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Halogen activation in the plume of Masaya volcano: field observations and box model investigations
2020
Volcanic emissions are a source of halogens in the atmosphere. Rapid reactions convert the initially emitted hydrogen halides (HCl, HBr, and HI) into reactive species such as BrO, Br2, BrCl, ClO, OClO, and IO. The activation reaction mechanisms in the plume consume ozone (O3), which is entrained by ambient air that is mixed into the plume. In this study, we present observations of the oxidation of bromine, chlorine, and iodine during the first 11 min following emission, examining the plume from Santiago crater of the Masaya volcano in Nicaragua. Two field campaigns were conducted: one in July 2016 and one in September 2016. The sum of the reactive species of each halogen was determined by g…
Development of a Method for Anodic Degradation of Lignin for the Analysis of Paleo‐Vegetation Proxies in Speleothems
2022
From omniscient narrator to involved participants: Places and spaces “activated” in the EHEC O104:H4 crisis 2011
2020
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 sector…
Opposite trends in Holocene speleothem proxy records from two neighboring caves in Germany : a multi-proxy evaluation
2021
Chemistry-climate interactions of aerosol nitrate from lightning
2016
Abstract. Lightning represents one of the dominant emission source for NOx in the troposphere. The direct release of oxidised nitrogen in the upper troposphere does not only affect ozone formation, but also chemical and microphysical properties of aerosol particles in this region. This study investigates the direct impact of LNOx emissions on upper tropospheric nitrate using a global chemistry climate model. The simulation results show a substantial influence of the lightning emissions on the mixing ratios of nitrate aerosol in the upper troposphere of more than 50%. In addition to the impact on nitrate, lightning substantially affects the oxidising capacity of the atmosphere with substanti…
Dynamic pressure variations in the lower crust caused by localized fluid-induced weakening
2022
When continents collide, the Earth’s crust experiences structural and metamorphic transformations that control the geodynamic evolution of the orogen. Metamorphism of dry, lower crust requires fluid supply and produce mechanically weaker rocks. Metamorphism is often localized in shear-zones, which provide the available fluid pathways. Several field-based studies show that shear zone development is preceded by brittle faults, frequently portraying evidence for seismic slip rates and introduction of externally derived fluids. However, despite the extensive documentation of lower crustal metamorphism and associated deformation features, a unifying model coupling deformation to fluid …
Combining inorganic and organic carbon stable isotope signatures in the Schwalbenberg Loess-Palaeosol-Sequence near Remagen (Middle Rhine valley, Ger…
2020
Western Central European Loess-Palaeosol-Sequences (LPS) provide valuable terrestrial records of palaeoenvironmental conditions, which formed in response to variability in the North Atlantic climate systems. Over the last full glacial cycle (∼130 ka), climate oscillations within these systems are best documented in deep sea- and ice cores; the responses of terrestrial systems are not yet fully understood. A better understanding of metabolism governing input and output variables of organic- and inorganic C pools is, however, crucial for investigating landscape-atmospheric feedback processes and in particularly, for understanding the formation of calcareous LPS as environmental archives. Here…
Hallazgos Mas dIs Foso 4
2012
Troballes al foso 4 del Mas d'Is
Análisis funcional de utillaje sobre caliza del nivel XII (MIS 6) de la Cova del Bolomor (Tavernes de la Valldigna, Valencia). Estudio experimental y…
2016
En el trabajo se analiza desde el punto de vista funcional un conjunto de materiales líticos del nivel XII de la Cova del Bolomor (Tavernes de la Valldigna, Valencia), compuesto en su mayoría por utillaje sobre lasca realizado en caliza.El tema de las tesis presenta, por tanto, dos ámbitos de investigación. Por un lado, y a través del análisis de las huellas de uso del material lítico de la Cova del Bolomor, proceder a la identificación de los aspectos funcionales de los útiles, los cuales pueden contribuir a la caracterización de las diferentes ocupaciones de la cueva, y suponen un avance en el conocimiento de las formas de vida de los grupos humanos del Pleistoceno Medio.Este estudio pres…
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