bluuebunny/crossref_metadata_2025 huggingface dataset:
Changes in ocean circulation and dissolved oxygen/nutrient distributions in the Canadian Basin
Authors: Nishino Shigeto , Jung Jinyoung , Cho Kyoung-Ho , Williams William , Fujiwara Amane , Murata Akihiko , Itoh Motoyo , Watanabe Eiji , Hatta Mariko , Yamamoto-Kawai Michiyo , Kikuchi Takashi , Yang Eun Jin , Kang Sung-Ho
Published: March 2024

The Arctic Ocean is facing dramatic environmental and ecosystem changes. To obtain the current baseline data, a coordinated multiship and multination pan-Arctic ship-based sampling campaign was implemented for the period between 2020 and 2022 under the project of Synoptic Arctic Survey (SAS). During the 2020 survey, unusually low dissolved oxygen and acidified water (salinity = 34.5) were found in a high-seas fishable area of the western (Pacific-side) Arctic Ocean. The data showed that the Beaufort Gyre (BG) shrunk to the east of the Chukchi Plateau (CP) and formed a front between the water within the gyre and the water from the eastern (Atlantic-side) Arctic. That phenomenon triggered a frontal northward flow along the CP. This flow likely transported the low oxygen and acidified water toward the high-seas fishable area; similar biogeochemical properties had previously been observed only on the shelf-slope north of the East Siberian Sea (ESS). Northward flows were also predominant west of the CP associated with the penetration of the water from the eastern Arctic. The northward flows would transport nutrient-rich shelf water (salinity = 32.5) from the ESS to the southwestern Canadian Basin (CB). Furthermore, the northeastward flow of the shrunk BG during the SAS period (2020-2022) could spread the nutrient-rich ESS shelf water to the northeastern CB. As a result, the nutrient concentration there during the SAS period was higher than the period when the BG enlarged to the west of CP, because the westward flow of the BG that overshot the CP inhibited the northward transport of the nutrient-rich ESS shelf water toward the southwestern CB. As a future study, we would like to combine the data from the Atlantic gateway because the ocean circulation and dissolved oxygen/nutrient distributions in the CB are largely influenced by the penetration of the water from the eastern Arctic. This is a reason why we have applied to present in this session.
Quantifying predictive uncertainty in satellite precipitation data correction using ensemble learning
Authors: Papacharalampous Georgia , Tyralis Hristos , Doulamis Nikolaos , Doulamis Anastasios
Published: March 2024

We present the first ensemble learning methods for quantifying predictive uncertainty in satellite precipitation data correction, as well as the large-scale comparison of these methods. Ensemble learning was performed by combining in multiple ways a variety of machine learning algorithms that are particularly suited for the task of interest. Monthly precipitation data from across the contiguous United States supported the comparison, which predominantly relied on skill scores and referred to the ability of the ensemble learning methods in delivering predictive quantiles at many levels. The results allow the ordering from the best to the worst of the ensemble learning methods.Acknowledgements: The research project was supported by the Hellenic Foundation for Research and Innovation (H.F.R.I.) under the “3rd Call for H.F.R.I. Research Projects to support Post-Doctoral Researchers” (Project Number: 7368).
Predictive uncertainty estimation in satellite precipitation data correction using machine learning
Authors: Tyralis Hristos , Papacharalampous Georgia , Doulamis Nikolaos , Doulamis Anastasios
Published: March 2024

Predictive uncertainty estimates for precipitation data acquired through merging satellite and ground-based observations are usually not provided. Here, we present the first benchmark experiments on the use of machine learning algorithms for fulfilling the task of delivering such estimates. These experiments compared six machine learning algorithms (i.e., quantile regression, quantile regression forests, generalized random forests, gradient boosting machines, light gradient boosting machines and quantile regression neural networks) and relied on 15-year-long monthly data that originate from across the contiguous United States. The comparison referred to the ability of the machine learning algorithms in delivering predictive quantiles at various levels. The results allow the ordering from the best to the worst of the machine learning algorithms for the problem of interest.Acknowledgements: The research project was supported by the Hellenic Foundation for Research and Innovation (H.F.R.I.) under the “3rd Call for H.F.R.I. Research Projects to support Post-Doctoral Researchers” (Project Number: 7368).
The combined time-depth conversion as a method for a better imaging of complex scenarios
Authors: Persico Raffaele , Catapano Ilaria , Esposito Giuseppe , Morelli Gianfranco , De Martino Gregory , Capozzoli Luigi
Published: March 2024

In this contribution we will propose a resume regarding the technique of the combined time depth conversion, which is relevant to particular cases in the framework of the GPR prospecting, that are of interest when layered scenarios are met, or in cases when electrically large cavities are likely found [1]. These cases are particularly relevant for the urban geophysics, because of the intrinsic layered structure of many engineering works and for the risk of subsidence due to unknown buried cavities.In these cases, the problem is often computationally too cumbersome to be afforded in its entire complexity [2]. On the other hand, a common GPR processing [3] might not provide a correct imaging of the buried scenario, because in layered media the first (shallower) layer would result spuriously compressed or spuriously dilatated with respect to the other ones, whereas a buried cavity would (and does) appear all the times incorrectly compressed.These well-known problems are due to the different propagation velocity of the electromagnetic waves within the different media.However, if one of these cases is recognizable from the data, it can be possible to operate a suitable localized expansion of the compressed parts of the image, that can be -let say- ironed up to its correct vertical size [4].This makes it possible to represent the different buried targets in more realistic reciprocal positions and proportions, so making clearer the image. In particular when a slicing is applied or (in some cases) a pseudo 3D perspective imaging, the combined time-depth conversion can meaningfully improve the interpretation of the buried scenario.At the conference, both simulated and experimental results in controlled condition will backup these reasoning. References[1] R. Persico, S. D'Amico, L. Matera, E. Colica, C. De, Giorgio, A. Alescio, C. Sammut and P. Galea, GPR Investigations at St John's Co‐Cathedral in Valletta. Near Surface Geophysics, vol. 17 n. 3, pp. 213-229. doi:10.1002/nsg.12046, 2019.[2] I. Catapano, L. Crocco, R. Persico, M. Pieraccini, F. Soldovieri, “Linear and Nonlinear Microwave Tomography Approaches for Subsurface Prospecting: Validation on Real Data”, IEEE Trans. on Antennas and Wireless Propagation Letters, vol. 5, pp. 49-53, 2006.[3] A. Calia, G. Leucci, M. T. Lettieri, L. Matera, R. Persico, M. Sileo, The mosaic of the crypt of St. Nicholas in Bari (Italy): Integrated GPR and laboratory diagnostic study, Journal of Archaeological Science, vol. 40, n. 12, pp. 4162-4169, December 2013.[4] R. Persico, F. Marasco, G. Morelli, G. Esposito, I. Catapano, “A posteriori insertion of information for focusing and time–depth conversion of ground-penetrating radar data”, Geophysical Prospecting, open access, https://doi.org/10.1111/1365-2478.13369, 2023.
Open Science Collaboration across Eath Observation Platforms
Authors: Simonis Ingo , Voidrot Marie-Francoise , Opitz Rachel , Zaborowski Piotr
Published: March 2024

Collaborative Open Science is essential to addressing complex challenges whose solutions prioritize integrity and require cross-domain integrations. Today, building workflows, processes, and data flows across domains and sectors remains technically difficult and practically resource intensive, creating barriers to whole-systems change. While organizations increasingly aim to demonstrate accountability, they often lack the tools to take action effectively. By making it simple to connect data and platforms together in transparent, reusable and reproducible workflows, the OGC Open Science Persistent Demonstrator (OSPD) aims to enable responsible innovation through collaborative open science. The OSPD focuses specifically on using geospatial and earth observation (EO) data to enable and demonstrate solutions that create capacity for novel research and accelerate the practical implementation of this research.Collaborative Open Science and FAIR (Findable, Accessible, Interoperable, Reusable) data are widely recognized as critical tools for taking advantage of the opportunities created through addressing complex social and environmental challenges. To date, many millions have been invested in hundreds of initiatives to enable access to analytical tools, provide data management, data integration and exchange, translate research results, and support reproduction and testing of workflows for new applications. These investments have resulted in a plethora of new data, protocols, tools and workflows, but these resources frequently remain siloed, difficult to use, and poorly understood, and as a result they are falling short of their full potential for wider impact and their long term value is limited.This presentation will illustrate how the OGC OSPD Initiative, through its design, development and testing activities, provides answers to leading questions such as:How can we design Open Science workflows that enable integration across platforms designed for diverse applications used in different domains to increase their value?
How can we lower barriers for end users (decision makers, managers in industry, scientists, community groups) who need to create Open Science workflows, processes, and data flows across domains and sectors remains technically difficult and practically resource intensive, creating?
How can Open Science workflows and platforms enable collaboration between stakeholders in different domains and sectors?
How can we empower organizations to demonstrate accountability in their analytical workflows, data, and representations of information through Open Science?
What Open Science tools do organizations need to take action effectively?
How can Open Science and FAIR data standards practically support accountability?
How can we make it simple to connect data and platforms together in transparent, reusable and reproducible (FAIR) workflows?
What are the specific challenges of using geospatial, earth observation (EO), and complementary data in this context?
Effect of Hydrophobicity on the Transport of Carbon Nanoparticles in Saturated and Unsaturated Porous Media
Authors: Hassanpour Bahareh , May Daniel , SinClair Laura , Steenhuis Tammo , Cathles Lawrence
Published: March 2024

Carbon-based nanoparticles (CNPs) are increasingly used for environmental and industrial applications such as in pharmaceuticals, energy production, and water and wastewater treatment. Thus, it is crucial to understand their interactions and transport in porous media. Here, we examine the impact of CNP hydrophobicity and porous medium surface area on their transport. We use CNPs that are synthesized from citric acid and ethanolamine and are fluorescent. They exhibit synthesis-temperature-dependent hydrophobicity and were synthesized at four temperatures: 190 °C, 210 °C, 230 °C, and 250 °C. The experiments were conducted by flowing these CNPs in sand-packed columns under saturated and unsaturated conditions. To examine the impact of the surface area of sand on CNP transport, the sands packed in the columns had three surface areas. In addition, a particle transport model in HYDRUS 1D was used to model the transport.Together, our experimental and modeling noted four important observations. The first observation indicated the importance of hydrophobicity on CNP transport. There was a 55% difference between the recovery of CNPs synthesized at 190 °C compared to those synthesized at 250 °C. Second, a five-fold increase in surface area yielded a 17% decrease in the recovery of CNPs, suggesting the role of sand surface area on CNP recovery. Third, due to the small size of CNPs relative to the water film on the sand surface, there were no significant differences in the mass recovery of CNPs under unsaturated and saturated conditions. Fourth, the particle transport model with a Langmuirian site blocking term successfully simulated the transport of CNPs. There was approximately a 10-fold increase in the adsorption coefficients for hydrophobic CNPs compared to hydrophilic ones. In sum, our observations and modeling demonstrated that hydrophobicity was a major factor that impacted the transport of CNPs.  
Enhanced nitrogen wet deposition induced by landfalling typhoon over East Asia: Mechanism and Implications
Authors: Ge Baozhu
Published: March 2024

Wet deposition of reactive nitrogen (Nr) induced by typhoons has significant eco-environmental impacts on the oceans, especially under the growing frequency of landfalling typhoons in East Asia. However, little is known about the mechanism of how anthropogenic activities influence the ocean ecosystem by interacting with landfalling typhoons. Based on the Nested Air Quality Prediction Modeling System, the Nr wet deposition induced by landfalling typhoon Hagupit 2020, and the ecological response, were explored. The Nr wet deposition over both the Yellow Sea and the Sea of Japan after landfall was found to have increased by up to 1000 times that of the pre-landfall ocean influenced by the typhoon. This high Nr wet deposition was mainly due to the “pumping effect” mechanism of the typhoon, which is strong uplifts of the typhoon rapidly carried surface air pollutants up to high altitudes from the land, following a large wet deposition through long-range transport towards downwind ocean, finally led to a high-concertation chlorophyll-a bloom. This study improves our understanding of Nr wet deposition induced by landfalling typhoons, and helps in the establishment of effective and active measures and to reveal marine ecology damaged by extremely strong convective weather systems
Reservoir characteristics and diagenetic evolution of Kukebai Formation in Kekeya area, Southwest Depression of Tarim Basin
Authors: Wang Hongdong , Zhang Liqiang
Published: March 2024

In order to explore the favorable reservoir characteristics and diagenetic evolution laws of the Cretaceous Kukebai Formation in the Kekeya area of the southwestern Tarim Basin, and provide theoretical basis for oil and gas exploration and development in the study area, comprehensive data such as core, cast thin sections, and carbon and oxygen isotopes were used to carry out the classification of diagenetic facies types and the study of diagenetic evolution models. The results indicate that the reservoir of the Kukebai Formation in the study area is mainly composed of feldspar lithic sandstone and lithic feldspar sandstone, with mainly developed diagenetic processes such as compaction, cementation, and dissolution. The diagenetic stage is in the middle diagenetic stage A. The Kukebai Formation reservoir mainly develops four types of diagenetic facies: moderately compacted dissolution facies, moderately compacted cementation facies, strongly compacted compaction facies, and strongly cemented facies. Among them, the strong compacted phase becomes a dense reservoir due to mechanical compaction in the early stage of diagenesis, and is mainly distributed in the sand mud interbedded layers of sedimentary microfacies between river channels and estuarine dams; The strongly cemented phase is densified in the early diagenetic stage due to the precipitation of a large amount of carbonate cement, mainly developed in the sand mud interbedded layers near the mud end of underwater distributary channels and the sedimentary microfacies of estuarine dams; The dissolution effect of medium compacted dissolution phase sandstone is strong, and the reservoir properties are the best, mostly appearing in the upper part of distributary channel sand bodies with strong sedimentation and water accumulation dynamics; The medium compacted and cemented sandstone has moderate compaction, and the reservoir properties are relatively good. It mainly develops in the lower part of distributary channel sand bodies with strong hydrodynamics. There are two types of favorable reservoirs in the study area, namely the medium compacted cementation phase and the medium compacted dissolution phase sandstone.
Trends and drivers of aerosol vertical distribution over China from 2013 to 2020: Insights from integrated observations and modeling
Authors: Chen Xi , Li Ke , Yang Ting , Yang Zhenjiang , Wang Xueqing , Zhu Bin , Chen Lei , Yang Yang , Wang Zifa , Liao Hong
Published: March 2024

Understanding aerosol vertical distribution is of great importance to climate change and air quality management, but there is a dearth of systematical analysis for aerosol vertical distribution amid rapid emission decline after 2013 in China. Here, the GEOS-Chem model and multiple-sourced observations were applied to quantify the changes of aerosol vertical distributions in response to clean air actions. In 2013–2020, the MODIS aerosol optical depth (AOD) presented extensive decreasing trends by −7.9 %/yr to −4.2 %/yr in summer and −6.1 %/yr to −5.8%/yr in winter in polluted regions. Vertically, the aerosol extinction coefficient (AEC) from CALIPSO decreased by −8.0 %/yr to -5.5 %/yr below ~1 km, but the trends weakened significantly with increasing altitude. Compared with available measurements, the model can reasonably reproduce 2013–2020 trends and seasonality in AOD and vertical AECs. Model simulations confirm that emission reduction was the dominant driver of the 2013–2020 decline in AOD, while the effect of meteorology varied seasonally, with contributions ranging from −2% to 13% in summer and −67% to −2% in winter. Vertical distributions of emission-driven AEC trends strongly depended on emission reductions, local planetary boundary layer height, and relative humidity. For aerosol components, sulfate accounted for ~50% of the AOD decline during summer, followed by ammonium and organic aerosol, while in winter the contribution of organic aerosol doubled (24%–35%), and nitrate exhibited a weak increasing trend. Chemical production and meteorological conditions primarily drove the nitrate contribution, but emission reduction and hygroscopicity were decisive for other components. This work highlights the importance of integrating observational and modeling efforts to better understand rapid changes in aerosol vertical distribution over China.
Oceanic and Atmospheric Drivers of Post-El-Niño Chlorophyll Rebound in the Equatorial Pacific 
Authors: Lim Hyung-Gyu , Dunne John , Stock Charles , Ginoux Paul , John Jasmin , Krasting John
Published: March 2024

The El Niño-Southern Oscillation (ENSO) strongly influences phytoplankton in the tropical Pacific, with El Niño conditions suppressing productivity in the equatorial Pacific (EP) and placing nutritional stresses on marine ecosystems. The Geophysical Fluid Dynamics Laboratory's (GFDL) Earth System Model version 4.1 (ESM4.1) captures observed ENSO-chlorophyll patterns (r = 0.57) much better than GFDL's previous ESM2M (r = 0.23). Most notably, the observed post-El Niño “chlorophyll rebound” is substantially improved in ESM4.1 (r = 0.52). We find that an anomalous increase in iron propagation from western Pacific (WP) subsurface to the cold tongue via the equatorial undercurrent (EUC) and subsequent post-El Niño surfacing, unresolved in ESM2M, is the primary driver of chlorophyll rebound. We also find that this chlorophyll rebound is augmented by high post-El Niño dust-iron deposition anomalies in the eastern EP. This post-El Niño chlorophyll rebound provides a previously unrecognized source of marine ecosystem resilience independent from the La Niña that sometimes follows.
Reclamation of moderately degraded urban soils: creation of a cognitive model to link soil organisms’ functional traits to soil processes & functions
Authors: Caron Lucie , Auclcerc Apolline , Séré Geoffroy
Published: March 2024

Human activities frequently cause soil degradation, altering its multifunctionality and therefore its capacity to provide ecosystem services. Urban soil degradation notably results in high bulk densities due to trampling and machine traffic, loss of biodiversity, and lack of organic matter. The anthropic and ecological functions of soils can then be dysfunctional.One of the major pillars in maintaining the balance of these ecosystems are the living organisms that populate them. Through their diverse lifestyles, soil fauna plays an active role in soil functions at different scales, through the prism of their functional traits.We would like to promote the development of “pedofauna engineering” as a tool for the ecological reclamation of moderately degraded urban soils.A conceptual framework has been created, linking functional traits of interest to soil fauna in the water cycle regulation function. We considered two sub-functions (infiltration and retention of water) and four soil processes in relation to them (creation of porosity, bioturbation, aggregation and organic matter fragmentation). To assess the success of reclamation through functional traits, it also appears that residual activities (e.g. burrows, biogenic aggregates) of soil organisms could be considered as relevant indicators of the ecological processes.In order to test these postulates, we have selected a list of functional traits and attributes of interest in relation to soil compaction. Three species of organisms carrying the traits of interest (Lumbricus terrestris anecic worm, Eisenia fetida epigeal worm and Porcelio scaber isopod) were introduced into cosmes with urban park soil, compacted at 1, 1.3 and 1.45 g cm-3.Our results demonstrate that soil organisms with their related functional traits and attributes "Strong capacity to dig burrows", "Strong capacity to move in the soil" and "Body length between 12 and 22 cm", led to the creation of macroporosity and enhance the infiltration of water into the soil.This conceptual framework is a work in progress but can surely provide a deeper and better understanding of the who and how of soil fauna's involvement in soil multifunctionality.
Long-term coupled variability of temperature and precipitationin eastern China and the underlying mechanisms
Authors: Zhang Yue , Zhou Wen
Published: March 2024

This study investigates the coupled variability of temperature and precipitation in eastern China during summer using empirical orthogonal function (EOF) analysis to better understand and mitigate simultaneous occurrences of extreme events,such as compound droughts and heat waves. Two dominant modes are identified: the first exhibits a strong warming and drying trend in the region north of the Yangtze River, with the opposite occurring in the south; the second illustrates decadal oscillations in temperature and precipitation, alternating between cool-wet conditions and warm-dry conditions in southern China. The underlying mechanisms for these leading modes are revealed through correlation, composite analysis,and model simulations. The first mode is associated with a negative Pacific-Japan teleconnection in the lower atmosphere and a stationary Rossby wave train across Eurasia in the upper troposphere, which are influenced by global warming and sea surface temperature anomalies in the western North Atlantic. The second mode is linked to alternating active periods of the North Atlantic Oscillation (NAO) and Pacific Decadal Oscillation (PDO). The NAO exerts a significant influence on the summer climate in eastern China during its active phases, while the PDO shows an opposite effect when the NAO is less active. These findings provide valuable implications for long-term planning and adaptation strategies to better cope with compound extreme events in eastern China.
The Mineralogy and Unique Widmanstatten Pattern in Iron Meteorites
Authors: Subhi Salma , Alowais Aisha
Published: March 2024

This research aims to investigate iron meteorites samples, in terms of their elemental composition, distinguished structure, and their role in enhancing our understanding of the early solar system astrophysical processes. Iron meteorites represent a distinctive category of extraterrestrial materials, provide valuable insights into the formation and composition of asteroids, and the historical evolution of the early solar system around 4.6 billion years ago. Physical tests, including magnetism, fusion crust, density, and the window test, were performed on 140 samples from 2017 to 2023, with 161 analyses being carried out.  In addition to that, the study sheds light on the metallic phases of an oriented intergrowth of kamacite and taenite bands, revealing their occurrence in a unique Widmanstatten pattern. This pattern is visible on the studied samples that have been cut, polished, and etched with a weak, nitric acid. This remarkable pattern provides essential information for unraveling the thermal and cooling histories of these celestial bodies. Advanced analytical techniques such as X-ray fluorescence (XRF), and X-ray diffraction (XRD), were employed to identify the mineralogy and chemical composition of a diverse array of specimens. Iron-nickel minerals such as Kamacite are commonly found in the studied samples as well as the presence of troilite (FeS) inclusions, and traces of other elements. Of the 140 samples, three samples from different countries were identified as iron meteorites, allowing for a nuanced exploration of their unique characteristics. The chemical composition and mineralogy of the samples, revealed by the mentioned techniques, lead us to conclude that these samples formed at the core of asteroids or fragmented planets. This research contributes significantly to the UAE’s planetary science program and enriches meteoritic studies for university students and researchers in this field.
The new thermodynamic potential of seawater in terms of Conservative Temperature 
Authors: McDougall Trevor
Published: March 2024

A new thermodynamic potential of seawater is found with the temperature variable being Conservative Temperature.  From this thermodynamic potential all the thermodynamic variables of seawater can be calculated.  This thermodynamic potential adds to the two other thermodynamic potentials, the Gibbs function and the Helmholtz function, which have been known for more than a century.  Because of the advantages of using Conservative Temperature instead of in situ temperature, it is expected that the new thermodynamic potential will replace the Gibbs function in oceanography.  The new thermodynamic potential can be expressed as the sum of two parts, one depending on enthalpy and the other on entropy, and it is shown that there is a clean separation between the thermodynamic properties such as specific volume and sound speed that depend only on enthalpy, and those that depend also on enthalpy such as in situ temperature. 
Study on the 3DVar emission inversion method combined with machine learning in CMAQ
Authors: Huang Congwu , Wang Tijian , Niu Tao
Published: March 2024

The air quality model is increasingly important in air pollution forecasting and controlling. Emissions significantly impact the accuracy of air quality models. This research studied the 3DVar (three-dimensional variational) emission inversion method based on machine learning in CMAQ (The Community Multiscale Air Quality modeling system). The ExRT(extremely randomized trees method) machine learning conversion matrixes were established to convert the pollutant concentration innovations to the corresponding emission intensity innovations, extended 3DVar to emission inversion. The O3 and NO2 concentration, NOx and VOCs emissions are modeled using machine learning, taking account of the nonlinearity of the O3-NOx-VOCs processes. This method significantly improved the simulation ability of O3. Taking the air pollution process in the BTH region from January 15 to 30, 2019 as an example, ExRT-3DVar (3DEx) and Nudging (Nud) emission assimilation experiments were caried out. Compared with the simulation without assimilation (NODA), the Nudging method has better assimilation effects on PM10 and NO2, with the regional errors reduced by 14%, 2%, and the temporal errors reduced by 31%, 34%; ExRT-3DVar has better effects on the assimilation of PM2.5, O3, SO2, the regional errors were reduced by 40%, 29%, 13%, and the temporal errors were reduced by 49%, 10%, 33%. This simplicity, efficiently and extensibility framework of ExRT-3DVar method has been proved to be a good way to adjust emissions in CMAQ and still remains much to be done in the future.
Observed responses of tides and gravity waves in the MLT region to the Madden-Julian Oscillation
Authors: Zhou Xu , Yue Xinan , Liu Libo , Chen Guiwan , Lu Xian , Yu You , Hu Lianhuan
Published: March 2024

This work analyzed the intraseasonal variability of non-migrating tides DE3 and gravity wave momentum fluxes (GWMF) in the mesosphere and lower thermosphere (MLT) region and discussed the possible connection with the tropospheric MJO. Based on the joint observations of the TIMED-TIDI satellite and the 120°E meridian meteor radar chain, we revealed a significant broad-band intra-seasonal signal in the DE3 amplitude around the equator with a clear seasonal dependence. The intraseasonal variability of DE3 in zonal winds (DE3-U) has a strong amplitude in boreal winter, up to 1-2 times the seasonal average, while the variability is usually within 20% during other seasons. The response of MLT DE3 tides to the MJO in different seasons was further discussed together with the MJO activity index. The results suggested that the DE3-U in boreal winter generally has a larger amplitude during MJO phases 4–6 (~10%–40%), while the amplitude is smaller for other MJO phases (~−10%–−40%). As for the GWMF estimation, the 12-year continuous observation of the Mohe meteor radar (53.5°N, 122.3°E) was analyzed. The results showed that intraseasonal GWMF variability is also prominent during boreal winter. Composite analysis for DJF season according to MJO phases revealed that the zonal GMWFs notably increased in MJO P4 by ~2–4 m2/s2, and a Monte Carlo test was designed to examine the statistical significance. The response in zonal winds differs from the GMWF response by two MJO phases (i.e., 1/2π). Additionally, time-lagged composites revealed the strengthened westward GWMF occurred ~25–35 days after MJO P4, coincident with the MJO impact on the polar vortex as previous works revealed. Overall, this work emphasized that the tropical sources (MJO) impress the intraseasonal signal from the troposphere to the MLT region, either tropics or extratropics.
Exploring the Mechanisms and Vegetative Influence on River Bank Migration in Sinuous Channels
Authors: Maurya Om Prakash , Modalavalasa Dr. Suresh , Das Saikat , Barman Pranay , Das Arpita , Nandi Dr. Ketan Kumar , Dutta Prof. Subashisa
Published: March 2024

The migration of alluvial river banks plays a crucial role in the degradation of fertile agricultural land and the displacement of floodplain communities. This study aims to investigate the mechanisms driving riverbank migration in sinuous channels, as well as the protective role of vegetation along the river banks. To comprehend these mechanisms, we conducted experimental studies at the IIT Guwahati fluvial laboratory and numerical simulations using Flow3D. For assessing the impact of vegetation, field observations and satellite imagery analyses were carried out. In examining vegetation influence, a critical stretch of the Nagavali River near Belmam village was identified. Upstream of the village, the outer river bank, lacking vegetation, migrated 100 meters over 12 years, while the downstream vegetated outer bank experienced negligible migration. A similar analysis was conducted on the Kaw River in different regions, revealing that non-vegetative banks migrated nearly 100% of the entire river width over 22 years. To unravel the mechanism behind bank migration, flume experiments and numerical simulations of sinuous channels were conducted. The findings indicated that at the outer bank, secondary currents dominated, emerging as a significant factor in migration. While the numerical study offered a detailed qualitative understanding of the mechanism, it exhibited an error ranging from 22% to 37% from the inner bank to the outer bank. This study extends its focus to a quantitative exploration of floodplain vegetation's role in riverbank protection and proposes a nature-inspired solution, against riverbank migration.
Population exposure to extreme precipitation under a changing climate in Eastern China
Authors: Sun Hemin , Yang Ruozi , Li Lin
Published: March 2024

Under the global warming, the frequency of extreme precipitation has increased, and the return period of it has changed. The original extreme analysis method based on stationary theory will underestimate the risk of extreme precipitation. Based on observed hourly precipitation data during 1960 to 2019, a non-stationary frequency analysis of the annual maximum (AM) precipitation for China was conducted, then estimate the difference between stationary and non-stationary estimated return periods using Bayesian inference. After that, projected the extreme precipitation risk under different SSP-RCPs scenarios by the CMIP6 models. The results shown that the trends of 1-, 2-, 3-, 6-, 12-, 24-, 48-, 96- and 168-hr AM precipitation in China are complex. The shorter the duration, the more stations that show an upward trend. For a 20-yr to 100-yr return period of 1-hr extreme precipitation, the difference between the non-stationarity and stationarity extreme precipitation is large, and at the station with the upward trend that a stationary assumption may lead to underestimation of extreme precipitation about 32%; the average difference over 24-hr is relatively small, and the difference at station with downward trend is about -17%～-23%. The difference between the extreme precipitation return period under non-stationarity and stationarity assumption decreases with the extension of the duration, and the uncertainty increases as the return period increases in all conditions. The ensembled GCMs show that the precipitation in the 21st century show a fluctuating upward trend in China. The 100-yr return period of 24 -, 48 -, 96 - and 168-hr extreme precipitation changed differently under different scenarios in the early period (2021-2040), the middle period (2041-2060) and the later period (2081-20100). The area exposed to extreme precipitation with 1995 to 2014 100-yr return period under different scenarios varies greatly, among which SSP5-8.5 is the largest and SSP1-1.9 is the smallest. In the short, medium and long period, with the increase of extreme precipitation intensity, the exposure area is increasing. Because of the population change, the characteristics of the exposed population and the exposed area are different. In the medium period, the exposed population is also the largest as the population reaches the peak. Under the assumption of a non-stationary climate, the social-economic exposure of extreme precipitation return level and return period providing new methods and scientific information for design, decision-making, and assessing the impacts of climatic events.
Critical Soil Moisture Content Estimated from Lysimeter Time Series for Different Soil, Vegetation and Weather conditions
Authors: Lu Xiao , Groh Jannis , Pütz Thomas , Graf Alexander , Javaux Mathieu , Vereecken Harry , Hendricks Franssen Harrie-Jan
Published: March 2024

Evapotranspiration (ET) is a crucial terrestrial ecosystem process that links water, energy, and carbon cycles. ET can be limited by either energy or water availability. The transition between water- and energy-limited regimes is associated with the soil moisture content, and can be postulated as the soil moisture content reaching a threshold, denoted as critical soil moisture (θcrit). Knowledge of θcrit is important for improving land surface, hydrological and crop models and predicting hydroclimate extremes such as droughts and heatwaves. However, the quantification of θcrit and the factors that impact θcrit are still not well understood. Here we used precise lysimeter observations to quantify θcrit by analyzing the relationship between soil moisture content and evaporative fraction (EF), as well as the relationship between soil moisture content and the actual ET/ potential ET ratio during drydowns. We estimated θcrit not only at the surface layer using in situ soil moisture measurements at 10 cm depth, but also for the root zone using vertically integrated in situ soil moisture (0–50 cm) observations. We estimated θcrit across various soil textures (e.g., sandy loam, silty loam, clay loam), vegetation types (grass, crop), as well as weather conditions from western and eastern Germany (spatial distances: 10 ~ 600 km). Especially, with some lysimeters that were taken from their original environment and translocated to other regions, we can identify the shift of θcrit with the same soil and vegetation but under different weather conditions, which can provide implication on changes of θcrit under global warming. We would expect a dependence of θcrit on soil texture and weather condition. We found for example that at the same site with the same crop rotation on the lysimeters but different soils, the sandy loamy soil experienced a lower θcrit (approximate 0.15 m3/m3) than the silty loamy soil (approximate 0.17 m3/m3), indicating that the higher content of sand would lead to the lower θcrit. In addition, an increase in θcrit was observed when the lysimeter was translocated from a site with a lower potential ET to a site with a higher potential ET.
Sedimentary Evolution Characteristics of Middle Cambrian Carbonate Platform in Tabei Area
Authors: Wang Jingxuan , Yu Kuanhong , Maimaiti Aizimaiti
Published: March 2024

Tabei area is an important area of Cambrian ultra deep exploration in Tarim Basin. Middle Cambrian dolomite reservoirs are developed and the relationship between reservoir and cap rock configuration is complex. Therefore, the study of sedimentary facies types and their distribution characteristics is of great significance for the next exploration plan in the region. This study is based on drilling and seismic data within the work area, and comprehensively analyzes the sedimentary evolution process of the Middle Cambrian platform in the Tabei area through petrology, seismic facies, and well connected sedimentary facies. The research results indicate that the Middle Cambrian in the study area is a typical bordered platform, which is influenced by ancient terrain and develops (evaporates) tidal flats, reef shoals, platform edge reef shoals, slopes, and basins from west to east. The overall trend of the facies belt shows an eastward migration. The Taiwan region mainly develops tidal flat, evaporative tidal flat, and granular beach, further divided into six microfacies such as argillaceous dolomite and micritic dolomite. Six stages of reef shoals are developed at the edge of the platform, stacked in an aggradation progradation manner. Based on comprehensive analysis, it is believed that in addition to the platform edge reef beach body, the dolomite behind the reef beach is another favorable facies zone with good exploration potential.
Perspectives for the lignite post-mining landscapes of the lignite mining landscapes under changing environmental conditions – what can we learn from a comparison between the Rhenish and the Lusatian regions in Germany?
Authors: Lehmkuhl Frank , Gerwin Werner , Raab Thomas , Birkhofer Klaus , Hinz Christoph , Letmathe Peter , Leuchner Michael , Roß-Nickoll Martina , Rüde Thomas R. , Trachte Katja , Wätzold Frank
Published: March 2024

The German government's decision to phase out lignite mining by 2038 or earlier, as recently 2030 has been agreed for the Rhineland, will trigger a number of transition processes in Germany's remaining lignite mining areas. The two largest lignite mining areas are located in geographically different regions: Rhineland in the west and Lusatia in the east. As the socio-economic and environmental conditions in these two mining areas are set to change dramatically, the German government has adopted extensive economic support measures. However, the environmental changes will also lead to changes in the ecosystem functions and services provided by the future post-mining landscapes.Gerwin et al. (2023) compare the two main lignite producing regions of Germany in terms of their natural and cultural environments. The economic situation and its history are reflected and differences are outlined. Part of the differences in cultural development can be explained by the natural conditions, especially the edaphic factors and the climatic situation. Because of the specific geological settings, tailored mining technologies were developed and used in the two regions, with different effects on the resulting post-mining landscapes.We conclude that the landscapes of Lusatia and the Rhineland have been radically restructured by the long and varied history of lignite mining. Both regions will change significantly as the mining industry continues to decline and is expected to cease altogether within the next decade. These changes in the post-mining landscapes and the ecosystem services will provide both challenges and opportunities. The preconditions for positive socio-economic development and for sustainable land use concepts that also consider ecological aspects are different for the two regions. The exchange of knowledge and experience between the two mining regions is crucial to the success of this major transformation process, despite, or perhaps because of, these differences.Gerwin, W., Raab, T., Birkhofer, K., Hinz, C., Letmathe, P., Leuchner, M., Roß-Nickoll, M., Rüde, T., Trachte, K., Wätzold, F., Lehmkuhl, F. (2023): Perspectives of lignite post-mining landscapes under changing environmental conditions: what can we learn from a comparison between the Rhenish and Lusatian region in Germany? Environmental Sciences Europe 35:36. https://doi.org/10.1186/s12302-023-00738-z
The origin of Jurassic FeMn deposits and their reliability as geochemical archives for Tethian seawater
Authors: Viehmann Sebastian , Klamt Viona , Kraemer Dennis , Horn Ingo , Rüscher Claus , Hohl Simon V. , Fernandez Oscar , Weyer Stefan
Published: March 2024

Modern to Cenozoic hydrogenetic FeMn nodules and crusts are reliable geochemical archives of past seawater chemistry. In this study, we report the first petrographic and geochemical data of Jurassic FeMn nodules and crusts from the Calcaereous Alps of the Pyhrntal area (Austria) that were formed ca. 170 million years ago and, thus, ~ 10 million years after the Toarcian extinction event. The combined approach of petrographic data, including XRD and SEM+BSE, with major and trace element signatures and stable U-Mo isotopes of individual FeMn nodule and crust layers obtained by tandem ICP-MS and MC-ICP-MS, respectively, is used to extend the geochemical record of marine FeMn deposits roughly 100 million years back in time and evaluate their reliability as archives for Jurassic seawater. Trace elements and redox-sensitive U-Mo isotopes aid in reconstructing the origin of the FeMn nodules and redox conditions of Tethian seawater in the aftermath of the Toarcian extinction event.The FeMn deposits of the Pyhrntal area can be subdivided into four types: Type I nodules rich in carbonates (< 90wt %; calcite, rhodochrosite) with minor Fe-oxides (10 wt%; hematite, goethite) and clays (< 20 wt %). Manganese-rich type II nodules (< 75 %; todorokite, ranceite) contain fewer carbonates (< 47 wt %), Fe oxides (
Analysis of seismic noise sources in an open pit mining environment.
Authors: Diaz Jordi , Torne Montserrat , Schimmel Martin , Rodríguez Susana , Martí David , Ruiz Mario , Seivane Helena , Sánchez-Pastor Pilar , Davoise Diego
Published: March 2024

We present the characterization of the seismic ambient noise wavefield in the open-pit Riotinto mine (southern Spain), in the mainframe of a collaborative research project aiming to use the ambient noise wave field to monitor structural subsurface changes in near real-time. Noise characterization is based on a dense seismic network of 30 stations located along a 1-km long segment of a tailings dam. We first describe the most frequent transient signals detected, including local and distant earthquakes, blasting, and vehicles. The time variations in the amplitude of the 10-40 Hz frequency band are then used to define three phases of activity during the recording period. The highest amplitudes are directly related to the regrowth of the dam wall carried out to properly store the constantly increasing amount of tailings. In the third phase, the seismic noise is dominated by the deposition of tailings into the deposit, allowing the use of seismic data to monitor in detail the evolution of the deposition process. The detailed knowledge of the sources of noise in the Riotinto mine provides the basis for developing ambient noise seismic interferometry methods to monitor the physical properties of the subsurface of this and other open-pit mining areas.This research is part of the R+D+I project CPP2021 009072 funded by MCIN/AEI/10.13039/501100011033 (Ministry of Science, Innovation and Universities/State Innovation Agency) with funds from the European Union Next Generation/PRTR (Recovery, Transformation, and Resilience Plan).