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Airborne in situ cloud measurements were carried out over the northern Fram Strait between Greenland and Svalbard in spring 2019 and summer 2020. In total, 811 min of low-level cloud observations were performed during 20 research flights above the sea ice and the open Arctic ocean with the Polar 5 research aircraft of the Alfred Wegener Institute. Here, we combine the comprehensive in situ cloud data to investigate the distributions of particle number concentration N, effective diameter Deff, and cloud water content CWC (liquid and ice) of Arctic clouds below 500 m altitude, measured at latitudes between 76 and 83∘ N. We developed a method to quantitatively derive the occurrence probability of their thermodynamic phase from the combination of microphysical cloud probe and Polar Nephelometer data. Finally, we assess changes in cloud microphysics and cloud phase related to ambient meteorological conditions in spring and summer and address effects of the sea ice and open-ocean surface conditions. We find median N from 0.2 to 51.7 cm−3 and about 2 orders of magnitude higher N for mainly liquid clouds in summer compared to ice and mixed-phase clouds measured in spring. A southerly flow from the sea ice in cold air outbreaks dominates cloud formation processes at temperatures mostly below −10 ∘C in spring, while northerly warm air intrusions favor the formation of liquid clouds at warmer temperatures in summer. Our results show slightly higher N in clouds over the sea ice compared to the open ocean, indicating enhanced cloud formation processes over the sea ice. The median CWC is higher in summer (0.16 g m−3) than in spring (0.06 g m−3), as this is dominated by the available atmospheric water content and the temperatures at cloud formation level. We find large differences in the particle sizes in spring and summer and an impact of the surface conditions, which modifies the heat and moisture fluxes in the boundary layer. By combining microphysical cloud data with thermodynamic phase information from the Polar Nephelometer, we find mixed-phase clouds to be the dominant thermodynamic cloud phase in spring, with a frequency of occurrence of 61 % over the sea ice and 66 % over the ocean. Pure ice clouds exist almost exclusively over the open ocean in spring, and in summer the cloud particles are most likely in the liquid water state. The comprehensive low-level cloud data set will help us to better understand the role of clouds and their thermodynamic phase in the Arctic radiation budget and to assess the performance of global climate models in a region of the world with the strongest anthropogenic climate change.

Potential vorticity (PV) analysis plays a central role in studying atmospheric dynamics and in particular in studying the life cycle of weather systems. The three-dimensional (3-D) structure and temporal evolution of the associated PV features, however, are not yet fully understood. An automated technique to objectively identify 3-D PV features can help to shed light on 3-D atmospheric dynamics in specific case studies as well as facilitate statistical evaluations within climatological studies. Such a technique to identify PV features fully in 3-D, however, does not yet exist. This study presents a novel algorithm for the objective identification of PV anomalies along the dynamical tropopause in gridded data, as commonly output by numerical simulation models. The algorithm is inspired by morphological image processing techniques and can be applied to both two-dimensional (2-D) and 3-D fields on vertically isentropic levels. The method maps input data to a horizontally stereographic projection and relies on an efficient computation of horizontal distances within the projected field. Candidates for PV anomaly features are filtered according to heuristic criteria, and feature description vectors are obtained for further analysis. The generated feature descriptions are well suited for subsequent case studies of 3-D atmospheric dynamics as represented by the underlying numerical simulation. We evaluate our approach by comparison with an existing 2-D technique and demonstrate the full 3-D perspective by means of a case study of an extreme precipitation event that was dynamically linked to a prominent subtropical PV anomaly. The case study demonstrates variations in the 3-D structure of the detected PV anomalies that would not have been captured by a 2-D method. We discuss further advantages of using a 3-D approach, including elimination of temporal inconsistencies in the detected features due to 3-D structural variation and elimination of the need to manually select a specific isentropic level on which the anomalies are assumed to be best captured. These advantages, as well as the suitability of the implementation to process big data sets, also open applications for climatological analyses. The method is made available as open-source for straightforward use by the atmospheric community.

Molt strategies have received relatively little attention in current ornithology, and knowledge concerning the evolution, variability and extent of molt is sparse in many bird species. This is especially true for East Asian Locustella species where assumptions on molt patterns are based on incomplete information. We provide evidence indicating a complex postbreeding molt strategy and variable molt extent among the Pallas's Grasshopper Warbler Locustella certhiola, based on data from six ringing sites situated along its flyway from the breeding grounds to the wintering areas. Detailed study revealed for the first time that in most individuals wing feather molt proceeds from the center both toward the body and the wing-tip, a molt pattern known as divergent molt (which is rare among Palearctic passerines). In the Russian Far East, where both breeding birds and passage migrants occur, a third of the adult birds were molting in late summer. In Central Siberia, at the northwestern limit of its distribution, adult individuals commenced their primary molt partly divergently and partly with unknown sequence. During migration in Mongolia, only descendantly (i.e., from the body toward the wing-tip) molting birds were observed, while further south in Korea, Hong Kong, and Thailand the proportion of potential eccentric and divergent feather renewal was not identifiable since the renewed feathers were already fully grown as expected. We found an increase in the mean number of molted primaries during the progress of the autumn migration. Moderate body mass levels and low-fat and muscle scores were observed in molting adult birds, without any remarkable increase in the later season. According to optimality models, we suggest that an extremely short season of high food abundance in tall grass habitats and a largely overland route allow autumn migration with low fuel loads combined with molt migration in at least a part of the population. This study highlights the importance of further studying molt strategy as well as stopover behavior decisions and the trade-offs among migratory birds that are now facing a panoply of anthropogenic threats along their flyways., Finanziert über die DEAL-Vereinbarung mit Wiley 2019-2022.

We present experimentally determined trace element partition coefficients (D) between pyrochlore-group minerals (Ca2(Nb,Ta)2O6(O,F)), Ca fersmite (CaNb2O6), and silicate melts. Our data indicate that pyrochlores and fersmite are able to strongly fractionate trace elements during the evolution of SiO2-undersaturated magmas. Pyrochlore efficiently fractionates Zr and Hf from Nb and Ta, with DZr and DHf below or equal to unity, and DNb and DTa significantly above unity. We find that DTa pyrochlore-group mineral/silicate melt is always higher than DNb, which agrees with the HFSE partitioning of all other Ti–rich minerals such as perovskite, rutile, ilmenite or Fe-Ti spinel. Our experimental partition coefficients also show that, under oxidizing conditions, DTh is higher than corresponding DU and this implies that pyrochlore-group minerals may fractionate U and Th in silicate magmas. The rare earth element (REE) partition coefficients are around unity, only the light REE are compatible in pyrochlore-group minerals, which explains the high rare earth element concentrations in naturally occurring magmatic pyrochlores., Finanziert über die DEAL-Vereinbarung mit Wiley 2019-2022.

We report on the detection of primordial organic matter within the carbonaceous chondrite Maribo that is distinct from the majority of organics found in extraterrestrial samples. We have applied high-spatial resolution techniques to obtain C-N isotopic compositions, chemical, and structural information of this material. The organic matter is depleted in ^15N relative to the terrestrial value at around δ^15N ~ -200‰, close to compositions in the local interstellar medium. Morphological investigations by electron microscopy revealed that the material consists of µm- to sub-µm-sized diffuse particles dispersed within the meteorite matrix. Electron energy loss and synchrotron X-ray absorption near-edge structure spectroscopies show that the carbon functional chemistry is dominated by aromatic and C=O bonding environments similar to primordial organics from other carbonaceous chondrites. The nitrogen functional chemistry is characterized by C-N double and triple bonding environments distinct from what is usually found in ^15N-enriched organics from aqueously altered carbonaceous chondrites. Our investigations demonstrate that Maribo represents one of the least altered CM chondrite breccias found to date and contains primordial organic matter, probably originating in the interstellar medium., Finanziert über die DEAL-Vereinbarung mit Wiley 2019-2022.

Funder: Bavarian Climate Research Network (BayKliF), Funder: Gutenberg Research College; Id: http://dx.doi.org/10.13039/501100004812, Dendroclimatology offers the unique opportunity to reconstruct past climate at annual resolution and wood from historical buildings can be used to extend such information back in time up to several millennia. However, the varying and often unclear origin of timbers affects the climate sensitivity of individual tree‐ring samples. Here, we compare tree‐ring width and density of 143 living larch (Larix decidua Mill.) trees at seven sites along an elevational transect from 1400 to 2200 m asl and 99 historical tree‐ring series to parametrize state‐of‐the‐art classification models for the European Alps. To achieve geographical provenance of the historical series, nine different supervised machine learning algorithms are trained and tested in their capability to solve our classification problem. Based on this assessment, we consider a tree‐ring density‐based and a tree‐ring width‐based dataset for model building. For each of these datasets, a general not species‐related model and a larch‐specific model including the cyclic larch budmoth influence are built. From the nine tested machine learning algorithms, Extreme Gradient Boosting showed the best performance. The density‐based models outperform the ring‐width models with the larch‐specific density model reaching the highest skill (f1 score = 0.8). The performance metrics reveal that the larch‐specific density model also performs best within individual sites and particularly in sites above 2000 m asl, which show the highest temperature sensitivities. The application of the specific density model for larch allows the historical series to be assigned with high confidence to a particular elevation within the valley. The procedure can be applied to other provenance studies using multiple tree growth characteristics. The novel approach of building machine learning models based on tree‐ring density features allows to omit a common period between reference and historical data for finding the provenance of relict wood and will therefore help to improve millennium‐length climate reconstructions.

The paper examines how U.S.-American movies stage and convey intercultural encounters. Drawing from the case study of cinematic New York City, it tackles intercultural encounters and spaces emerging from interactions of protagonists that are staged as being ‘culturally different’. Theoretical ideas on urban encounters, interculturality, and boundaries are intertwined. A comparative analysis 17 movies reveals three key dimensions of intercultural spaces: boundary drawing, boundary crossing, and boundary commuting. As polysemous staging strategies these provide insight into how movies display everyday intercultural encounters in an urban context. The paper concludes that New York City is imagined as a place in which intercultural encounters are consciously reflected as cultural coexistence—the cinematic city serves as canvas for a culturally separated society. This finding disenchants the medially widespread urban myth of New York City being a harmonious intercultural metropolis.

Currently, numerous physician practices in industrial and emerging countries are being taken over by private equity firms and integrated into novel physician corporations. This involves private equity firms producing a global wealth chain (GWC) between their investors and the target asset, using offshore financial centres to facilitate tax-avoiding reflux of capital. Moreover, they are opening up ambulatory health care as an asset for capital investment by overcoming previous market barriers to ambulatory health care via a legal construct. In this paper, we trace the spatial links of these finance-side and sector-specific corporate chains based on a capital flow analysis of private equity takeovers of Medical Care Centres (MCCs) in Bavaria, Germany. With our heuristics of a double-layered GWC, which enables the extraction of value from the German health system, we contribute to the emerging GWC debate that aims to conceptualise the complex and often opaque spatialisations of financialisation processes.

This paper introduces a multi-method approach for Film Geography that intertwines spatial analysis, cartography, textual analysis, discourse analysis, field research, and expert interviews. Historically, film studies has focused on textual analysis whereas geography has emphasized the material aspect of space through field research. However, if cinema is a double ontology of image and industry film geographers must engage with both to make a meaningful contribution to the complex interwoven discourses on cinematic space. This case study focuses on the Nate Starkman Building, a frequently filmed warehouse located in the Arts District of Los Angeles, California. This case study acts as an example of how a multi-method approach can be applied to on-location filming. I demonstrate how the methods can be combined to contextualize and pinpoint previously invisible interactions between the on-screen appearance and the cultural politics of film production and placemaking. I argue that film-geographic analysis allows for a more in-depth look into the Hollywood-machinery that has led to these unique socio-economic structures.

Subduction provides the primary driving force for plate tectonics. However, the mechanisms leading to the formation of new subduction zones remain debated. An example is the Lesser Antilles Arc in the Atlantic. Previous initiation mechanisms have implied the transmission of subduction from the Pacific Ocean or the impact of a plume head. Here, we use geodynamic models to simulate the evolution of the Caribbean region during the Cretaceous, where the eastern Pacific subduction triggered the formation of a new subduction zone in the Atlantic. The simulations show how the collision of the old Caribbean plateau with the Central America margin lead to the formation of a new Atlantic subduction zone by polarity reversal. The results further show how subduction renewal on the back of the old Caribbean plateau (present-day Central America) resulted in a major mantle flow reorganization that generated a subduction-induced plume consistent with the formation of the Caribbean Large Igneous Province.

Das Interesse von Lernenden ist eine zentrale Voraussetzung sowie die Förderung des Interesses ein wichtiges Ziel des Geographieunterrichts. Es wurde bisher vorwiegend in Bayern oder Nordrhein-Westfalen erforscht. Diese Arbeit untersucht daher das geographische Interesse von Lernenden Sachsen-Anhalts an Regionen sowie die Einflüsse verschiedener unabhängiger Variablen darauf. Die Untersuchung wurde mit insgesamt 390 Lernenden aus gymnasialen Jahrgangsstufen 7 und 10 durchgeführt, sowie mit Daten von 400 Lernenden aus NRW und Bayern verglichen. Die Ergebnisse zeigen ein besonders starkes Interesse an europäischen und außereuropäischen Regionen, insbesondere bei den Mädchen. Jungen zeigen generell ein geringeres Interesse, mit Ausnahme an deutschen Regionen. Jüngere Lernende sind interessierter an Regionen als ältere, große Unterschiede zeigen sich dabei vor allem für Deutschland. In Sachsen-Anhalt ist gegenüber anderen Bundesländern ein besonders starkes Interesse an Europa erkennbar, sowie eine geringere Ausprägung einer Ost-West-Interessendiskrepanz., Student interest is a central prerequisite as well as its promotion an important goal of geographical learning. So far, however, this has been researched mainly in Bavaria or North Rhine-Westphalia. Therefore, this study investigates the geographic student interest in Saxony-Anhalt in regions in its expression as well as the influences of different independent variables on it. The survey was conducted with a total of 390 learners from gymnasium grades 7 and 10; for some analyses, data from 400 learners from North Rhine-Westphalia and Bavaria from 2015 were also included. The results show a particularly strong interest in European and non-European regions, especially among girls. Boys generally show less interest, especially in Germany. Younger learners are more interested in regions than older learners, with large differences showing up especially for Germany. In Saxony-Anhalt, a particularly strong interest in Europe is evident compared to the other German states, as well as a lower expression of an East-West interest discrepancy., Abbildungsverzeichnis ..... II Tabellenverzeichnis ..... II 1 Einleitung ..... 1 2 Theoretische Grundlagen und Forschungsstand ..... 2 2.1 Pädagogisch-psychologische Interessensforschung ..... 2 2.1.1 Münchener Interessenkonstrukt ..... 3 2.1.2 Interessenentwicklung ..... 5 2.1.3 Interesse im schulischen Kontext ..... 6 2.2 Geographische Regionen ..... 7 2.2.1 Regionsbegriff ..... 7 2.2.2 Abgrenzungsmöglichkeiten ..... 9 2.2.3 Regionen im Geographieunterricht ..... 10 2.3 Forschungsstand zum Interesse von Schülerinnen und Schülern an Regionen ..... 11 3 Fragestellung ..... 16 4 Methodik ..... 18 4.1 Design und Datenerhebung ..... 18 4.1.1 Erhebungsmethode ..... 18 4.1.2 Entwicklung des Messinstruments ..... 19 4.1.3 Stichprobe und Datenerhebung ..... 20 4.2 Datenaufbereitung ..... 21 4.3 Güte der Untersuchung ..... 23 5 Ergebnisse ..... 25 5.1 Auswertung der gesamten Stichprobe ..... 25 5.2 Einfluss und Bedeutung der unabhängigen Variablen ..... 28 6 Diskussion ..... 32 7 Fazit ..... 37 Literaturverzeichnis ..... 39 Anhang ..... 43 Danksagung ..... 53

Zusammenfassung: Umweltchemie befasst sich mit den Quellen und Senken, dem Transport und der Verteilung sowie mit Reaktionen und Wirkungen von Stoffen in Wasser, Boden und Luft und deren Einwirkung auf Lebewesen (Menschen, Tiere, Pflanzen, Mikroorganismen) sowie auf Gegenstände (z.B. Bauwerke, Werkstoffe). Im Mittelpunkt der Umweltchemie stehen die Eigenschaften der chemischen Stoffe und deren Wirkungen in der Umwelt und die Erkenntnisse über die komplexen Zusammenhänge zwischen den Ursachen und den Wirkungen, die sich daraus ableiten. Bei der Untersuchung von Stoffkreisläufen im System Erde ist es von Bedeutung zu ermitteln, ob dieuntersuchten Stoffe durch menschliche Aktivitäten oder über natürliche Prozesse freigesetzt wurden. Umweltchemie ist eine naturwissenschaftliche Disziplin mit Wurzeln in der Chemie (Allgemeine Chemie, Analytische Chemie), in den →Geowissenschaften (Stoffkreisläufe, Umweltarchive, Anthropozän) (→Geographie), in der →Umweltphysik (Umweltmesstechnik, Modellierung von Prozessen) und in der Biologie (Ökotoxikologie) umfasst.

The aim of this work is to establish an overview of the tin isotope ratios of cassiterite and stannite from various mineralized regions in Europe, the Mediterranean and Central Asia in order to assess the possibility to geochemically discriminate tin ore deposits, which could have been exploited in ancient times. The motivation for this study was to eventually relate the tin found in ancient bronze objects to specific tin ore deposits and thus to clarify the origin and distribution of the tin bronze technology in the Bronze Age of the so-called Old World. For this purpose, we determined 413 primary and secondary cassiterite and stannite samples from the major tin provinces in SW England and Ireland, the Saxonian-Bohemian province, the Iberian Peninsula, France, Italy, Serbia, Egypt and Central Asia. The tin isotope compositions were analysed in solution with a multi-collector inductive-coupled plasma mass spectrometer (MC-ICP-MS) in the Curt-Engelhorn-Zentrum Archäometrie in Mannheim. The samples mainly derive from granitic pegmatites and hydrothermal vein mineralizations of tin ore deposits associated with granite complexes in the Variscan and Asian fold belts. Overall, the isotope ratios in primary and secondary cassiterites are highly variable and range from δ124Sn/120Sn -0.82 to 0.85 ‰. This variation is observed in the tin ore samples from SW England which have an average δ124Sn/120Sn of 0.10 ± 0.59 ‰ (2SD). Among the tin provinces of the Variscan fold belt in Europe those of SW England and the Saxonian-Bohemian province (δ124Sn/120Sn = 0.12 ‰ ± 0.37) show the largest variations but the ranges of isotope ratios in both regions overlap to a large extent. Despite the large overlap, cassiterite from Spain (δ124Sn/120Sn = -0.07 ‰ ± 0.35) and France (δ124Sn/120Sn = -0.005 ‰ ± 0.31) tend to have on average lighter isotopic compositions than SW England, the Saxonian-Bohemian province or Portugal (δ124Sn/120Sn = 0.07 ‰ ± 0.40). However, the stannite samples from SW England and the Saxonian-Bohemian province have significantly lighter isotope ratios than the associated cassiterites. The tin ores from Central Asia exhibit the largest total variation of 1.94 ‰ ranging from -1.27 to 0.67 ‰ for δ124Sn/120Sn. This extent of fractionation is observed in cassiterites from Afghanistan and Uzbekistan. Afghanistan with its pegmatitic cassiterite has the lightest isotopic composition of all investigated areas with -0.38 ± 0.84 ‰ for δ124Sn/120Sn and, therefore, stands out as an identifiable source. Similar to the European stannites, the Asian stannites also have significantly lighter isotope compositions. Because of the large overlap and the highly variable isotope composition of cassiterites from all tin provinces a clearcut discrimination based on tin isotope ratios is difficult. But on a more detailed scale within each tin province it is possible to distinguish several mining or granite areas by their Sn isotope composition. However, it is also difficult to distinguish between different mineralization types.

Magma stored in the crust may exsolve a significant amount of volatiles, primarily CO2, but also H2O and SO2 if cooling promotes crystallisation and volatile exsolution. These volatiles may, over time, segregate and accumulate into a gas-rich foam at the roof of the magma body. This is the underpinning process to explain the frequently observed ‘excess gas’ produced in explosive eruptions, where the amount of erupted SO2 is much larger than can be explained by the mass of erupted products and the initial dissolved S content.Here, we examine and quantify the buoyancy force exerted on the crust due to the presence of accumulated volatiles in the roof of a magma reservoir of exsolved volatiles. This foam has a significantly lower density than magma or the crust, and will therefore produce a buoyancy force which will manifest as deformation of the volcanic edifice above. A key concept in this work is that the accumulation of the foam layer may occur slowly over long time periods and therefore be challenging to detect. However, upon eruption, the gas phase will be suddenly lost, and the removal of the buoyant volatiles will result in syn-eruptive subsidence, in addition to that expected from the eruption of lavas.We present three-dimensional, visco-elasto-plastic, thermomechanical modeling results which quantify the ground deformation arising from the growth and sudden release of a volatile reservoir. We find that the deformation is independent from the thermal structure of the crust and the shapes of the volatile and magma reservoirs. Instead, it is a function of the volume, density and depth of the volatile reservoir and crustal rigidity. This allows us to derive a scaling law for the volatiles’ contribution to syn-eruptive subsidence.Applying our scaling law to the April 2015 eruption of the Chilean stratovolcano Calbuco, together with estimates of the pre-accumulated volatile mass, suggests that up to 25% of the observed syn-eruptive subsidence can be explained by the release of a buoyant reservoir of exsolved volatiles. Our results highlight the key role that volatile-driven buoyancy can have in volcano deformation and show a new link between syn-eruptive degassing and deflation. They also highlight that shallow gas accumulation and release may have a major impact on ground deformation of volcanoes and can serve as an explanation for inflation/deflation of up to a few cm.

Sulfur compounds in the upper troposphere and lower stratosphere (UTLS) impact the atmosphere radiation budget, either directly as particles or indirectly as precursor gas for new particle formation. In situ measurements in the UTLS are rare but are important to better understand the impact of the sulfur budget on climate. The BLUESKY mission in May and June 2020 explored an unprecedented situation. (1) The UTLS experienced extraordinary dry conditions in spring 2020 over Europe, in comparison to previous years, and (2) the first lockdown of the COVID-19 pandemic caused major emission reductions from industry, ground, and airborne transportation. With the two research aircraft HALO and Falcon, 20 flights were conducted over central Europe and the North Atlantic to investigate the atmospheric composition with respect to trace gases, aerosol, and clouds. Here, we focus on measurements of sulfur dioxide (SO2) and particulate sulfate (SO42-) in the altitude range of 8 to 14.5 km which show unexpectedly enhanced mixing ratios of SO2 in the upper troposphere and of SO42- in the lowermost stratosphere. In the UT, we find SO2 mixing ratios of (0.07±0.01) ppb, caused by the remaining air traffic, and reduced SO2 sinks due to low OH and low cloud fractions and to a minor extent by uplift from boundary layer sources. Particulate sulfate showed elevated mixing ratios of up to 0.33 ppb in the LS. We suggest that the eruption of the volcano Raikoke in June 2019, which emitted about 1 Tg SO2 into the stratosphere in northern midlatitudes, caused these enhancements, in addition to Siberian and Canadian wildfires and other minor volcanic eruptions. Our measurements can help to test models and lead to new insights in the distribution of sulfur compounds in the UTLS, their sources, and sinks. Moreover, these results can contribute to improving simulations of the radiation budget in the UTLS with respect to sulfur effects.

Flooding is one of the leading challenges faced by delta cities in the world. Flood risk management using flood control infrastructure (FCI) is a popular solution to prevent flood damage; however, this is receiving enormous criticism due to its negative impacts on urban ecosystems. Recently, there have been new approaches to flood risk management that gradually shifted the focus away from FCI, such as ecological infrastructure (EI) based approaches. However, the conventional thinking that cities cannot be safe without FCI seems an immutable one, especially in developing countries. This study firstly assessed human–river interaction in direct relation to FCI and outlined the limitations of FCI. Then, an urban ecology research model was used to conduct a case study in the Vietnamese Mekong Delta (VMD), in which the interaction between factors, including riverine urbanization, FCI formation dynamics, the changing hydrological regime, flood risk, and riverine ecosystem degradation were evaluated. Due to the dynamism and complexity of the interactions between humans and rivers at the VMD, this study attempts to demonstrate that building the ability to adapt to flood risks based on EI will have a crucial role in enhancing the sustainability of delta cities. Through a case study in My Tho City (MTC) a flood resilience management scenario for a riverine urban area along the Mekong River was developed to discuss the role of EI in flood risk reduction and the restoration of riverine native ecosystems. The findings from this study suggests that EI should be considered as an effective and indispensable design tool for the conservation of riparian ecological corridors and public open spaces—which is a major challenge for urban areas in the context of increasing climate change impacts in the VMD., Finanziert durch den Open-Access-Publikationsfonds der Westfälischen Wilhelms-Universität Münster (WWU Münster).

Die Kritische Stadtgeographie hat das Selbermachen für sich entdeckt. Ob in der Debatte um Recht auf Stadt, DIY-Urbanismus oder eine neue „Angewandte Kritische Geographie“ – überall werden Banden gebildet, wird Stadt von unten und selbst gemacht. Bei so viel kritischer Aktivität bleibt es gerade für eine emanzipatorisch orientierte Praxis sinnvoll und notwendig, die Voraussetzungen des eigenen Tuns mit zum Gegenstand von Kritik zu machen. Dazu gehören auch vermeintliche Wahrheiten und Selbstverständlichkeiten. Der Beitrag fragt nach der Rolle eines solch selbstreflexiven Moments in der gegenwärtigen Angewandten Kritischen Stadtgeographie., Finanziert durch den Open-Access-Publikationsfonds der Westfälischen Wilhelms-Universität Münster (WWU Münster).

The mixing ratios of methane (CH_4) were recorded with high temporal and spatial resolution in Münster, Germany, to identify urban CH_4 sources and to quantify the overall inner city CH_4 emissions. Both mobile and stationary measurement techniques were employed. The background mixing ratios showed a diurnal cycle with higher values at night under stable stratification conditions. In the industrial park, periodic peaks were detected. Ten mappings of the urban CH_4 mixing ratio were made with an instrumented cargo bicycle. Repeated local increases in mixing ratios were found at 13 individual locations. The emission rate was estimated to be 22.0 g h^-1 km^-1. A total of five leaks from the underground gas distribution network were identified. From the increase in background mixing ratio, the overall source strength of the study area was estimated to be 24.6 g m^-2 a^-1, which is approximately three times the total CH_4 emissions from the city’s most recent emissions report. The contribution of point sources was 0.64 g m^-2 a^-1, suggesting that significant additional CH_4 sources exist within the study area. In the interest of climate protection, there is an urgent need for further research on the urban CH_4 sources and emission fluxes in detail., Finanziert durch den Open-Access-Publikationsfonds der Westfälischen Wilhelms-Universität Münster (WWU Münster).

The different structural features of labradorite and its incommensurate atomic structure have long been in the eye of science. In this transmission electron microscopy (TEM) study, all of the structural properties of labradorite could be investigated on a single crystal with an anorthite–albite–orthoclase composition of An53.4Ab41.5Or5.1. The various properties of labradorite could thus be visualized and connected to form a hierarchical structure. Both albite and pericline twins occur in the labradorite. The size of alternating Ca-rich and Ca-poor lamellae could be measured and linked to the composition and the color of labradorescence. Furthermore, a modulation vector of 0.0580(15)a* + 0.0453(33)b* − 0.1888(28)c* with a period of 3.23 nm was determined. The results indicate an eα labradorite structure, which was achieved by forming Ca-rich and Ca-poor lamellae. The average structure and subsequently the incommensurate crystal structure were solved with a three-dimensional electron diffraction (3DED) data set acquired with automated diffraction tomography (ADT) from a single lamella. The results are in good agreement with the structure solved by X-ray diffraction and demonstrate that 3DED–ADT is suitable for solving even incommensurate structures.

In mammals, complex dental microwear textures (DMT) representing differently sized and shaped enamel lesions overlaying each other have traditionally been associated with the seeds and kernels in frugivorous diets, as well as with sclerotized insect cuticles. Recently, this notion has been challenged by field observations as well as in vitro experimental data. It remains unclear to what extent each food item contributes to the complexity level and is reflected by the surface texture of the respective tooth position along the molar tooth row. To clarify the potential of seeds and other abrasive dietary items to cause complex microwear textures, we conducted a controlled feeding experiment with rats. Six individual rats each received either a vegetable mix, a fruit mix, a seed mix, whole crickets, whole black soldier fly larvae, or whole day-old-chicks. These diets were subjected to material testing to obtain mechanical properties, such as Young’s modulus, yield strength, and food hardness (as indicated by texture profile analysis [TPA] tests). Seeds and crickets caused the highest surface complexity. The fruit mix, seed mix, and crickets caused the deepest wear features. Moreover, several diets resulted in an increasing wear gradient from the first to the second molar, suggesting that increasing bite force along the tooth row affects dental wear in rats on these diets. Mechanical properties of the diets showed different correlations with DMT obtained for the first and second molars. The first molar wear was mostly correlated with maximum TPA hardness, while the second molar wear was strongly correlated with maximum yield stress, mean TPA hardness, and maximum TPA hardness. This indicates a complex relationship between chewing mechanics, food mechanical properties, and observed DMT. Our results show that, in rats, seeds are the main cause of complex microwear textures but that hard insect body parts can also cause high complexity. However, the similarity in parameter values of surface textures resulting from seed and cricket consumption did not allow differentiation between these two diets in our experimental approach.

City centers have to cope with an increasing amount of air pollution. The supply of fresh air is crucial yet difficult to ensure, especially under stable conditions of the atmospheric boundary layer. This case study used the PArallelized Large eddy simulation (LES) Model PALM to investigate the wind field over an urban lake that had once been built as a designated fresh air corridor for the city center of Münster, northwest, Germany. The model initialization was performed using the main wind direction and stable boundary layer conditions as input. The initial wind and temperature profiles included a weak nocturnal low-level jet. By emitting a passive scalar at one point on top of a bridge, the dispersion of fresh air could be traced over the lake’s surface, within street canyons leading to the city center and within the urban boundary layer above. The concept of city ventilation was confirmed in principle, but the air took a direct route from the shore of the lake to the city center above a former river bed and its adjoining streets rather than through the street canyons. According to the dispersion of the passive scalar, half of the city center was supplied with fresh air originating from the lake. PALM proved to be a useful tool to study fresh air corridors under stable boundary layer conditions., Finanziert durch den Open-Access-Publikationsfonds der Westfälischen Wilhelms-Universität Münster (WWU Münster).

Ambient air pollution caused by fine particulate matter (PM) and trace gases is a pressing topic as it affects the vast majority of the world's population, with a particularly heavy influence in densely populated urban environments. Alongside nitrogen oxides (NOx) and PM, ammonia (NH3) is also a relevant air pollutant due to its role as a precursor of particulate ammonium. This is a study about the short-term temporal dynamics of urban NH3 concentrations in Münster, northwest Germany, the role of road traffic and agriculture as NH3 sources and about the importance of ammonia for secondary particle formation (SPF). The NH3 mixing ratio was rather high (mean: 17 ppb) compared to other urban areas and showed distinct diurnal maxima around 10 a.m. and during the night at 9 p.m. The main source for ammonia in Münster was agriculture, but road traffic also contributed through local emissions from vehicle catalysts. NH3 from surrounding agricultural areas accumulated in the nocturnal boundary layer and contributed to SPF in the city center. Modeled emissions of NH3 as estimated by the Handbook for Emission Factors in combination with traffic counts were in the same magnitude for NH3. The size-resolved chemical composition of inorganic ions in PM10 was dominated by NH4+ (8.66 µg m–3), followed by NO3– (3.89 µg m–3), SO42– (1.58 µg m–3) and Cl– (1.33 µg m–3). Particles in the accumulation range (diameter: 0.1–1 µm) showed the highest inorganic ion concentrations. The ammonium neutralization index J (111%) indicated an excess of NH4+ leading to mostly alkaline PM. High ammonia emissions from surrounding agricultural areas combined with large amounts of NOx from road traffic play a crucial role for SPF in Münster., Finanziert durch den Open-Access-Publikationsfonds der Westfälischen Wilhelms-Universität Münster (WWU Münster).

The release of arsenic (As) adsorbed onto iron oxide (Fe-oxide) surfaces is affected by dissolved organic matter (DOM), phosphate (hereafter referred to as PO4), and silicic acid (H4SiO4). Further, the reductive dissolution of As from Fe-oxide phases is also affected in reduced soils and sediments. Thus, the aim of this study was to understand the adsorption competition and redox-related mechanisms by which DOM affects As mobilization from Fe-oxide in a complex system containing both H4SiO4 and PO4. The results demonstrated that the DOM-driven, microbially mediated As biotransformation, and, thus, mobilization of As significantly increased when both dissolved inorganic H4SiO4 and PO4 were present, as the co-presence of H4SiO4 and PO4 decreased As adsorption sites on Fe-oxides. The availability of DOM in the co-presence of H4SiO4 and PO4 increased the microbial activity in the system by providing more substrates for microbial metabolism, which also decreased the redox potential (reducing conditions) and consumed acidity, causing the pH to increase from 4 to 6.8. In addition, DOM, H4SiO4, and PO4 competed with As for sorption sites on Fe-oxides. The effects of DOM on As mobility by DOM-mediated or -triggered redox reactions were apparently stronger in the co-presence of H4SiO4 and PO4 than DOM competition with arsenate for sorption sites on Fe-oxide alone. These findings advance our understanding of As mobilization processes in natural systems and can provide information for soil As management., Finanziert durch den Open-Access-Publikationsfonds der Westfälischen Wilhelms-Universität Münster (WWU Münster).

The study of the chemical composition of volcanic emissions is an important method for obtaining information about volcanic systems and providing indirect and unique insights into magmatic processes. However, there is a non-negligible risk associated with sampling directly at volcanic craters or maintaining geochemical monitoring stations at such locations. Spectroscopic remote sensing methods, in turn, can measure only a few species. Here, drones offer the opportunity to bring measurement systems to the scene. Standard parameters that are commonly measured are SO2 and CO2 concentrations, as well as a number of meteorological parameters. The in-flight transmission of data by radio telemetry plays an important role, since visual localization of the volcanic plume from a distance of several kilometers is practically impossible. Until now, larger and quite cost-intensive drones have been used for this purpose, which must first be transported to the site of operation at great expense. Here, we present the development and successful deployment of a very small drone system (empty weight < 0.9 kg) for chemical characterization of volcanic plumes that can be easily transported on foot to difficult-to-access terrain and, moreover, requires only minimal flight and administrative preparations for operation as an aerial observation platform.

The role of clouds for radiative transfer, precipitation formation, and their interaction with atmospheric dynamics depends strongly on cloud microphysics. The parameterization of cloud microphysical processes in weather and climate models is a well‐known source of uncertainties. Hence, robust quantification of this uncertainty is mandatory. Sensitivity analysis to date has typically investigated only a few model parameters. We propose algorithmic differentiation (AD) as a tool to detect the magnitude and timing at which a model state variable is sensitive to any of the hundreds of uncertain model parameters in the cloud microphysics parameterization. AD increases the computational cost by roughly a third in our simulations. We explore this methodology as the example of warm conveyor belt trajectories, that is, air parcels rising rapidly from the planetary boundary layer to the upper troposphere in the vicinity of an extratropical cyclone. Based on the information of derivatives with respect to the uncertain parameters, the ten parameters contributing most to uncertainty are selected. These uncertain parameters are mostly related to the representation of hydrometeor diameter and fall velocity, the activation of cloud condensation nuclei, and heterogeneous freezing. We demonstrate the meaningfulness of the AD‐estimated sensitivities by comparing the AD results with ensemble simulations spawned at different points along the trajectories, where different parameter settings are used in the various ensemble members. The ranking of the most important parameters from these ensemble simulations is consistent with the results from AD. Thus, AD is a helpful tool for selecting parameters contributing most to cloud microphysics uncertainty., Plain Language Summary: The formation of clouds is determined by processes that act on smaller scales than weather prediction models can resolve. Consequently, a parameterization with typically hundreds of parameters is constructed to determine the effects of these processes on the resolved larger scales. These parameters are a well‐known source of uncertainty in weather and climate models. Classical attempts to quantify this uncertainty are typically limited to a few parameters. We propose algorithmic differentiation (AD) as a tool to detect parameters with the largest impact for any of the hundreds of parameters on multiple model state variables at every time step in our simulation. This increases the computational cost by roughly a third. The relevance of the AD‐estimated impact is demonstrated by comparing the AD results with ensemble simulations, where different parameter settings are used in the various ensemble members. The ranking of the most important parameters from these ensemble simulations is consistent with the results from AD. Thus, AD is a helpful tool to identify parameters objectively that contribute most to uncertainty in cloud parameterizations., Key Points: Quantification of multi‐parameter uncertainty of cloud microphysical evolution of WCB trajectories using algorithmic differentiation. Uncertainty at every time step derived with algorithmic differentiation representative for key uncertainty over at least 30 min intervals. Parameterization of CCN activation, diameter size, and fall velocity of hydrometeors have the largest mean impact on water vapor contents., Deutsch Forschungsgemeinschaft DFG

The selection of a nest site is crucial for successful reproduction of birds. Animals which re-use or occupy nest sites constructed by other species often have limited choice. Little is known about the criteria of nest-stealing species to choose suitable nesting sites and habitats. Here, we analyze breeding-site selection of an obligatory “nest-cleptoparasite”, the Amur Falcon 'Falco amurensis'. We collected data on nest sites at Muraviovka Park in the Russian Far East, where the species breeds exclusively in nests of the Eurasian Magpie 'Pica pica'. We sampled 117 Eurasian Magpie nests, 38 of which were occupied by Amur Falcons. Nest-specific variables were assessed, and a recently developed habitat classification map was used to derive landscape metrics. We found that Amur Falcons chose a wide range of nesting sites, but significantly preferred nests with a domed roof. Breeding pairs of Eurasian Hobby 'Falco subbuteo' and Eurasian Magpie were often found to breed near the nest in about the same distance as neighboring Amur Falcon pairs. Additionally, the occurrence of the species was positively associated with bare soil cover, forest cover, and shrub patches within their home range and negatively with the distance to wetlands. Areas of wetlands and fallow land might be used for foraging since Amur Falcons mostly depend on an insect diet. Additionally, we found that rarely burned habitats were preferred. Overall, the effect of landscape variables on the choice of actual nest sites appeared to be rather small. We used different classification methods to predict the probability of occurrence, of which the 'Random forest' method showed the highest accuracy. The areas determined as suitable habitat showed a high concordance with the actual nest locations. We conclude that Amur Falcons prefer to occupy newly built (domed) nests to ensure high nest quality, as well as nests surrounded by available feeding habitats., Finanziert über die DEAL-Vereinbarung mit Wiley 2019-2022.

Reducing wind turbine noise recorded at seismological stations promises to lower the conflict between renewable energy producers and seismologists. Seismic noise generated by the movement of wind turbines has been shown to travel large distances, affecting seismological stations used for seismic monitoring and/or the detection of seismic events. In this study, we use advanced 3D numerical techniques to study the possibility of using structural changes in the ground on the wave path between the wind turbine and the seismic station in order to reduce or mitigate the noise generated by the wind turbine. Testing a range of structural changes around the foundation of the wind turbine, such as open and filled cavities, we show that we are able to considerably reduce the seismic noise recorded by placing empty circular trenches approx. 10 m away from the wind turbines. We show the expected effects of filling the trenches with water. In addition, we study how relatively simple topographic elevations influence the propagation of the seismic energy generated by wind turbines and find that topography does help to reduce wind-turbine-induced seismic noise., Finanziert durch den Open-Access-Publikationsfonds der Westfälischen Wilhelms-Universität Münster (WWU Münster).

To understand global soil organic matter (SOM) chemistry and its dynamics, we need tools to efficiently quantify SOM properties, for example, prediction models using mid-infrared spectra. However, the advantages of such models rely on their validity and accuracy. Recently, Hodgkins et al. (2018) developed models to quantitatively predict peat holocellulose and Klason lignin contents, two indicators of SOM stability and major fractions of organic matter. The models may help to understand large-scale SOM gradients and have been used in various studies. A research gap to fill is that these models have not been validated in detail yet. What are their limitations and how can we improve them? This study provides a validation with the aim to identify concrete steps to improve these models. As a first step, we provide several improvements using the original training data. The major limitation we identified is that the original training data are not representative for a range of diverse peat samples. This causes both biased estimates and extrapolation uncertainty under the original models. In addition, the original models can in practice produce unrealistic predictions (negative values or values >100 mass-%). Our improved models partly reduce the observed bias, have a better predictive performance for the training data, and avoid such unrealistic predictions. Finally, we provide a proof of concept that holocellulose contents can also be predicted for mineral-rich samples (e.g., peat with mineral admixtures or potentially mineral soils). A key step to improve the models will be to collect training data that are representative for SOM formed under various conditions. This study opens directions to develop operational models to predict SOM holocellulose and Klason lignin contents from mid-infrared spectra., Finanziert durch den Open-Access-Publikationsfonds der Westfälischen Wilhelms-Universität Münster (WWU Münster).

Urban wind fields are of concern because the near-ground wind vector drives the ventilation of cities, which involves, among other things, the translocation and dilution of air pollutants. To study flow patterns in the urban atmospheric boundary layer, turbulence-resolving tools are needed since numerous roughness elements are present that cause the flow to be of highly turbulent nature. Therefore, we developed a mobile, fastresponse measurement platform that is situated on a cargo bicycle. This mobile platform was deployed in a case study collecting data at street level within a complex, urban area that includes street canyons, open squares, street intersections as well as courtyard entrances. Results were compared to numerical large eddy simulation (LES) data from the model PALM. Outcomes of both methods were qualitatively analyzed; results show that both methods were able to identify complex flow patterns, including small-scale structures such as jetting flows, vortices, recirculation areas, and a convergence zone where air masses collide. Results of both methods generally matched well, even for areas that featured highly complex, three-dimensional flow structures. We conclude that both the model PALM and the mobile platform are valuable tools for gathering insights about complex flow structures in real-world environments., Finanziert durch den Open-Access-Publikationsfonds der Westfälischen Wilhelms-Universität Münster (WWU Münster).

Traffic monitoring is key to modern city planning. However, the costs associated with monitoring devices limit the large-scale deployment of existing traffic monitoring systems. In this article, we propose and evaluate an algorithm to automatically count the number of vehicles that have passed through a low-cost system for traffic monitoring. The system uses deviations in the Wi-Fi signals strength to predict the presence of a vehicle on the road and its type (car, bus). The study further systematically compares six analytical techniques for the classification of detected vehicles. The methods were tested with data from three road scenarios in the city of Münster, Germany. Vehicle classification accuracy ranged from 83% up to 100% in our study. We also observed that a higher Wi-Fi frequency (5 GHz) was superior to the 2.4 GHz for improving the overall vehicle detection and the results of the classification algorithms. The results suggest that the Wi-Fi-based techniques proposed in this study are promising for cost-efficient traffic monitoring in cities in a privacy-preserving manner.

Modelling the response of seismic wavefields to sharp lateral variations in crustal discontinuities is essential for the application of seismic tomography and the correction of path effects in earthquake source characterization. Researchers generally focus on travel times and amplitudes of a limited number of phases, simplifying the underlying physics and reducing computational times. However, this approach offers insufficient resolution across oceanic basins while leaving a large part of the information contained in seismic records unexploited. Here, we model the sensitivity of wave propagation to crustal structural variations in the Southern Tyrrhenian basin by fitting the data produced by the Accumoli earthquake (Central Italy, 2016) and recorded at the national INGV (Istituto Nazionale di Geofisica e Vulcanologia) network. As a result, we reconstruct the velocity, Moho, and sediment structures in the basin and improve estimates of earthquake-source characteristics. P-, S- and coda-wave are first modelled and fitted to data acquired by a single station in Sicily; then, the procedure is extended to seismic receivers of the INGV network that contour the basin. The optimal fits are obtained using a deep Moho (~ 18 km) in the middle of the basin and a crustal pinch between the basin and the continental crust in Sicily. The deep Moho corresponds to the Issel Bridge, a portion of continental crust trapped between the Vavilov and Marsili volcanic centres. The Accumoli earthquake is optimally described using a boxcar source time function with a rise time of 6 s, a depth of 7.3 km, and the radiation pattern previously identified by INGV. Correlation analyses performed on data recorded across the network demonstrate the improvement in P-, S- and coda waveform fitting relative to previous Moho models obtained inverting single-phase observations. The early S-wave coda comprises trapped and reverberating phases that are particularly sensitive to crustal interfaces. With our approach, full-waveform simulations become a viable strategy for the inversion of Moho depths across the Southern Tyrrhenian using regional earthquakes.

Shells of bivalve mollusks serve as archives for past climates and ecosystems, and human-environmental interactions as well as life history traits and physiology of the animals. Amongst other proxies, data can be recorded in the shells in the form of element chemical properties. As demonstrated here with measured chemical data (10 elements) from 12 Arctica islandica specimens complemented by numerical simulations, mistakes during sclerochronological data processing can introduce significant bias, adding a further source of error to paleoenvironmental or biological reconstructions. Specifically, signal extraction from noisy LA-ICP-MS (Laser Ablation—Inductively Coupled Plasma—Mass Spectrometry) data generated in line scan mode with circular LA spots requires a weighted rather than an arithmetic moving average. Otherwise, results can be in error by more than 41%. Furthermore, if variations of seasonal shell growth rate remain unconsidered, arithmetic annual averages of intra-annual data will be biased toward the fast-growing season of the year. Actual chemical data differed by between 3.7 and 33.7% from weighted averages. Numerical simulations not only corroborated these findings, but indicated that arithmetic annual means can overestimate or underestimate the actual environmental variable by nearly 40% relative to its seasonal range. The magnitude and direction of the error depends on the timing and rate of both seasonal shell growth and environmental change. With appropriate spatial sampling resolution, weighting can reduce this bias to almost zero. On average, the error reduction attains 80% at a sample depth of 10, 92% when 20 samples were analyzed and nearly 100% when 100 samples were taken from an annual increment. Under some exceptional, though unrealistic circumstances, arithmetic means can be superior to weighted means. To identify the presence of such cases, a numerical simulation is advised based on the shape, amplitude and phase relationships of both curves, i.e., seasonal shell growth and the environmental quantity. To assess the error of the offset induced by arithmetic averaging, Monte Carlo simulations should be employed and seasonal shell growth curves randomly generated based on observed variations.

Fil: Guardo, Roberto Antonino. Universidad Nacional de Río Negro. Instituto de Investigación en Paleobiología y Geología. Río Negro; Argentina. Fil: De Siena, Luca. Johannes Gutenberg University. Mainz; Germany Active seismic experiments allow reconstructing the subsurface structure of volcanoes with unprecedented resolution and are vital to improve the interpretation of volcanic processes. They require a quality assessment for thousands of seismic waveforms recorded at hundreds of stations in the shortest amount of time. However, the processing necessary to obtain reliable images from such massive datasets demands signal processing and selection strategies specific to the inversions attempted. Here, we present a semi-automated workflow for data selection and inversion of amplitude-dependent information using the original TOMODEC2005 dataset, recorded at Deception Island (Antarctica). The workflow is built to tomographic techniques using amplitude information, and can be generalised to passive seismic imaging. It first selects data depending on standard attributes, like the presence of zeroes across all seismic waveforms. Then, waveform selections depend on inversion-specific attributes, like the delay of the maximum amplitude of the waveform or the quality of coda-wave decays. The automatic workflow and final visual selections produce a dataset reconstructing anomalies at a node spacing of 2 km, imaging a high-attenuation anomaly in the centre of the Deception Island bay, consistent with previously-published maps. Attenuation models are then obtained at a node spacing of 1 km, highlighting bodies of highest attenuation scattered across the island and a NW-SE trend in the high-attenuation anomaly in the central bay. These results show the effect of the local extension regime on volcanic structures, providing details on the eruptive history and evolution of the shallow magmatic and hydrothermal systems. The selection workflow can be easily generalised to other amplitude-dependent tomographic techniques when applied to active seismic surveys. Image improvements from the original dataset are minor when selecting data using standard attributes, like signal-to-noise ratios. Tomographic maps become drastically more stable and consistent between different frequencies and resolutions when data selection targets attributes specific to the inversion.

Imaging of fluid pathways is crucial to characterize processes taking place in hydrothermal systems, a primary cause of volcanic unrest and associated hazards. The joint imaging of seismic absorption and scattering is an efficient instrument to map fluid flow at crustal scale, and specifically in volcanoes; however, this technique has so far been applied to image volcanoes and hydrothermal systems at the kilometre scale. Here, we use data from a meter-scale, active seismic survey inside the shallow structure of the Solfatara crater to obtain the first frequency-dependent near-surface scattering and absorption model of a hydrothermal system. The Solfatara crater is the place used to monitor historic unrest at Campi Flegrei caldera (Italy), a high-risk volcano under continuous surveillance due to its closeness to a densely populated area. Improving the imaging of the shallow part of this system is crucial to broaden the understanding of unrest processes that are progressively characterizing other portions of the eastern caldera. The scattering contrasts highlight the primary structural feature, a fault separating the hydrothermal plume from zones of CO2 saturation nearing fumaroles. While high-absorption anomalies mark zones of high soil temperatures and CO2 fluxes, low-absorption anomalies indicate zones of very shallow upflow and are caused by contrasts between liquid-rich and vapour-rich fluids coming from mud pools and fumaroles, respectively. All maps show a SW-NE trend in anomalies consistent with fluid-migration pathways towards the eastern fumaroles. The results provide structural constraints that clarify mechanisms of fluid migration inside the crater. The techniques offer complementary geophysical images to the interpretation of hydrothermal processes and prove that seismic attenuation measurements are suitable to map fluid pathways in heterogeneous media at a detailed scale.

Insbesondere in Städten werden Gesundheitsungleichheiten individuell verkörpert. Gleichzeitig werden sie in Recht-auf-Stadt-Kämpfen kollektiv adressiert. Dennoch bleibt das Verhältnis zwischen Gesundheit und Ungleichheit in der Kritischen Stadtgeographie unterrepräsentiert. Wie genau werden Machtverhältnisse in Form von Gesundheit und Krankheit konkret und ortsspezifisch ungleich verkörpert und mit welcher Raumwirksamkeit? Mithilfe eines relationalen Gesundheitsverständnisses fragen wir, wie Machtverhältnisse – vermittelt über Gesellschaftsstrukturen und (politisch konstruierte) Umwelten – krank machen. Urbane Gesundheitsinitiativen verfolgen vielfältige räumliche Strategien zur Sichtbarmachung und Bearbeitung krank machender Verhältnisse. Mithilfe des Konzepts Worlding tragen wir das verstreut vorliegende Wissen dieser Initiativen bezogen auf Stadtteilgesundheit, Frauen- und migrantische Gesundheit zum Einfluss bioökosozialer Verhältnisse auf Gesundheit zusammen. Wir diskutieren die Raumrelevanz für die Hervorbringung von Krankheit und die kollektive Repolitisierung von Gesundheit auf Stadtteilebene. Damit tragen wir zu einer Kritischen Stadtgeographie verkörperter Ungleichheiten bei, die zeigt, wie Machtverhältnisse sich in Form von Krankheit und Gesundheit in Körper einschreiben., Finanziert durch den Open-Access-Publikationsfonds der Westfälischen Wilhelms-Universität Münster (WWU Münster).

Steadily increasing inputs of microplastics pose a growing threat to aquatic fauna, but laboratory studies potentially lack realism to properly investigate its effects on populations and ecosystems. Our study investigates the trophic and ontogenetic transfer of microplastics in a near-natural exposure scenario. The controlled outdoor freshwater mesocosms were exposed to polyamide (PA) 5–50 µm in size in concentrations of 15 and 150 mg L−1 and a control without microplastic addition. To verify the uptake of particles via the food chain, larvae and imagines of the midges Chaoborus crystallinus and C. obscuripes were examined, which feed on zooplankton during their larval stage. Larvae were captured after 117 days and imagines were caught in emergence traps that were emptied weekly. To detect the microparticles within the organisms, 200 larvae and 100 imagines per application were macerated and treated with fluorescent dye before investigation under a fluorescent microscope. We could detect up to 12 PA particles per individual larvae, while nearly no plastic was found in the imagines. This shows that, while Chaoborus sp. takes up microplastics via predation, most of the pollutant is egested through regurgitation and remains in the water, where it can further accumulate and potentially harm other organisms., Finanziert durch den Open-Access-Publikationsfonds der Westfälischen Wilhelms-Universität Münster (WWU Münster).

Crisis management is often conceived from the position of an omniscient narrator, albeit the general consensus that crises are subjectively interpreted and experienced. The paper makes an analytical attempt to de-homogenize the notion of crisis. We argue that the perception of crises differs and present a spatial perspective on crisis to foreground the positionality of different actor groups. By referring to the EHEC outbreak 2011 in Germany, we explore two spatial configurations that seem to be of particular relevance: territories embedded in a nested hierarchy and topologies of interconnected places. State authorities think and act strongly in terms of territorial borders and along sectoral boundaries. From their point of view, the crisis tends to be threatening due to its "transboundary" character. Medical experts, in contrast, coped with the crisis in trans-local networks of colleagues. For this group, the crisis was also an opportunity to substantially enhance professional knowledge.

Social, burrowing mammals such as prairie dogs, ground squirrels or marmots are keystone species in grassland ecosystems. Grasslands have been converted into cropland or pastures globally, yet it remains virtually unknown how this has affected the biogeography of burrowing mammals, as efficient, broad-scale survey methods are lacking. We aimed to test whether structures created by burrowing rodents can be reliably detected on publicly available, very-high-resolution satellite images, in order to assess rodent distribution and abundance. We identified burrows of Bobak marmot (Marmota bobak), a keystone burrowing steppe rodent, on 1300 randomly selected plots of 1 km diameter (78.53 ha) across the species’ range (~950 000 km²) in Kazakhstan and southern Russia using Google Earth and Bing images. We then used burrow occurrences and species distribution models to map marmot distribution. We assessed how marmot occurrence and density vary across land-use types. We also combined satellite-based burrow densities and ground-survey data to derive a new population estimate for the species across Kazakhstan. We mapped a total of 7425 burrows from the satellite imagery. Field visits at a subsample of burrows suggested that burrow occurrence was detected reliably. Broad-scale marmot distribution was mainly determined by summer rainfall, land use and elevation. Occurrence probability was highest on arable croplands, followed by abandoned croplands and grazed steppe. The current Bobak marmot population size for Kazakhstan was estimated at 6.1 (±2.4) million individuals. Our results demonstrate that publicly available, very-high-resolution images can be used to reliably map the distribution of burrowing mammals across large geographic scales. The observed and predicted distributions indicate that the Bobak's range has remained almost unchanged in Kazakhstan since the 1950s, despite several drastic episode of land-use change. This suggests that burrowing mammals can be remarkably resilient to land-use pressure, questioning prevailing narratives of population collapse in these species following agricultural expansion., Finanziert über die DEAL-Vereinbarung mit Wiley 2019-2022.

In Quellwasserproben rund um den Ringseitert-Vulkankomplex südöstlich der Gemeinde Kirchweiler (Westeifel) wurden weit über dem Geringfügigkeitsschwellenwert erhöhte Vanadiumkonzentrationen mit einem Maximalwert von 28 μg/l nachgewiesen. Generell zeigten die im Bereich der Känozoischen Vulkanite entnommenen Wasserproben erheblich höhere Konzentrationen als die im umliegenden Paläozoikum. Lokale Vulkanitproben weisen bis zu vierfach über dem Krustenmittel erhöhte Gesamtgehalte an Vanadium auf. Elutionsuntersuchungen ergaben eine erhöhte Vanadiumfreisetzung. Zur weiteren mikroanalytischen Suche nach der geogenen Quelle für diese Anomalie wurden Dünnschliffe der Gesteinsproben hergestellt und mittels Elektronenmikrosonde analysiert. Die Elementverteilungsbilder zeigten nicht die erwartete Korrelation zwischen den Elementen Fe und V, wohl jedoch eine Korrelation zwischen P und V. Hotspot-Analysen von V‑reichen Mineralkörnern weisen auf das Mineral Fluorapatit mit bis zu 5 Gew.-% Vanadat als Substitution für das Phosphat als geogene Vanadiumquelle in den Vulkaniten hin. Eine hydrogeochemische Modellierung mit PhreePlot zeigt übereinstimmend, dass die Wasserproben mit erhöhten Vanadiumkonzentrationen alle im pe/pH-Prädominanzfeld der Vanadat(V)-Komplexe liegen., Johannes Gutenberg-Universität Mainz (1030)

The stable isotope composition of lacustrine sediments is routinely used to infer Late Holocene changes in precipitation over Scandinavia and, ultimately, atmospheric circulation dynamics in the North Atlantic realm. However, such archives only provide a low temporal resolution (ca. 15 years), precluding the ability to identify changes on inter-annual and quasi-decadal timescales. Here, we present a new, high-resolution reconstruction using shells of freshwater pearl mussels, Margaritifera margaritifera, from three streams in northern Sweden. We present seasonally to annually resolved, calendar-aligned stable oxygen and carbon isotope data from 10 specimens, covering the time interval from 1819 to 1998. The bivalves studied formed their shells near equilibrium with the oxygen isotope signature of ambient water and, thus, reflect hydrological processes in the catchment as well as changes, albeit damped, in the isotope signature of local atmospheric precipitation. The shell oxygen isotopes were significantly correlated with the North Atlantic Oscillation index (up to 56 % explained variability), suggesting that the moisture that winter precipitation formed from originated predominantly in the North Atlantic during NAO+ years but in the Arctic during NAO− years. The isotope signature of winter precipitation was attenuated in the stream water, and this damping effect was eventually recorded by the shells. Shell stable carbon isotope values did not show consistent ontogenetic trends, but rather oscillated around an average that ranged from ca. −12.00 to −13.00 ‰ among the streams studied. Results of this study contribute to an improved understanding of climate dynamics in Scandinavia and the North Atlantic sector and can help to constrain eco-hydrological changes in riverine ecosystems. Moreover, long isotope records of precipitation and streamflow are pivotal to improve our understanding and modeling of hydrological, ecological, biogeochemical and atmospheric processes. Our new approach offers a much higher temporal resolution and superior dating control than data from existing archives.

Climate change causes more extreme droughts and heat waves in Central Europe, affecting vegetative fuels and altering the local fire regime. Wildfire is projected to expand into the temperate zone, a region traditionally not concerned by fire. To mitigate this new threat, local forest management will require spatial fire hazard information. We present a holistic and comprehensible workflow for quantifying fuels and wildfire hazard through fire spread simulations. Surface and canopy fuels characteristics were sampled in a small managed temperate forest in Northern Germany. Custom fuel models were created for each dominant species (Pinus sylvestris, Fagus sylvatica, and Quercus rubra). Canopy cover, canopy height, and crown base height were directly derived from airborne LiDAR point clouds. Surface fuel types and crown bulk density (CBD) were predicted using random forest and ridge regression, respectively. Modeling was supported by 119 predictors extracted from LiDAR, Sentinel-1, and Sentinel-2 data. We simulated fire spread from random ignitions, considering eight environmental scenarios to calculate fire behavior and hazard. Fuel type classification scored an overall accuracy of 0.971 (Kappa = 0.967), whereas CBD regression performed notably weaker (RMSE = 0.069; R2 = 0.73). Higher fire hazard was identified for strong winds, low fuel moisture, and on slopes. Fires burned fastest and most frequently on slopes in large homogeneous pine stands. These should be the focus of preventive management actions., Finanziert durch den Open-Access-Publikationsfonds der Westf��lischen Wilhelms-Universit��t M��nster (WWU M��nster).