bluuebunny/crossref_metadata_2025 huggingface dataset:
Taking care of our planet: measuring and managing the environmental impact
Authors: Stornelli Caterina
Published: February 2023

The hydrosphere characterizes our planet distinguishing it from the others in the solar system. The purpose of this work is to sensitize high school students to the Goal 14 of Agenda 2030. This goal is about conserving and sustainably using the oceans, seas, and marine resources.The students, after studying the main chemical-physical and biological characteristics of marine waters, continental waters and glaciers, will calculate their ecological footprint on the Global Footprint Network website, by using the Ecological Footprint Calculator. Then they will be asked to reflect on their behavior to understand how an individual behavior or a government can influence environmental sustainability.In second step, the effects of ocean acidification, the impact of plastic and microplastic pollution, climate change and fishing will be evaluated.In the first phase of the study, the students will carry out activities in the chemical-biological laboratory of the school for the characterization of marine water. The following measurement will be performed: pH, density, temperature, effects of acid pH on the calcareous structures of marine animals.
Spatial patterns of droughts in the Northeastern Carpathians
Authors: Kholiavchuk Dariia
Published: February 2023

Hydroclimatic extremes like droughts are among the main indicators of climate change in the mountains. They are often associated with elevation-dependent warming. However, terrain features and regional circulation patterns shape local spatial patterns of droughts in the midlatitude mountains. The northeastern area in the Carpathians is suggested to have a less prominent elevation-dependent warming signal in the recent investigations of climate change. Thus, the research aims at identifying the drought distribution response to the features mentioned in the Northeastern Carpathians based on Standardized Precipitation-Evapotranspiration Index (SPEI) and Standardized Precipitation Index (SPI). For the calculation of SPEI and SPI, a newly available homogenized dataset of long gridded time series of essential climate variables for Ukraine, covering the period of 1946–2020 at 0.1°×0.1° spatial resolution is tested. The comparison of both indicators at 3-, 6- at 12-month time scales within the defined period is provided. The interplay effect of the North Atlantic, Mediterranean, and Polar atmospheric circulations is found in different spatial drought patterns throughout the year on southeastern and northwestern macroslopes. Preliminary results confirm that the low-mountain areas with broad-leaf and mixed forests are most exposed to drought intensification especially in the closed inner valleys and on the border of the Western and Eastern Carpathians. The continentality is revealed in the insignificant drying of the low-mountain areas of the Northeastern Carpathians towards the east over time. 
How often did Mediterranean regions transition to different hydroclimatic regimes in the last millennium?
Authors: Sanz i Gil Arnau , Rahmati Ziveh Akbar , Abbasizadeh Hossein , Thakur Vishal , Hanel Martin , Maca Petr , Rakovec Oldrich , Markonis Yannis
Published: February 2023

The Mediterranean has been characterized as a region of enhanced climatic variability. Transitions between dry and wet conditions have repeatedly occurred over the last millennium in various spatial and temporal scales. However, the frequency of these shifts is poorly assessed due to the low amount of paleoclimatic reconstructions and the substantial heterogeneity of the Mediterranean. Here, we examine how often Mediterranean regions have transitioned between different hydroclimatic regimes over the last millennium. For this purpose, we use the Paleo Hydrodynamics Data Assimilation (PHYDA) simulation results to identify transitional changes based on Köppen-Geiger climate types. Our results indicate which regions are more likely to experience transitions between hydroclimatic regimes and their duration distribution. We also examine how the intensity of the shifts have fluctuated during the study period and quantify the uncertainties involved. Our findings contribute to a better understanding of the past hydroclimatic variability, which is crucial for further determining the current state and future aridification in the Mediterranean region.  
Using spatial crop modeling to improve the regional agricultural water planning.
Authors: Saddique Qaisar , Ajaz Ali , Jain Shubham
Published: February 2023

Climate change is increasingly affecting agriculture water resources. This adverse situation can be addressed by developing approaches focusing on optimization for agricultural water management.  Groundwater depletion is a serious issue for the sustainability of irrigated agriculture in the southern and central parts of the High Plains Aquifer (HPA), USA. Crops that require more water to grow (e.g., maize) may not receive sufficient irrigation due to decline in pumping capacities, and growers can experience yield loss, jeopardizing the farm profits. Geospatial crop modeling can be seen as a tool to simulate different scenarios of water availability for crops in regions like Texas and Oklahoma Panhandle. Open-source version of AquaCrop (AC-OSPy) was run under a gridded environment on the maize pixels of crop frequency layer developed by National Agricultural Statistics Service. Long-term simulations for past 30-year period (1991-2020) were run using the historical weather data for multiple irrigation application rates. Also, deficit irrigation was tested to assess the impact of skipping irrigation in different crop stages. The simulations were able to capture the variation of weather and soil patterns in the region. Mean irrigation requirement ranged between 78 mm and 314 mm under 50% available water capacity irrigation threshold, and mean yield varied from 8.8 to 14.3 Mg-ha-1. Deficit irrigation showed a potential of water saving during initial and vegetative stages (up to 113 mm), whereas a significant decline in yields was noted for skipping irrigation during flowering. Overall, the results of the study showed great potential of using geospatial crop modeling approach for regional agricultural water planning and drought mitigation efforts.  
Comparison of different variants of storm maximization method for Probable Maximum Precipitation estimation in changing climate
Authors: Bhatt Jaya , Srinivas Vemavarapu Venkata , Srinivas Vemavarapu Venkata , Srinivas Vemavarapu Venkata
Published: February 2023

Design and risk assessment of large hydraulic structures, whose failure can cause catastrophic damage to the environment, ecology, life and property, are based on Probable Maximum Precipitation (PMP). It is deemed as the theoretical upper bound of the maximum precipitation that is physically possible over a given area for a specified duration. The conventional approaches for estimating PMP are based on stationarity assumption, i.e., the current climatic conditions will remain unchanged even in the future. But the recent increase in extreme precipitation events across the globe and projected increase in the same for future climatic scenarios raises questions on the validity of the stationarity assumption. This issue has gained attention in recent years, and efforts have been directed towards improving existing approaches and devising novel methodologies that would yield reliable PMP estimates in changing climatic conditions. Several researchers have proposed different variations of the widely used storm maximization method to account for non-stationarities arising due to changing climate. The variations imbibe the potential change in PMP resulting either from the trend in precipitable water or from the complex interaction of drivers of PMP. There is a need to compare their relative performance to quantify if the improvement offered by complex variants is significant compared to simple variants in different parts of the globe. In this study, it is investigated through a case study on the frequent flood-prone Mahanadi River Basin in India. For this analysis, future projections of various atmospheric variables (e.g., precipitation, dew point temperature, precipitable water) were obtained from 5 GCMs (General Circulation Models) corresponding to two CMIP6 SSP (Coupled Model Intercomparison Project-6 Shared Socioeconomic Pathways) forcing scenarios namely, SSP1-2.6 and SSP5-8.5. The PMP estimates obtained from improved variants were also compared with their conventional stationary counterpart to assess the effect of dispensing the stationarity assumption.
Temporal and Spatial distribution of scoria cones in the Paricutin-Tancítaro volcanic region, Mexico: A morpho-chronometric approach to monogenetic hazard evaluation
Authors: De la Cruz-Reyna Servando
Published: February 2023

The Paricutin-Tancítaro region (PTR), located in the SW sector of the Michoacán-Guanajuato monogenetic field, in central Mexico, is characterized by a high spatial density of monogenetic scoria cones around Tancítaro, a stratovolcano active in the middle Pleistocene. The PTR area has been active for around one million years, and the latest eruption, beginning in 1943, formed the Paricutin volcano. We use the Average Erosion Index (AEI) to estimate the relative ages of 170 PTR scoria cones located within latitudes 19°N and 20°N and longitudes -102.0° E and -102.7° E. The AEI quantifies the erosional state of scoria cones from a morphological analysis of their level contours extracted from a high-resolution DEM (the 12-m TanDEM-X in this case). The analysis provides a metric for the undulations along the level contour curves at different altitudes, reflecting the width and amplitude of erosional rills and gullies on the cone’s surface. We compute a functional relationship between AEI and age by correlating 10 published radiometric ages with the measured AEIs of those cones. Then, using that function, we assign an age to each of the 170 cones, assuming that all the monogenetic volcanoes in the analysis have been exposed to similar erosive conditions. Finally, we tessellate the study area with a 0.1° x 0.1° grid and identify the number of events per grid module to compute the probability of at least one eruption occurring in the module in a specific time, using a Poisson process distribution obtained from the count of the number of events per 20 ky time intervals. Our results suggest that the dispersed volcanic activity in the PTR started to increase after the last eruption of Tancitaro (~237 ka), with a further activity increase during the Holocene, mainly concentrated on the NE sector of Tancítaro, where Paricutin is located. Holocene vents align to the NE, parallel to the Tepalcatepec-Tangancícuaro normal fault system. Furthermore, our results suggest a spatial coincidence between the regions with a higher probability of an eruption, based on the obtained eruption history, and the location of the recent seismic swarms in the PTR, the last two in 2020-2021, suggesting an increase in volcanic and seismic hazards in that area. To what extent? It is the subject of our forthcoming research.
Numerical modeling of Miocene dyke opening in the Cserhát Hills, Hungary
Authors: Juhász Dorina , Lanzi Chiara , Váradi Kitti , Szijártó Márk , Fodor László , Sigmundsson Freysteinn
Published: February 2023

The Cserhát Hills are located in mid-North Hungary, at the northern edge of the Pannonian Basin, and are parts of the Miocene Inner Carpathian volcanic arc. The Cserhát Hills were strongly influenced by the Miocene volcanism and are built up by polycentric domes, stratovolcanoes, and radial a dyke-system, consistent with their location in an extinct volcanic arc. In the following research we are focusing on this radial dyke-system, which is often segmented and shows changes in its strike-direction. The main strike directions are E-W and N-S, but the dykes with different striking orientations may belong to different volcanic systems and have different ages, respectively. The thickness of the dykes varies between 3 m and 25 m, and the length of the segments varies between 1 km and 5 km. Partial re-mapping of the area was carried out. For studying the stress field in the area of diking and its evolution, we carry out FEM (finite element method) numerical model of dyke opening by using COMSOL Multiphysics. For mapping the dykes some geophysical methods were tried as well, including multielectrode method and RMT (radio magnetotelluric) measurements.The extensional structures, which were measured in the bedrock, agree with the stress-fields of previous studies. To expand the previous datasets of the stress field, the cooling joints of the dykes were measured as well. Two sets of cooling joints were identified in the field, one with strike parallel to the dyke, which probably developed during the propagation, and the second is perpendicular to the dyke, which might be the consequences of the dyke intrusion. These data gave a base for the modeling. The aim is to compare numerical models with field observations to shed light on the local and tectonic stress fields, and pressure conditions in the magmatic systems involved. The numerical models provide insight on how large stress was needed to open Cserhát Hills dykes, and if the previous strain field in the area had an influence in this.
Internal-tide-induced fluctuations of hydrography and biogeochemical properties modulated by mesoscale eddies: Observation evidences
Authors: Wu Wei-Chang , Yang Yiing-Jang , Wei Ching-Ling
Published: February 2023

Mesoscale eddy plays an important role in physical and biochemical processes in the upper ocean, it could redistribute seawater masses, heat, and biogeochemical properties. The region of the Subtropical Countercurrent (STCC) within the northwestern subtropical Pacific Ocean (NWSTP) is characterized by an abundance of mesoscale eddies caused by baroclinic instability. The NWSTP serves a good place for studying variations of dissolved oxygen (DO) concentration and temperature induced by eddies. Observed by two metocean moored buoys deployed in the NWSTP, there was one cyclonic eddy (CE) and one anti-cyclonic eddy (ACE) during the summer of 2018 to 2020. Time series dataset of hydrography, DO concentration and chlorophyll-a in the upper subsurface layer provided precious in-situ observations, which helps us better understand physical dynamics under the influence of eddies and improve numerical model forecasts. The results of analysis showed that there was a significant difference between two types of eddies in the upper layer ocean. During the CE period, DO concentration and temperature had significant fluctuations up to 30 μM and 5 ℃, respectively, at depth of 50 meter. In response to diurnal and semi-diurnal tidal processes, their variations gradually decreased toward deep ocean; whereas their amplitude narrowed to 5 μM and 1 ℃, respectively, during the ACE period. During the non-eddy period, there was a small amplitude of fluctuations in the tidal bands except at 150 meter. The phenomenon could be associated with modulated thermal structure under the influence of CE and ACE through upwelling and downwelling, respectively. This led to changes in the vertical structure of the internal tide amplitude and concentration gradient. The combination of these two factors consequently resulted in different amplitude of fluctuations in DO concentration and temperature during two types of eddies passing through. These results will be presented herein in detail.
Assessment of empirical relationship among cross-shore beach profile morphotypes, sediment characteristics, and wave signature in beaches in estuaries and bays (BEBs)
Authors: Gazi Md. Yousuf , Vila-Concejo Ana , Fellowes Thomas
Published: February 2023

Beaches in estuaries and bays (BEBs) are usually distinct from open coast beaches in terms of environment, process, and morphology, and their morphodynamics remain unresolved. The present study aims to establish a relationship between profile morphology, sediment characteristics, and hydrodynamic forces. We investigated four beaches of Gamay (Botany Bay) located in the south of Sydney, SE Australia. Profiles of these beaches were measured regularly from 2016 to 2022 and sediment samples were collected from each beach. Wave data were recorded from the Sydney Waverider buoy. We used principal component analysis (PCA) to ascertain the temporal and spatial scales of the data variability, and spectral analyses to investigate the waves. Sediment samples were analyzed by Laser Diffraction Particle Size Analyzer (Mastersizer 3000).Our preliminary results indicate that different profile morphotypes are associated with different sediment characteristics and wave climates on BEBs.  BEBs with the least exposure to ocean swell waves have the narrowest and steepest profiles, with BEBs more exposed to ocean swells having moderately steep profiles. BEBs containing coarser sediments show steep profiles compared to beaches with fine to very fine-grained sediments. In general, the shape of profiles changes in order from straight-through concave to convex-concave with increasing wave energy. Current research aims to parameterize these relationships with offshore and locally generated wave parameters. The insights obtained from this study will assist to understand fundamental mechanisms governing the morphological evolution of BEBs.
Controls on the Dynamics of Subducting Slabs in a 3-D Spherical Shell Domain
Authors: Davies Rhodri , Chen Fangqin , Goes Saskia , Suchoy Lior
Published: February 2023

It has long been recognised that the shape of subduction zones is influenced by Earth’s sphericity, but the effects of sphericity are regularly neglected in numerical and laboratory studies that examine the factors controlling subduction dynamics: most existing studies have been executed in a Cartesian domain, with the small number of simulations undertaken in a spherical shell incorporating plates with an oversimplified rheology, limiting their applicability. There are therefore many outstanding questions relating to the key controls on the dynamics of subduction. For example, do predictions from Cartesian subduction models hold true in a spherical geometry? When combined, how do subducting plate age and width influence the dynamics of subducting slabs, and associated trench shape? How do relic slabs in the mantle feedback on the dynamics of subduction? These questions are of great importance to understanding the evolution of Earth's subduction systems but remain under explored.In this presentation, we will target these questions through a systematic geodynamic modelling effort, by examining simulations of multi-material free-subduction of a visco-plastic slab in a 3-D spherical shell domain. We will first highlight the limitation(s) of Cartesian models, due to two irreconcilable differences with the spherical domain: (i) the presence of sidewall boundaries in Cartesian models, which modify the flow regime; and (ii) the reduction of space with depth in spherical shells, alongside the radial gravity direction, the impact of which cannot be captured in Cartesian domains, especially for subduction zones exceeding 2400 km in width. We will then demonstrate how slab age (approximated by co-varying thickness and density) and slab width affect the evolution of subducting slabs, using spherical subduction simulations, showing that: (i) as subducting plate age increases, slabs retreat more and subduct at a shallower dip angle, due to increased bending resistance and sinking rates; (ii) wider slabs can develop along-strike variations in trench curvature due to toroidal flow at slab edges, trending toward a `W'-shaped trench with increasing slab width, and (iii) the width effect is strongly modulated by slab age, as age controls the slab's tendency to retreat. Finally, we will show the diverse range of ways in which remnant slabs in the mantle impact on subduction dynamics and the evolution of subduction systems.
Sensitivity of projected storm track and jet latitude changes to the parameterization of convection: implications for mechanisms of the future poleward shift
Authors: White Ian , Garfinkel Chaim , Keller Benny , Lachmy Orli , Gerber Ed , Jucker Martin
Published: February 2023

While a poleward shift of the jet stream and storm track in response to increased greenhouse gases appears to be robust, the magnitude of this changeis uncertain and differs across models, and the mechanisms for this change are poorly constrained. An intermediate complexity GCM is used to explorethe factors governing the magnitude of the poleward shift and the mechanisms involved. The degree to which parameterized subgrid-scale convection is inhibited has a leading-order effect on the poleward shift, with a simulation with more convection (and less large-scale precipitation) simulating a significantly weaker shift, and eventually no shift at all if convection is strongly preferred over large-scale precipitation. Many of the mechanisms that have been proposed to lead to the poleward shift are present in all simulations (even those with no poleward shift), and hence we can conclude that these mechanisms are not of leading-order significance for the poleward shift in any of the simulations. In contrast, the thermodynamic budget is able to diagnose the reason the jet and storm track shift differs among the simulations, and helps identify midlatitude latent heat release as the crucial differentiator. These results have implications for intermodel spread in the jet, hydrological cycle, and storm track response to increased greenhouse gases in intermodel comparison projects.
Structure and evolution of the active Ulsan Fault Zone, SE Korea: New insights from geophysical studies
Authors: Cheon Youngbeom , Shin Young Hong , Park Samgyu , Choi Jin-Hyuck , Kim Dong-Eun , Ko Kyungtae , Ryoo Chung-Ryeol , Son Moon
Published: February 2023

Integration of geophysical and geological data is essential to illuminate the configuration and geometry of surface and subsurface structures as well as their long-term evolution history. The NNW–SSE-striking incised valley and parallel mountain range in southeastern margin of the Korean peninsula, extended from Gyeongju to Ulsan cities (~50-km-long on land), have been regarded as the most active geographical feature in Korea, which was named as the Ulsan Fault zone (or system). This study presents a new insight of the structural architecture and its deformation history during the Cenozoic based on a combined data of gravity and electronic survey results with previous field observations. Our major results based on integrated data are as follows. First, the incised fault valley is divided into (1) the northern part of several distributed, buried and exposed fault strands and (2) the southern part of a concentrated deformation zone. Different deformation features between the two parts are controlled by the distribution pattern of the pre-existing Miocene structures (i.e., Yeonil Tectonic Line, YTL). Second, the Ulsan Fault is only constrained as a NNW–SSE-striking Quaternary fault zone within the incised valley-mountain range. The fault zone is composed of several interconnected and disconnected strands forming an imbricate thrust zone located along the western front of the mountain range (or eastern margin of the >2-km-wide incised valley). The constituent fault strands mainly exhibit an east-side-up geometry with moderate to low dip angles and reverse-dominant kinematics in near-surface. These strands are interpreted as reactivated ones of the pre-existing subvertical structures, such as the YTL. In here, we newly designate ‘the Ulsan–Yeonil Fault system’, composed of all NNW–SSE to N–S-striking buried and exposed faults on the incised valley-mountain range, regardless of tectonically controlled sequence of movement stages. Third, movements of the NNW–SSE-striking fault system during the Miocene to Quaternary were arrested by the NNE–SSW-striking Yangsan Fault, which is pre-formed prominent mature structure. Our results highlight the spatiotemporal structural characteristics in SE Korea, emphasizing that the configuration of pre-formed structures have strongly controlled the distribution and characteristics (i.e., geometry and kinematics) of the subsequent deformation during the Cenozoic crustal deformation.
Full-wave anisotropy tomography for the upper mantle of Northeast China using SKS splitting intensities
Authors: Suwen Junliu , Lin Yi , Zhao Li , Chen Qi-Fu
Published: February 2023

Northeast (NE) China is located in the eastern Central Asian Orogenic Belt, and has a complex deformation history. The evolution of NE China has been controlled by the (Paleo-)Pacific Plate since the late Mesozoic and was affected by the closure of the Paleo-Asian and Mongol–Okhotsk oceans. Meanwhile, large strike-slip faults and extensive intraplate volcanisms characterize active tectonics in NE China. Different mechanisms have been proposed to interpret the origin of the intraplate volcanism, such as interactions between the lithosphere and the big mantle wedge, and the subduction-induced upwelling within the gap of the stagnant Pacific slab.Seismic anisotropy describes the directional dependence of the seismic velocities. In NE China, seismic anisotropy not only reveals the past and present deformations in the lithosphere but also helps us clarify the possible intraplate volcanism. In this study, we apply the full-wave multi-scale anisotropy tomography method to investigate the seismic anisotropy in NE China. We measure the splitting intensities of SKS waves, which can be linearly inverted for the 3D variation of anisotropy. We employ broadband seismograms recorded at ~450 regional seismic stations (including ~250 temporary stations deployed for 2 years) of unprecedented density from teleseismic events of magnitudes greater than 5.5 occurring in 2009-2018. We obtain a total of 4249 splitting intensity measurements, and perform the multi-scale inversion using sensitivity kernels computed by normal-mode summation. The resulting 3D anisotropic model of the upper mantle in NE China shows a dominant NW-SE fast axis, which highlights a strong correlation between the intraplate volcanoes and upper-mantle seismic anisotropy, and indicates that NE China is still mainly controlled by the Pacific Plate.
Size–resolved mixing state of ambient refractory black carbon aerosols in Beijing during the XXIV Olympic Winter Games
Authors: Zhang Yuting , Pan Xiaole
Published: February 2023

Atmospheric loading of black carbon aerosols influences air quality and visibility, and their mixing state and aerosol chemistry were sensitive to both emission scenarios and regional transport. In this study, the aerodynamic size-resolved mixing state of refractory black carbon aerosols (rBC) and elemental composition were investigated using a novel tandem system consisting of an aerodynamic aerosol classifier (AAC), a single particle soot photometer (SP2), and single-particle-aerosol mass spectrometry (SPA-MS) during the XXIV Olympic Winter Games (OWG) at an urban site in Beijing. We found that rBC-containing particles with an aerodynamic diameter (Dae) of 300 nm were characterized by a rBC core with a count median diameter (CMD) of 108±4 nm that typically have regular morphology ( , higher relative coating thickness (RCT: mean ~1.8), and strong light absorption enhancement (Eabs: mean ~1.4). The rBC-containing particles with Dae = 200 nm normally had irregular shapes and weak Eabs. Classification based on air mass clustering and air pollution level revealed that the coating thickness of rBC particles only exhibited unimodal patterns under clean air conditions but bimodal distributions under heavy pollution conditions, implying multiple origins of rBC particles, even during OWG periods. Furthermore, the chemical compositions of the rBC coating quantitatively determined by SPA-MS were used to estimate the possible origins of rBC with Dae = 300 nm. Our results showed that rBC particles were primarily mixed with organics, nitrate, and sulfate during the XXIV OWG period. The organic components have a limited role in increasing rBC coatings under polluted conditions, while the alkali metal ions (K and Na) associated with traffic emissions and the secondary inorganic species favor the formation of thick coatings. Higher RH makes limited contributions to rBC mixed with sulfate and organics only (BCOC*_S) and pure BC. The relatively fresh BC could directly mix with organics and sulfate at low RH levels while evolving to mix with nitrate at high RH conditions. In addition to high concentrations of locally emitted precursors and high RH that tend to form thick coatings of nitrate-related rBC aerosols, secondary transport from the west and southwest also contributes to rBC aerosols mixed with nitrate with relatively thick coatings.
Future changes in Antarctic coastal polynyas and bottom water formation simulated by a high-resolution coupled model
Authors: Jeong Hyein , Lee Sun-Seon , Park Hyo-Seok , Stewart Andrew
Published: February 2023

Antarctic coastal polynyas produce Dense Shelf Water, a precursor to Antarctic Bottom Waters (AABW) that supply the global abyssal circulation. Recent studies suggest that increasing atmospheric CO2 concentrations will weaken AABW export by suppressing heat loss to the atmosphere. However, future projections of DSW formation are hindered by the small spatial scales of atmosphere-sea ice-ocean interactions in polynyas. Here, using a high-resolution ocean-ice-atmosphere coupled model, this study shows that wintertime sea ice production rates are still active under elevated CO2 concentrations, although delayed freeze-up decreases autumn sea ice production. In winter, Antarctic coasts exhibit a nonlinear response CO2 concentration: doubling CO2 decreases sea ice production only by around 6–8%, versus 10–30% under CO2 quadrupling. Despite continued sea ice production in winter, doubling or quadrupling CO2 substantially freshens Dense Shelf Water, primarily due to increased precipitation, implying a shutdown of AABW formation.
Origin of basaltic rocks of Nagaland-Manipur Hill Ophiolite (NMHO) complex in North-Eastern India: Inferences from mantle melting models.
Authors: Saikia Ashima , KIso Eyozele
Published: February 2023

Basaltic samples from Nagaland-Manipur Hill Ophiolite (NHMO) complex in north-eastern India comprise predominantly of plagioclase with small amounts of pyroxene and exhibit porphyritic texture. In whole rock Zr/Ti vs. Nb/Y discrimination diagram, these rocks are classified as basalt (TiO2 < 2 wt.%) and alkali basalt (TiO2 < 2 wt.%). Based on whole rock and clinopyroxene composition, basalt and alkali basalt show tectonic affinities to MORB and WPB, respectively. In N-MORB normalized trace element plot, basalt display near-horizontal trend at rock/N-MORB = ~1 and show positive anomalies at Pb, Th and Sr, whereas alkali basalt display increasing enrichment from left to right with marked negative anomalies at Ti and Sr. In chondrite normalized REE plot, basalt display near-parallel horizontal pattern similar to average N-MORB, whereas alkali basalt show parallel but increasing enrichment pattern from HREE to LREE similar to average OIB. Incompatible trace element ratios Sm/Yb, La/Sm, TiO2/Yb and Nb/Yb suggest N-MORB- and OIB-type parental magma for basalt and alkali basalt, respectively.Dynamic melting inversion model for alkali basalt suggests melting of OIB-like spinel lherzolite composition (S1) at F = ~5%, with S1 being more enriched in MREE, LREE, Nb and Zr as compared to DMM. Non-modal batch melting model for basalt suggests melting of N-MORB-like spinel lherzolite composition (S2) at F = ~5 - 10%, with S2 being very similar to DMM. Constraints from trace elements indicate that basalt with N-MORB signatures is believed to be part of an ophiolite suit, whereas the alkali basalt with OIB signatures is likely due to some localized plume activity.
Major Role of Surface-groundwater Interactions for Sustaining Spring Wetlands of the Great Artesian Basin, Australia
Authors: Kaushik Pankaj R. , Ndehedehe Christopher E. , Burrows Ryan M. , Noll Mark R. , Kennard Mark J.
Published: February 2023

Groundwater is an essential resource for sustaining human life and associated ecosystems such as rivers and springs. Springs, fed by groundwater on the surface, regulate ecosystem services, including drought mitigation and support for biodiversity. However, climate variability and groundwater extraction for domestic and industrial use in the Great Artesian Basin (GAB) are contributing to groundwater stress, limited surface water in springs, and slowing groundwater recharge processes. Thus, an improved understanding of surface-groundwater interactions in springs is required in the GAB region.  This study demonstrates the potential of the Gravity Recovery and Climate Experiment (GRACE) satellite observations to determine groundwater storage variation through validation with borewell monitoring data in the GAB. An important aspect of this study was to assess the surface-groundwater interactions to better explain the variability of spring extent in the GAB for the five spring supergroup sites: Springvale, Flinders, Eulo, Barcaldine, and Springsure. We used Partial Least Square Regression (PLSR) method to assess the response of groundwater storage to hydrological variables (e.g., surface water extent, rainfall, soil moisture storage, evapotranspiration, and surface water level) and vegetation greenness between 2002 and 2017 in the spring supergroups. The predicted and observed groundwater storage is well correlated with hydrological variables post La-Niña (2011-2017) compared to the pre La-Niña (2002-2010) period. This study revealed the importance of variations in climate in understanding how groundwater responds to predictors (vegetation greenness and soil moisture storage) in spring supergroups. Overall, groundwater responses to several predictors (NDVI, mNDWI, rainfall, SWL, ET, and SMS), even before the heavy rainfall season were the strongest in the Flinders spring supergroup. The preliminary results from this method provide information and directions that underpins sustainable groundwater management in the complex geological GAB region and associated ecosystem services such as nutrient recycling and sustaining biodiversity.   
Human intervention against drought in Seyhan River Basin, Turkey
Authors: Cavus Yonca , Aksoy Hafzullah , Stahl Kerstin
Published: February 2023

Impacts of a drought on society and hydrological processes cover a wide range of issues such as environment, economy, management and water structures. Here we present a case study addressing challenges in water management under drought conditions and human influence by focusing on developing a storyline for future reflections. With rich and fertile lands, the Seyhan River Basin in Turkey has an international importance for agricultural production as large quantities of vegetables are exported globally. The basin was exposed to an extreme drought at various intensities in the year 2008 when the river basin received the lowest precipitation ever recorded. The drought reduced total water availability throughout the river basin by triggering a series of cascading impacts such as reducing agricultural yield, increasing food prices, adversely affecting farmers’ income, leading a migration of regional farmers from rural regions toward urban centers. The migration caused population growth in big cities, alterations in water consumption habits by increasing socioeconomic development, and growth in urbanization and water-dependent sectors. These cascading impacts of the drought showed that the event indirectly fed back to affect the river basin hydrology as well. In order to avoid or minimize drought impacts, decision-makers and water managers implemented a number of water supply techniques and adopted temporary management policies, which resulted in increasing and unsustainable water demand under drought conditions. The paradoxical intervention can only mitigate negative effects of drought at short term but we need long-term drought mitigation measures. In addition, we understood that such short-term interventions should be avoided in the absence of an effective water management plan under drought conditions. An effective management plan requires that water managers, city planners, and all related governance levels interpret solutions together without challenging the entire system.
Development and validation of a global 1/32° surface wave-tide-circulation coupled ocean model: FIO-COM32
Authors: Xiao Bin , Qiao Fangli , Shu Qi , Yin Xunqiang , Wang Guansuo , Wang Shihong
Published: February 2023

Model resolution and the included physical processes are two of the most important factors those determine the realism or performance of ocean model simulations. In this study, a new global surface wave-tide-circulation coupled ocean model FIO-COM32 with a resolution of 1/32°×1/32° is developed and validated. Promotion of the horizontal resolution from 1/10° to 1/32° leads to significant improvements in the simulations of surface eddy kinetic energy (EKE), main paths of the Kuroshio and Gulf Stream, and the global tides. We propose the Integrated Circulation Route Error (ICRE) as a quantitative criteria to evaluate the simulated main paths of Kuroshio and Gulf Stream. The non-breaking surface wave-induced mixing (Bv) is proven to still be an important contributor that improves the agreement of the simulated summer mixed layer depth (MLD) against the Argo observations even with a very high horizontal resolution of 1/32°. The mean error of the simulated mid-latitude summer MLD is reduced from -4.8 m in the numerical experiment without Bv to -0.6 m in experiment with Bv. By including the global tide, the global distributions of internal tide can be explicitly simulated in this new model and are comparable to the satellite observations. Based on Jason3 along-track sea surface height (SSH), wave number spectral slopes of mesoscale ranges and wave number-frequency analysis show that the unbalanced motions, mainly internal tides and inertia-gravity waves, induced SSH undulation is a key factor for the substantially improved agreement between model and satellite observations in the low latitudes and low EKE regions. For ocean model community, surface waves, tidal currents and ocean general circulations have been separated artificially into different streams for more than half a century. This paper demonstrates that it should be the time to merge these three streams for new generation ocean model development.
Normalising Flows for Bayesian Gravity Inversion
Authors: Rakoczi Henrietta , Hammond Giles , Messenger Christopher , Prasad Abhinav
Published: February 2023

This work is concerned with applying machine learning to Bayesian gravity inversion. While various Bayesian frameworks have been explored for this application, these methods are not ideal due to the associated long computation time and can become intractable for a high-dimensional parameter space. For many applications, machine learning can offer a faster approach to obtaining posterior approximations, while not sacrificing accuracy. Normalising flows, which are based on the simple principles of the change of variables formula, recently have become a focus of development for a wide variety of applications. They are a popular alternative to other generative Bayesian frameworks due to their relative ease to train and their simple principles and architecture, making them more transparent and trustworthy for researchers. This work explores how this type of architecture can be applied to the common inverse problem in gravimetry and how it can improve on traditional methods. As a first application, results are shown for the inverse modelling of cuboid underground objects from a variety of gravimetry survey configurations. These simple shapes are not defined by a small number of parameters, rather the model is kept as a 3-dimensional density map defined by a grid of single-density voxels. This decision results in a more difficult problem with a high dimensional posterior space, however, it allows the approach to be more flexible and be directly applicable to the modelling of irregular bodies. Finally, it is discussed how the method performs compared to other traditional and Bayesian inversion methods.
The precision of satellite-based net irrigation quantification in the Indus and Ganges basins
Authors: Kragh Søren Julsgaard , Fensholt Rasmus , Stisen Simon , Koch Julian
Published: February 2023

Even though irrigation is the largest direct anthropogenic interference with the terrestrial water cycle, limited knowledge on the amount of water applied for irrigation exist. Quantification of irrigation via evapotranspiration (ET) or soil moisture residuals between remote sensing models and hydrological models, with the latter acting as baselines of natural conditions without the influence of irrigation, have successfully been applied in various regions. Here, we implement an novel ensemble methodology to estimate the precision of ET-based net irrigation quantification by combining different ET and precipitation products in the Indus and Ganges basins. A multi-model calibration of 15 models independently calibrated to simulate natural rainfed ET was conducted prior to the irrigation quantification. Based on the ensemble average, the 2003-2013 net irrigation amounts to 233.4 mm/year (74.4 km3/year) and 101.4 mm/year (66.7km3/year) in Indus and Ganges basin, respectively. Net irrigation in Indus basin is evenly split between dry and wet period, whereas 70% of net irrigation occurs during the dry period in Ganges basin. We found that although annual ET from remote sensing models varied by 91.5 mm/year, net irrigation precision was within 25.3 mm/season during the dry period, which emphasizes the robustness the applied multi-model calibration approach. Net irrigation variance was found to decrease as ET uncertainty decreased, which related to the climatic conditions, i.e. high uncertainty under arid conditions. A variance decomposition analysis showed that ET uncertainty accounted for 74% of the overall net irrigation variance and that the influence of precipitation uncertainty was seasonally dependent, i.e. with an increase during the monsoon season. The results underline the robustness of the framework to support large scale sustainable water resource management of irrigated land.
Can we trust our data sources? A case study presenting limits of spatial detail of sediment transport modelling
Authors: Bauer Miroslav , Dostal Tomas , Krasa Josef , Schwartz John , Bynum Karina
Published: February 2023

The paper discusses the limits of data sources that are widely available, used and applicable for soil erosion and sediment transport modelling. It emphasizes the accuracy and spatial detail of land use and stream topology data. These two inputs are critical in terms of sediment transport dynamics. The aim of the paper is to point out the error propagation into results at the small catchment scale if the data is used inappropriately. In contrast, we show how the quality and accuracy can be significantly improved by checking, verifying and modifying the directly available data sources to make them applicable at the scale of smaller catchment (tens of km2). The accuracy that can be achieved by directly measuring and describing the real situation in the field (land use, streams, crops) is discussed.WaTEM/SEDEM (based on RUSLE and sediment transport capacity assessment) was selected as a modelling approach. The results will be interpreted using a case-study of the Oostanaula watershed, Tennessee, USA, approximately 10km2. Modelling utilized the most recent available DEM, land use and soil data in raster resolution 10x10 m.Research has been supported by project TUDI (European Union's Horizon 2020 research and innovation programme under grant agreement No 101000224), LTA-USA 19019 (Ministry of Education of the Czech Rep.), TAČR SS02030027 and SS05010180 (Technology Agency of the Czech Republic)
The influence of upstream conditions on heavy ion escape at Mars
Authors: Zhang Qi , Holmström Mats , Wang Xiaodong , Nilsson Hans
Published: February 2023

We apply a recently presented method to estimate ion escape to Mars. The method combines in-situ observations and a hybrid plasma model (ions as particles, electrons as a fluid). Observed upstream solar wind conditions from the Mars Atmosphere and Volatile Evolution (MAVEN)  are used as input to the model.  We then vary ionospheric ion production until the solution fits the observed bow shock location.  With this method, we investigate how upstream conditions, including solar EUV, solar wind dynamic pressure, Interplanetary Magnetic Field (IMF) strength and cone angle, affect the heavy ions loss. The results indicate that the heavy ions escape rate is higher in high EUV and the tail flux is sensitive to EUV variety while the plume is not. The ion escape rate increases as solar wind dynamic pressure increases. 
Comparison of optimization approaches for the well placement of groundwater heat pumps
Authors: Halilovic Smajil , Böttcher Fabian , Zosseder Kai , Hamacher Thomas
Published: February 2023

Groundwater heat pumps (GWHP) use the thermal energy stored in groundwater. Therefore, GWHP systems extract groundwater via extraction wells and, after heat exchange, return it to the same aquifer via injection wells. The returned water has a lower temperature than the pumped water since the GWHP extracts heat for domestic heating. This causes the development of so-called thermal plumes in the aquifer. The thermal plume dissipates downstream according to the local groundwater flow direction and can reach the extraction wells of neighboring systems. Depending on their mode of operation, this altered water can significantly reduce their efficiency. To ensure optimal use of geothermal potential, such negative interactions between neighboring systems must be avoided and are legally constrained to a maximum temperature change of 1K in downstream extraction wells. One way to avoid the negative interactions and to maximize the spatial utilization is the optimal placement of GWHPs and their wells. In addition, the optimal placement of wells is important within a system to avoid significant thermal recycling. To determine the optimal placement of wells, estimations of thermal plumes are required. These calculations can be performed using analytical or numerical (PDE-based) models.In this contribution, we compare two different optimization approaches for the placement of GWHP wells. The first approach is based on the linear advective heat transport model (LAHM), which is an analytical model, and integer linear programming. The second approach is based on numerical simulation of groundwater flow and heat transport and the adjoint optimization method. We first present these two recently developed optimization approaches and then analyze their potential applications (optimal management of the geothermal resource, optimal system design, urban energy planning, etc.), limitations, and future possibilities. We use real case studies to analyze and compare the approaches.