Das Projekt "Exzellenzcluster 80 (EXC): Ozean der Zukunft" wird vom Umweltbundesamt gefördert und von Leibniz-Institut für Troposphärenforschung e.V. durchgeführt. 95% of the incoming solar radiation at the sea surface is absorbed by the ocean body. This process is an integral part of the oceanic heat budget, drives most of the global biological production and, thus, almost all major nutrient and carbon cycles in the ocean. This emphasizes the need of a proper understanding of the transport of solar radiation into the ocean. While previous research has been devoted to the mean energy input by solar radiation into the ocean, effects of the temporal and spatial fluctuations of the incoming solar radiation including its distribution with depth are poorly known, although certainly of large importance. Such fluctuations are caused by variations in the atmospheric transmission, sea surface roughness and spray, turbulent fluctuations in density, plankton, gelbstoff and other biological parameter. Since both the radiative transfer and the physical, biological and chemical response in the upper ocean are non-linear processes, temporal and spatial variability in the radiation yields a systematically different mean response compared to more homogeneous forcing. An existing Monte-Carlo radiative transfer code will be modified to simulate variability in light penetration through observed and simulated physical and biological states of the upper ocean. The results will be applied to ocean circulation models and to models of biological and chemical tracer cycles. Furthermore, the effect of radiation variability on algal physiology, i.e. photosynthetic performance and physiological acclimation, will be explored.
Das Projekt "Globales Klima und CO2: Die Rolle der Ozeanzirkulation" wird vom Umweltbundesamt gefördert und von Max-Planck-Institut für Meteorologie durchgeführt. Objective: To enhance our understanding of the role of ocean circulation changes in controlling the equilibrium concentration of carbon dioxide in the atmosphere. General information: The data from Cambridge and gif-sur-yvette will constitute an unique data base to compare with the simulations provided by the Hamburg ocean GCM. The modelling project planned by the MPI consists of the following activities: 1) computation of the mean ocean circulation for the various climatic epochs (18000 b.p., last glacial to interglacial transition, 125000 b.p.) using reconstructed or assumed boundary values as input data. 2) sensitivity studies to determine the sensitivity of computed ocean circulation states on boundary values (e.g. extent of sea ice, wind forcing, air temperature, fresh water influx from glacier) and on parametrization of physical processes (e.g. deep water formation). 3) repeat of the studies (1) and (2) with the ocean carbon cycle model to estimate earlier CO2 levels in the atmosphere and ocean, 13c/12c ratios,.....(the m.p.i. model is based on a 7 component carbon chemistry plus phytoplancton, detritus, nutrient and oxygen). 4) theoretical and numerical model studies of the interactions between ice sheets, ocean, atmosphere and the carbon cycle to ascertain the inherent stability or instability of the coupled system on a 10 3 to 10 5 time scale. These studies will include milankovitch and stochastic forcing. The goal is to test various published hypothesis and possibly gain new insights into the causes of climate variability on these time scales.
Das Projekt "Sub project: Climatic impact on temperature and mixing regime of polymictic lakes and its consequences for lake ecosystems" wird vom Umweltbundesamt gefördert und von Forschungsverbund Berlin, Leibniz-Institut für Gewässerökologie und Binnenfischerei durchgeführt. The project aims at estimation of the freshwater lakes response to possible climatic changes. The study is focused on characteristics of vertical mixing in small or polymictic lakes (i.e., those mixed till the bottom at least once during summer heating periods), which are majority of the European lakes. Special attention is to be paid to possible climatically-driven switching of the lake mixing regime between polymictic and dimictic ones that would effect drastically the lake's ecolopy. As a result, criteria will be elaborated, associating possibility of such regime transition with existing climatic trends. A shallow lake physical model will be developted for this purpose, describing mixing and heat exchange processes in the entire sediments-water-ice system. Parameterization of lake morphometry in frames of one-dimensional modeling approach is foreseen as an important result of the project. Subsequent model experiments and comprehensive data analysis will allow determinling the relation between annual micing cycle, climatic conditions and lake morphometry. The second step will consist in analysis of possible changes in hydrological regime of German lakes based on atmospheric input from the modern climatic scenarios for the next 50 years. Thus, a background will be created for estimation of shallow lake ecosystem response to variability in atmospheric forcing on climatic scales. Intergration of the new physical model into the shallow lake ecosystem model EMMO will be performed and first estimations of climatic changes impact on lake biologcial communities will be given.
Das Projekt "Teilprojekt 2: Modellierung der Methanemissionen von Feucht- und Permafrostgebieten mit Hilfe von LPJmL" wird vom Umweltbundesamt gefördert und von Potsdam-Institut für Klimafolgenforschung e.V. durchgeführt. The overarching goal during the first four years is to interactively simulate the full methane cycle during deglaciation within the model CLIMBER-LPJmL. This includes the simulation of natural wetlands as the largest natural source of methane within the land surface models, as well as the simulation of the atmospheric sink where methane is oxidized to CO2. Using these two components, the atmospheric concentration of methane will be determined, allowing a comparison to proxy data from ice cores. The transient simulation of climate changes from last glacial maximum to present day including a fully interactive methane cycle has never been attempted before. If successful, this will substantially improve the knowledge on patterns of methane emissions under a wide range of climate states, as well as the atmospheric sink of methane under a variety of boundary conditions. This goal will require a fully interactive model simulation of both sources and sinks of methane. Scientific questions to be investigated include - How can we explain the 75% increase in atmospheric methane between LGM and early Holocene? - What caused the large fluctuations in atmospheric methane during the YD/BA? - How does the distribution of methane sources change between LGM and Holocene? - How do the changes in climate affect the atmospheric oxidation of methane? The postdoc will be responsible for the integration and calibration of permafrost carbon cycle, wetland carbon accumulation and wetland methane emission routines in LPJmL. While the seamless integration of these routines remains a challenge requiring considerable expertise, the development for LPJmL is considerably more advanced than for JSBACH. Therefore less time is required for implementation and integration, making development on a 75% position feasible. Nontheless, the computational tasks in the project are very ambitious. Throughout the project a substantial number of model experiments will have to be carried out for model development and validation, and the sensitivity experiments envisaged will be close to computational limits.
Das Projekt "Teilprojekt 2" wird vom Umweltbundesamt gefördert und von AUD Analytik- und Umweltdienstleistungs GmbH durchgeführt. Die direkte und indirekte Einleitung salzhaltiger Wässer in die Vorflut stellt eine erhebliche ökologische Beeinträchtigung der Oberflächengewässer dar und führt in Folge dessen zu einer zunehmenden Grundwasser- und Bodenversalzung. Dies wiederum zieht eine ganze Reihe weiterer Probleme, wie z.B. die Beeinträchtigung der Trinkwassergewinnung aus den oberflächennahen Grundwasserleitern, nach sich. Das Konsortium beabsichtigt deshalb Thermalwassermanagementkonzept zu entwickeln, das es den Nutzern geothermalen Wassers erlaubt, ihren Energiebedarf zu senken, den Restenergiebedarf weitestgehend durch regenerative Energien zu decken und den Schadstoff-Output auf kostengünstige Weise zu minimieren. Dieses Software-basiertes Entscheidungsunterstützungssystem auf der Basis eines Ökobilanzmodells soll die Berechnung standortspezifischer und variantenabhängiger Wärmestrom-, Stoffstrom-, Energie- und Wirtschaftlichkeitsbilanzen ermöglichen. Arbeitsteilung 3 spezialisierter Firmen und einer Hochschule mit folgenden Schwerpunkten: 1. Recherche aller relevanter Daten, 2. Datenauswertung und Modellvorbereitung, 3. Erarbeitung des Konzeptes zum umweltgerechten Kreislaufmanagement salzhaltiger Wässer, 4. , Durchführung und Auswertung Projekt -begleitender Versuche (Laborversuche, Freilandtests, Ökologisch-ökonomisches Bilanzmodell) und 5. Präsentation/Dokumentation der Ergebnisse. Arbeitsplan mit Meilensteinen, die auf den vierteljährlichen Projekttreffen (Pflichtenhefte) abgeglichen werden.
Das Projekt "Dynamic of Matter Transfer and Biogeochemical Cycles: Their Modelling in Coastal Systems of the Mediterranean Sea" wird vom Umweltbundesamt gefördert und von Universität Kiel, Geologisch-Paläontologisches Institut und Museum durchgeführt. General Information/Objectives: The project Metro-Med aims to study and model the key processes of matter transfer (exchange and storage) and the biogeochemical cycles in the coastal zone system. Contents: The functioning of the coastal environment, the factors that control the inflow and the transfer of matter in the marine ecosystem and the fluxes between the different compartments of the coastal zone (mixed zone fresh water/saline water, normal marine water, benthic nepheloid layer (BNL), bottom sediment) will be studied. The estimation of the environmental capacity of the coastal zone regarding the anthropogenic inputs mainly from the rivers, and the understanding and description of the main processes controlling the cycles of organic carbon, nutrients and trace elements in the coastal environment will be approached. These processes will be studied in two sites in the Mediterranean Sea: a) Thermaikos Gulf in Northern Greece; b) Gulf of Lions in Southern France. The project is structured in five main tasks: Task 1: the processes of matter transfer in the fresh/salt water interface; Task 2: the transfer of suspended particulate matter and the resuspension processes in the shelf environment; Task 3: biogeochemical cycles; Task 4: data management, GIS, socio-economic approach; Task 5: synthesis and integration of results of mechanistic modelling, prognostic modelling and field and laboratory measurements - feasibility assessment of model transfer. The linking between the study of the natural processes and the socio-economic development will be approached, too. The various hydro dynamical models, available to the participants in the corresponding tasks, will be extended so that matter transfer and biogeochemical processes at the appropriate spatial and temporal scales will be included. Technical approach: For the implementation of the scientific objectives, 'conventional' methods and 'conventional' equipment, advanced techniques (for laboratory and field experiment) as well as new observational and sample technology will be used. The processes of matter transfer and of the biogeochemical cycles will be described with process-based models. Modelling will be implemented in conjunction with a data base - data management system and with the use of GIS-techniques. Achievements: It is aimed to produce new environmental data, to use all the existing and available data and to model the processes of matter transfer and the biogeochemical processes in the coastal environment. Prime Contractor: National Centre for Marine Research, Institute of Oceanography, Department of Marine Gology and Geophysics; Attiki; Greece.
Das Projekt "Trend der Quecksilberkonzentration in der Luft" wird vom Umweltbundesamt gefördert und von Fraunhofer-Gesellschaft zur Förderung der Angewandten Forschung, Fraunhofer-Institut für Atmosphärische Umweltforschung durchgeführt. In den Jahren 1975 - 1980 wurden in mehreren Messkampagnen die Quecksilberkonzentrationen in der Luft der beiden Hemisphaeren gemessen. Aus den Ergebnissen dieser Messungen konnte das atmosphaerische Quecksilberreservoir quantifiziert und die Aufenthaltsdauer des Quecksilbers in der Atmosphaere und somit auch die globalen Quell- und Senkstaerken abgeschaetzt werden. Die Daten von drei Schiffsexpeditionen in den Jahren 1978 bis 1980 deuteten auf einen starken globalen Anstieg der Quecksilber-Konzentration von einigen Prozent pro Jahr hin. Dieses Ergebnis war jedoch aufgrund des kurzen zeitlichen Abstands der Messungen von nur 24 Monaten unsicher. Das Ziel dieses Vorhabens ist es deshalb, mit der gleichen Messtechnik vom Schiff aus die Nord-Sued-Verteilung des atmosphaerischen Quecksilbers erneut im Abstand von 10 Jahren zu vermessen und damit die Existenz des damals angedeuteten Trends zu bestaetigen oder zu widerlegen.
Das Projekt "The effect of synoptic-scale wave breaking on cross tropopause transport and trace gas distribution" wird vom Umweltbundesamt gefördert und von Johannes Gutenberg-Universität Mainz, Institut für Physik der Atmosphäre durchgeführt. The tropopause and the so-called tropopause inversion layer (TIL), which is a layer of high static stability act as a partly permeable barrier to trace gas exchange between the troposphere and the stratosphere. The tropopause region is of particular importance for climate. The processes which lead to the formation of the TIL and their role for stratosphere-troposphere-exchange (STE) and the chemical composition of the tropopause region are incompletely understood. Experiments with idealized models show that synoptic scale wave breaking in baroclinic life cycles leads to TIL formation. The dynamical conditions during such an event are favorable for STE and an irreversible constituent exchange across the tropopause. This project will constitute a novel approach to identify the effect of synoptic-scale wave breaking and TIL formation on STE combining idealized models and observations with statistical methods. For this purpose we will apply: (i) the same analysis methods for idealized models containing artificial tracers and trace gas observations (ii) aquaplanet simulations with a full chemical scheme and the physics of a global model, to identify the global effect of baroclinic life cycles on TIL formation and the related trace gas distribution.
Das Projekt "Constraining carbon gross fluxes with oxygen isotopes (COCO)" wird vom Umweltbundesamt gefördert und von Max-Planck-Institut für Biogeochemie durchgeführt. Oxygen isotopes in atmospheric carbon dioxide can be used to obtain a better understanding of biospheric carbon fluxes, which must be understood in order to predict vegetation and climate change in response to anthropogenic greenhouse forcing. The main objective of this proposal is therefore to improve understanding of carbon flow in the biosphere by enhancing a comprehensive global 3D model of the movement of stable oxygen isotopes in plants, soil and the atmosphere. This objective will be achieved by measuring unknown fractionation factors, and by improving descriptions of plant and soil processes, including processes that had previously been omitted, and incorporating complementary tracers in the existing model. The resulting model will be the most comprehensive description of oxygen isotopes in atmospheric carbon dioxide up-to-date, where complementary tracers constrict individual aspects of the isotope cycle. The model will strictly constrain gross biospheric carbon fluxes, allowing direct comparison between measured and modelled oxygen isotope ratios in atmospheric carbon dioxide. This isotope model will then be incorporated in an Earth Systems Model (ESM) currently being developed. This will allow further detailed studies of biosphere/hydrosphere, biosphe re/atmosphere and biosphere/climate interactions, as well as studies of human influences on the Earth climate system. The ability to track oxygen isotopes in the biosphere components of the ESM will substantially reduce the uncertainty in inferred carbon sources and sinks on scales ranging from regions to continents, thus greatly improving the ESM's predictions of climate change and climate variability.
Das Projekt "Teilprojekt: INFRO Stoffstromanalyse Holz" wird vom Umweltbundesamt gefördert und von Udo Mantau INFRO - Informationssysteme für Rohstoffe durchgeführt. INFRO wird im Rahmen des Projektes Modellierung der Bioökonome sektorale Modelle für Forst- und Holzwirtschaft für Deutschland entwickeln. Darin wird der Stoffstrom der gesamten Wertschöpfungskette von Ressourcen über halbfertige Produkte (z. B. Paneel, Zellstoff) bis zu fertigen Produkten (z. B. Möbel, Papier) abgebildet. Reststoffe treten in allen Verarbeitungsschritten (Rohstoff, Halbfertig- und Fertigprodukte) auf. Die Analyse der Recyclingprodukte ist durchgängig nur über den Stoffstrom im Endwarensektor darzustellen. Dies setzt Analysen der Holzanteile in den Produkten voraus. Der vollständig quantifizierte Materialfluss ist die Grundlage für die Anwendung der LCA-Wirkungsanalyse auf Marktflüsse. Auf der Grundlage der Fallstudie für Holz soll ein verallgemeinerter Ansatz für die Materialflussanalyse für andere Ressourcen entwickelt werden. Die Ergebnisse werden in Form von Materialbilanzen und Stoffströmen dargestellt. Die Quantifizierung der einzelnen Stoffströme ermöglicht die Abbildung eines vollständigen Kreislaufmodells und die Berechnung von Kaskadenfaktoren. Darüber hinaus wird die das Verhältnis von stofflicher und energetischer Nutzung berechnet. Schließlich werden die sehr umfangreichen Erfahrungen in der Analyse von Stoffströmen im Bereich der Holzbiomasse auf ihre grundsätzlichen Strukturen zurückgeführt, um sie ggf. auch auf andere Sektoren wie den Agrarbereich zu übertragen.
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