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The iron-snow regime in Fe-FeS cores: a numerical and experimental approach

In the Earth, the dynamo action is strongly linked to core freezing. There is a solid inner core, the growth of which provides a buoyancy flux that drives the dynamo. The buoyancy in this case derives from a difference in composition between the solid inner core and the fluid outer core. In planetary bodies smaller than the Earth, however, this core differentiation process may differ - Fe may precipitate at the core-mantle boundary (CMB) rather than in the center and may fall as iron snow and initially remelt with greater depth. A chemical stable sedimentation zone develops that comprises with time the entire core - at that time a solid inner core starts to grow. The dynamics of this system is not well understood and also whether it can generate a magnetic field or not. The Jovian moon Ganymede, which shows a present-day magnetic dipole field, is a candidate for which such a scenario has been suggested. We plan to study this Fe-snow regime with both a numerical and experimental approach. In the numerical study, we use a 2D/3D thermo-chemical convection model that considers crystallization and sinking of iron crystals together with the dynamics of the liquid core phase (for the 3D case the influence of the rotation of the Fe snow process is further studied).The numerical calculations will be complemented by two series of experiments: (1) investigations in metal alloys by means of X-ray radioscopy, and (2) measurements in transparent analogues by optical techniques. The experiments will examine typical features of the iron snow regime. On the one hand they will serve as a tool to validate the numerical approach and on the other hand they will yield important insight into sub-processes of the iron snow regime, which cannot be accessed within the numerical approach due to their complexity.

Use cases from the German NTSPortal on the systematic use of high-resolution mass spectrometry non-target screening data in environmental monitoring and chemicals management

Background Society aims for a pollutant-free environment, reflected in initiatives under the European Green Deal, which seek to reduce hazardous substances and promote safe, sustainable chemical use. Comprehensive exposure data are needed to identify sources, understand mixtures and eliminate sources of chemical pollution. High-resolution mass spectrometry non-target screening (HRMS NTS) is increasingly used in environmental regulatory context to chemically characterise the environment as completely as possible and retrospectively screen for known and emerging substances. Results This study provides use cases for monitoring and chemicals management with data from the German NTSPortal, a database and visualisation tool for HRMS NTS data from surface water and suspended particulate matter of major German rivers. Its internal spectral library enables substance identification comparable to standardised target analysis, supporting regulatory acceptance of HRMS NTS data for prioritisation and mixture assessment. To demonstrate its potential to research and regulation, we characterised the spatial and temporal distribution of riverine chemical mixtures and present selected use cases relevant to EU environmental, emission, and chemical legislation. Despite pronounced spatial variability, mixture composition based on presence–absence data remained stable over time, with 855 of 1721 substances detected at least once and 247 occurring ubiquitously. Declining trends for regulated substances such as carbendazim and climbazole illustrate the effectiveness of regulatory measures. Overall, the results showed that NTS data repositories can help overcome fragmented exposure information and enable more consistent use of monitoring data across policy areas, including evaluation of the revised Urban Waste Water Treatment Directive and One Health concepts. Conclusions Data from the German NTSPortal enabled a multi-matrix and temporal characterisation of riverine chemical mixtures, revealing both stable mixture compositions over time and persistent, catchment-specific substances. These data facilitated high-resolution mixture assessments across space and time, alongside trend analyses that meet regulatory needs in environmental monitoring and chemical risk assessment. Further temporal, spatial, chemical and matrix-spanning expansion of HRMS NTS repositories will enhance their value for environmental monitoring programmes. Strengthening interoperability, implementing FAIR data principles, and developing advanced tools for prioritisation, quantification and toxicity prediction, including AI-based approaches, will be crucial to fully realise the regulatory potential of NTS portals in the future. © The Author(s) 2026.

Residence times across scales: from plot to catchment scale

Residence times is a key signature to characterize flow and transport at all temporal and spatial scales in different hydrological compartments. It is assumed that the spatial organisation of the landscape controls space-time organisation of the water cycle and related processes and hence the residence time. Combining flux and residence concentration data of natural tracers in water, stable isotopes, and artificial tracers will allow us to predict residence time and flow pathways in the different hydrological compartments as well as integrative for entire watersheds. We will investigate with different methods the fingerprint of hydrological processes found in the signal of isotopic composition and natural and artificial tracers of soil, ground and stream water in space and time. The temporal variability of isotopes in soil water, groundwater and stream water will be combined to benchmark transport and flow models and to derive a new functional form of short to long-term transit time distributions. The spatial patterns of stable isotopes in the saturated and unsaturated zone will be used to derive long-term flow pathways, mixing patterns and the proportion of evaporation to transpiration. Artificial tracer experiments using salt and electric resistivities will vizualize and quantify internal flow pathways in particular preferential flow pathways.

Hydrochemistry, carbon dynamics, and calculated pCO2 and CO2 fluxes, and soil-derived natural organic matter characteristics from the White Main, a granitic headwater stream in Germany, 2023-2024

This dataset contains hydrochemical and soil data collected along the first 1.3 km downstream of the White Main spring in northern Bavaria, Germany, from March 2023 to November 2024. Stream water samples were analyzed for in situ parameters, including discharge, water temperature [°C], pH [-], redox potential [mV], and electrical conductivity [µS/cm], as well as laboratory-measured parameters, including major ions and trace metals [mmol/l], alkalinity [mmol/l], dissolved inorganic and organic carbon concentrations (DIC, DOC [mmol/l]), and their stable isotope ratios (δ13CDIC/DOC [‰ VPDB]). In addition, calculated partial pressure of CO2 (pCO2 [µatm]) and carbon dioxide fluxes (FCO2 [mmol m⁻² d⁻¹]) are provided for the stream water samples. The dataset also contains laboratory measurements related to soil-derived natural organic matter from acid and base extracts of soil samples, including zeta potential [mV], particle size distribution [%], ultraviolet-visible absorbance (UV-VIS), and fluorescence measurements. UV-VIS absorbance and fluorescence measurements were additionally performed on stream water samples. The datasets were collected to characterize hydrochemistry, carbon concentrations, carbon dioxide dynamics, and soil-derived organic matter properties in a granitic headwater stream and to provide a basis for reuse in studies of headwater biogeochemistry, carbon cycling, and soil-water interactions.

Wechselwirkungen zwischen saisonale arktische Meereisprozessen und Stabilität der Halokline – auf dem Weg zum Verständnis arktischer Gas- und Stoffflüsse

In Folge des globalen Klimawandels hat sich die Meereisdecke in der Arktis dramatisch verändert. Im derzeitigen Zustand spielt die arktische Eisdecke eine wichtige Rolle; so schirmt sie das Oberflächenwasser, die sogenannte arktische Halokline (Salzgehaltsschichtung), von der Erwärmung durch die sommerliche Sonneneinstrahlung ab. Zudem wird die Halokline durch die Salze, welches beim Gefrierprozess des Meerwassers aus der Kristallstruktur austritt, gebildet und stabilisiert. Gleichzeitig wirkt die Halokline als Barriere zwischen der Eisdecke und dem darunter liegenden warmen atlantischen Wasser und trägt so zum Erhalt der arktischen Meereisdecke bei. Dieses Gleichgewicht ist nun durch die insgesamt wesentlich dünnere arktische Meereisdecke und ihre verringerte sommerliche Ausdehnung gestört. Im Meerwasser sind zudem Gase und biogeochemisch wichtige Spurenstoffen enthalten. Diese werden durch die Gefrierprozesse eingeschlossen, beeinflusst und wieder ausgestoßen. So beeinflusst die Meereisdecke die Gas- und Stoffflüsse zwischen Atmosphäre, Eis und oberer Wasserschicht. Durch die Eisbewegung findet außerdem ein Transport statt z.B. in der sogenannten Transpolarendrift von den sibirischen Schelfgebieten, über den Nordpol, südwärts bis ins europäische Nordmeer. Nun wird mit den weitreichenden Veränderungen des globalen und arktischen Klimawandels bereits von der „neuen Arktis“ gesprochen, da angenommen wird, dass sich die Arktis bereits in einem neuen Funktionsmodus befindet. Dabei ist jedoch weitgehend unbekannt wie dieses neue System funktioniert, sich weiterentwickelt und wie sich dies auf die Eisbildungsprozesse und damit die Stabilität der Halokline und die damit verbundenen Gas- und Stoffflüsse auswirkt. Für solche Untersuchungen werden über den Jahresverlauf Proben der oberen Wassersäule und der Eisdecke benötigt. Ermöglicht wird dies durch die wissenschaftliche Initiative MOSAiC. Mithilfe der stabilen Isotope des Wassers (?18O und ?D) aus dem Eis und der Wassersäule kann Rückschlüsse auf die Herkunftswässer und den Gefrierprozess gezogen werden und diese Ergebnisse sollen in direkten Zusammenhang mit Gas- und biogeochemischen Stoffuntersuchungen (aus Partnerprojekten) gesetzt werden. Dabei können z.B. Stürme, Schmelzprozesse, Schneebedeckung, Teichbildung und Alterungseffekte des Eises eine Rolle spielen. Untersucht wird parallel die Veränderung der Wassersäule welche z.B. durch Wärmetransport, wiederum die Eisdecke beeinflussen kann.Diese prozessorientierten Untersuchungen der saisonalen Eisbildungsprozesse in Eis und Wassersäule der zentralen Arktis, werden einen wichtigen Beitrag zum Verständnis der Stabilität der arktischen Halokline und der arktischen Gas- und Stoffflüsse liefern. Da sich die Gase und Stoffe nicht-konservativ verhalten, während die Isotope im Gefrierprozess konservativ sind, erwarten wir aus der Diskrepanz wiederum wichtige Informationen z. B. über wiederholtes Einfrieren von Süßwasserbeimengungen ableiten zu können.

NECPR: Additional Reporting Obligations in the area of Energy Efficiency (Annex XVII) dataset

Additional reporting obligations in the area of energy efficiency' is a dataset reported by EU Member States and Contracting Parties of the Energy Community under the Governance Regulation. The dataset includes information on reasons why energy consumption is stable or growing per sector, floor area of government buildings not meeting energy performance requirements, number of energy audits carried out in large companies, applied national primary energy factor for electricity, number and floor area of new and renovated nearly zero-energy buildings (NZEB), and internet links to lists/interfaces of energy services.

Agricultural And Aquaculture Facilities / Tierhaltungs- und Aufzuchtanlagen in Brandenburg

Der Datensatz Agricultural And Aquaculture Facilities / Tierhaltungs- und Aufzuchtanlagen in Brandenburg ist die Datengrundlage der interoperablen INSPIRE-Darstellungs- (WMS) und Downloaddienste (WFS): Tierhaltungsanlagen nach BImSchG in Brandenburg - Interoperabler INSPIRE View-Service (WMS-AF-TIERE) Tierhaltungsanlagen nach BImSchG in Brandenburg - Interoperabler INSPIRE Download-Service (WFS-AF-TIERE) Der Datenbestand beinhaltet die Punktdaten zu den betriebenen Tierhaltungsanlagen aus dem Anlageninformationssystem LIS-A. Die Angaben zu den Anlagen enthalten jeweils den Standort und die genehmigte Leistung. Dabei erfolgte eine sog. Schematransformation und Belegung der INSPIRE-relevanten Attribute. Der Datensatz Agricultural And Aquaculture Facilities / Tierhaltungs- und Aufzuchtanlagen in Brandenburg ist die Datengrundlage der interoperablen INSPIRE-Darstellungs- (WMS) und Downloaddienste (WFS): Tierhaltungsanlagen nach BImSchG in Brandenburg - Interoperabler INSPIRE View-Service (WMS-AF-TIERE) Tierhaltungsanlagen nach BImSchG in Brandenburg - Interoperabler INSPIRE Download-Service (WFS-AF-TIERE) Der Datenbestand beinhaltet die Punktdaten zu den betriebenen Tierhaltungsanlagen aus dem Anlageninformationssystem LIS-A. Die Angaben zu den Anlagen enthalten jeweils den Standort und die genehmigte Leistung. Dabei erfolgte eine sog. Schematransformation und Belegung der INSPIRE-relevanten Attribute.

Vorhabenbezogener BPlan - Tierhaltungsanlage Schulze-Zumkley

Vorhabenbezogener BPlan

Seasonal nutrient dynamics in the Elbe estuary

In this publication, we investigated the spatial and temporal distribution of nutrients in the Elbe estuary, Northern Germany, in 2022. In seasonal transect cruises, physicochemical parameters were measured continuously along a transect from the North Sea (53.98°N 8.36°E) to the port of Oortkaten in the upstream Elbe River (53.46°N 10.06°E). The study focus was set on the interplay of eutrophication and in-stream nutrient regeneration. At ~40 stations along the estuary, we measured the concentration of dissolved nutrients (nitrate, nitrite, ammonium, phosphate, silicate) and nitrate dual stable isotope signatures (δ15N-NO3, δ18O-NO3) as well as characteristics of suspended particulate matter (δ15N-SPM, chlorophyll a concentration and C/N ratio).

Submarine groundwater discharge in front of a coastal peatland: Seepage rates and hydrochemistry

Coastal peatlands are important carbon, nutrient, and trace metal stores, which might be mobilized and released to the adjacent sea upon rewetting. The objectives of this study were to quantify submarine groundwater discharge (SGD) in front of a rewetted coastal peatland at the southern Baltic Sea coast, to estimate associated fluxes of solutes, and to characterize the discharged water using stable oxygen, hydrogen, and carbon isotope composition. We directly measured SGD rates and collected the discharging water using seepage meters in summer and autumn 2021. SGD, seawater and groundwater were analyzed for major ion, nutrient, DOC/DIC and trace metal concentrations as well as the composition of water and carbon isotopes. Racasa et al. (2026) is based on this dataset.

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