bluuebunny/crossref_metadata_2025 huggingface dataset:
A study on morphology and microphysics of clouds during southwest monsoon over Western Ghats, India, using multi-platform observations
Authors: Leena Parakkatt Parambil , Varghese Mercy , .S.Kumar Jithin , Kumar Vasudevan Anil , Pandithurai Govindan , .D.Patil Rohit , Resmi Eruthiparambil Ayyappan , .V.Prabha Thara
Published: February 2023

Clouds play a significant role in the dynamics and thermodynamics of the atmosphere. To understand the impact of clouds on climate and for better representation of these in the global models, accurate information about the temporal, spatial and vertical distribution of cloud properties such as microphysical, morphological and types are essential. In the present work, vertical structure and microphysics of clouds during southwest (SW) monsoon has been studied from a high altitude site (Mahabaleshwar (17.92°N, 73.66°E, and 1348 m above mean sea level (MSL)) and within ± 0.1 degrees) over Western Ghats, India. Vertical structure of the clouds has been detailed using radiosonde observations. Warm cloud microphysics was investigated using in-situ ground and aircraft cloud measurements. Radiosonde profiles showed the presence of single and multi-layered clouds over the observational site. Higher occurrence frequency for cloud layers below 2 km and above 6 km altitude compared to mid-level clouds (2 to 6 km) during SW monsoon were noticed. Higher occurrences of single layer clouds during June and September (transition period) were noticed whereas frequency of two-layer was higher in July and August (core period). Low (~30%) and high-level (~60%) clouds were dominantly seen compared to mid-level clouds over the observational site during SW monsoon. Warm cloud microphysics was investigated using collocated ground and airborne in situ measurements. Cloud microphysical properties such as cloud droplet number concentration (CDNC), liquid water content (LWC), droplet effective diameter (ED), droplet mean radius (Rm) respectively were analyzed. The cloud liquid water content and the effective droplet diameter showed increase with altitude. Analyzed cloud droplet size distribution (DSD) showed a steep decrease in number concentration of droplets above 25 µm diameters at altitudes above 1800 m, suggesting active collision-coalescence. This is the first such report combining in situ observations from two different platforms to study the vertical structure of monsoon clouds over a complex terrain like the Western Ghats in India.  
Statistical analysis of Europium anomalies in detrital zircons record major transitions in Earth geodynamics at 2.5 Ga and 0.9 Ga
Authors: Triantafyllou Antoine , Ducea Mihai , Jepson Gilby , Bisch Alex , Ganne Jerome
Published: February 2023

Trace elements in zircon are a promising proxy to quantitatively study long-term Earth’s lithospheric processes and its geodynamic regimes. The zircon Eu anomaly reflects the crystallization environment of its felsic or intermediate parental magma. It specifically provides insight into the water content, magmatic redox conditions, and the extent of pla­gioclase fractionation in the source rock or its occurrence as a cogenetic crystallizing phase from the magma. We performed a statistical analysis of Eu anomaly from a global compilation of detrital zircons and display it as a timeseries and found a major decrease in Eu anomaly ca. 2.5 Ga and an important increase ca. 0.9 Ga. Combining these trends with thermodynamic modelling, we suggest that these variations could be due to long-term change in the chemical system of the mafic source from which the intermediate to felsic melt and derived zircons are produced. The 2.5 Ga drop was likely associated with an enrichment in incompatible elements in the mafic source, which extended the pressure-temperature field of plagioclase stability as a cogenetic melt phase. We interpret the 0.9 Ga rise to record increasing hydration of magmagenetic sites due to the general development of cold subduction systems, which would delay and/or suppress the saturation of plagioclase in hydrous magmagenetic sites.
Vegetation patterns affect soil aggregate loss during water erosion
Authors: Zhao Zhun , Shi Peng
Published: February 2023

Soil aggregates are important for improving the soil quality and structure. Soil erosion causes the fragmentation and migration of soil aggregates. Vegetation restoration is an effective method for controlling soil erosion, and the vegetation distribution on the slope changes the hydrological processes. However, there is a lack of studies on the regulation of vegetation patterns with respect to soil aggregate loss. In this study, four different vegetation patterns were used to study the loss characteristics of soil aggregates during erosion: no vegetation (pattern A), upslope vegetation (pattern B), middle-slope vegetation (pattern C), and downslope vegetation (pattern D). The results show that the proportions of microaggregates (<0.25 mm) in the sediments during erosion are 65.2%, 72.4%, 77.7%, and 87.7% for patterns A, B, C, and D, respectively. The loss of macroaggregates (>0.25 mm) in the sediment is significantly higher in pattern A than in the other patterns (P < 0.05): A (34.8%) > B (27.6%) > C (22.3%) > D (12.3%). Vegetation on the slope reduces the mean weight diameter (MWD) of aggregates in the sediments by 66.0%–70.0% and the fractal dimension increases by 0.42%–0.96%. The vegetation pattern has different effects on the enrichment rate of aggregates in sediments: the enrichment ratio of macroaggregates decreases by 20.9%–64.7% and the enrichment ratio of microaggregates increases by 11.1%–34.5%. These results indicate that downslope vegetation effectively reduces soil erosion and the loss of soil macroaggregates.
Building Vulnerability Assessment using Artificial Intelligence forLandslide Susceptibility Zone in Champawat District, India
Authors: Sharma Yaggesh , Tyagi Arun , Sharma Mukat Lal , Sharma Priyanka , Aggarwal Ashish
Published: February 2023

The evaluation of the vulnerability of society aroused to landslide-related tragedy is an enlargedtopic. Few studies talk about this issue and limited research has been carried out on therelationship between landslides and their potential impact on buildings and infrastructure.Uttarakhand Province in India is a highly landslide-prone area in the Himalayan region. Thepresent study focused on assessing the building vulnerability for the landslide susceptibility zonein the Champawat district of Uttarakhand state. The building footprint areas are identified byusing an image segmentation algorithm in artificial intelligence. Moreover, the landslide-pronezone was identified based on the historical and recent information collected from variousauthenticated sources and the field investigations made on the recent landslides whereas, morethan ten landslide causative parameters/landslide conditioning factors (LCF) have been used togenerate a susceptibility map. The frequency ratio method has been applied to carry out thesusceptibility zone in the entire study area. Most buildings are found in dangerous areas that arehighly correlated by using published and in-situ datasets.Keywords: Landslide Susceptibility Zone, Artificial Intelligence, Vulnerability, Building Footprints
Comparison Of Northern And Southern Hemispheric SSW Using Reanalysis Data
Authors: Ramatheerthan Sunil Kumar , Laštovička Jan , Kozubek Michal
Published: February 2023

Sudden Stratospheric Warming (SSW) is an extreme dynamical event observed in the middle atmosphere. During this event, there will be changes in circulation behaviour in the middle atmosphere followed by a sudden warming in the polar stratosphere. The warming scenario is preceded by the polar vortex disruption due to the non-linear interaction of extra-tropical planetary waves from the troposphere with the mean flow. SSW affects both the upper and lower atmosphere, irrespective of latitude. It is known that warming events are more frequent in the northern hemisphere than in the southern hemisphere. The study investigates the evolution of warming events in both the northern and southern hemispheres. We use the reanalysis data to compare the 2013 - 2014 northern hemisphere and 2002 southern hemisphere SSW. To understand the forcing and responses in both hemispheres, we conducted meteorological and statistical analyses of SSW using temperature, zonal wind, meridional wind, and geopotential height. The factors that modulate the intensity of warming events in both hemispheres have been discussed in detail.
Groundwater flow impacts on microbial communities and biogeochemistry in seafloor pockmarks
Authors: Purkamo Lotta , von Ahn Cátia M. Ehlert , Jilbert Tom , Muniruzzaman Muhammad , Kock Annette , Bange Herrman , Jenner Anna , Böttcher Michael E. , Virtasalo Joonas
Published: February 2023

Biogeochemical processes and microbial community structure were investigated in sediment cores from three pockmarks in Hanko, Finland, in the northern Baltic Sea, and compared to groundwater and seawater measurements. Three studied pockmarks varied with the rate of submarine groundwater discharge (SGD). Based on e.g., chloride and DIC concentrations from sediment porewaters, pockmark D had the strongest groundwater influence, while in pockmark E SGD had ceased and therefore this pockmark resembled typical Baltic Sea water and sediment. The pockmark B was the intermediate representative of SGD. The inactive pockmark E had orders of magnitude higher methane concentrations compared to the active pockmarks, but interestingly, this did not reflect on the copy numbers of methanogenesis marker gene (mcrA) results, as pockmark B had equal methanogenesis gene pool as the pockmark E. Sulfate reducer numbers measured with dsrB marker gene was highest in pockmark E sample but also many orders of magnitude higher in other pockmark sediments compared to seawater and groundwater, where the sulfate reducer numbers were only negligible. Reactive transport modeling (RTM) established that the porewater systems in pockmarks D and B were dominated by groundwater advection pushing reactants for biogeochemical reaction into a narrow zone at sediment surface. The advection reduced the organic matter accumulation which results in absence of sulfate-methane transition zone in these pockmarks and concentrates the microbial activity to these habitats. Microbial community structure revealed with phylogenetic marker gene amplicon sequencing reflects the groundwater in active pockmarks, as notable populations of ammonia-oxidizing archaea and nitrifying bacteria in pockmarks are mainly originating from groundwater. RTM also estimated low rates of sulfate consumption and low rates of methane, ammonium and DIC in the active pockmarks.
A global, cross-disciplinary inventory of mountain monitoring infrastructure
Authors: Thornton James , Palazzi Elisa , Adler Carolina
Published: February 2023

Multi-variate in situ observations from the Earth’s extensive mountain regions are crucial for a plethora of important applications, such as ground truthing remotely sensed data and downscaling climate model outputs. However, as a result of their inhospitable conditions and remoteness, mountains are extremely challenging environments in which to conduct systematic, long-term, and spatially dense in situ monitoring of bio-physical processes, leading to various real or perceived deficiencies in mountain data coverage (or “data gaps”). Gaining a thorough appreciation of these coverage deficiencies is complicated by the very heterogenous nature of the in situ mountain monitoring “landscape”; many different institutions and initiatives, often research-orientated as opposed to operational, employ a high diversity of techniques for a range of different applications. As such, it is currently extremely challenging for stakeholders to efficiently obtain an overview of who is measuring what, where, when, how, and why in a given region of interest. Information on the coverage of data beyond core climatic variables such as air temperature or precipitation is especially lacking. In this context, we present the GEO Mountains In Situ Inventory of Observational Infrastructure. The latest version (v2) contains key metadata for over 51,000 mountain monitoring stations, station networks, experimental basins, or other monitoring locations (e.g. repeated vegetation monitoring sites) across the world’s mountains. It can be viewed using a web mapping application, with the underlying table also available for direct download. Via a system that enables individuals or institutions to propose additions and improvements, we intend to continue developing the inventory in an iterative, community-based fashion. Overall, this effort should expedite access to the corresponding observations (e.g., time-series), reduce infrastructural redundancy, and improve interdisciplinary collaboration around existing sites. Once further expanded, the inventory may also facilitate more extensive and thematically broad data coverage analyses than those hitherto possible, which in turn could inform monitoring infrastructure installation and maintenance investment decisions. In conclusion, we will reflect on potential links between the inventory and a recently proposed set of Essential Mountain Climate Variables.GEO Mountains (2022). Inventory of in situ mountain observational infrastructure, v2.0. https://www.geomountains.org/resources/resources-surveys/inventory-of-in-situ-observational-infrastructure. doi: 10.6084/m9.figshare.14899845.v2
Over-reliance on water infrastructure can erode resilience of drylands pastoralists
Authors: Piemontese Luigi , Terzi Stefano , Di Baldassarre Giuliano , Castelli Giulio , Bresci Elena
Published: February 2023

Climate change is increasing the frequency and intensity of droughts across drylands, with negative consequences on local communities. Small water infrastructure (e.g. wells, ponds and small dams) are increasingly supported by many NGOs and national governments to increase water availability and help pastoralists cope with the effects of climate change. However, as opposed to large dams, very little is known about the potential cumulative impact of small water infrastructures and their cascading effects on the resilience of pastoral communities. Pastoralists of drylands across the world, who constitute large, marginalized groups in many low-income countries, practice mobility as one of the main adaptation strategies to water variability and uncertainty. Here we show that while developing fixed water points in dryland can provide additional water to pastoral communities, these short-term benefits can be offset by counterintuitive long-term effects such as the erosion of mobility practices and over-reliance on agriculture, thus decreasing resilience to climate change. Combining system dynamics and resilience thinking approaches, we explain the complex consequences of different water resource development strategies and their long-term cascading effects on the resilience of pastoral communities. We then show how our model can capture early signals of resilience loss in Angolan drylands, where water infrastructures are being planned at a large-scale in the pursuit of increasing climate resilience, with unclear long-term understanding of the effects of socio-hydrological dynamics on communities’ resilience.
Molecular characterization of coral reef exometabolites
Authors: Haas Andreas , Nelson Craig , Arts Milou , Mueller Benjamin , Hopmans Ellen , Kelly Linda
Published: February 2023

Marine DOM constitutes one of the most complex chemical mixtures on earth containing hundreds of thousands of different compounds. In nearshore systems like coral reefs metabolites exuded by primary producers comprise a significant fraction of this marine DOM pool. To learn more about the chemical composition we performed untargeted molecular analysis of exudates released by coral reef primary producers (corals and algae) using liquid chromatography–tandem mass spectrometry. Of 10,568 distinct ion features recovered from reef waters, 1,667 were primary producer exudates; the majority (86%) of these exudates were organism specific, reflecting a clear divide between coral and algal exometabolomes. The stoichiometric analyses of the exudates revealed a significantly reduced nominal carbon oxidation state of algal- compared to coral exometabolites, illustrating an ecological mechanism by which algal phase shifts engender fundamental changes in the biogeochemistry of reef biomes. Coral exometabolomes were enriched in diverse sources of nitrogen and phosphorus, including tyrosine derivatives, oleoyltaurines, and acyl carnitines. In contrast DOM released by algae was dominated by nonnitrogenous compounds, including diverse prenol lipids and steroids. Additional experiments indicate that exudates, specifically exudates unique to the respective treatment, were the main substrate used by heterotrophic microbes exposed to the respective exometabolome. This data provides molecular-level insights into biogeochemical cycling on coral reefs and illustrates how changing benthic cover on reefs influences reef water chemistry with implications for microbial metabolism.
Changes in Compound Flood Event frequency in Northern and Central Europe under climate change
Authors: Heinrich Philipp , Hagemann Stefan , Weisse Ralf
Published: February 2023

The simultaneous occurrence of increased river discharge and high coastal water levels may cause compound flooding. Compound flood events can potentially cause greater damage than the separate occurrence of the underlying extreme events, making them essential for risk assessment. Even though a general increase in the frequency and/or severity of compound flood events is assumed due to climate change, there have been very few studies conducted for larger regions of Europe. Our work, therefore, focuses on the high-resolution analysis of changes in extreme events of coastal water levels, river discharge, and their concurrent appearance at the end of this century in Northern and Central Europe (2070-2100). For this, we analyse downscaled data sets from two global climate models for the two emissions scenarios RCP2.6 and RCP8.5.First, we compare the historical runs of the downscaled GCMs to historical reconstruction data to investigate if they deliver comparable results for Northern and Central Europe. Then we study changes in the intensity of extreme events, their number, and the duration of extreme event seasons under climate change. Our analysis shows increases in compound flood events over the whole European domain, mostly due to the rising sea level. This increase is concomitant with an increase in the annual compound flood event season duration.Furthermore, the sea level rise associated with a global warming of 1.5K will result in a 50% increase in compound flood events for nearly every European river considered.
Uncertainties in geomechanical models – A novel concept to data-driven stress modelling
Authors: Ziegler Moritz , Heidbach Oliver
Published: February 2023

The undisturbed stress state of the subsurface is a key parameter for the assessment of geological barrier integrity in deep geological repositories. A robust knowledge of the stress state is required for forward simulations that predict the evolution of the deep geological repository during building, canister emplacement, and post-closure phase. However, stress magnitude data will always be sparse and point-wise and thus not sufficient to allow a continuous characterization of the stress field. 3D geomechanical-numerical models are incorporated to mitigate this shortcoming. The significance of such a model is tied to the stress magnitude data records whose availability is generally low and subject to measurement errors. In turn, the uncertainties of the modelled 3D stress state are large which lowers the predictive values of the ensuing forward models. Here, we present a novel approach to reduce the uncertainties of a modelled stress state (Ziegler and Heidbach, 2023).In a first step we estimate all possible and realistic stress states with respect to the available stress magnitude data and their uncertainties. This provides an overall quantification of the range of stress states that are supported by data. In a second step we limit this usually very large range of stress states using additional indirect stress information to determine upper and lower limits. Formation integrity tests (FITs) are used as a lower limit for the stress state. Observed borehole wall failures (drilling induced tensile fractures and borehole breakouts) provide an estimate of the quality of a modelled stress state in relation with estimations of the rock strength. Observed seismicity and observed seismological quiescence in connection with a failure criterion is used as an upper constraint of the stress state. These additional data allow to identify the probability of a modelled stress state based on its agreement with observations. A weight is estimated for each modelled stress state in a formalized Bayesian approach. This allows an improvement in the significant interpretation of the initial stress state in terms of its robustness and transparency.Results from an explanatory model and a case study in the Bavarian Molasse Basin show an improved significance in terms of clearly reduced model uncertainties. The amount of uncertainty reduction, however, depends significantly on the quality, suitability and assessment of the additional information. Reference:Ziegler, M. O., & Heidbach, O. (2023). Bayesian quantification and reduction of uncertainties in 3D geomechanical-numerical models. Journal of Geophysical Research: Solid Earth, 128, e2022JB024855. https://doi.org/10.1029/2022JB024855
Resolution sensitivity of tropical turbulent fluxes and precipitation in NorESM models
Authors: Tian Fangxing , Keenlyside Noel , Bethke Ingo , Koseki Shunya , Li Fei
Published: February 2023

We evaluated the ¼° model NorESM1.3 in which the well-known “double-ITCZ problem” in the Pacific is mitigated. However, excessive precipitation is produced in the northern branch of the ITCZ. The excessive precipitation is consistent with overevaluated latent heat flux in the tropical ocean. Further analysis shows that in NorESM1.3, the latent heat flux is too sensitive to the surface wind. The increased sensitivity in the ¼° model is partly contributed by small-scale air-sea interaction. The sensitivity of latent heat flux to surface wind, with the scale finer than 2.5°, is up to 40 (Wm-2 / ms-1), which is almost twice of that with scale coarser than 2.5°. This study helps to understand extra air-sea interaction resolved by higher-resolution models, and helps to tune and correct the related model bias.  
Factors Influencing Diurnal Variations of Cloud and Precipitation in the Yushu Area of the Tibetan Plateau
Authors: Cao Bangjun
Published: February 2023

Using data from cloud radar, ground observations and ERA5 reanalysis data, the factors influencing nighttime precipitation during summer in the Yushu area of the Tibetan Plateau (TP) were investigated. The cloud top height (CTH), cloud base height (CBH) and liquid water content (LWC) were compared between non-precipitating days and precipitating days. The results showed that the average CTH on precipitating days in Yushu was below 10 km above ground level (AGL) in the daytime, whereas it exceeded 10 km AGL at night, with the maximum at 2300 Beijing Standard Time (BST = Coordinated Universal Time + 8 h). The CBH was in-phase with the dewpoint spread. The precipitation intensity and CTH were in-phase with the LWC. The hourly averaged precipitation intensity and convective available potential energy in ERA5 reached their maximums at 2100 BST, which was 3 h ahead of their observed counterparts. There was descending motion in the middle of the day on non-precipitating days, whereas there was ascending motion at night on precipitating days. In addition, the horizontal wind direction in the lower level (below 5000 m) showed clockwise rotation from morning to night. Wind shear occurred in the middle level of the atmosphere, accompanied by a subtropical westerly jet in the upper level. The difference in horizontal wind speed between 200 hPa and 500 hPa was positively related to the LWC, thereby contributing to the formation of upper-level cloud.
Functional relationships reveal differences in the water cycle representation of global water models
Authors: Gnann Sebastian , Reinecke Robert , Stein Lina , Wada Yoshihide , Thiery Wim , Müller Schmid Hannes , Satoh Yusuke , Pokhrel Yadu , Ostberg Sebastian , Koutroulis Aristeidis , Hanasaki Naota , Grillakis Manolis , Gosling Simon N. , Burek Peter , Bierkens Marc F. P. , Wagener Thorsten
Published: February 2023

Global water models are widely used for policy-making and in scientific studies, but substantial inter-model differences highlight the need for additional evaluation. Here we evaluate global water models by assessing so-called functional relationships between system forcing and response variables. The more widely used comparisons between observed and simulated fluxes provide insight into model behavior for the representative area of an observation, and can therefore potentially improve the model for that area. Functional relationships, by contrast, aim to capture how system forcing and response variables co-vary across large scales, and thus offer the potential for model improvement over large areas. Using 30-year annual averages from 8 global water models, we quantify such functional relationships by calculating correlations between key forcing variables (precipitation, net radiation) and water fluxes (actual evapotranspiration, groundwater recharge, total runoff). We find strong disagreement for groundwater recharge, some disagreement for total runoff, and the best agreement for evapotranspiration. Observation- and theory-derived functional relationships show varying agreements with models, indicating where model representations and our process understanding are particularly uncertain. Overall, our results suggest that model improvement is most important for the representation of energy balance processes, recharge processes, and generally for model behavior in dry and cold regions. We argue that advancing our ability to simulate global hydrology requires a better perceptual understanding of the global water cycle. To evaluate if our models match that understanding, we should explore alternative evaluation strategies, such as the use of functional relationships.
Data-driven simulation of the coronal mass ejection of October 28 202
Authors: Schmieder Brigitte , Guo Jin Han , Devi Pooja , Chandra Ramesh , Guo Yang , Chen Pen Feng , Poedts Stefaan
Published: February 2023

The event of October 28 2021 was very geoeffective with particles accelerated to high energies resulting in ground level enhancements (GLEs). It is important to understand the scenario leading to such energetic particle acceleration which can be done by studying the origin of this event from the Sun to the Earth through the heliosphere.  The acceleration of particles was justified by two acceleration processes, one due to the flare during the impulsive phase, and the second by the coronal mass ejection (CME), which prolonged the low level proton emission (Zhang, Gan et al 2022, Klein et al 2022).The first step of our study  was to understand the relationship between the  flare, the EUV wave and the CME  using the SDO, STEREO- A/COR1 and SOHO/LASCO observations (Devi et al 2022).  The second step was to model the CME (Guo et al 2023).We found that a fast-mode EUV wave front propagates ahead  the CME front. The eruption was modeled by a flux rope using the Regularized  Biot-Savart Laws in a data-driven background obtained with HMI magnetograms. The CME was well recovered with its three components and the shock fitted with the observations.  We plan to study the evolution of  this flux rope in the solar wind by using  EUHFORIA.
Soft-linking climate-land-water-energy assessment and planning models for sustainable development in rural Africa: preliminary results from the LEAP-RE RE4AFAGRI project
Authors: Falchetta Giacomo , Awais Muhammad , Byers Edward , Giordano Vittorio , Ireland Gregory , Semeria Francesco , Tuninetti Marta , Vinca Adriano , Zulu Ackim
Published: February 2023

In rural areas of Africa most communities live in poverty and lack access to services such as electricity and clean cooking fuels, water supply that is safe for human use, sufficient and nutritious food, crop irrigation systems, and appliances and services that can foster income generation. Promoting sustainable development requires an integrated understanding and planning along such dimensions. In the context of the RE4AFAGRI (“Renewables for African Agriculture”) project of  LEAP-RE (Long-Term  Joint  Research  and  Innovation  Partnership  on  Renewable  Energy between  the European Union and the African Union), four models representing land-water-crop-food-energy requirements and dynamics (WaterCROP, M-LED, OnSSET and MESSAGE-NEST) are calibrated and soft-linked. The ultimate aim is to enable a multi-scale, multi-sectoral assessment and planning of technologies and policies that can promote integrated sustainable development in the region. Here we present preliminary results for a set of scenarios in the country-study of Zambia. Results can inform both public decision-makers and private companies engaging in those sectors. The approach and open-source modelling platform are readily scaled and adapted to other countries and regions.
GEOMODELATOR – from static geologic models to structured grids for numerical simulations
Authors: Nakaten Benjamin , Kempka Thomas
Published: February 2023

Conversion of static geologic models into numerical simulation grids is a pre-requisite to undertake site-specific assessments of geologic subsurface utilisation in terms of risk assessments, design and operational optimisations as well as long-term predictions.GEOMODELATOR is a Python-based Open Source software package which enables modellers to translate static geologic models into regular structured simulation grids with element partitions following a complex model geometry.For that purpose, geologic models generated by means of Geographic Information Systems (GIS), Computer-Aided Design (CAD) or other specific geologic modelling software packages are integrated in form of point cloud data together with the desired structured simulation grid geometry.GEOMODELATOR maps geometric features such as lithologic horizons, faults and any kind of other geometric data by 3D Delaunay triangulation onto the pre-defined grid element centres, and provides the modeller with Visualization Toolkit (VTK) data and Python numpy arrays for visual model inspection and their direct application in numerical simulations, respectively.The present contribution shows the application of GEOMODELATOR to different numerical simulation studies addressing fluid flow as well as transport of heat and chemical species in geological subsurface utilisation.
Comparison of water use patterns of sand-binding species in an alpine semi-arid desert
Authors: Tian Lihui , Wu Huawu , Zhang Dengshan
Published: February 2023

The processes of species obtaining water resources are crucial to evaluate the adaptability of plantations, which can affect the establishment and survival of restored ecosystems and functions of water-limited ecosystems. However, there are still limitations in understanding water use patterns of different four plantations (Populus sylvestris, Salix cheliophe, Hippophae rhamnoides and Artemisia ordosica) in the Qinghai Lake basin. Stable isotopes of xylem water of four individual species were analysed at different dunes located at the eastern shore of Qinghai Lake in 2018 and 2019. The purpose of this study was to explore potential water sources used by different life form plants, to identify whether the soil moisture content and root distribution determined the plants water use patterns. Results from the MixSIAR models showed that all species mainly uses three levels of soil water, but they extracted soil water from different layers in different growing seasons among species. All species primarily depended on water from upper soil layers at the early growing stage, but P. sylvestris and S. cheliophe also absorbed much proportion middle and deep soil layers’ water in dry year of 2019. All four species shift to use middle or deep soil layer water rather than shallow water in July with the most rainfall and soil water content. However, it was only used by P. sylvestris and H. rhamnoides in 2018. In all, seasonal water use pattern of different species was affected by soil water content, soil texture and root distribution. Compared with moratorium plantations such as S. cheliophe, mixed afforestation of P. sylvestris and H. rhamnoides maximized of soil water sources absorbed by the plants. The study can shed light on plant-water relationships to facilitate the woody species for afforestation and desertification restoration management in the semi-arid desert ecosystem.
Comparison between seismic amplification factors from building code and those obtained by data from Italian seismic microzonation studies
Authors: Paolucci Enrico , Tanzini Anna , Albarello Dario
Published: February 2023

Given their ease of use, the simplified approaches based on the use of some seismic “proxies” and contained in the most common building code provisions are the most widespread methods in the professional activity to estimate the ground-motion amplification due to the local seismo-stratigraphical features. This kind of approach is also present in Italy in the actual national building code. As is now well known, this procedure assigns an acceleration response spectrum through the estimation of the soil class of the investigated site, which is identified by the values of two proxies, that is the seismic bedrock depth H (i.e., the layer with Vs ≥ 800 m/s) and the time average Vs down to H (VSH) or to 30 m depth (VS30), if H is lower or higher than 30 m respectively. The objects of this study are the seismic Amplification Factors (AFs) refer to each soil class, defined as the ratio between the integral of the acceleration response spectrum of soil classes B, C, D, E respectively and the integral of the response spectrum of the soil class A. These values were computed for three period intervals (0.1–0.5 s, 0.4–0.8 s and 0.7–1.1 s) and are determined for all the Italian municipalities considering the response spectra referred to the Italian Seismic Hazard Map relative to the ground motion expected to be exceeded with a probability equal to 10% in 50 years. The aim of this work is to test the effectiveness of these AF estimates verifying if these values are enough conservative with respect to those obtained by 1D numerical simulations carried out in the same sites. To perform this analysis, we evaluate if the number of excesses from these estimates is significant from the statistically point of view or it can be considered as a random fluctuation. On this purpose, outcomes from the “Italian Map of Expected Values of Amplification Factors” obtained in the framework of a national project in 2019-2021 were considered. In particular, seismo-stratigraphical and geotechnical data from sesimic microzonation studies of 1689 Italian municipalities were used to perform 1380600 1D equivalent linear numerical simulations, from which it was possible to compute the AFs value from the ratio between the integrals of the relevant output and input response spectra. For each simulated profile, AF value from building code is then retrieved estimating the soil class and considering the municipality of the data origin. Finally, the two AF datasets were compared following the statistical approach mentioned above.
Vegetation effects and sediment deposition in a mesotidal wetland
Authors: Carrasco A. Rita , Kombiadou Katerina , Matias Ana
Published: February 2023

Many studies have been carried out in the last decade to assess the rates of sediment transport and deposition on tidal flats and salt marshes, however, a need to characterize the transport fluxes between the various habitats as a function of tidal range, their position relative to mean sea level, and flow-asymmetries in the vegetation effect remain. This study uses fieldwork data to characterize the sediment fluxes and deposition from the tidal flats towards the marsh platform, in a channel margin of the Ria Formosa coastal lagoon (south Portugal). Sediment fluxes were measured in a cross-shore transect, during neap and spring tide conditions. The dominant intertidal species are Spartina maritima and the seagrass Zostera noltei. Current measurements were used to assess bottom shear stress conditions. Deposition rates, instantaneous suspended sediment, and near-bed velocities were linked through theoretical formulas and used to characterize time-averaged conditions for sediment delivery and deposition to the site.The results showed that suspended sediment concentrations and sediment deposition varied across-shore with no specific relation to elevation. Maximum current velocities were recorded in the vegetated tidal flat, in the order of 0.20 m/s, and in the low marsh due to flow-plant interactions and an increase in turbulence. Deposition rates ranged between 20 to 45 g/m2/hr, after a complete tidal cycle, and were higher in the mid-upper marsh. The hydroperiod was not the main contributor to sediment deposition in the study area. Measured sediment transport was tidally driven, with shifting current angles during the cycle and major alongshore components during peak flood velocities. Flow-spartina interference in the low marsh significantly affected local sediment resuspension. The obtained results provide insights into the dynamics and variability of flow and mass transfer along a transition from the vegetated tidal flat to the upper marsh and can be used in sediment transport models for mesotidal marsh systems.Acknowledgments: A. Rita Carrasco was supported by the contract DL57/2016/CP1361/CT0002, and Katerina Kombiadou was supported by the institutional contract CEECINST/00146/2018, both funded by Fundação para a Ciência e Tecnologia (FCT). This study had also the support of FCT under the project LA/P/0069/2020 granted to the Associate Laboratory ARNET and CIMA BASE UID/00350/2020.
Sensitivity Analysis of WRF’s PBL Schemes in detecting thunderstorm characteristic features
Authors: Chhari Abhishek , Chakravorty Aniket , Shirivastav Abhay , Kundu Shyam Sunder , Gogoi Rekha Bharali , Agarwal Shiv Prasad
Published: February 2023

Thunderstorms are among the deadly natural disasters, accompanied by lightning, heavy rainfall, high-speed gusty winds, hail and flash floods. Prediction of these thunderstorms can be done by NWP models, which could reduce the associated damages and casualties. For NWP models to achieve good prediction accuracy for thunderstorms, it is essential to resolve associated physical parameters correctly. Physical parameters and processes associated with planetary boundary layer (PBL) play a significant role in development of thunderstorm events. In the present study we simulate two severe thunderstorm events which occurred over Nagaon district and South Garo Hill region in the northeastern part of India, using a high resolution WRF model. A sensitivity analysis of PBL schemes in the WRF model was done to simulate the characteristic features of these thunderstorm events. We selected three PBL schemes for this study,  the Mellor Yamada Janjic (MYJ), Yonsei University (YSU) and the asymmetric convective model, version 2 (ACM2). Characteristic features of a thunderstorm, like Vertical Wind Velocity, Relative Humidity, Cloud Ice Water content, Cloud Fraction and Radar Reflectivity events, were simulated using these PBL schemes. These simulations were then validated against observations from DWR, INSAT-3D and ERA5 Reanalysis data. It was found that among the three PBL schemes, WRF performed better with the MYJ scheme in capturing the major variations in most of the characteristic features of these thunderstorm events.
Pressure-temperature-time evolution of a blueschist and an eclogite from the Vestgötabreen Complex, Svalbard
Authors: Kośmińska Karolina , Majka Jarosław
Published: February 2023

The pressure-temperature-time (P-T-t) history of a blueschist and an eclogite from the high pressure-low temperature Vestgötabreen Complex, Svalbard, has been constrained using the conventional geothermobarometry, trace elements thermometry, and elastobarometry coupled with Lu-Hf garnet, U-Pb monazite, and U-Pb zircon dating. Three evolutionary stages for the eclogite have been distinguished thanks to the different textural positions and zoning of major minerals. The prograde growth (M1) happened at 15.9 kbar and 460°C, then the peak-P conditions (M2) 23.5 kbar at 507°C, followed by peak-T conditions (M3) of 21.4 kbar at 553°C. Only peak conditions of ca. 18 kbar at 520-550°C have been estimated for the blueschist. These P-T results indicate a low geothermal gradient of 7-8°C, as suggested by Agard et al. (2005). Secondary ion mass spectrometry (SIMS) analyses of zircon rims from the eclogite yielded the lower intercept of concordia at 478±17 Ma (n=11, MSWD=1.1), which is interpreted as a prograde growth. Monazite from the matrix and inclusions in garnet rim give a 206Pb/238U weighted mean age of 471±6 Ma (n=7, MSWD=1.4). Monazite could have formed due to florencite and/or lawsonite breakdown somewhere between M2 and M3 stages. Garnet in the eclogite is strongly zoned and Lu is concentrated mostly in the rims. Lu-Hf dating yields the age of ca. 471 Ma for the biggest fraction and ca. 466 Ma for smaller garnet separates. Monazite from the blueschist gives a 206Pb/238U weighted mean age of 486±6 Ma (n=4, MSWD=0.32) interpreted as a prograde growth. Lu-Hf dating of garnet from the blueschist provides an age of a peak metamorphism of 471.1±3.8 Ma (n=10, MSWD=2.8). in our opinion, the Vestgötabreen Complex represents the earliest Paleozoic subduction system, which could have developed proximally to the Baltican margin.This work is supported by the National Science Centre of Poland project no. 2021/43/D/ST10/02305.References:Agard P, Labrousse L, Elvevold S, Lepvrier C (2005). Discovery of Palaeozoic Fe–Mg carpholite (Motalafjella, Svalbard Caledonides): a milestone for subduction zone gradients. Geology 33: 761–764.
Forecasting High-Latitude Ionospheric Convection Using the BAS Reanalysis of SuperDARN Data
Authors: Lam Mai Mai , Shore Robert , Chisham Gareth , Freeman Mervyn , Grocott Adrian , Walach Maria-Theresia , Orr Lauren
Published: February 2023

Forecasting of the effects of thermospheric drag on satellites will be improved significantly with more accurate modelling of space weather effects on the high-latitude ionosphere, in particular the Joule heating arising from electric field variability. This is the largest uncertainty in orbit prediction for satellites and space debris. We use a regression analysis to build a forecast model of the ionospheric convection E×B drift velocity which is driven by relatively few solar and solar wind variables. The model is developed using a solar cycle’s worth (1997 to 2008 inclusive) of 5-minute resolution reanalysis data derived from Super Dual Auroral Radar Network (SuperDARN) line-of-sight observations of the convection velocity across the high-latitude northern hemisphere ionosphere. At key stages of development of the forecast model, we use the Priestley skill score to see how well the model reproduces the reanalysis dataset. The final forecast model is driven by four variables: (1) the interplanetary magnetic field component By, (2) the solar wind coupling parameter epsilon ε, (3) a trigonometric function of day of year, (4) the monthly f10.7 index. The forecast model can reproduce the reanalysis plasma velocities, with a characteristic skill score of 0.7. The forecast and reanalysis data compare best around the solar maximum of 2001. The forecast skill is lower around solar minimum, due to occasional limitations in the geographical and temporal coverage of the SuperDARN instrumentation. In addition, this may also indicate the need to modify our model of driving processes around the minimum of the solar cycle.
Aerosol hygroscopic growth study from synergy between Mie-Raman-Fluorescence Lidar and Microwave Radiometer
Authors: Miri Robin , Goloub Philippe , Pujol Olivier , Hu Qiaoyun , Veselovskii Igor , Podvin Thiery , Ducos Fabrice
Published: February 2023

This study focuses on the characterization of aerosol hygroscopicity using remote sensing techniques. A Mie-Raman-Fluorescence lidar, developed at the Laboratoire d’Optique Atmosphérique in Lille, France, in combination with a Microwave radiometer, allow to monitor continuously both aerosols and water vapor. Hygroscopic growth cases can be identified when an aerosol layer presents an increase in both aerosol backscattering coefficient and relative humidity. Looking at the class of the aerosol among the layer, determined from clustering methods, and the fluorescence backscattering coefficient, which is expected to be unaffected by the presence of water, it is possible to verify that the aerosol layer is homogeneous. Therefore, the change in the backscattering coefficient is then only due to water uptake. The Hänel theory describes the evolution of the backscattering coefficient with relative humidity and introduces a hygroscopic coefficient, γ which depends on the aerosol type and the relative humidity threshold of the dry condition. One case study has been identified on 10 March 2021 for a smoke aerosol layer. For this case, γ was determined at  for . This value is consistent with other values found in the literature for smoke particles. Other cases have been analyzed and this set of example illustrates the potentiality of the methodology presented here.