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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.

Results of palynological analysis from 2020 of the varved MO-05 core from Lake Mondsee (Austria) section (249-526 cm)

This study reports a precisely dated pollen record with a 20-year resolution from the varved sediments of Lake Mondsee in the north-eastern European Alps (47°49′N, 13°24′E, 481 m above sea level). The analysed part of core spans the interval between 1500 BCE and 500 CE and allows changes in vegetation composition in relation to climatic changes and human activities in the catchment to be inferred. Intervals of distinct but modest human impact are identified at ca. 1450-1220, 740-490 and 340-190 BCE and from 80 BCE to 180 CE. While the first two intervals are synchronous with prominent salt mining phases during the Bronze Age and Early Iron Age at the nearby UNESCO World Heritage Site of Hallstatt, the last two intervals fall within the Late Iron Age and Roman Imperial Era, respectively. Comparison with published records of extreme runoff events obtained from the same sediment core shows that human activities (including agriculture and logging) around Lake Mondsee were low during intervals of high flood frequency as indicated by a higher number of intercalated detrital event layers, but intensified during hydrologically stable intervals. Comparison of the pollen percentages of arboreal taxa with the stable oxygen isotope and potassium ion records of the NGRIP and GISP2 ice cores from Greenland reveals significant positive correlations for Fagus and negative correlations for Betula and Alnus. This underlines the sensitivity of vegetation around Lake Mondsee to temperature fluctuations in the North Atlantic as well as to moisture fluctuations controlled by changes in the intensity of the Siberian High and the North Atlantic Oscillation (NAO) regime.

Water isotope values in shore samples collected in March and July 2020 from northeastern German lake systems

Water isotopes (δ2H and δ18O) were analyzed in samples collected in lakes associated to major riverine systems in northeastern Germany throughout 2020. This sub-dataset is derived from water samples collected from lake shores. Samples were taken in March and July 2020 with a pipette from 40-60 cm depth below water surface and directly transferred into a measurement vial. Stable isotope analysis was conducted at IGB Berlin, using a Picarro L2130-i cavity ring-down spectrometer. The data give information about the seasonal isotope amplitude in the sampled lakes and about spatial isotope variability in different branches of the associated riverine systems.

Seasonal Dataset of DIC, δ13CDIC, DOC, δ13CDOC, pCO2(aq), FCO2 and Biogeochemical Parameters in the Danube River (2023–2024)

This dataset contains dissolved inorganic/organic carbon (DIC/DOC) concentrations, its stable isotope ratios (δ13CDIC/DOC), partial pressure of carbon dioxide in the water column pCO₂(aq) (pCO2(aq)) and area-integrated CO₂ emission rates derived from flux calculations (FCO2; g C d⁻¹), along with corresponding parameters (temperature, pH, calcium, bicarbonate) collected from the Danube River and its key tributaries during five seasonal sampling campaigns in 2023 and 2024. Water samples were collected using a weighted 2 L sampling bottle submerged 1–2 meters below the surface, with sampling conducted from the river center via bridges or passenger boats, and occasionally from the riverbank. In situ temperature measurements were taken with a multiparameter instrument (HQ40d, HACH™, Loveland, CO, USA). δ13ODIC/DOC was analyzed using a OI Analytical Aurora 1030W-IRMS. This dataset is providing valuable insights into carbon dynamics in a large river system and support investigations of biogeochemical cycling. It further can inform ecosystem management and conservation strategies under changing environmental conditions.

ISLAS2022: Calibrated stable water isotope measurements and aerosol measurements around the Nordic Seas

During a 4-week measurement campaign (ISLAS2022) in March and April 2022, we collected a comprehensive dataset characterizing the atmospheric water vapour and precipitation isotope composition within weather systems in the European Arctic and sub-Arctic. Focusing on an area covering the Nordic Seas and Northern Scandinavia, stable water isotope measurements with cavity ring-down spectrometers (CRDS) were taken from a research aircraft stationed at Kiruna, Sweden; from a Research Vessel going from Tromsø to the western ice edge in Greenland, and from measurements at supersites at Andenes on the Lofoten archipelago, Abisko, and Kiruna. Water vapour and precipitation isotope measurements from different sites and platforms were complemented by additional instrumentation to characterize the atmospheric conditions. Advanced instrumentation included wind LIDAR, ground-based vertical-pointing rain radar, and aerosol measurements at Andenes, two-directional depolarising aerosol LIDAR and horizontal cloud RADAR on the aircraft. Controlled meteorological balloons were launched from Ny-Ålesund, Svalbard into cold-air outbreak conditions. Surface precipitation samples were collected from a surface network including Abisko, Andenes, Kiruna, Longyearbyen, Ny-Ålesund, Jan Mayen, Bjørnøya, Tarfala, Ålesund, and Bergen. Surface snow was repeatedly sampled along a detailed transect from Kiruna to Lofoten archipelago. Citizen science snow sampling contributed to distributed surface snow sampling in Northern Scandinavia. All stable water isotope measurements have been calibrated onto the VSMOW-SLAP scale. The data from the ISLAS2022 measurement campaign enables the comprehensive assessment of air mass transformation and water turnover during cold-air outbreak conditions using stable water isotopes as a constraint.

Interoperabler INSPIRE View-Service: Agricultural And Aquaculture Facilities / Tierhaltungsanlagen nach BImSchG in Brandenburg - Interoperabler INSPIRE View-Service (WMS-AF-TIERE)

Der interoprable INSPIRE-Viewdienst (WMS) Agricultural and Aquaculture Facilities gibt einen Überblick über die Tierhaltungs- und Aufzuchtanlagen im Land Brandenburg. Der Datensatz umfasst Geflügel, Rinder, Kälber, Schweine und gemischte Bestände. Die Datenquelle ist das Anlageninformationssystem LIS-A. Gemäß der INSPIRE-Datenspezifikation Agricultural and Aquaculture Facilities (D2.8.III.9_v3.0) liegen die Inhalte INSPIRE-konform vor. Der WMS beinhaltet 2 Layer: AgriculturalHolding und Sites. Der Holding-Layer wird gem. INSPIRE-Vorgaben nach Wirstschaftszweigen (NACE-Kategorie "A") untergliedert in: - AF.GrowingOfPerennialCrops: Anbau mehrjähriger Pflanzen (NACE-Kategorie "A.01.2") - AF.AnimalProduction: Tierhaltung (NACE-Kategorie "A.01.4") - AF.MixedFarming: Gemischte Landwirtschaft (NACE-Kategorie "A.01.5")

Seasonal water isotope values in eastern German lakes and rivers (Spree, Dahme, Elster and Mulde systems) in March, July, October 2022, and March 2023

Water isotopes (δ²H and δ¹⁸O) were analyzed in samples from lakes and rivers in eastern Germany. This sub-dataset is derived from water samples collected from lake and river shores. Seasonal samples were collected in March, July, October 2022, and in March 2023, with a plastic syringe from 20-50 cm depth below water surface and directly filtered and transferred into a measurement vial. Stable isotope analysis was conducted at IGB Berlin, using a Picarro L2130-i cavity ring-down spectrometer. Measurement uncertainty was quantified to <0.5 ‰ for δ²H and <0.2 ‰ for δ¹⁸O. Water chemical parameters were determined in-situ with a portable WTW-multiparameter probe. The data give information about the seasonal isotope amplitude at the sampled spots and about spatial isotope variability in different branches of the associated river systems.

Water isotope values in samples collected June 2019, March 2020 and July 2020 along estuarine systems at the Baltic Sea coast

Stable isotopes (δ2H and δ18O) were analyzed in water samples collected at 68 spots along the Schlei, the Zingster Bodden chain, and the Rügener and Greifswalder Boddens in June 2019, March 2020, and July 2021. Transect samples were taken at shores from 0.3 to 0.6 m below water surface, using a pipette, and directly transferred into measurement vials. Isotope analysis was conducted at IGB Berlin, using a Picarro L2130-i cavity ring-down spectrometer. Water chemical parameters were measured in-situ with a WTW multiparameter device (Multi 3630 IDS), equipped with a WTW TetraCon 925 electrical conductivity measuring cell. The data give information about the spatial isotope variability along the transects.

Water isotope time series (March 2020 - March 2021) of samples collected in Kloster, Hiddensee

Time series of stable isotopes (δ2H and δ18O) were analyzed in water samples taken near the harbour of Kloster (Hiddensee), in biweekly to monthly intervals between March 2020 and March 2021. Water was sampled with a pipette from ca. 0.5 m below water surface and directly transferred into a measurement vial. Isotope analysis was conducted at IGB Berlin, using a Picarro L2130-i cavity ring-down spectrometer. Water chemical parameters were measured in-situ with WTW multiparameter measurement devices. The data give information about the seasonal isotope amplitude at the sampled locations and about spatial variability along the transects.

Produktion von Milch in Weide- oder Stallhaltung: Ein Verfahrensvergleich - Teilprojekt: Betriebswirtschaftliche Bewertung verschiedener Milchviehhaltungssysteme

Die Milchviehhaltung und Milcherzeugung hat für die niedersächsische Landwirtschaft eine große Bedeutung. Vor allem in den Grünlandregionen erzielen die landwirtschaftlichen Betriebe ihr Einkommen maßgeblich aus der Rinderhaltung. In der öffentlichen Wahrnehmung genießt die Milchrinderhaltung gegenüber anderen landwirtschaftlichen Nutztierhaltungen ein gutes Ansehen; positive Assoziationen der Verbraucher mit der Milchviehhaltung werden im Zusammenhang mit der Weidewirtschaft gesehen. De facto ist der Anteil von den Milchviehbetrieben, die den Tieren Weidegang erlauben, seit Jahren rückläufig. Weniger als 40 % der Kühe werden ganztägig geweidet. Die Konsequenzen des sukzessiven Übergangs von einer weidebasierten zu einer rein stallbasierten Micherzeugung werden zunehmend diskutiert; vielfach fehlen aber die Grundlagen für eine wissenschaftlich fundierte Auseinandersetzung. Ziel des Forschungsverbundes Systemvergleich Milch ist es daher, die Bedingungen und Leistungen Weide und Stall basierter Systeme grundlegend zu untersuchen. Die Untersuchungen betreffen die Tiergesundheit, das Verhalten und Wohlbefinden der Tiere, die Belastung mit Parasitosen, die Umsetzbarkeit der Futternährstoffe bei der ruminalen Fermentation, die optimierte Gestaltung der Weidewirtschaft zur Bereitstellung ausreichender Mengen und Qualitäten von Weidefutter und zur Verringerung von Nährstoffverlusten, die Konsequenzen verschiedener Milcherzeugungssysteme für Umwelt, Klima und Ressourceneffizienz, die betriebswirtschaftliche Bewertung der verschiedenen Milcherzeugungsoptionen sowie die Wahrnehmung und die Präferenzen der Konsumenten von Milch. Die wissenschaftlichen Arbeiten basieren zum einen auf einem umfassenden Betriebsvergleich in Niedersachsen, bei dem Milchviehbetriebe nach dem Grad der Weidenutzung klassifiziert und im Hinblick auf die o.g. Merkmale analysiert werden. Andererseits werden unter weitgehend kontrollierbaren Bedingungen Produktionsexperimente mit klassischen experimentellen Designs durchgeführt. Hier stehen Fragen der Verwertung der Futternährstoffe auf der Weide sowie der Leistungsfähigkeit und Ressourceneffizienz der Weidewirtschaft im Vordergrund.

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