Das Projekt "Der Einfluss der SML auf die Spurengasbiogeochemie und den Ozean-Atmosphäre-Gasaustausch" wird vom Umweltbundesamt gefördert und von Helmholtz-Zentrum für Ozeanforschung Kiel (GEOMAR), Forschungsbereich 2: Marine Biogeochemie durchgeführt. Labor- und Feldstudien zeigen, dass die Oberflächengrenzschicht des Ozeans (â€Ìsurface microlayerâ€Ì, kurz SML) die biogeochemischen Kreisläufe von klimaaktiven und atmosphärisch wichtigen Spurengasen wie Kohlenstoffdioxid (CO2), Kohlenstoffmonoxid (CO), Methan (CH4), Lachgas (N2O) und Dimethylsulfid (DMS) stark beeinflusst: (i) Jüngste Studien aus den PASSME- und SOPRAN-Projekten haben hervorgehoben, dass Anreicherungen von oberflächenaktiven Substanzen (d.h. Tensiden) einen starken (dämpfenden) Effekt sowohl auf die CO2- als auch auf die N2O-Flüsse über die SML/Atmosphären-Grenzfläche hinweg haben und (ii) Spurengase können durch (mikro)biologische oder (photo)chemische Prozesse in der SML produziert und verbraucht werden. Daher kann der oberste Teil des Ozeans, einschließlich der SML, verglichen mit dem Wasser, das in der Mischungsschicht unterhalb der SML zu finden ist, eine bedeutende Quelle oder Senke für diese Gase sein, was von sehr großer Relevanz für die Forschungseinheit BASS ist. Die Konzentrationen von CO2, N2O und anderen gelösten Gasen in der SML (oder den oberen Zentimetern des Ozeans) unterscheiden sich nachweislich von ihren Konzentrationen unterhalb der SML. Typischerweise werden die Nettoquellen und -senken wichtiger atmosphärischer Spurengase mit Konzentrationen berechnet, die in der Mischungsschicht gemessen wurden und mit Gasaustauschgeschwindigkeiten, die die SML nicht berücksichtigen. Diese Diskrepanzen führen zu falsch berechneten Austauschflüssen, die in der Folge zu großen Unsicherheiten in den Berechnungen der Klima-Antrieben und der Luftqualität in Erdsystemmodellen führen können. Durch die Verknüpfung unserer Spurengasmessungen mit Messungen von (i) der Dynamik und den molekularen Eigenschaften der organischen Materie und speziell des organischen Kohlenstoffs (SP1.1; SP1.5), (ii) der biologischen Diversität und der Stoffwechselaktivität (SP1.2), (iii) den optischen Eigenschaften der organischen Materie (SP1.3), (iv) der photochemischen Umwandlung der organischen Materie (SP1.4) und (v) den physikalischen Transportprozessen (SP2.3) werden wir ein umfassendes Verständnis darüber erlangen, wie die SML die Variabilität der Spurengasflüsse beeinflusst.
Das Projekt "Support to Member States in improving waste management based on assessment of Member States' performance" wird vom Umweltbundesamt gefördert und von BIPRO Beratungsgesellschaft für integrierte Problemlösungen GmbH durchgeführt. Implementation of EU waste legislation shows large differences in the EU Member States especially with regard to municipal waste management. Major discrepancies prevail particularly in the implementation and application of the Waste Framework Directive and proper transposition of EU requirements into national legislation. The waste management performance of all EU Member States was subject to screening to identify those Member States with the largest implementation gaps, in particular in relation to municipal waste management. For screening the main elements and legal requirements stemming from EU waste directives (mainly from the Waste Framework and the Landfill Directive) were considered for the design of suitable criteria. These core elements comprise the practical implementation of the waste management hierarchy, application of economic and legal instruments to move up the waste hierarchy, sufficiency of treatment infrastructure and quality of waste management planning, the fulfilment of targets and infringement procedures. These elements were assessed by 18 criteria for each Member State taking into account information sources at EU, national or regional level. Latest available statistical data and data of former years for comparison of development within a country were extracted from the EUROSTAT database. References comprised reports published by the European Commission, the European Topic Centre on Sustainable Consumption and Production, internal working documents of EUROSTAT and the EU Commission as well as national/regional Waste Management Plans. Where available also Waste Prevention Programmes were screened. The screening results confirmed the assumption of large differences within the EU-27 with regard to treatment of municipal waste, compliance with the WFD and Landfill Directives and application of legal or economic instruments as well as planning quality. For each criterion two, one or zero points could be achieved, leading to maximum points of 42 for all criteria. The methodology includes weighting of results for three selected criteria related to the application of the treatment options recycling, energy recovery and disposal of municipal waste.
Das Projekt "Discrepancy between long-term trends of the 10Be- and 14C-inferred radionuclide production rate: Likely reasons and implications" wird vom Umweltbundesamt gefördert und von Universität Heidelberg, Institut für Umweltphysik durchgeführt. The atmospheric production rate of cosmogenic radionuclides depends on the variable shielding effects of cosmic rays by the solar activity and the geomagnetic field intensity. The history of these production rate changes can be basically inferred from 14C tree ring/sediment records as well as from 10Be archived in polar ice cores. However, while both reconstruction efforts agree fairly well in view of their decadal to centennial variability, they systematically deviate, for unknown reasons, on the millennia time scale, particularly in the early Holocene and late Glacial. The project aims at pinning down the main reasons for this apparent inconsistency by combining a global carbon cycle model with an atmospheric 10Be cycle model, supported by an air/firn transfer module. This innovative attempt comprises the extension of an existing carbon cycle box model to the simulation of aerosol-borne radionuclides, backed up by novel 10Be and 7Be aerosol data as well as dedicated sensitivity studies. Thereby, the various impacts of non-production related changes on the 14C and 10Be archive data shall be investigated, focusing on possible long term changes, related to the carbon and to the atmospheric 10Be cycles. Final evaluation of the results aims at depicting realistic scenarios, which allow to reduce the reconstruction mismatch, and thus, to improve the understanding of past cosmogenic production rate changes.
Das Projekt "Standortskarte des Nationalparks Berchtesgaden" wird vom Umweltbundesamt gefördert und von Technische Universität München, Fachgebiet Geobotanik durchgeführt. The goal of the project is to establish a site map of the Berchtesgaden Nationalpark on the basis of existing information and maps. The following information has to be integrated into the site map: soil, vegetation, geologic and geomorphic maps as well as existing climatic data from the weather stations in the park as well as weather information from the German and Austrian weather service as well as from forest-inventory data gathered in 1983/84 and 1995/97. During the first year of the project the existing information was checked, links between existing data established and plausibility checks tested and documented. Where necessary checks were made on the original data and corrections made. Subsequently the soil types were classified according to substrate groups and the necessary climatic parameters from the nationalpark weather stations compiled and as available, integrated into the soil information over the area of the park. Further climatic parameters still need to be analyzed and be integrated into the map. Combining the soil map with the vegetation map or the forest inventory map of the nationalpark brought large discrepancies with the geometry of the soils map to light. In order to bring out a meaningful interface between the existing information and the soils map considerable refitting of the data must be carried out. Since this time consuming work was not expected at the beginning of the project, the project has been extended for 4 months in agreement with the administration of the Nationalpark Berchtesgaden.
Das Projekt "Model coupling and complex structures - Investigating transfer fluxes induced by turbulent free flow and affected by multiphase processes in porous media" wird vom Umweltbundesamt gefördert und von Universität Stuttgart, Institut für Wasser- und Umweltsystemmodellierung durchgeführt. Flow and transport processes in domains composed of a porous medium and an adjacent free-flow region appear in a wide range of industrial, medical and environmental applications. Our focus is on evaporation from unsaturated soils under influence of a turbulent free flow. The modeling of such coupled systems is a challenging task especially at the interface of the two domains. In preliminary work a REV-scale model has been developed, which couples the Navier-Stokes equation for the free flow with the Darcy equation for the porous-medium flow. It is possible to simulate the evaporation processes for non-isothermal, laminar conditions and a multiphase, multicomponent flow. However, there is a discrepancy between the simulated evaporation rates and rates which have been measured in lab experiments. Therefore the model will be extended with RANS turbulence models. The vision is to develop a model which can reproduce the complex interaction between the two domains and predict the exchange fluxes. This is achieved with a numerical stable description for the turbulent free flow and by gaining inside into the complex processes at the interface. Different scenarios will be analyzed with respect to the required model complexity aiming at a 'intelligent interface' description and an improved modeling on the field scale.
Das Projekt "Berücksichtigung von Lebensdauern von Tracern bei der Bestimmung des stratosphaerischen Luftalters und der Brewer-Dobson-Zirkulation (CoLiBri)" wird vom Umweltbundesamt gefördert und von Karlsruher Institut für Technologie (KIT), Institut für Meteorologie und Klimaforschung - Atmosphärische Spurenstoffe und Fernerkundung (IMK-ASF) durchgeführt. Die Intensität der Brewer-Dobson-Circulation wird üblicherweise charakterisiert durch das sogenannte mittlere stratosphärische Luftalter, d.h. durch die Zeit, die ein Luftpaket benötigt, um vom stratosphärischen Eintrittspunkt zu dem Ort zu gelangen, wo es beobachtet wurde. Diese Zeit wird abgeschätzt durch Konzentrationsmessungen langlebiger Spurengase, die einen troposphärischen Trend aufweisen. Besonders geeignet hierfür ist SF6, da es keine stratosphärischen Senken hat. Dennoch gibt es mit dieser Standardmethode Probleme: Zum einen hat SF6 eine mesosphärische Senke, so dass das stratosphärische Luftalter im Fall von Eindringen mesosphärischer Luft zu alt geschätzt wird. Zum anderen unterliegt das beobachtete Luftpaket auf dem Weg vom Eintrittspunkt zum Beobachtungspunkt Mischungsprozessen, die dazu führen, dass das Luftalter nicht klar definiert ist, sondern stattdessen durch ein Altersspektrum charakterisiert werden muss. Unsicherheiten in der Form des Altersspektrums bewirken Unsicherheiten bei der Umrechnung der gemessenen SF6 Mischungsverhältnisse in Luftalter. Um diesen Problemen zu begegnen, wurde eine neue Methode entwickelt, die die Zirkulationsvektoren und Mischungskoeffizienten einer zonal gemittelten Atmosphäre durch die Inversion der Kontinuitätsgleichung direkt aus den an zwei Zeitpunkten gemessenen Dichte- und Spurengasverteilungen ableitet. Wenn die beiden Zeitpunkte hinreichend nahe beieinander liegen, sind Senkenprozesse weitgehend unschädlich, da der bis zum ersten Zeitpunkt geschehene Abbau irrelevant ist. Das lässt das Problem der mesosphärischen Intrusionen und macht den Weg frei zu Verwendung von Spurengasen, die langsamem stratosphärischen Abbau unterliegen. Da die Morphologie der Verteilungen verschiedener solcher Gase (CH4, N2O, CFCs, etc) unterschiedlich ist, steht damit mehr unabhängige Information fär die Lösung des Inversionsproblems zur Verfägung. Ebenso ist das Altersspektrum kein Problem mehr, da Mischungsprozesse vor dem Anfangszeitpunkt irrelevant sind. Im Gegensatz zur Luftaltersmethode erhält man mit der neuen Inversionsmethode zeitlich aufgelöste Information über die stratosphärische Zirkulation. Die Methode wurde auf MIPAS-Spurengasverteilungen angewendet, die in diesem Projekt validiert wurden. Die zweidimensionale Kontinuitätsgleichung wird mit dem MacCormack-Verfahren integriert, um aus den Anfangsdichte- und Mischungsverhältnisverteilungen die Endverteilungen bei gegebenen Anfangsschätzwerten der Geschwindigkeiten und Mischungskoeffizienten zu berechnen. Das Residuum zwischen diesen und den am zweiten Zeitpunkt gemessenen Werten wird minimiert, indem die verallgemeinerte Inverse der Jacobi-Matrix berechnet wird. Letztere beschreibt die Abhängigkeit der Endverteilungen von den Geschwindigkeiten und Mischungsverhältnissen...
Das Projekt "Overlap and discrepancies between ecotypes, genotypes and morphotypes of Antarctic and Arctic nanofauna" wird vom Umweltbundesamt gefördert und von Universität Köln, Institut für Zoologie, Biozentrum Köln, Arbeitsgruppe Allgemeine Ökologie durchgeführt.
Das Projekt "Catchment classification and regionalisation with Self-Organising Maps (SOMs) and flexible model structures" wird vom Umweltbundesamt gefördert und von Universität Trier, Fachbereich VI Raum- und Umweltwissenschaften, Fach Physische Geographie durchgeführt. The major research objective of the project is catchment classification with a view to regionalization. Three different clustering methods serve as a basis for catchment classification: Self Organising Maps (SOMs), a benchmark conceptual model and the SUPERFLEX modelling framework. We will classify catchments by runoff behaviour and by hydroclimatic and physiographic properties. The project will use data from approximately 100 catchments in western Germany. Next, the classification methods will be compared and based on the best classification method we will regionalize runoff and model parameters to test its suitability for regionalization.Catchment classification as well as regionalization will be used to gain insight into the functioning of meso-scale river basins: to uncover resemblances and discrepancies, to interpret their hydrological behaviour and to provide meaningful data-backed-up hypothesis. Furthermore, we will develop auto-mated procedures of our methods and assemble them into a toolbox, which can be used by a wide group of users. This study will strive for a dual approach: firstly, to implement novel clustering methods with a view to regionalization and secondly, to stimulate the ongoing and highly relevant discussion on catchment classification and regionalisation.
Das Projekt "First-principles kinetic modeling for solar hydrogen production" wird vom Umweltbundesamt gefördert und von Technische Universität München, Fakultät für Chemie, Lehrstuhl für Theoretische Chemie durchgeführt. The development of sustainable and efficient energy conversion processes at interfaces is at the center of the rapidly growing field of basic energy science. How successful this challenge can be addressed will ultimately depend on the acquired degree of molecular-level understanding. In this respect, the severe knowledge gap in electro- or photocatalytic conversions compared to corresponding thermal processes in heterogeneous catalysis is staggering. This discrepancy is most blatant in the present status of predictive-quality, viz. first-principles based modelling in the two fields, which largely owes to multifactorial methodological issues connected with the treatment of the electrochemical environment and the description of the surface redox chemistry driven by the photo-excited charges or external potentials.Successfully tackling these complexities will advance modelling methodology in (photo)electrocatalysis to a similar level as already established in heterogeneous catalysis, with an impact that likely even supersedes the one seen there in the last decade. A corresponding method development is the core objective of the present proposal, with particular emphasis on numerically efficient approaches that will ultimately allow to reach comprehensive microkinetic formulations. Synergistically combining the methodological expertise of the two participating groups we specifically aim to implement and advance implicit and mixed implicit/explicit solvation models, as well as QM/MM approaches to describe energy-related processes at solid-liquid interfaces. With the clear objective to develop general-purpose methodology we will illustrate their use with applications to hydrogen generation through water splitting. Disentangling the electro- resp. photocatalytic effect with respect to the corresponding dark reaction, this concerns both the hydrogen evolution reaction at metal electrodes like Pt and direct water splitting at oxide photocatalysts like TiO2. Through this we expect to arrive at a detailed mechanistic understanding that will culminate in the formulation of comprehensive microkinetic models of the light- or potential-driven redox process. Evaluating these models with kinetic Monte Carlo simulations will unambiguously identify the rate-determining and overpotential-creating steps and therewith provide the basis for a rational optimization of the overall process. As such our study will provide a key example of how systematic method development in computational approaches to basic energy sciences leads to breakthrough progress and serves both fundamental understanding and cutting-edge application.
Das Projekt "Steady-State Dilution and Mixing-Controlled Reactions in Three-Dimensional Heterogeneous Porous" wird vom Umweltbundesamt gefördert und von Eberhard Karls Universität Tübingen, Zentrum für Angewandte Geowissenschaften (ZAG), Arbeitsgruppe Hydrogeology durchgeführt. Understanding transport of contaminants is fundamental for the management of groundwater re-sources and the implementation of remedial strategies. In particular, mixing processes in saturated porous media play a pivotal role in determining the fate and transport of chemicals released in the subsurface. In fact, many abiotic and biological reactions in contaminated aquifers are limited by the availability of reaction partners. Under steady-state flow and transport conditions, dissolved reactants come into contact only through transverse mixing. In homogeneous porous media, transverse mixing is determined by diffusion and pore-scale dispersion, while in heterogeneous formations these local mixing processes are enhanced. Recent studies investigated the enhancement of transverse mixing due to the presence of heterogeneities in two-dimensional systems. Here, mixing enhancement can solely be attributed to flow focusing within high-permeability inclusions. In the proposed work, we will investigate mixing processes in three dimensions using high-resolution laboratory bench-scale experiments and advanced modeling techniques. The objective of the proposed research is to quantitatively assess how 3-D heterogeneity and anisotropy of hydraulic conductivity affect mixing processes via (i) flow focusing and de-focusing, (ii) increase of the plume surface, (iii) twisting and intertwining of streamlines and (iv) compound-specific diffusive/dispersive properties of the solute species undergoing transport. The results of the experimental and modeling investigation will allow us to identify effective large-scale parameters useful for a correct description of conservative and reactive mixing at field scales allowing to explain discrepancies between field observations, bench-scale experiments and current stochastic theory.
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