Das Projekt "D 1.2: Reducing alternation and production of off-season fruits in Lychee, Longan and Mango" wird vom Umweltbundesamt gefördert und von Universität Hohenheim, Institut für Kulturpflanzenwissenschaften (340), Fachgebiet Düngung und Bodenstoffhaushalt (340i) durchgeführt. The aim and vision of sub-project D1.2 was and is to encourage hillside farmers to plant erosion resistant fruit trees instead of erosion susceptible annual plants. For that reason, experiments to overcome the irregular bearing behaviour of the three most common fruit tree species in Northern Thailand (Litchi, Longan and Mango) from the first SFB period will be continued in order to make their planting more attractive to the farmers. Considerable progress has been made in D1 during the past 3 years to induce flowers and fruit in Longan trees by the application of KClO3 . With this technique, it was not only possible to induce year around flowers and fruit (off season fruit) but also to overcome the generally rather irregular fruiting behaviour of these trees. A similar technique is now being developed for Mango by using an inhibitor of the bio-synthesis of the plant hormone gibberellin. Only Litchi still resist this kind of manipulation by an 'off season technique' (OST). Great effort will therefore be devoted establishing a similar system for this species as well. Reliably, this can only be done by gaining a much better knowledge of the - most certainly hormonal - regulatory system that governs flower induction in trees. Investigations into the hormonal changes taking place during natural and induced flower induction is, therefore, one of the central objectives in this sub-project, with the goal to better understand the process of flower induction. Until now most of the progress in this area is entirely empirical in nature and a more specific manipulation therefore difficult. While the ability to produce off season fruit all year around and under various weather conditions has brought about a great number of new possibilities, new challenges will still be faced with regard to these methods. These circumstances will affect the whole production chain from the orchard to the market and consumer. In order to better investigate and understand these new situations, a large model experiment with Mango will be set up and problems like tree pruning, water and nutrient demand, phytopathological problems, demand on work force, fruit processing and drying etc. will be investigated by the interdisciplinary co-operation of 8 sub-projects within the SFB. The results obtained during these investigations will be shared with hillside farmers enabling them to take advantage of these new possibilities, which will provide for more reliable yields and allow them to market fruit year around. In general, these new opportunities should encourage farmers to plant more trees and thus reduce erosion. However, to make this system not only reliable and economic but also ecologically and socially beneficial to the society all potential benefits as well as risks have to be evaluated carefully from all different aspects.
Das Projekt "Sub project: Tree species effects on the release of dissolved organic carbon and nitrogen from decomposing logs" wird vom Umweltbundesamt gefördert und von Universität Bayreuth, Fachgruppe Geowissenschaften, Bayreuther Zentrum für Ökologie und Umweltforschung (BayCEER), Lehrstuhl für Bodenökologie durchgeführt. The release of dissolved organic matter (DOM) from decomposing logs might be a significant contribution to their mass loss and an important C input to the soil underneath the logs. Here we will contribute to the BeLongDead initiative by investigating concentrations, properties and fluxes of DOM as influenced by tree species, forest management, climatic conditions and time of log exposure. Furthermore we will follow the fluxes of mineral N and establish DOM and N budgets of the logs by comparing throughfall fluxes and fluxes with runoff from the logs. The runoff water from the logs will be collected periodically at selected sites using small gutters placed underneath the logs. In total, runoff water from 120 logs will be sampled. All 13 tree species will be studied in the Hainich sites, while at Schorfheide and Schwäbische Alb sites only beech, spruce and oak logs are compared. The elemental composition of DOM (C, N), its spectroscopic properties and 13C signatures will be determined. In addition, the mineralization of DOM to CO2 by soil organisms is investigated in laboratory incubations. In cooperation with the other members of we will be able to achieve ground braking progress on the processes driving the decomposition of logs, the related DOM release and N turnover as influenced by tree species, wood properties, climate, insect and fungi invasion.
Das Projekt "Transport und Zusammensetzung der UTLS der Südhemisphäre (SOUTHTRAC)" wird vom Umweltbundesamt gefördert und von Johann Wolfgang Goethe-Universität Frankfurt am Main, Institut für Atmosphäre und Umwelt durchgeführt. Änderungen der Verteilung von Spurengasen wie Wasserdampf und Ozon in der oberen Troposphäre und unteren Stratosphäre (UTLS) beeinflussen den Strahlungsantrieb und das Klima sowie die Oberflächentemperaturen und haben eine Schlüsselbedeutung für das Verständnis des Klimawandels. Auf Grund der hohen Sensitivität des atmosphärischen Strahlungsantriebs gegenüber Änderungen der Konzentrationen dieser Substanzen gerade in der kalten Tropopausenregion haben kleine Änderungen z.B. des Wasserdampfgehaltes der unteren Stratosphäre eine große Wirkung auf die Variabilität der Oberflächentemperatur. Überdies sind Prognosen des zukünftigen Wasserdampf- und Ozongehaltes des UTLS nach wie vor mit großen Unsicherheiten behaftet, was exakte Vorhersagen des Strahlungsantriebs vor dem Hintergrund des wieder zunehmenden stratosphärischen Ozons und der damit verbundenen Prozesse erschwert. Mehrere Studien haben gezeigt, dass Klima-Chemie-Modelle sogar unterschiedliche Vorzeichen des Strahlungsantriebes durch die Ozonzunahme zeigen, da gerade im Bereich der Tropopause große Unsicherheiten bezüglich der simulierten Zusammensetzung, insbesondere des Ozons und Wasserdampfs auftreten. Aufgrund des unterschiedlichen Wellenantriebs in beiden Hemisphären und auch aufgrund des stark unterschiedlichen Polarwirbel, werden große Unterschiede des Transports und der Zusammensetzung zwischen der UTLS der Nord- und der Südhemisphäre erwartet. Trotz der Bedeutung der globalen UTLS wurden bisher kaum Studien zu Transportprozessen und Zusammensetzung sowie der Dynamik der südlichen UTLS durchgeführt. Frühere Kampagnen hatten die antarktische Ozonzerstörung und Vortexprozesse oder die Tropen oder die troposphärische Zusammensetzung zum Ziel. Außerdem beeinflusst die Südhemisphäre im Winter die globale stratosphärische Zirkulation, da die Anden dann ein globales Maximum der Schwerewellenaktivität bilden. Die Ausbreitung dieser Wellen und ihr Einfluss auf die Zirkulation sind noch nicht vollständig verstanden. Deshalb schlagen wir eine HALO Kampagne vor um die UTLS der Südhemisphäre zu untersuchen. Spezifische Aspekte, die hierbei im Fokus stehen, sind: (1) Austauschprozesse an der südhemisphärischen Tropopause (2) Schwerewellen in der Südhemisphäre (3) Einfluss von Biomassenverbrennung auf die südhemisphärische UTLS (4) Einfluss des antarktischen Polarwirbels auf die UTLS
Das Projekt "Model coupling and complex structures - Evaporation-driven transport and precipitation of salts in porous media" wird vom Umweltbundesamt gefördert und von Universität Stuttgart, Institut für Wasser- und Umweltsystemmodellierung durchgeführt. Degradation of the soil productivity due to salt accumulation (salinization) is a major concern in arid, semi-arid and coastal regions. Soil salinization is an old issue but encouraged irrigation practices have been rapidly increasing its intensity and magnitude in the past few decades. Studies have shown that excess of the irrigated water contributes significantly to evaporation from the bare soil surface and therefore to the salinization. In some parts of the world soil salinity has grown so acute that the agricultural lands have been abandoned. Evaporation salinization is mainly influenced by interaction between the flow and transport processes in the atmosphere and the porous-medium. On the atmosphere side, wind velocity, air temperature and radiation have a strong impact on evaporation. Furthermore, turbulence causes air mixing, influences the vapor transport and creates a boundary layer at the soil-atmosphere interface which indeed influences evaporation. On the porous-medium side, dissolved salt is transported under the influence of viscous forces, capillary forces, gravitational forces and advective and diffusive fluxes. The water either directly evaporates from the water-filled pores or it is transported to air due to diffusive processes. Continuous evaporation promotes salt accumulation and precipitation resulting in soil salinization. In the scope of this work we attempt to develop a model concept capable of handling flow, transport and precipitation processes related to evaporative salinization of an unsaturated porous-medium.
Das Projekt "Veränderungen des Süßwassers im westlichen Europäischen Nordmeer" wird vom Umweltbundesamt gefördert und von Alfred-Wegener-Institut Helmholtz-Zentrum für Polar- und Meeresforschung durchgeführt. The goal of this project is to capture and analyse fluctuations of the fresh water in the western Nordic Seas and to understand the related processes. The East Greenland Current in the Nordic Seas constitutes an important conduit for fresh water exiting the Arctic Ocean towards the North Atlantic. The Arctic Ocean receives huge amounts of fresh water by continental runoff and by import from the Pacific Ocean. Within the Arctic Ocean fresh water is concentrated at the surface through sea ice formation. The East Greenland Current carries this fresh water in variable fractions as sea ice and in liquid form; part of it enters the central Nordic Seas, via branching of the current and through eddies. It controls the intensity of deep water formation and dilutes the water masses which result from convection. The last decades showed significant changes of the fresh water yield and distribution in the Nordic Seas and such anomalies were found to circulate through the North Atlantic. In this project the fresh water inventory, its spatial distribution and its pathways between the East Greenland Current and the interior Greenland and Icelandic seas shall be captured by autonomous glider missions. The new measurements and existing data will, in combination with the modeling work of the research group, serve as basis for understanding the causes of the fresh water variability and their consequences for the North Atlantic circulation and deep water formation.
Das Projekt "Benchmarking of the European Hydrogen Energy Roadmap HyWays with International Partners (HYWAYS-IPHE)" wird vom Umweltbundesamt gefördert und von Ludwig-Bölkow-Systemtechnik GmbH durchgeführt. Objective: HyWays-IPHE is an SSA to assess and compare the development efforts for the European Hydrogen Energy Roadmap prepared by HyWays with international road mapping or comparative activities of IPHE partner countries. Step 1 aims at an in-depth assessment and comparison of the individual elements of the national/ regional strategies, modelling approaches and experiences in EU & US. This will include infrastructure analysis, stakeholder consultation processes, actor analysis, economic modelling, WtW- & cashflow analyses and interaction between the different types of models used, scenario development, etc. In workshops modellers shall compare their models and experiences to foster a better mutual understanding of the models, facilitate the exchange of the methodologies and endorse the adoption of individual approaches. This may include tasks and goals of expected results, models used, stakeholders involved, process related issues, timelines and progress. A benchmarking between individual models (e.g. for the EU-US case: E3database and H2A+GREET) may be performed. Step 2 aims at broadening its scope within IPHE by involving other IPHE partner countries like J, CN and IND. In workshops these partners will be introduced into the EU-US work and engaged in this process. The deliverables of the project shall be reports presenting the assessment and comparison activities, for both steps. The learning effects for each IPHE partner shall be an important outcome from these comparative and benchmarking exercises leading to common elements of approaches on how to implement hydrogen technologies and infrastructures and to a better alignment of the road mapping activities. Future hydrogen roadmap development and proceeding implementation efforts in these partner countries shall benefit from the results, especially by avoiding mistakes, eliminating redundancies, inefficiencies and removing, unfounded frictions and misunderstandings between the different approaches and underlying drivers.
Das Projekt "Stochastic treatment of cloud related processes in nonhydrostatic weather prediction models" wird vom Umweltbundesamt gefördert und von Rheinische Friedrich-Wilhelms-Universität Bonn, Meteorologisches Institut durchgeführt. Cloud processes have a strong influence on the energy and moisture budget of the atmosphere. Since in numerical weather prediction (NWP) models cloud related processes usually are of subgrid scale, they have to be parameterized in a set of parameterization schemes describing e.g. grid scale clouds and precipitation, subgrid scale cumulus convection and atmospheric radiative transfer. The aim of the proposed research project is to develop a new stochastic physics approach (SPA) for the treatment of cloud related processes in nonhydrostatic NWP models. The stochastic approach shall represent unresolved subgrid scale variability and model parameter uncertainties. For this purpose, selected fixed model parameters will be replaced by appropriate stochastic processes.The application of the SPA shall increase the forecast skill of the hosting NWP model. In an ensemble prediction system (EPS) the ensemble spread shall grow to more realistic values and thus help to overcome the current problem of too small spread (underdispersion) when only considering uncertainties in the initial or boundary conditions. The algorithms of the stochastic approach and the EPS will be developed for use in any nonhydrostatic NWP model that includes prognostic microphysics/precipitation, a radiation scheme with fractional cloud cover and an arbitrary mass flux convection scheme.
Das Projekt "Hydrogeological and hydrochemical modelling of density-driven flow in the Tiberias Basin, in particular between Ha'on and Tiberias Regions, Jordan Valley" wird vom Umweltbundesamt gefördert und von Bundesamt für die Sicherheit der nuklearen Entsorgung durchgeführt. Die zweite Phase wird genutzt, um ein 3D Modell für das hoch spezialisierte Untersuchungsgebiet zu erstellen und um die Versalzungsvorgänge im Bereich des Sees Genezareth (TB) in Beziehung zu Störungen und tektonischen Gegebenheiten des Beckens zu verstehen. Eventuell wird der vorliegende Antrag zu einem ersten regionalen Modell mit Dichte-getriebenen Fluidbewegung für die Studienregion führen. Da das 2D und das vorläufige 3D Modell einen Einblick in den möglichen Transport Mechanismus gehen, ist es klar, dass ein 3D Modell basierend auf realen Strukturen ein besseres Verständnis der hydrologischen Vorgänge in Bezug auf Wärme- und Sole Migration in gefalteten Becken geben werden. Obgleich das 2D Modell physikalisch korrekt ist, sind geothermale Systeme mit Störungen komplex und weisen große geologische und physikalische Unterschiede auf. Eine Folge dieser Komplexität ist, dass ein 2D Modells kein vollständiges Bild eines Systems liefert, da es unmöglich ist die Wechselbeziehung zwischen verschiedenen 2D Schnitten zu extrapolieren. In dem Manuskript wird darauf verwiesen, dass Konvektionszellen meistens dreidimensional sind und deshalb in einem 3D Modell zu behandeln sind. Die vorläufigen 3D Modelle bestätigen diesen Aspekt (siehe 3D Abstract).Das Hauptziel ist die strukturellen, physikalischen und chemischen Eigenschaften an die Erfordernisse eines 3D numerischen Modells zu adaptieren. Um dieses Problem zu lösen, wird zunächst ein regionales Modell des Untersuchungsgebietes in (T3) erstellt, um in (T1) die Bildung eines vorläufigen 3D numerischen Modells basierend auf wirklichen Strukturdaten zu ermöglichen. Das geologische Modell wird fortlaufend blockweise verbessert, d.h. größere geologisch strukturelle Einheiten werden identifiziert entsprechend ihren (i) natürlichen Gegebenheiten (Störung, Faltung, Schichtung ), (ii) geochemischen Daten (T3 und T2) und (iii) verbesserten numerischen Ergebnissen (T1). Dies benötigt eine gut durchdachte Planung und Koordination des multidisziplinären Herangehens. Zurzeit ist das 2D und vorläufige 3D beendet. Sie zeigen mehrere Konvektionssysteme (siehe Manuskript). Offene Fragestellungen sind:-Wie entwickeln sich 2D Muster in 3D?-Wie können wir die Theorie (z.B. Rayliegh, Nusselt) korrekt anwenden, um den Fortsetzung von 3D Konvektionen auf Störungen und benachbarte Gebiete voraussagen?-Unter welchen Bedingungen können konvektive Bewegungen immer noch als 3D oder 2D betrachtet werden? Die Lösung dieser Schlüsselfragen wird erklären:-den treibenden Mechanismus von aktivem Fluidtransport Prozess in gestörten Systemen,-die beobachtete Temperatur von Solen und ihrer chemischen Derivate im Tiberias Becken, im Besonderen zwischen den westlichen und östlichen Solen in HTR-Das Studium der 3D Konvektionsmuster und die Rolle von Bruchstrukturen und mehr permeabler Bereichen auf die tiefe Fluidbewegung, ihren Einfluss auf den Massen- und Energie Transport.
Das Projekt "3D tomography for SCIAMACHY limb and nadir measurements: retrieval of stratospheric NO2, BrO and OClO profiles and their application for the investigation of stratospheric chemistry" wird vom Umweltbundesamt gefördert und von Max-Planck-Institut für Chemie (Otto-Hahn-Institut) durchgeführt. Satellite measurements strongly contribute to the understanding of the processes related to stratospheric ozone loss, e.g. by global and long term monitoring of ozone and its depleting substances. For instance, measurements performed in limb geometry by SCIAMACHY on ENVISAT largely improved the knowledge about the vertical distribution of species like BrO and OClO only recently. However, there are still important open questions, like e.g. the chlorine activation processes on different kinds of aerosols and polar stratospheric clouds. Also, the role of very short lived species in the stratospheric bromine budget or the effects of a possible enhancement of the Brewer-Dobson circulation are not fully understood.Globally, the vertical distribution of ozone depleting species varies significantly in space and time due to solar illumination, atmospheric chemistry and transport. Especially strong gradients occur near the twilight zone or across stratospheric transport barriers (polar vortex boundary, subtropical transport barriers). These regions are of particular importance for chemistry and transport of the lower stratosphere and upper troposphere, since they separate air masses on large scales but also enable exchange between them.Standard 1-D profile retrievals, which assume horizontal homogeneity, result in large systematic biases due to neglecting the effect of horizontal gradients on the measurement. We propose to develop, improve and apply a tomographic profile retrieval algorithm, which optimally combines the information provided by the SCIAMACHY limb and nadir measurements. An improved global dataset of 3D stratospheric profiles for NO2, BrO and OClO for the 10 years of the SCIAMACHY mission (2002-2012) will be developed, compared to atmospheric chemistry simulations and applied to selected questions of atmospheric science. The dataset developed in this project will be very useful for investigating the complex interplay of stratospheric chemistry and transport processes, and will help to reduce the uncertainties in the distribution of ozone depleting species, in particular for regions with large horizontal inhomogeneity.
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.
| Origin | Count |
|---|---|
| Bund | 22 |
| Type | Count |
|---|---|
| Förderprogramm | 22 |
| License | Count |
|---|---|
| open | 22 |
| Language | Count |
|---|---|
| Deutsch | 22 |
| Englisch | 21 |
| Resource type | Count |
|---|---|
| Keine | 17 |
| Webseite | 5 |
| Topic | Count |
|---|---|
| Boden | 17 |
| Lebewesen & Lebensräume | 19 |
| Luft | 16 |
| Mensch & Umwelt | 22 |
| Wasser | 18 |
| Weitere | 22 |