand of drinking water, irrigation, and environment. The study reveals a decrease in TWS from 2002 to 2020 in the study area. Although surface water increased following the operation of the Middle Route of the South-to-North Water Diversion Project in December 2014, groundwater continued to decline until 2020 and remained stable from 2020 to 2022. This study represents the first use of 4-year ICESat-2 data to monitor water bodies of all sizes (from 100 km2). Leveraging the exceptional capability of ICESat-2 data in modeling small water bodies, this study advances the prospect of achieving a comprehensive simulation of inland water resources.
A Prediction index of volatile organic compounds pollution conditions in chemical industry park based on atmospheric stability
Authors: Chen Xi
Published: March 2024

Volatile organic compounds (VOCs), as common precursors of ozone (O3) and fine particulate matter (PM2.5), are a focus of air pollution prevention and control. Furthermore, with the rapid development of industry, industrial sources have become the largest source of anthropogenic VOCs emissions, leading to economic development while causing great harm to the environment. It is becoming meaningful to efficiently predict the future total volatile organic compounds (TVOC) pollution conditions in chemical industry parks (CIPs), which can assist managers in carrying out corporate emission management in advance. In this study, TVOC monitoring data and meteorological data from January 1, 2022, to December 31, 2022, were used to innovatively construct the TVOC pollution index. This index comprehensively considers the atmospheric stability and localized horizontal diffusion conditions and can quickly and accurately predict the variation in the TVOC in a CIP in the next 7 days. In addition, we used synoptic weather patterns and backward trajectory analysis to explore the mechanism of VOCs pollution formation in a CIP. The results show that the combined influences of a westerly wind pattern, temperatures above 30°C, a subtropical high pressure system, more upwind pollutants, and the horizontal and vertical diffusion conditions in the CIP were unfavorable, leading to VOCs pollution.
 A comprehensive wind-fire-smoke simulation tool based on physical models and geospatial information.
Authors: Asensio María Isabel , Cascón José Manuel , Iglesias José Manuel
Published: March 2024

We present a comprehensive simulation toolset for the analysis and prediction of wind fields, wildfire spread, and the propagation of their resulting smoke. It is composed of three physical simulation models that work together: HDWind, PhyFire and PhyNX.The wind field simulation model, HDWind, is a mass consistent vertical diffusion wind field model based on an asymptotic approximation of the Navier-Stokes equations, providing a 3D wind field (which satisfies the incompressibility condition in the air layer) governed by a 2D equation that id adjusted to meteorological data obtained in a small number of points by solving an optimal control problem. PhyFire is a simplified 2D one-phase fire spread simulation model based on the principles of mass and energy conservation and that considers the radiation and convection (i.e., driven by wind and terrain slope) means of propagation, featuring the most relevant 3D effects, the influence of humidity, ambient temperature, wind, and the fuel types as well as their moisture content. The atmospheric dispersion model PhyNX is an urban scale Eulerian non-reactive multilayer air pollution model, able to describe convection, turbulent diffusion, and emission, considering the 3D wind field provided by the HDWind, and the smoke emission provided by PhyFire. The three models are solved using mainly the finite element method and some numerical and computational procedures to reduce the computational cost.The required data to feed the simulation models such as cartographic and meteorological information are obtained from online geospatial information systems (GIS) in an automated way with little user intervention, thanks to the integration of the models with the geospatial library GDAL/OGR, which enables easy interpolation with most used standard GIS formats and services. An integration of this toolset into an easy-to-use webgis platform for their exploitation for professionals in the field of wildfire prevention will be demonstrated.
Understanding the inner magnetospheric drivers of the geospace plume evolution through magnetosphere-ionosphere coupling
Authors: Bao Shanshan , Wang Wenbin , Sorathia Kareem , Merkin Viacheslav , Toffoletto Frank , Lin Dong , Pham Kevin , Garretson Jeffrey , Wiltberger Michael , Lyon John , Michael Adam
Published: March 2024

The geospace plume, referring to the combined processes of the plasmaspheric and the ionospheric storm-enhanced density (SED)/total electron content (TEC) plumes, is one of the unique features of geomagnetic storms. The apparent spatial overlap and joint temporal evolution between the plasmaspheric plume and the equatorial mapping of the SED/TEC plume indicate strong magnetospheric-ionospheric coupling. However, a systematic modeling study of the factors contributing to geospace plume development has not yet been performed due to the lack of a sufficiently comprehensive model including all the relevant physical processes. In this paper, we present a numerical simulation of the geospace plume in the March 31, 2001 storm using the Multiscale Atmosphere Geospace Environment model. The simulation reproduces the observed linkage of the two plumes, which, we interpret as a result of both being driven by the electric field that maps between the magnetosphere and the ionosphere. The model predicts two velocity channels of sunward plasma drift at different latitudes in the dusk sector during the storm main phase, which are identified as the sub-auroral polarization streams (SAPS) and the convection return flow, respectively. The SAPS is responsible for the erosion of the plasmasphere plume and contributes to the ionospheric TEC depletion in the midlatitude trough region. We further find the spatial distributions of the magnetospheric ring current ions and electrons, determined by a delicate balance of the energy-dependent gradient/curvature drifts and the E´B drifts, are crucial to sustain the SAPS electric field that shapes the geospace plume throughout the storm main phase.
AGSDF: A Multiscale Attention Guided DeepOptimization Network for Spatiotemporal Fusion
Authors: Jin Decai
Published: March 2024

Satellites strive to strike a delicate balance between temporal and spatial resolution, thereby rendering the achievement of high resolution in both aspects challenging. In particular, Earth observations at sub-daily intervals are more diffuclt. Spatiotem-poral fusion algorithms have emerged as a promising solution to tackle this challenge. However, the current spatiotemporal fusion methods still face a critical challenge: accurately and efficiently predicting fine images in large-scale area applications, while en-suring robustness. To address this challenge, the study proposes a multiscale Attention-Guided deep optimization network for Spatiotemporal Data Fusion (AGSDF) method. An optimization strategy is employed to directly predict high-resolution image at multi-scales based coarse-resolution image. Specifically, a varia-tion attention module is proposed to focus on the edges and tex-tures of abrupt land cover changes. The spatiotemporal fusion kernel is developed to provide essential spatial details for spatio-temporal fusion. Furthermore, the implementation of spatiotem-poral fusion at multiple scales improves the reliability of predic-tion. The performance and robustness of AGSDF were evaluated and compared to nine methods at six sites worldwide. The exper-imental results indicate that AGSDF achieves a better overall performance in quantitative accuracy assessment, transfer ro-bustness, predictive stability and efficiency. Consequently, AGSDF holds the high potential to produce accurate remote sens-ing products with high temporal and spatial resolution across extensive regions.
Radiative contributions of different cloud types to regional energy budget over the SACOL site
Authors: Wang Meihua
Published: March 2024

Different cloud types have distinct radiative effects on the energy budget of the earth–atmosphere system. To better understandthe cloud radiative impacts, it is necessary to distinguish the effects of different cloud types, which can be achieved throughthe cloud radar data that can provide cloud profiles for both day-to-day and diurnal variations. In this study, we use 6-yearhigh-temporal resolution data from the Ka-Band Zenith Radar (KAZR) at the Semi-Arid Climate and Environment Observa-tory of Lanzhou University (SACOL) site to analyze the physical properties and radiative effects of main cloud types. Thethree types of clouds that occur most frequently at the SACOL site are single-layer ice clouds, single-layer water clouds, anddouble-layer clouds with the annual occurrence frequencies being 29.1%, 3.4%, and 8.3%, respectively. By using the Fu–Liouradiative transfer model simulation, it is found that the distinct diurnal variations of both the occurrence frequency and theirmacro- and micro-physical properties significantly affect the cloud-radiation. On annual mean, the single-layer ice cloudshave a positive radiative forcing of 7.4 W/m 2 to heat the system, which is a result of reflecting 12.9 W/m 2 shortwave (SW)radiation and retaining 20.3 W/m 2 longwave (LW) radiation; while the single-layer water clouds and double-layer cloudshave much stronger SW cooling effect than LW warming effect, causing a net negative forcing of 8.5 W/m 2 . Although allthese clouds have an overall small cooling effect of 1.1 W/m 2 on the annual radiative energy budget, the significant differ-ences of the diurnal and seasonal distributions for different type clouds can lead to distinct radiative forcing. Especially theLW warming effect induced by the exclusive ice clouds in the cold season may have an important contribution to the rapidwinter warming over the semi-arid regions.
New approaches for monitoring forest functioning in a changing climate - crossing scales from molecular mechanisms to stand wide processes
Authors: Gessler Arthur
Published: March 2024

Long-term forest monitoring has a long tradition and provides important information for science-based decisions in forest management and policy. Until recently, mainly “classical” measurements of e.g., radial growth increment, defoliation and mortality have been performed and they are and in future will be core tools for describing forest vitality and functioning. However, new tools are now available that might provide additional information on mechanisms and environmental cause-effect relationships, and I will here give examples spanning from metabolomics via close-to-real-time assessments of growth and water relations to drone-based remote sensing. These methods help to understand the mechanisms which lead to impaired forest functioning and to inform forest adaptive management.We linked assessments of the leaf and root metabolic profile in Scots pine to defoliation and observed homoeostatic levels across a wide range of defoliation classes. Only at very strong defoliation, levels of metabolites related to defence, oxidative stress, osmoregulation and energy supply strongly decreased in the roots but where upregulated in needles indicating a negligence of root functioning at the expense of aboveground tissues.Close-to-real-time assessments with point dendrometers allow to dynamically monitor growth and tree water deficit responses to atmospheric and soil drought complementing annual stem diameter measurements. Species-specific risk assessments can be made and the seasonality of specific environmental factors impairing functioning can be quantified. In combination with xylem flow sensors and in situ water isotopologue monitoring systems, the origin of water taken up by trees can be quantified. With such methods it is possible to assess if trees can switch to deeper soil water resources during drought and how fast they recover their water use after a drought event.With ground-based monitoring it is sometimes not easy to see the forest for the trees. Drone based proximate sensing allows to receive overhead imagery of the crowns and with wavelength-specific sensors reflectance indices can be determined that show stress signals before any classical visual assessment. Drone-based imagery can thus provide early warning signals as well as a link to satellite remote sensing.Such new suites of methods combined with classical forest monitoring and satellite remote sensing are able to detect early warning signals of loss of forest functioning and might allow to determine areas at particular risk, where adaptive forest management needs to be implemented with high priority.
Sequestration of soil organic matter in broadleaf and coniferous forests in soil at various stages of pedogenesis
Authors: Hüblová Lucie , Frouz Jan
Published: March 2024

Soil contains three times more carbon (C) than the atmosphere and biosphere combined. It therefore represents an important tool for removal of carbon dioxide (CO2) from the atmosphere and its long term sequestration. However, in the current climate crisis, C that is already stored in soil reservoir represents a potential threat because different fractions of C in soil have different stability against the rising global temperatures. C is stored in soil in the form of soil organic matter (SOM) which is a mixture of many different organic components. Based on different properties we can divide SOM into two pools. The first pool is represented by small fragments of dead biomass referred to as free particulate organic matter (FPOM). The other pool is comprised of organic matter, usually chemically transformed or converted to microbial necromass, which is in various ways associated with soil mineral matrix. This pool is referred to as mineral associated organic matter (MAOM). It is assumed that MAOM becomes C saturated during soil development because it is limited by the amount of available mineral surfaces. FPOM, on the other hand, does not saturate and can therefore play an important role in later stages of soil development. Beside this some OM is stored in organic horizons in forest floor (Oe layer), which we expect will have similar pattern as FPOM. However, there is scarcity of studies that examine this assumption. In this work we studied the hypothesis that soils in different stages of development will differ in the amount of C stored in FPOM and MAOM fractions. On top of that, we assumed that this difference will be affected by the dominant tree species growing on the soil and the effect of tree species and soil age will not always be additive. We tested this hypothesis by analyzing C storage in soil and amount of C in FPOM and MAOM using two types of soils - recultivated spoil heap (immature soil) and forest soil in the surrounding area (mature soil). Plots with only one type of tree species (spruce or alder) in 3 replications were present on each of these soil types. Our results show that different tree species have different effects on the amount of C stored in mineral soil and Oe layer in immature and mature soils. In mineral soil more, C was sequestered under alder on recultivated heap, while in the surrounding area no difference between tree species was found. In Oe layer more C was sequestered under spruce in both types of soils. Soils did not differ in the amounts of FPOM and MAOM present in soil, but they did differ in the amount of C stored in these fractions. In young soil, MAOM fraction stored more C under alder than spruce. For mature soil the opposite was true. For FPOM fraction no significant effect of tree species or soil age was found but in young soil higher C storage in FPOM was found under alder compared to spruce.
Greater Omnidirectional Ascertain Technology (GOAT) of the Monitoring Vibrations and Perturbations in the Lithosphere, Atmosphere, and Ionosphere (MVP-LAI) Array
Authors: Chen Chieh-Hung , Sun Yang-Yi , Lin Kai , Zhang Xuemin
Published: March 2024

The Monitoring Vibrations and Perturbations in the Lithosphere, Atmosphere, and Ionosphere (MVP-LAI) instrumental array was established in Sichuan, China, in 2021. The MVP-LAI station has demonstrated its efficacy in investigating the causal mechanisms of LAI coupling among multiple geophysical parameters in the vertical direction above a specific area on the Earth's surface during natural hazards such as earthquakes, volcanic eruptions, and landslides. Another MVP-LAI station will be established in Yunnan, approximately 200 km away from the first one, this year. Additionally, a high-frequency Doppler sounder array, comprising two transmitters with distinct frequencies and eight receivers, will be installed in areas covering both MVP-LAI stations to monitor vertical changes in ionospheric layers at two specific altitudes. It is noteworthy that observations from seismometers, magnetometers, and ground-based GNSS receivers in this area can be utilized to capture waves and/or perturbations propagating along the horizontal layer at the Earth's surface, at altitudes of approximately 100 km and 350 km, respectively. The two frequencies employed by the high-frequency Doppler sounder array can aid in comprehending how waves and/or perturbations propagate along the horizontal layers at approximately 200 km and 250 km in altitude. When the two MVP-LAI stations, the high-frequency Doppler sounder array, and substations are integrated, vibrations and/or perturbations propagate both vertically and along the five horizontal layers, even in slant directions, can be detected. The collaboration between MVP-LAI stations and horizontal observations forms the Greater Omnidirectional Ascertain Technology (GOAT), which enhances the understanding of the proportional mechanism for the LAI coupling.
Domino effects of Climate Change on Financial Capital of India under CMIP6 Projections
Authors: Ganesh Vivek , Goswami Santonu , Nagendra Harini
Published: March 2024

Climate change is a major driver of increased flood risk, which is causing economic meltdown in many parts of the world. Globally, economic losses incurred by floods are estimated at around 453 billion USD. In the Asian region, India experienced the third highest economic loss of 4.2 billion USD due to flooding. Mumbai, India’s financial capital, faces climate change threats due to rising sea level, increased rainfall, and intense cyclones, posing risks to infrastructures, economy, and population, especially in low-lying areas. The Mithi river which overflows during monsoon season, plays a crucial role in carrying storm water to the sea in Mumbai. As it flows through an international airport, major industrial complexes and densely populated residentials, these areas became more vulnerable to flooding. This study demonstrates the domino effects of climate change on Mithi River watershed by utilising CMIP6 13 GCM ensembled daily mean precipitation model data for the near future 2030 under shared socio-economic pathways (SSP) 245 and 585 scenarios. Using the Hydrodynamic model GeoHECRAS, the flood inundation depth and extent were estimated. Under both projections, July 25-26, 2030, observed maximum rainfall and exhibited maximum streamflow with a peak discharge of 51.2 m3/sec (SSP245) and 38.5 m3/sec (SSP585). A quantitative risk assessment conducted based on the domino effects triggered by flooding to determine the projected impacted population and economic losses. The annual projected impacted population under both scenarios is observed as SSP245: Very High (0.24M), High (0.74M), Moderate (0.80M), Low (2.90M), and SSP585: Very High (0.68M), High (0.70M), Moderate (0.86M), Low (2.45M). The annual expected amount of urban property damaged due to this effect will range from $157 billion to $535 billion, with a projected affected GDP of more than $84 billion. This cascading effect is likely to disrupt Mumbai's million-dollar trade, affecting global financial flows. This study will be useful to understand the domino effect and raising the flood risk awareness for the development of sustainable policies.Keywords: Domino effects, CMIP6, economic loss, hydrodynamic, flood depth and extent
A daily evapotranspiration-based drought indicator in characterizing spatiotemporal evolution of flash droughts
Authors: Zhang Xia , Duan Jianping , Cherubini Francesco , Ma Zhuguo
Published: March 2024

Droughts cause multiple ecological and social damages. Reliable drought monitoring and forecasting can benefit various sectors by allowing adequate lead times for drought mitigation efforts. Drought indices are key tools to quantify drought severity, but they are currently limited to timescales of monthly or longer. However, shorter-timescale (e.g., daily) drought indices enable more accurate identification of drought characteristics (e.g., onset and cessation time), especially for flash droughts. Here, we propose a daily drought index named daily evapotranspiration deficit index (DEDI) that is constructed based on actual and potential evapotranspiration data. Through comparisons with multiple reference indices and observations, DEDI can well characterize the spatiotemporal evolution of regional drought events that occurred in North China, Southwest China, eastern Northwest China, and Northeast China in the spring and summer of 2019. We have publicly shared the DEDI dataset with a high spatial resolution (0.25°) and a long time series (1979–2022) covering global land areas, available at https://doi.org/10.5281/zenodo.7768534. The dataset has also been validated to have the capability to capture dry and wet variations and to detect ecology- or agriculture-related droughts at a global scale. Overall, the DEDI indicator could be regarded as a practical solution to facilitate flash drought monitoring and early warning.
Study on the collapse characteristics and threshold behavior of the subsurface stormflow mechanism
Authors: Song Yuanxin , Zhang Yanjun , Li Shanqi , Yang Jiahui
Published: March 2024

Abstract: Subsurface stormflow is the dominant runoff generation mechanism during certain flash flood events. The collapse characteristics and threshold behavior are critical to the transition from the slow runoff stage to the rapid runoff stage and the relevant study is not only essential for hydrology theory but also for flash flood disaster prevention. In recent years, efforts have been made to explore the common principles of hydrological processes under strong spatial heterogeneity, but findings from field experiments and numerical studies were difficult to apply to the modeling process. Furthermore, we have yet to develop a deeper understanding of the mechanisms for the impact of complex factors on subsurface stormflow and lack a comprehensive understanding of the formation mechanism of threshold. This presentation discusses how we plan to address this research gap. Firstly, around the phenomenon of “burst-block-burst” in the subsurface stormflow runoff generation process, rainfall-runoff simulation experiments were carried out and factor analysis was conducted to determine the main influencing factors of subsurface stormflow runoff generation. The main influencing factors include soil texture factors, collapse state factors, initial state factors, and other factors, and the influence of these four types of factors decreases in turn. In the second step, we constructed a field hydrological station in the Huanggou Watershed located in Hubei Province, China, collected the rainfall-runoff data, and found that the subsurface stormflow process shows a three-stage-double-threshold behavior: the water storage stage, the initial flow stage, and the rapid flow stage. In the third step, synthesizing the main influencing factors, the three-stage double-threshold process was quantified. Further, the three-stage subsurface stormflow-based model (TSSM) was developed and applied to the Huanggou Hillslope and the Huanggou Watershed. The results show that TSSM performed well, with NSEs of 0.82 and 0.67 in the calibration and verification periods of the Huanggou slope, and NSEs of 0.76 and 0.74 in the calibration and verification periods of the Huanggou Watershed, respectively. This study elucidated the collapse characteristics and threshold behavior of subsurface stormflow and developed an effective simulation model, which contributes to increasing our understanding of three-stage subsurface stormflow and is beneficial for hydrologists to develop more realistic hydrological models.Keywords: Subsurface stormflow; Collapse characteristics; Threshold behavior; Three-stage subsurface stormflow mechanism; TSSM
Numerical Modeling of Fluid Flow in Gas Hydrate Bearing Sediments in Black Sea
Authors: Güvem Bahar , Düşünür Doğan Doğa
Published: March 2024

It is important to understand the stability, behavior and environmental effects of hydrates because gas hydrate reserves are being evaluated as potential energy sources of the future. Many studies have been conducted support that the Black Sea has suitable pressure and temperature conditions for gas hydrate formation, and it has been proven that there are signs of gas hydrate in marine sediments.  In this article, it is aimed to evaluate the effects gas hydrate-derived free gas (methane) found in Black Sea marine sediments and the chemical reaction of hydrate with groundwater over time by using a numerical modeling program. ANSYS Fluent, which is a computational fluid dynamics (CFD) program and works on the principle of finite volumes and whose suitability has been confirmed in past studies in fields with gas hydrate, was used as a numerical modeling program. For the purpose of numerical modeling, a previously collected and published depth-converted seismic reflection profile was selected as a reference model. This reference model includes the Bottom Simulating Reflector (BSR) seismic signature, which serves as a possible indicator of the presence of gas hydrates. Additionally, it incorporates a fault-like irregularity to examine its impact on the model. Through the simulations, the study will be investigated the fluid flow dynamics and the interaction between hydrate-derived free gas and groundwater within the model. The research will be focused on examining the temporal changes in the mass ratios of methane (CH4) as well as the byproducts of this chemical reaction, namely carbon dioxide (CO2) and hydrogen (H2). In addition to the time-depend changes mentioned, the study also involves modeling the impact of the fault, which created discontinuities within the system, on the reactants and byproducts. The movement of these substances within the model, their accumulation within the sediment, and their dispersion or migration away from the model is presented. Simulation results show that dissolution time of methane and production time of carbon dioxide and hydrogen is strongly affected by the presence of faults, sea bottom morphology and initial rate of methane within marine sediments.
Teleconnections among tipping elements in the Earth system
Authors: Liu Teng , Chen Dean , Yang Lan , Meng Jun , Wang Zanchenling , Ludescher Josef , Fan Jingfang , Yang Saini , Chen Deliang , Kurths Jürgen , Chen Xiaosong , Havlin Shlomo , Schellnhuber Hans Joachim
Published: March 2024

Tipping elements are components of the Earth system that may shift abruptly and irreversibly from one state to another at specific thresholds. It is not well understood to what degree tipping of one system can influence other regions or tipping elements. Here, we propose a climate network approach to analyse the global impacts of a prominent tipping element, the Amazon Rainforest Area (ARA). We find that the ARA exhibits strong correlations with regions such as the Tibetan Plateau (TP) and West Antarctic ice sheet. Models show that the identified teleconnection propagation path between the ARA and the TP is robust under climate change. In addition, we detect that TP snow cover extent has been losing stability since 2008. We further uncover that various climate extremes between the ARA and the TP are synchronized under climate change. Our framework highlights that tipping elements can be linked and also the potential predictability of cascading tipping dynamics.
A Study on the Economic Valuation of the Korean Seabed Geological Map
Authors: Park Jungkyu , Um Inkwon
Published: March 2024

The government project to publish the geological map of the seabed of South Korea was initiated in 1975. Over the course of 40 years, until 2015, the geological map of the seabed for the regional scale (1:250,000) covering a total area of 350,000 km2 under the jurisdiction of South Korea was successfully completed. Subsequently, starting in 2016, a new seabed mapping program for the coastal zones of South Korea at a more precise scale (1:100,000) has been in preparation.The geological map of the seabed in South Korea comprises 5 to 8 thematic map sheets, including seabed topography, surface sediment average particle size distribution, surface sediment type distribution, and seabed surface acoustic distribution. These maps play a crucial role in various national infrastructure aspects such as resource development, defense security, educational research, and marine construction. Despite their significance, there exists a lack of public understanding and consensus regarding the necessity and importance of geological seabed maps. This is attributed to their nature as special public goods, not directly utilized by the public and not traded in the market.In light of this, this study aims to evaluate the economic value of the geological map of the seabed, shedding light on the necessity of its preparation and emphasizing its importance. The study measures the range of applications for the geological seabed map, distinguishes consumers and beneficiaries, and quantifies the value of the geological map of the seabed in South Korea using the conditional value method—an established valuation technique for non-market goods.
Connecting Arctic Changes to Global Weather Patterns: Exploring the Interplay
Authors: Meng Jun
Published: March 2024

Embarking on an urgent exploration of the profound decline in Arctic sea ice, this presentation underscores its extensive impact on global weather patterns and stresses the importance of comprehending Arctic weather variability (WV) for accurate forecasting and analysis of extreme weather events. In addressing the challenge of quantifying WV and its implications amidst human-induced climate change, we introduce an innovative complexity-based approach. Our investigation reveals a robust statistical correlation between intraseasonal WV in the Arctic and the Arctic Oscillation, shedding light on the heightened daily variability in Arctic sea ice—an outcome of its accelerated decline due to global warming. Delving into the interconnected dynamics, we unveil atmospheric teleconnections influencing regional patterns, posing elevated risks to human activities and forecast predictability. The analyses unearth a positive feedback loop between Arctic and global weather instabilities, providing profound insights into the intricate ways Arctic changes resonate worldwide. This comprehensive framework bridges complexity science, Arctic WV, and the wide-reaching implications that warrant collective attention and action.