ALBERT

Description: Institutions for biodiversity governance are located at the interface of human and ecological systems. The analysis of such institutions is challenged due to addressing a multitude of complex interactions between these two systems occurring at different natural scales and levels of human organization. Due to this complexity, empirical analysis of biodiversity management often leads to context-specific explanations, providing little scope for comparative work or the development of more generalised, theory-based accounts. We aim at reducing complexity in understanding human-biodiversity relations, making cases comparable across sites, and propose that, in order to address complexity, we need a method of abstraction that leads to the development of a more structured analysis, based on selection of explanatory factors according to cconceptual models as well as empirical significance. We suggest that the stylisation of typical "resource use-perspectives" - the combination of typical transactions that are inextricably linked by the interest of the actor - can be a useful method for realizing appropriate model selection. In this paper, we provide an account of how use-perspectives can be developed and to what kind of analysis they can contribute, using the example of agrobiodiversity in grain as seed, food, or genetic material.

Description: Abstract. It has been claimed for more than a century that atmospheric new particle formation is primarily influenced by the presence of sulfuric acid. However, the activation process of sulfuric acid related clusters into detectable particles is still an unresolved topic. In this study we focus on the PARADE campaign measurements conducted during August/September 2011 at Mt Kleiner Feldberg in central Germany. During this campaign a set of radicals, organic and inorganic compounds and oxidants and aerosol properties were measured or calculated. We compared a range of organic and inorganic nucleation theories, evaluating their ability to simulate measured particle formation rates at 3 nm in diameter (J3) for a variety of different conditions. Nucleation mechanisms involving only sulfuric acid tentatively captured the observed noon-time daily maximum in J3, but displayed an increasing difference to J3 measurements during the rest of the diurnal cycle. Including large organic radicals, i.e. organic peroxy radicals (RO2) deriving from monoterpenes and their oxidation products, in the nucleation mechanism improved the correlation between observed and simulated J3. This supports a recently proposed empirical relationship for new particle formation that has been used in global models. However, the best match between theory and measurements for the site of interest was found for an activation process based on large organic peroxy radicals and stabilised Criegee intermediates (sCI). This novel laboratory-derived algorithm simulated the daily pattern and intensity of J3 observed in the ambient data. In this algorithm organic derived radicals are involved in activation and growth and link the formation rate of smallest aerosol particles with OH during daytime and NO3 during night-time. Because the RO2 lifetime is controlled by HO2 and NO we conclude that peroxy radicals and NO seem to play an important role for ambient radical chemistry not only with respect to oxidation capacity but also for the activation process of new particle formation. This is supposed to have significant impact of atmospheric radical species on aerosol chemistry and should be taken into account when studying the impact of new particles in climate feedback cycles.

Description: Variations in the poleward-directed Atlantic heat transfer was investigated over the past 135ka with special emphasis on the last and present interglacial climate development (Eemian and Holocene). Both interglacials exhibited very similar climatic oscillations during each preceding glacial terminations (deglacial TI and TII). Like TI, also TII has pronounced cold-warm-cold changes akin to events such as H1, Blling/Allerd, and the Younger Dryas. But unlike TI, the cold events in TII were associated with intermittent southerly invasions of an Atlantic faunal component which underscores quite a different water mass evolution in the Nordic Seas. Within the Eemian interglaciation proper, peak warming intervals were antiphased between the Nordic Seas and North Atlantic. Moreover, inferred temperatures for the Nordic Seas were generally colder in the Eemian than in the Holocene, and vice versa for the North Atlantic. A reduced intensity of Atlantic Ocean heat transfer to the Arctic therefore characterized the Eemian, requiring a reassessment of the actual role of the ocean-atmosphere system behind interglacial, but also, glacial climate changes.

Description: The use of fossil hydrocarbons in the energy and transport sectors is a major source of greenhouse gas emissions. It also ties our society to ever dwindling reserves. Synthetic fuels could play a crucial role in establishing a carbon neutral energy supply.