Geodätische Pegelinformationen für Pegel entlang der Deutschen Küsten und Ästuaren. Die Informationen beinhalten geodätische Pegelinformationen der oben genannten Pegel. Dies beinhaltet in erster Linie die geometrischen Beziehungen zwischen Pegelfest- und Pegelnullpunkt. Mithilfe dieser Informationen können Staffel- und Pegelnullpunktsverschiebungen rückgängig gemacht werden. Zur vereinfachten Nutzung sind vorbereitete Korrekturzeitreihen im Datensatz enthalten.
Das Projekt "Element cycles in mountain regions under various land use" wird vom Umweltbundesamt gefördert und von Universität Bayreuth, Fachgruppe Geowissenschaften, Bayreuther Zentrum für Ökologie und Umweltforschung (BayCEER), Lehrstuhl für Agrarökosystemforschung durchgeführt. Research question: What is the role of agricultural land use in changes of nutrient cycles and losses dependingon surface slope and climate? Approach: Annual balance of main nutrients for 3-4 main agricultural farms based on fertilizer input, partitioning of nutrients in above and below ground plant parts, output with harvest, losses with DOM and erosion (in collaboration with other TP). The balances will be done depending on agricultural practices in Eger and Haean Catchment and will be compared with adjacent grassland and forest. Obtained element cycles will be upscaled from farm area to the level of both catchments basins depending on specific land use, surface slope and climate. Research question: Can we reconstruct previous erosion and nutrient losses and separate them under forest and under agricultural use? Approach: Undisturbed sediment cores (7 for Eger and 7 for Haean) will be taken from the lakes and soils of landscapes subordinated to agricultural fields. Three radiocarbon data of wood particles at increasing depth for each sediment core will be used as references. The age of the bottom sediment layer should be less than 1000 years. The total content of C, N, P, K, Mg, Ca, Si will be analyzed in individual laminae or sediment layers. Conclusions will be drawn based on the thickness of the laminae, their elements content and the ratio between nutrients and Si. The conclusions will be proven by 13C (vegetation change) and 15N (N input by fertilizers) of individual laminae. Research question: What are the best management practices for sloping uplands? Approach: Measured element cycles and losses under various agriculture practice will be analysed and practices with the least nutrient losses and erosion will be selected. The best management practices for landscapes with different slopes will be elaborated.
Das Projekt "Formation of brine channels in sea ice" wird vom Umweltbundesamt gefördert und von Fachhochschule Münster, Fachbereich Physikalische Technik durchgeführt. Within this interdisciplinary project the formation of brine channels in sea ice will be explored. The microscopic properties of sea ice, especially the permeability plays an important role for the energy exchange between ocean and atmosphere and is determined by the brine channel volume. The brine channel structure will be measured by computer tomography and image analysis. We intend to describe the channel structure by two phenomenological models, a morphogenesis approach of Alan Turing in connection with the phase transition theory of Ginzburg and Landau, and the phase field method with respect to the Cahn-Hilliard equation. We solve these nonlinear evolution equations in two and three dimensions and compare the size and texture of the brine channels with the measurements. In addition to the phenomenological equations we support our studies with molecular dynamics simulations and the density functional theory in order to obtain deeper insights at the molecular scale. Comparative first-principles studies will then enhance the trust in the extracted parameters and will lead to classical density functional for the two phases. We will discuss the phase transitions in terms of a phenomenological theory based on microscopic parameters and try to extract the underlying mechanism for the formation of water-ice boundaries. Specifically, we want to explore three theoretical questions: (i) How are ice-water melting fronts moving, (ii) How are brine channels formed and (iii) How do surface properties influence the structure formation of brine channels. The project is based on the experiences of three fields, the theoretical biological physics, chemical physics and the many-body theory. The final aim of the project is to provide input parameters for global climate models.
Das Projekt "Teilprojekt 2: Akustik" wird vom Umweltbundesamt gefördert und von Stiftung Alfred-Wegener-Institut für Polar- und Meeresforschung e.V. in der Helmholtz-Gemeinschaft (AWI) durchgeführt. Diel vertical migration and geographical distribution of our target organism krill (Euphausia superba, E. crystallorophias) but also other species e.g. myctophids, copepods (Calanus propinquus, Rhincalanus gigas), and other zooplankter (salps, pteropods, chaetognaths, amphipods) are detected by means of a four-split beam acoustic array (38, 72, 120, 200 kHz). Our major questions are: Do organisms migrate daily in relation to the light field, feeding conditions and/or to the predator field? Do populations of different species and/or different developmental stages of one species segregate in certain environmental conditions or different times of the year? How does the ocean current system influence the geographical distribution of zooplankton or krill populations? Is the geographical distribution of species subject to change and if so, what are the possible causes?
Das Projekt "Plant-soil interactions in changing rice cropping systems and their influence on C and N dynamics" wird vom Umweltbundesamt gefördert und von Universität Bonn, Institut für Nutzpflanzenwissenschaften und Ressourcenschutz - Pflanzenernährung (Prof. Werner) durchgeführt. Plant-soil interactions drive the input, cycling and losses of C and N in soil. This subproject aims at elucidating the input and fate of C in the soil-plant systems and its effect of N retention in soil under different paddy management (continuous vs. alternating with maize cropping). In particular we will investigate (i) how much of the assimilate C is released by the plants into the rhizosphere soil, and how this rhizodeposition is affected by N supply, soil density and crop variety during plant development, (ii) how the exudation of C and N responds to land use change, (iii) how C released into the rhizosphere affects the turnover of soil C and utilization of fertilizer N, and (iv) to what degree leaching contributes to the loss of C and N from the rooted surface soil. To answer these questions, we will combine the use of isotopic 13C and 15N labeling in laboratory and field experiments with a sophisticated characterization of root exudates, root border cells, and compound-specific isotope tracing in the residues of bacteria and fungi in rhizosphere, bulk soil as well as within different dissolved organic and inorganic carbon species in soil leachates. In this way and in collaboration with SP 2, 5, 6, and 7 of this research unit, our project links the cycling of C and N in paddy soils to one of its most prominent drivers, the release of organic compounds by roots.
Das Projekt "Phase 1: Earth and Space Based Power Generation Systems" wird vom Umweltbundesamt gefördert und von Deutsches Zentrum für Luft- und Raumfahrt, Institut für Technische Thermodynamik, Abteilung Systemanalyse und Technikbewertung durchgeführt. This study has to be understood in the frame of the global Energy Policy. A great part of world energy production is currently based on non-renewable sources: oil, gas and coal. Global warming and restricted fossil energy sources force a strong demand for another climate compatible energy supply. Therefore, fossil energy sources will nearly disappear until the end of this century. The question is to find a viable replacement. By using viable' it is meant a low-cost and environmental friendly energy. In other words, the question is to find an alternative to nuclear energy among all proposed but still not mature renewable energies. One of the solutions proposed is solar energy. Yet, two major concerns slow down its development as an alternative: first, it lacks of technological maturity and secondly it suffers from alternating supply during days and nights, winters and summers. The idea proposed by Glaser in the sixties to bypass this inconvenient is to take the energy at the source (or at least, as near as possible): in other words, to put a solar station on orbit that captures the energy without problems of climatic conditions and to redirect it through a beam to the ground. That is the concept of Solar Power Satellites. Its principal feasibility was shown by DOE / NASA in 1970 years studies (5 GW SPS in GEO). Project objectives: This phase 1 study activity is to be seen as the initial step of a series of investigations on the viability of power generation in space facing towards an European strategy on renewable, CO2 free energy generation, including a technology development roadmap pacing the way to establish in a step-wise approach on energy generation capabilities in space. The entire activity has to be embedded in an international network of competent, experienced partners. As part of this, an interrelationship to and incorporation of activities targeting the aims of the EU 6th FP ESSPERANS should be maintained. In particular, the activities related to following objectives are described: The generation of scientifically sound and objective results on terrestrial CO2 emission free power generation solutions in comparison with state-of-the-art space based solar power solutions The detailed comparison and trades between the terrestrial and the space based solutions in terms of cost, reliability and risk The identification of possible synergies between ground and space based power generation solutions The assessment on terrestrial energy storage needs by combining ground based with space based energy generation solutions The investigation of the viability of concepts in terms of energy balance of the complete systems and payback times.
Das Projekt "Tropical High Altitude Clouds and their Impact on Stratospheric Humidity" wird vom Umweltbundesamt gefördert und von Leibniz-Institut für Troposphärenforschung e.V. durchgeführt. Clouds play a key role in the Earth's climate system by regulation of the incoming and outgoing radiation, chemical and dynamical processes. Ice clouds at high altitudes in the tropics, the so called tropical tropopause layer, are particularly important since this is the main region where air ascends slowly from the troposphere into the dry stratosphere. Thus, these ice clouds affect the stratospheric water vapour content which in itself is a main driver of radiative and chemical processes, e.g. ozone depletion, there. These clouds can either be of convective nature, or occur in convective overshooting cloud turrets, or they form in situ by large scale upwelling and cooling as subvisible cirrus. Although the latter occur frequently, little is known about the exact microphysical formation mechanisms and how they can be maintained. Previous modelling efforts using various different mechanisms, however, have failed to agree with the observed properties. This project aims to improve our knowledge of the impact clouds in the tropical tropopause layer have on stratospheric humidity, by studying their formation, maintenance, and occurrence frequencies.A set of state-of-the-art numerical models will be used to simulate the clouds in the tropical tropopause layer, taking advantage of their particular strengths. These models are the Weather Research and Forecasting (WRF) Model, the GLObal Model of Aerosol Processes (GLOMAP), and the Australian Community Climate and Earth-System Simulator (ACCESS). First, the questions related to the formation and maintenance of subvisible cirrus will be addressed. In a second step the impact of subvisible cirrus and overshooting convection on the stratospheric humidity will be assessed. Both the direct effects (e.g. injection of ice particles into the stratosphere) and indirect effects (e.g. change in dynamical processes) will be studied. In order to estimate the net effect, occurrence frequencies of both cloud types will be derived from a complementary set of ground based remote sensing observations from the Darwin site and satellite observation from the International Satellite Cloud Climatology Project. The data of airborne in situ measurements which I analyzed during my PhD will help to constrain and test the model simulations. A better understanding of the complex processes related to the clouds in the tropical tropopause layer will improve their representation in numerical models and thus, enhance the quality of model predictions. This will improve our ability to constrain climate predictions due to highly uncertain ice cloud processes. Additionally, knowing the impact of these clouds on stratospheric humidity will enable an improved quantification of their climate impact.
Das Projekt "Transports and variability-driving mechanisms in Flemish Pass at the western boundary of the subpolar North Atlantic (FLEPVAR)" wird vom Umweltbundesamt gefördert und von Universität Hamburg, Fachbereich Geowissenschaften, Institut für Meereskunde durchgeführt. Labrador Sea Water (LSW) formed in the Labrador Sea constitutes the lightest contribution to North Atlantic Deep Water (NADW), a conglomerate of water masses that form the cold return flow of the Atlantic meridional overturning circulation (MOC). Climate variability can be modulated by changes in the MOC strength; such changes are thought to be linked to variations in LSW formation. The Deep Western Boundary Current (DWBC) is the main southward pathway for newly formed LSW. Topographic obstacles at the southern exit of the Labrador Sea split the DWBC into an upper branch carrying LSW through Flemish Pass (1200m sill depth) and a branch carrying all NADW components along the continental slope around Flemish Cap. Up to now, transports through Flemish Pass and their contribution to the MOC are still uncertain, the importance of the pass for the export of LSW and its associated variability are yet unknown. In this project the transports through Flemish Pass will be quantified, and mechanisms driving and governing the variability of the flow will be investigated. The project focuses on the following questions: What is the magnitude of transports for waters passing through Flemish Pass and their associated variability? Which processes drive the variability? What is the relevance of the deep water export through Flemish Pass for the MOC, especially when compared to the DWBC export? Are both deep water export pathways (through Flemish Pass or around Flemish Cap) coupled? What processes govern the inflow of deep water into Flemish Pass? To answers these questions, ship-based measurements and time series from moored instruments in the Flemish Pass will be analyzed in conjunction with output from two state-of-the-art Ocean models run at high-resolution.
Das Projekt "Effects of biochar amendment on plant growth, microbial communities and biochar decomposition in agricultural soils" wird vom Umweltbundesamt gefördert und von Forschungsinstitut für biologischen Landbau Deutschland e.V. durchgeführt. Biochar has a great potential to ameliorate arable soils, especially those that are low in organic matter due to intensive use or erosion. Biochar is carbonised organic material with high porosity that brings about changes in physical, chemical and biological soil functions. Biochar amended soils show a higher water and cation exchange capacity with reduced leaching and enhanced availability of plant nutrients. The microbial biomass in biochar amended soils is enhanced and more diverse. Biochar is stabilised organic material, which is likely to remain for hundreds of years in the soil. Photosynthetically fixed atmospheric CO2 stabilised in biochar may thus act as a direct carbon sink and help to mitigate climate change. As feedstock and production conditions produce different biochar qualities predictions of effects in soil need to consider biochar and soil properties case by case. To date biochar has been approved to ameliorate highly weathered tropical soils with positive effects on crop growth and yield. Distinct microbial groups were reported to be enhanced in soils but if this depends on the particular soil or biochar or a combination of both is an open question, especially in temperate climates. Likewise, it is not known if microorganisms colonising biochar surfaces are responsible for its mineralization or if they just use the new niches provided. The aim of the proposed project is to investigate the influence of two biochar types on soil-plant systems by determining i) soil nutrient availability, plant growth and nutrient uptake, ii) structure and function of soil microbial communities, iv) the decomposition and fate of biochar in soils. We will use two loessial soils from the well-known DOK-trial with different soil organic matter content. Other soils from the region will be selected to provide a wider range of soil quality, in particular pH. The biochars will be produced by pyrolysis and hydrothermal carbonization (HTC) from the C4-plant Miscanthus gigantea. Pyrolysis derived material has bigger pore sizes due to the evaporating gasses and is commonly alkaline, whereas the HTC derived biochar has a finer pore size, a much higher oxygen content and more acidic functional groups.
Das Projekt "BIOACID / BIOACID II - Biological Impacts of Ocean" wird vom Umweltbundesamt gefördert und von Universität zu Kiel, Institut für Volkswirtschaftslehre, Lehrstuhl für Umwelt-, Ressourcen- und Ökologische Ökonomik durchgeführt. Phase I: September 2009 - August 2012. Phase II: September 2012 - August 2015. BIOACID - Biological Impacts of Ocean Acidification, funded by the German Federal Ministry of Education and Research, deals with the questions of 1. What are the effects of ocean acidification on marine organisms and their habitat, 2. What are the underlying mechanisms of responses and possible adaptations on the level of populations and communities, how are they modulated by other environmental stressors, and 3. What are the consequences for marine ecosystems, ocean biogeochemical cycles, and possible feedbacks to the climate system? Our group will further develop the ecological-economic viability-method towards a general approach for integrated assessment of human actions influencing ocean acidification and the consequences for human well-being that takes uncertainties about future development into account.