bluuebunny/crossref_metadata_2025 huggingface dataset:
Navigating Climate Change: Exploring Plenter Forest Potential in Styria, Austria
Authors: Leiter Mathias , Pucher Christoph , Hönigsberger Ferdinand , Kessler Michael , Lexer Manfred J. , Vacik Harald , Hasenauer Hubert
Published: March 2024

Forests stand at the forefront of climate change adaptation strategies, with their ability to sequester and store carbon, sustain bioeconomies, foster biodiversity, and provide a whole range of other ecosystem services. There is an increasing trend of promoting this multipurpose functionality of forests, resulting in a shift towards silvicultural practices that differ heavily from the now dominant even-aged, clear-cut forestry. One of these alternative management practices to promote multipurpose functionality is plenter forest management, a type of uneven-aged selection cutting system. Only little is known about the applicability of this management system on a regional or national scale. Therefore, this study assesses the potential expansion of plenter forest management, crucial for climate change mitigation. Focusing on tree species suitability, harvesting constraints, and road accessibility, we analysed factors impacting plenter management for the Austrian province of Styria for current and future climate conditions. Our findings reveal that while current forestry predominantly features even-aged Norway spruce, approximately 14% of the forest area could be managed as mixed-species plenter forests under current conditions. This research contributes to understanding potential in transforming forest practices for enhanced biodiversity, ecosystem services, and climate resilience on a regional scale.
Ocean-driven basal channel growth at Fimbulisen
Authors: Zhou Qin , Hattermann Tore , Zhao Chen , Gladstone Rupert , Morris Ashely , Uotila Petteri
Published: March 2024

Small-scale basal features, such as channels and crevasses, are abundant on many ice shelves.  These features may, either directly or via modulating basal melting, impact ice shelf stability and, therefore, also global sea level. However, simulating the effect of these features on ice shelves at a hundred-meter scale or smaller is still challenging even for dedicated regional simulations, which typically ignore the small-scale features and smooth the ice draft. Fine-resolution (8 m) basal topography retrieved from the Reference Elevation Model of Antarctica (REMA) data reveals that channelized basal features of several tens of kilometers traverse the ice base both along and across the Jutulstraum ice stream on the Fimbulisen Ice Shelf (FIS). The FIS cavity is currently filled with fresh and cold Eastern Shelf Water (ESW), and recent observations have shown a sustained inflow of Warm Deep Water (WDW) since 2016. In this study, we first assess the effect of the basal channels on the cavity circulation and basal melting of the FIS with a fine-scale unstructured grid Finite-Volume Community Ocean Model (FVCOM) model of the FIS ice cavity. The grid resolution varies from 50 m in the focused region along the ice stream to 1500 m in the open ocean. Sensitivity studies are carried out using the high-resolution ice draft from REMA and a smoothed version of it, combined with varying proportions of WDW in the cavity. Our results show that the basal channels lead to (i) a redistribution of basal melting, (ii) a net melt increase at the deep ice area, and (iii) the entrapment of melt-modified WDW in the channels where WDW reaches the deep ice area. Using an idealized ice sheet model, we demonstrate that this entrapment of warm water in the channel results in a net melt increase with a preferential melt that promotes channel growth and migration, forming a positive feedback loop. We further investigate the positive feedback mechanism using an Elmer/Ice–FVCOM model setup with the same fine-scale mesh as the ocean model. This ocean-driven coupled evolution of the channelized system may occur on other shelves in East Antarctica where ESW and WDW coexist. Considering this coupled process in generating sea level projections could constrain East Antarctica's contribution to future sea level rise. 
Exploring Sources of Multi-year Predictability of Terrestrial Ecosystem
Authors: Lee June-Yi , Kim Yong-Yub , Yun Jeongeun
Published: March 2024

The demand for decision-relevant and evidence-based near-term climate information is increasing. This includes understanding and explaining the variability and changes in ecosystems to support disaster management and adaptation choices. As climate prediction from seasonal to decadal (S2D) expands to encompass Earth system dimensions, including terrestrial and marine ecosystems, it is crucial to deepen our scientific understanding of the long-term predictability sources for ecosystem variability and change. Here we explore to what extent terrestrial ecosystem variables are driven by large-scale - potentially predictable -climate modes of variability and external forcings or whether regional random environmental factors are dominant. To address these issues, we utilize a multi-year prediction system based on Community Earth System Model version 2 (CESM2).  The system consists of 50-member uninitialized historical simulations, 20-member ocean assimilations, and 20-member hindcast initiated from every January 1st integrating for 5 years from 1961 to 2021. The key variables assessed are surface temperature, precipitation, soil moisture, wildfire occurrence, and Gross Primary Productivity. Our results suggest that land surface processes and ecosystem variables over many parts of the globe can be potentially predictable 1 to 3 years ahead originating from anthropogenic forced signals and modes of climate variability, particularly El Nino and Southern Oscillation and Atlantic Multi-decadal variability. These global modes of climate variability shift regional temperature and precipitation patterns, leading to changes in soil moisture, wildfire occurrence, and terrestrial productivity.  
Demonstration of a city-scale geothermal resource assessment using a statistical archetypes-based approach
Authors: Kreitmair Monika , Makasis Nikolas , Chen Kecheng , Choudhary Ruchi , Soga Kenichi
Published: March 2024

Growing demand for space in urban areas is accelerating the utilisation of the shallow subsurface for residential and commercial spaces, transport systems, industrial processes, and energy applications. The associated underground infrastructure can act as a source and sink of heat within the subsurface, altering the ambient temperature of the soil. The extent and magnitude of such a temperature anomaly is affected by the type and density of the structures in the ground, the environmental hydraulic conditions governing groundwater flow, and the geological properties impacting conductive heat transfer. As a result, temperature distributions will vary spatially beneath a given city, thereby also affecting the geothermal potential available for heating and cooling. Knowledge on where the greatest geothermal potential lies within a city can be crucial for large-scale planning of geothermal systems, and incorporating these within building and district-level systems.We present a methodology to map the geothermal potential under cities, extending on a recently developed and published large-scale subsurface temperature modelling methodology, which statistically identifies commonalities in how natural and anthropogenic features affect subsurface heat transfer and creates subsurface archetypes. The extension entails incorporating ground heat exchanging structures, e.g. boreholes, within the archetypes to further subdivide existing thermal archetypes into geothermal archetypes and thus enable comparison of the relative performance of a ground heat exchanger in different areas of a city. The methodology is applied to the city of Cambridge, UK to generate a map of geothermal potential. Additionally, the demand for the city, computed using field data, is mapped to produce a demand-to-capacity map of the city. By exploring different exploitation scenarios of the geothermal potential, i.e. first-come-first-served vs. co-ordinated, we further determine the ability of the resulting deployment patterns to meet likely changes in future demand under the effects of climate change.
Improving process understanding using multi-criteria model comparison for different catchments
Authors: Guse Björn , Herzog Anna , Houska Tobias , Spieler Diana , Thober Stephan , Staudinger Maria , Wagner Paul , Düthmann Doris , Loritz Ralf , Ehret Uwe , Kiesel Jens , Müller Sebastian , Melsen Lieke , Pool Sandra , Tarasova Larisa , Mai Juliane , Wagener Thorsten , Tetzlaff Doerthe , Fohrer Nicola ,   other members of the DFG scientific network IMPRO
Published: March 2024

Hydrological models differ in the way how hydrological processes are implemented. A rigorous comparison of different hydrological model structures is needed to disentangle the link between similarities and differences in process representations and simulated hydrological processes, states and fluxes. A major challenge in model comparison is to identify effects of individual processes. To move a step in this direction, we developed controlled experiments and compared three hydrological models (HBV, mHM, SWAT+) in nine German catchments (400-3000 km²) along an elevation gradient. We aim at presenting a framework for a consistent comparison of process representations in model structures consisting of three steps:(1) A model comparison protocol was developed for a detailed comparison of process representations in model structures. Consistency was achieved by using the same input data for all models. By grouping the processes in a standardized way, differences and similarities between the models were identified.(2) To investigate the dominant model components, a daily parameter sensitivity analysis was carried out for the three models with different hydrological variables as target variables (e.g. actual evapotranspiration, soil moisture, snow and discharge). The dominant model parameters and associated processes vary more between the models than between the catchments. This also applies to the temporal variability of the parameter sensitivity.(3) The model performance was analysed for a set of different performance criteria. The optimal parameter values differ greatly depending on which performance criteria were selected. This is in particular true for soil and evapotranspiration parameters. Typical patterns can be derived between catchments of different landscapes.The joint analysis of these three methodological steps demonstrates the benefit of a detailed process analysis in model structures for a better understanding of suitable process representations. Therefore, it shows the potentials for improving model structures.
Building and establishing the open collection of geoscience graphics
Authors: Straume Eivind Olavson , Shephard Grace , Crameri Fabio
Published: March 2024

Launched in early 2022, the s-Ink project makes high-quality (geo)scientific figures freely available via an always-on online platform, https://s-ink.org. The website hosts figures that can be searched and downloaded by everyone, including students, researchers, teachers, the media, and the public. Hosted content is intentionally broad in nature, and can include data visualisations, animations, artistic impressions, icons, templates, and more.The open graphics collection, that is also designed for you to share your own graphics, is built around the fundamental principles of science: accuracy, accessibility, and acknowledgment. First, the graphics hosted on s-ink.org are subject to transparent and permanent community-review, versioned and therefore updatable to the latest understanding – an academic novelty. Second, s-Ink graphics are, without exception, universally readable, also to colour-blind viewers – an academic rarity. Third, all content has metadata and is licenced (e.g., via Creative Commons), so those who create the images and the sources they are based on will receive credit.The s-Ink.org initiative is currently coordinated by three scientists, working on a volunteer-based approach with non-permanent contracts (one a free-lancer, two with the backing of employers). We are finding financial sponsors to cover the minimal costs involved and actively bridge other valuable community initiatives by hosting their graphical and providing our educational resources.Both the collection and the contributing creators are ever-growing, and the rising views and downloads are signalling the demand. The open collection of geoscience graphics that we envisage (see Crameri et al., 2022) is of direct use well beyond to geoscience community. Indeed, somewhat of a holy grail to science communication.Crameri, F., G.E. Shephard, and E.O. Straume (2022, Pre-print), The open collection of geoscience graphics, EarthArXiv, https://doi.org/10.31223/X51P78
TROPOMI-based NOx emission estimates of individual ships
Authors: Rieß Christoph , van Vliet Jasper , Boersma Folkert
Published: March 2024

Maritime transportation is a substantial contributor to anthropogenic NOx emissions and coastal air pollution. Recognizing this, the International Maritime Organization (IMO) has implemented stricter emission standards for NOx and SO2 in recent years. However, monitoring emissions of sea-bound vessels possesses inherent challenges, prompting the exploration of satellite observations as a promising solution. This study presents a first-ever satellite-based NOx emission inversions for multiple individual ships based on TROPOMI-observed NO2 plumes and AIS data over the Mediterranean Sea in 2019. Our inversion approach accounts for the complex, high-resolution atmospheric dynamics and chemistry that drive the relationship between the NOx emissions and observable NO2 plume. Additionally, we test how an updated Air Mass Factor (AMF) scheme – using high-resolution local plume NO2 profiles from  PARANOX simulations – improves the inversion. For the inversion, we create a large library of pseudo-observations of NO2 plumes with the Gaussian Plume Model PARANOX and test these with the large eddy simulation model MicroHH, which was run with an atmospheric chemistry scheme. The plume dispersion of the two models shows good agreement and the simulated in-plume NO2 differs by only 6%, making PARANOX a suitable (and computational efficient) model choice, especially when considering the large uncertainties related to satellite retrievals above sea.The PARANOX library shows that background ozone and the effective wind speed determine the relationship between the ship NOx emission strength and the observable NO2 plume: Ozone drives the partitioning of the emitted NOx between NO and (observable) NO2 and the wind speed dictates the mixing and therefore lifetime of NOx in the plume. This explains the frequent occurrence of detectable ship NO2 plumes in the Eastern Mediterranean in summer, when background ozone is high and wind speeds are moderate. We study 130 NO2 plumes of individual ships found in TROPOMI data over the Mediterranean Sea in 2019, most of which are from container ships. In the early afternoon, the observed ships in the Mediterranean Sea emit on average 76g NO2 /s but reaching up to 240 g/s. Finally, these fluxes are compared against both the current IMO emission limits and the requirements for a future Emission Control Area in the Mediterranean Sea.
Impacts of dynamically simulated biogenic particles and iron on the marine carbon cycle
Authors: Adloff Markus , Dinauer Ashley , Laufkötter Charlotte , Pöppelmeier Frerk , Jeltsch-Thömmes Aurich , Fortunat Joos
Published: March 2024

We present a novel mechanistic representation of both organic and inorganic marine particles within the Bern3D Earth system model of intermediate complexity, which is based on the columnar particle flux model MSPACMAM. This new approach moves away from the assumption of globally and temporally invariant sinking profiles. Instead, the new scheme calculates sinking speeds and remineralisation and dissolution rates based on local temperature, density, and seawater chemistry. When combined with an improved representation of dynamic iron release and scavenging, this scheme introduces new dynamic feedbacks in the response of the biological pump to climate and circulation changes in the Bern3D model. Particle remineralisation and dissolution rates are now functions of temperature, oxygenation, saturation state, and sinking speed. The sinking rate is in turn modulated by changes in export production (amount and composition) as well as the viscosity of seawater. In addition to light and macronutrients, export production is affected by iron availability, which is depending on the rate of iron removal through scavenging and iron release from decaying particles and sediments, both processes that depend on organic particle fluxes and local oxygen concentrations. We demonstrate the non-linear interactions between these new dependencies in transient and steady-state simulations of various climatic boundary conditions. The newly introduced particle concentrations sensitive to changes in temperature and density result in shallower carbonate dissolution and deeper organic particle remineralisation in the Southern Ocean under full glacial conditions. In idealized scenarios of anthropogenic climate change, there is a smaller decline of export production but faster oxygen depletion than with the old static particle decay scheme. In addition, organic particle fluxes affect sedimentary iron release, which can lead to a positive feedback on export production if the released iron reaches the surface ocean.
Fracture network analysis of Jebel Madar (North Oman): new perspectives from very-high resolution Digital Outcrop Modelling
Authors: Menegoni Niccolò , Panara Yuri , Iakusheva Regina , Lamarche Juliette , Richard Pascal , Finkbeiner Thomas
Published: March 2024

Jebel Madar is located in the Adam Foothills of North Oman. It has been interpreted as a salt-cored, faulted anticline caused by the movement of the Precambrian-Cambrian Ara salt Fm, during the orogeny of the Oman mountains. The out-cropping Shuaiba and Natih carbonate rocks are reservoirs analogues for numerous Omani hydrocarbon fields. The maximum depth of burial is interpreted to be similar to those observed in the sub-surface fields. Therefore, Jebel Madar is considered a perfect structural analogue of fracture and fault dominated reservoirs above a salt dome in sub-surface conditions. Previous fracture studies focused mostly on the peripheral parts of Jebel Madar (i.e., Natih Fm.). Thus, fracture patterns are described as being radial, independent from regional fault and fracture pattern, and therefore, hypothesized as controlled by salt doming.Recently, we conducted a high-resolution drone photogrammetry survey focused on the central parts of the jebel, in order (1) to update and detail fault and fracture patterns; (2) to refine our understanding of its structural evolution model; (3) to serve as a foundation for virtual reality field trips and courses.The dataset comprises ~ 37,000 drone photographs with a total aerial coverage of ~ 6 km2 and a resolution between 3cm and 1 mm. This enables us to develop 44 Digital Outcrop Models (DOMs), with a total of ~ 10.2 billion points. This unique database allows us to quantify the fault and fracture networks of Jebel Madar, in terms of orientation, intensity and 3D arrangement. The DOMs also provide a unique opportunity to map, analyze and interpret fractures and faults that are not accessible by field geology, but only accessible by drone.This contribution shows early results of the high-resolution Digital Outcrop Model-based fault and fracture analysis. We will illustrate the impact of mechanical stratigraphy on fracture distributions in 3D and re-evaluate the impact of regional tectonics on the structural rise of the dome.
Is temperature a key driver of microbial community composition in urban shallow groundwater? – A case study from Vienna
Authors: Cukusic Angela , Karwautz Clemens , Englisch Constanze , Kaminsky Eva , Steiner Cornelia , Stumpp Christine , Griebler Christian
Published: March 2024

Increasing urbanization puts pressure on urban subsurface temperatures and the impact on groundwater quality and human health. However, consequences of the subsurface urban heat island phenomenon, i.e. heat anomalies due to the urban lifestyle, on groundwater ecosystems have rarely been addressed to date. Of particular interest are microorganisms, who are omnipresent in groundwater and intimately involved in the cycling of carbon and nutrients, the (im)mobilization of metals, the natural attenuation of contaminants, and providing essential ecosystem services. In the framework of the research project ‘Heat below the City’, 150 groundwater wells located in the city of Vienna were sampled twice, once in spring and once in autumn 2021. A multitude of physical-chemical and biological parameters of the groundwater samples were analyzed, including the characterization of the microbial community via 16S rDNA amplicon sequencing. Groundwater temperature, combined with other stressors, such as organic and inorganic pollutants, as well as lack of dissolved oxygen, was hypothesized to prominently impact the composition, diversity and activity of microbial communities. The results revealed a complex interplay of hydrogeological and physico-chemical conditions and microbial community parameters. Microbial diversity and activity showed both increasing and decreasing trends with increasing groundwater temperature, depending on the hydrogeological aquifer type. The dominant microbial taxa were not directly impacted by the observed temperature gradients. The number of heat sources in the vicinity of a sampling well explained microbial community composition better, than any specific heat source alone. Current attempts to explore urban groundwater microbial communities of Berlin and Munich are being pursued, with the aim to improve the fundamental understanding of the relationship between hydrogeology and pressures from urbanization on the groundwater microbiome.
Temperature increases the versatility of belowground plant-microbiota interactions in cold climates
Authors: in 't Zandt Dina , Aldorfová Anna , Šurinová Mária , in ‘t Zandt Michiel H. , Vandvik Vigdis , Münzbergová Zuzana
Published: March 2024

The ongoing change in climate extensively alters belowground interactions between plants and microbiota. Alterations in plant-microbiota interactions have significant implications for the functioning of ecosystems. To predict ecosystem change and protect vulnerable systems, it is therefore crucial to understand how climate shapes belowground plant-microbiota interactions. We test how prokaryote and fungal rhizosphere and root-associated communities of the perennial grass Festuca rubra are affected by temperature and precipitation in cold climate settings. We found that microbial communities were strongly shaped by temperature and to a lesser extent by precipitation. Temperature decreased relative habitat specialisation of the rhizosphere community and the fungal root-associated community. These effects were mediated by an increase in forb cover and a decrease in soil pH with temperature. Our findings indicate that with a rise in temperature in cold environments, plant-microbiota interactions become more versatile and adapted to a broader range of environmental conditions.
Turbulent oxygen transport across the halocline of the central Baltic Sea: Identification of key physical processes
Authors: Thiele Oliver , Holtermann Peter , Umlauf Lars
Published: March 2024

Anoxia in the central Baltic Sea is caused by the disproportion of the oxygen demand below the Baltic Sea halocline and the capability to transport sufficient amounts of oxygen from the well oxygenated upper water column through the halocline into the deeper Baltic Sea. Despite the fact of anoxia below the halocline, there is a growing evidence for a considerable oxygen transport through the halocline by turbulent mixing at the basin boundaries, i.e. the location where the halocline gets in the vicinity of the seafloor.We used velocity data from moorings and ship based velocity shear microstructure measurements using a MSS profiler. The data was acquired during three different cruises/seasons in the Eastern Gotland Basin to identify key processes responsible for oxygen mixing events across the strong halocline. The MSS was equipped with a fast oxygen sensor allowing to quantify the vertical oxygen flux.We focused on specific events with inertial waves, mean currents, and topographic waves as major dominating processes. During these events properties such as vertical shear, stratification and oxygen fluxes were analysed. With this information we were able to estimate the potential of the processes for the diapycnal oxygen transport. We found that inertial waves do not contribute much to the overall oxygen flux across the halocline, whereas topographic waves increase the oxygen flux considerably. Also the mean current lead to significant oxygen fluxes under certain shear and stratification conditions, suggesting that further attention should be turned to those.
Geomorphica: The Diamond Open-Access Journal for Geomorphology
Authors: Burrows Katy , Fernandez Roberto , Giaime Matthieu , Goodwin Guillaume , Grimm Bastian , Lai Larry Syu-Heng , de Lange Sjoukje , Lefebvre Alice , Stammler Melanie
Published: March 2024

Geomorphica (http://geomorphica.org) is a community-led and -driven scientific journal that fosters academic discourse and research advances in the field of geomorphology. It is hosted by Penn State University Libraries and supported by the International Association of Geomorphology. Geomorphica adds to the growing family of Diamond Open-Access journals in the Geosciences alongside Volcanica, Tektonika, Seismica, and Sedimentologika. Diamond Open-Access publishing is free to access and publish, with no subscription fees or article processing charges, promoting inclusivity and eliminating barriers in scientific communication.Over the past two years, we have established an initiative with more than 30 volunteers who contribute to all functions including administration, editing, reviewing, typesetting, and visual branding. Geomorphica has been officially launched since June 2023 and is open for manuscript submissions related (but not limited) to landscapes and landforms, Earth’s and planetary near-surface processes, and the mechanisms, dynamics and timescales pertaining to these processes. Experts in related fields are encouraged to join our reviewer database (https://geomorphicaadmin.pythonanywhere.com/) to participate in the quality control of scientific advances or to get in contact if they are interested in volunteering. To reduce bias, we have developed a triple-anonymous review policy, whereby the authors, reviewers and the associate editor making the recommendation are anonymous to each other. The reviewer’s reports and authors’ rebuttals will become publicly available along with the published articles. In this presentation, we will introduce our diverse editorial board, celebrate our first article submissions, and share our experiences during recent progress. We welcome feedback from the broader community to help us continually improve Geomorphica and look forward to your involvement with the initiative.
Palaeoclimate evolution over the last 10,000 years in Caumont cave in Normandy, France 
Authors: Bejarano Arias Ingrid , Nehme Carole , Breitenbach Sebastian F.M. , Couchoud Isabelle , Pons-Branchu Edwige , Baldini James , Mouralis Damase
Published: March 2024

Speleothem-based palaeoclimate studies proliferate globally, but some regions remain poorly covered, including NW France. The cave and quarry system of Caumont, Normandy, develops in chalk limestone and contains speleothem formations that cover the Holocene. A new study on a recent stalagmite from the quarry (the last ca. 100 years) and detailed cave monitoring show that in this system speleothems form under near-equilibrium isotopic conditions (Bejarano et al. 2024). Monitoring shows that the δ13C signal in speleothems reflects summer prior carbonate precipitation as a response to infiltration dynamics while speleothem δ18O is mostly a signal of precipitation composition (with a bias towards winter). Thus, detailed study of stalagmite isotope records seems promising for the reconstruction of Holocene climate change in Normandy. Here, we focus on 5 stalagmites collected from the Robots stream (SW) and La Jacqueline passages in the natural conduits of Caumont cave. All samples have been U-Th dated, yielding an age range of 10 to 0.3 ka for the two stalagmites from Robots stream, and 7 to 3 ka for the three stalagmites from La Jacqueline. We find several hiatuses and growth changes in the tested samples. All 5 stalagmites were sampled for stable isotopes (SI, δ18O and δ13C). In addition, and from one stalagmite from Robots was analysed for trace elements using laser ablation. We complement the SI and trace element data and discuss the evolution of the stalagmites growing periods and hiatuses for the last 10 ka. The stable isotope records reflect variations in palaeoclimate conditions that follow global patterns such as, increasing humid conditions during the Holocene optimum. The carbon isotope profile indicates drier conditions during early Holocene and wetter conditions between 8 and 5 ka. The oxygen isotope record also suggests more rain/snow infiltration during the mid-Holocene, with more negative values than in the early Holocene. These inferred changes are corroborated by Sr, Ba, Mg and Ca. We compare the new multi-proxy dataset with independent local studies and speleothem reconstructions from NW Europe to contextualise climate dynamics in Normandy within the broader Holocene development in Central Europe.
Verifying the impact of additional breaks in station coordinates on VLBI scale drift
Authors: Kern Lisa , Krasna Hana , Böhm Johannes , Nothnagel Axel
Published: March 2024

With the establishment of the International Terrestrial Reference Frame 2020 (ITRF2020), investigations revealed an unexpected positive VLBI scale drift after about 2014.0. Given the crucial role of Very Long Baseline Interferometry (VLBI) in determining the ITRF scale, this peculiar behavior raises concerns. Within the VLBI community, several studies have been conducted to decipher the cause behind this pattern. A recent study by the Onsala Space Observatory (OSO) explored the introduction of additional discontinuities in the station positions of NYALES20 and/or in the positions of MATERA, WETTZELL, and ONSALA60 due to repairs or replacements. They found that the introduction significantly mitigated the scale drift with respect to ITRF2020.Utilizing our newest state-of-the-art combination software, VieCompy, developed at the Vienna Center for VLBI, we independently assess the impact of these additional breaks on session-wise estimated scale through a combination of VLBI sessions at the normal equation level.
Systematic Assessment of station configuration on moment tensor estimation and associated uncertainties
Authors: Mahanta Rinku , Silwal Vipul
Published: March 2024

The earthquake source mechanism is mathematically represented by a 3x3 moment tensor (MT) matrix. It is typically obtained by comparing observed waveforms with synthetic seismograms, generated using varying fault plane solutions and a known velocity model. The best-fitting MT solution and its probability depend vastly on observed data quality and station coverage. We present a comparative assessment of multiple station configurations and their impact on the obtained MT solution.  A circular array of virtual seismic stations is arranged to capture the seismic signals. Synthetic seismograms are generated from Green’s functions obtained using the frequency-wavenumber method for the Mahesh2013 one-dimensional velocity model. The synthetic source is placed at a depth varying from surface to 50 km, at 5 km intervals, with a fixed orientation (strike-dip-rake) and magnitude. Random noise is added to the resulting synthetic seismograms to serve as the observed data for subsequent analysis. A waveform-based approach, the Cut And Paste (CAP) method,  is used to estimate the MT by comparing the observed data with the synthetics.We further present the results for linear, rectangular, star-shaped, and randomly distributed station arrays. An Uncertainty Quantification for each MT solution is performed to assess the influence of varying station configurations on the final solution. The MT estimations obtained through this synthetic approach contribute to a better understanding of the effect of different station arrays, thereby providing valuable information for application-specific permanent or temporary deployment.
Review the IGS Strategy for Precise Point Positioning Applications
Authors: Dach Rolf , Arnold Daniel , Brockmann Elmar , Kalarus Maciej , Prange Lars , Schaer Stefan , Stebler Pascal , Jäggi Adrian
Published: March 2024

Within the IGS, it was agreed that Precise Point Positioning (PPP) based on satellite orbit and clock corrections of the IGS analysis centers allow a direct access to the IGS realization of the International Terrestrial Reference Frame (ITRF). This convention is considered convenient for all PPP users and should not be changed in future.On the other hand, the groups determining the GNSS satellite orbits do prefer an origin of the frame that is related to the Earth instantaneous center of mass since this is the reference of the gravitational orbit force model. With this background, some discussions take place to change the convention related to the origin of the terrestrial frame because it is convenient for the orbit determination. This convention is, however, in contradiction to the expected needs of the PPP users that do prefer a stable coordinate origin in time.We will introduce a strategy to serve both needs by applying the center of mass corrections for the orbit determination only.
Understanding Human-Water feedbacks
Authors: Kreibich Heidi , Haeffner Melissa , Krüger Tobias , Pande Saket , Van Loon Anne
Published: March 2024

The International Commission on Human-Water Feedbacks of the International Association of Hydrological Sciences (IAHS) focuses on better understanding the feedbacks between humans and water over decadal and centennial time scales. We are inclusive and interdisciplinary, inviting members from all research fields interested in this topic, including social sciences, economics, engineering, hydrology, etc.Societies respond to hydrometeorological hazards by developing management measures, which can have a major, if not dominant, influence on risk and water ressources. For example, natural river systems in Europe have been greatly affected by the construction of dams and canals, which have altered the course of rivers and allowed the urbanisation of flood plains. However, the long-term effects of such measures are largely unknown due to complex interactions with other developments in the human-water system, such as climate change or socio-economic development. An example of a hypothesised long-term feedback mechanism is the construction of reservoirs for irrigation and the resulting population growth, which increases the exposure and vulnerability of society and leads to the construction of even more reservoirs, thus creating a feedback loop. There is an urgent need to understand the long-term dynamics of the human-water system in order to successfully implement climate change adaptation, disaster risk reduction, post-disaster recovery decisions, and to achieve the Sustainable Development Goals.The aim of this presentation is to present and further motivate community activities that aim to better understand human-water feedbacks.
Origin of trondhjemite leucosome in a kyanite-grade migmatite from the Higher Himalaya Crystalline (Bhagirathi valley): Insight into leucosome forming processes
Authors: Kushwaha Aman , Singh Sandeep , Putlitz Benita , Baumgartner Lukas
Published: March 2024

K2O-poor or trondhjemite leucosome is a common feature of migmatites in the Himalayas and other orogens. The origin of K2O-depleted leucosomes has been attributed to several melting scenarios, such as residuum left after melt extraction and magma accumulation. However, the process leading to the formation of leucosome of trondhjemite composition needs to be better understood. In the kyanite zone of the Higher Himalaya Crystallines (HHC) along the Bhagirathi valley, partial melting of metapelite resulted in the formation of two types of leucosomes: K2O enriched granitic L-1 leucosomes formed stromatic veins of variable thickness and K2O poor trondhjemitic L-2 leucosomes occur as patches and lenses. The L-1 leucosomes are characterized by positive and negative Eu anomaly, variable depleted REE content, and represent in-source leucosomes. The L-2 leucosomes are REE depleted, have small negative Eu anomaly (0.8-0.9), and show a clear trend for anatectic melt-residuum-protolith in major-oxide plots of compatible versus incompatible elements. The overall depletion of REE, Sc, V, Cr, Ni, Co, Ti, Th, Nb, Hf, P2O5, and Zr/Zr*
Microstructural relationships from locally equilibrated domains in UHP eclogites (Snieznik Massif, NE Bohemian Massif)
Authors: Nowak Malgorzata , Tajcmanova Lucie , Szczepanski Jacek , Dabrowski Marcin
Published: March 2024

The Snieznik eclogites experienced peak ultrahigh-pressure (UHP) metamorphism in around ~770°C at ~3.2 GPa followed by isothermal decompression and amphibolite-facies retrogression during Variscan Orogeny. The well-preserved peak metamorphic assemblage of these UHP eclogites comprises garnet + omphacite + kyanite + phengite + rutile + coesite. The mineral assemblage connected with the isothermal decompression episode is present in the form of diopside-amphibole-plagioclase symplectites that are locally disintegrating the main foliation.Here, we investigate plagioclase rims developed around kyanite at the interface with quartz and diopside-plagioclase symplectite. They are present only around kyanite occurring in the vicinity of zones developed during the isothermal decompression event. In some parts, the plagioclase rims are locally replaced by the diopside-plagioclase symplectite. The monomineralic plagioclase rims, having max. 20 µm radial thickness, are polycrystalline. They consist of individual plagioclase grains (each 2-15 µm in diameter) with different crystallographic orientations. The rims as a whole exhibit zoning with the highest Ca content observed at the contact with the kyanite grains. The measured CaO content increases from ~2% near quartz and diopside-plagioclase symplectite to ~6% at the kyanite boundary.In this contribution we investigate the chemical and mechanical effects, that might have contributed to the preservation of the observed zoning and the microstructural heterogeneity of the rims.
Gravity Waves and Turbulence indicating multistep vertical coupling near the Polar Vortex Edge
Authors: Baumgarten Gerd , Franco-Diaz Eframir , Fiedler Jens , Gerding Michael , Latteck Ralph , Mossad Mohammed , Renkwitz Toralf , Strelnikova Irina , Strelnikov Boris , Wing Robin
Published: March 2024

Throughout the winter, extreme circumpolar wind patterns are found in the altitude range of 30 to 70 km, reaching wind speeds up to 500 km/h. The circumpolar wind patterns form the Stratospheric Polar Vortex. In the Northern Hemisphere, weather extremes are known to be linked to distortions of the Polar Vortex. Recently, studies using observations and modelling have indicated that the extreme winds at the Polar Vortex Edge also play a crucial role in multistep upward coupling through gravity waves. Variations in the wind profiles affect gravity wave propagation and lead to wave generation and breakdown. Direct measurements of the mean winds and waves at the Polar Vortex Edge are rare and technically challenging. We use lidar and radar instruments to measure temperature, wind, and the occurrence of layered phenomena over northern Norway (ALOMAR, 69°N) and northern Germany (Kühlungsborn, 54°N). Using more than 10 years of measurements, we have collected a unique dataset, which contains measurements both inside and outside the Polar Vortex.These observations are used to explore upward- and downward-propagating gravity waves in the complex dynamical setting near the Polar Vortex Edge. These unique wave-vortex interactions play a role in coupling layers above and below, and link large-scale flow to turbulence, frequently observed as layered phenomena, such as Polar Mesosphere Winter Echoes. The link between waves, turbulence, and the polar vortex will be discussed using observations and model data. 
Life below the City – Impacts of urbanization and subsurface heat islands on groundwater fauna in the city of Vienna
Authors: Englisch Constanze , Kaminsky Eva , Steiner Cornelia , Nyéki Eszter , Stumpp Christine , Griebler Christian
Published: March 2024

Groundwater is one of our most important and heavily utilized resources. However, it is also home to a variety of microbes and fauna, that have adapted to a dark, cold, and typically energy-poor environment for thousands of years. Therefore, groundwater is a habitat with high numbers of endemic and cryptic species as well as hidden biodiversity hotspots. These highly specialised animals, while assumed to provide vital ecosystem services including water purification, are susceptible to intermediate-term (years to decades) changes in environmental conditions. In urban areas, a multitude of pressures like increased temperatures, extensive surface sealing and pollution are impacting groundwater ecosystems with deteriorating effects on biodiversity and groundwater quality. Aiming to reveal key factors of spatio-temporal biodiversity patterns, fauna community composition and links between subsurface urban heat islands, species richness and water quality, 150 groundwater wells in the city of Vienna were sampled in autumn 2021 and in spring 2022 to include seasonal variability. Focusing on subsurface heat accumulation as a main driver, a large set of biotic and abiotic variables was analysed as part of the project “Heat below the City”. The results show that the mean groundwater temperature of 14°C in Vienna is about 2 K above the natural background, with anthropogenic heat sources having an impact on the degree of warming and groundwater fauna composition. The absence of dissolved oxygen (DO) and NO3- as well as the presence of dissolved Fe2+, HS- and CH4 hint at zones with reducing conditions correlated with low faunal biodiversity. The application and comparison of several groundwater ecosystem health indices as well as the development of a robust habitat suitability assessment for groundwater fauna contribute to the establishment of an integrative groundwater management strategy, combining groundwater quality aspects, its sustainable use as source for drinking water, heating and cooling, and conservation strategies for groundwater biodiversity in the future.
Towards Fiber-optics-based, Next-generation Observational Platforms for Investigating the Urban Subsurface: the InDySE Project
Authors: Rodríguez Tribaldos Verónica , Krawczyk Charlotte , Ehsaninezhad Leila , Martínez-Garzón Patricia , Bohnhoff Marco
Published: March 2024

Urban sustainable development and improved resilience to geohazards requires an exhaustive understanding of the geological structure, physical properties and dynamics of the shallow subsurface underneath urbanized areas at the sub-kilometer scale. Yet, our current understanding of the urban subsurface is limited by our ability to image its structure and temporal variations at high resolution using classical geophysical approaches. Recently, the application of conventional ambient noise interferometry analysis to dynamic strain data recorded using Distributed Acoustic Sensing (DAS) deployed on unused telecommunication fiber-optic cables (dark fibers) has emerged as an attractive alternative for cost-efficient, regional scale (10’s of km) seismic imaging and monitoring at high spatial and temporal resolution. Still, its application to urban environments remains vastly underutilized. One of the most significant hurdles is the lack of adequate and efficient data exploration and processing tools to address and harness the unique challenges associated with DAS-based urban seismic noise recordings, which include the complexity of the noise field, unconventional array geometries and non-uniform coupling conditions, and increasingly massive data volumes.The InDySE project (Interrogating the Dynamic Shallow Earth) aims at addressing these challenges to develop and validate the next-generation of subsurface imaging and monitoring platforms in urban areas based on the combination of existing fiber-optic networks and high-frequency infrastructure noise. The project comprises (1) developing high-performance computational tools, advanced processing workflows and machine learning approaches for efficient data exploration, selection and processing using existing datasets, (2) field experiments in target areas to retrieve high-resolution velocity models and monitor changes in seismic velocities, (3) integrating the resultant high-resolution seismic models with complementary datasets such as deformation maps derived from InSAR measurements. One of the selected study areas is the highly populated metropolitan area of Istanbul (Turkey), where understanding the structure, properties and dynamics of the shallow subsurface at high-resolution is critical for evaluating geohazard exposure. Among our objectives will be illuminating potential hidden faults underneath the city, obtaining high-resolution maps of geological materials and subsurface properties that can be translated into maps of local site response to large earthquakes, and tracking seismic velocity changes linked to hydrological dynamics that are known to be responsible for ground movements such as landsliding and subsidence. Ultimately, InDySE aims at developing efficient approaches for using dark fiber and ambient noise in urban subsurface investigations with implications in geohazard assessment.