Das Projekt "The role of turgor in rain-cracking of sweet cherry fruit" wird vom Umweltbundesamt gefördert und von Leibniz Universität Hannover, Institut für Biologische Produktionssysteme, Fachgebiet Obstbau durchgeführt. Rain-cracking limits the production of many soft and fleshy fruit including sweet cherries world wide. Cracking is thought to result from increased water uptake through surface and pedicel. Water uptake increases fruit volume, and hence, turgor of cells (Pcell) and the pressure inside the fruit (Pfruit) and subjects the skin to tangential stress and hence, strain. When the strain exceeds the limits of extensibility the fruit cracks. This hypothesis is referred to as the Pfruit driven strain cracking. Based on this hypothesis cracking is related to two independent groups of factors: (1) water transport characteristics and (2) the intrinsic cracking susceptibility of the fruit defined as the amount of cracking per unit water uptake. The intrinsic cracking susceptibility thus reflects the mechanical constitution of the fruit. Most studies focussed on water transport through the fruit surface (factors 1), but only little information is available on the mechanical constitution (i.e., Pfruit and Pcell, tensile properties such as fracture strain, fracture pressure and modulus of elasticity of the exocarp; factors 2). The few published estimates of Pfruit in sweet cherry are all obtained indirectly (calculated from fruit water potential and osmotic potentials of juice extracts) and unrealistically high. They exceed those measured by pressure probe techniques in mature grape berry by several orders of magnitude. The objective of the proposed project is to test the hypothesis of the Pfruit driven strain cracking. Initially we will focus on establishing systems of widely differing intrinsic cracking susceptibility by varying species (sweet and sour cherry, Ribes and Vaccinium berries, plum, tomato), genotype (within sweet cherry), stage of development and temperature. These systems will then be used for testing the hypothesis of Pfruit driven strain cracking. We will quantify Pfruit und Pcell by pressure probe techniques and compression tests and the mechanical properties of the exocarp using biaxial tensile tests. When the presence of high Pfruit and Pcell is confirmed by direct measurements, subsequent studies will focus on the mode of failure of the exocarp (fracture along vs. across cell walls) and the relationship between failure thresholds and morphometric characteristics of the exocarp. However, when Pfruit und Pcell are low, the hypothesis of Pfruit driven strain cracking must be rejected and the mechanistic basis for low pressures (presence of apoplastic solutes) clarified on a temporal (in the course of development) and a spatial scale (exocarp vs. mesocarp). We focus on sweet cherry, because detailed information on this species and experience in extending the short harvest period is available. Where appropriate, other cracking susceptible species (sour cherry, plum, Vaccinium, Ribes, tomato) will be included to further extend the experimental period and to maximize the range in intrinsic cracking susceptibility.
Das Projekt "Sea Surface Topography and Mass Transport of the Antarctic Circumpolar Current (GEOTOP)" wird vom Umweltbundesamt gefördert und von Technische Universität München, Institut für Astronomische und Physikalische Geodäsie durchgeführt. GeoTop3 is the third phase of a DFG project and belongs to the DFG priority progamme 1257 Mass Transport and Mass Distribution in the Earth System . It aims at the determination of the absolute, but temporally changing ocean circulation flow field and of associated mass and heat transports. It is based on a state-ofthe-art circulation model assimilating geodetic data of the dynamic ocean topography (DOT) and oceanographic in-situ data. The ocean model is focused on the Atlantic sector of the Antarctic Circumpolar Current (ACC) and the Weddell Sea. This is one of the most dynamic ocean areas and one of the most critical regions for global climate, due to the impact of circumpolar bottom water production on global deep sea circulation. The regional model is embedded into a coarser global model to avoid systematic distortions. The expected results of this project extension are: 1. A stationary DOT with highest achievable spatial resolution from GRACE and in particular GOCE geoid models and multi-mission altimeter data with error propagation for both, geoid and sea surface. 2. The geoid models will be combined with regional Antarctic gravity data for higher resolution. ICESat data will be used to deal with seasonal sea ice concentrations. 3. A time-variable DOT, sufficiently smoothed to reduce the signal-to-noise ratio and to match the spectral and spatial resolution characteristics of the numerical model. 4. A calculation of the sensitivity of major ocean features such as strength of the Weddell Gyre on the accuracy and resolution of the geoid (and dynamical height) determination in view of the high resolution GOCE geoid model and improved geoid estimates in Weddell Sea area. 5. Model runs, in particular for the mass and heat transport in the Antarctic Circumpolar Current and the Weddell Gyre, the mean oceanographic DOT and its variability as well as their interpretation and quality assessment.
Das Projekt "A European Tracking System für Electricity - Phase II (E-Track II)" wird vom Umweltbundesamt gefördert und von Öko-Institut. Institut für angewandte Ökologie e.V. durchgeführt. *Phase II of the project will refine the proposed tracking standard, by integrating the new Guarantees of Origin for cogeneration, the implementation of which was due in 2007. A focus on the specific requirements from new Member States will be made. Furthermore, consumer organisations will be supported in defining their requirements on tracking systems and the related policies, and the views of non-domestic consumer groups will be sought. Finally, the action will develop a strategy for the further development of energy-related certification schemes and their potential integration. With Directives 96/02/EC and 2003/54/EC, the EU has introduced liberalisation of the electricity markets in its Member States and has created the framework for an internal European market for electricity. Directives 2001/77/EC and 2004/8/EC contain regulations on Guarantees of Origin, which serve to enable producers to demonstrate that the electricity they sell is produced from renewable energy sources or high efficiency cogeneration. Directive 2003/54/EC requires suppliers to provide details about their fuel mix and the respective environmental impact (disclosure). Disclosing a fuel mix or a green power product requires a procedure to track electricity generation attributes , such as fuel type, CO2 emissions etc.. from generators to electricity suppliers and their customers. Support systems for RES electricity and high efficiency cogeneration may require similar allocation systems. Such accounting systems can significantly contribute to transparency for the consumers choice and to improved market functioning. Harmonisation of such tracking schemes across Europe is a keystone for the development of a transparent internal European market for electricity. The E-TRACK project, which was terminated in June 2007, has successfully developed a blueprint for a European tracking standard. Principles of the standard have been taken over by several countries. However, tracking systems used in Europe are still far from being coordinated, and double counting and other errors can occur, which compromises the reliability of information provided to consumers and other actors.
Das Projekt "Integrating Cloud Observations from Ground and Space - a Way to Combine Time and Space Information (ICOS)" wird vom Umweltbundesamt gefördert und von Universität Köln, Institut für Geophysik und Meteorologie, Bereich Meteorologie, Arbeitsgruppe Integrierte Fernerkundung durchgeführt. Cloud processes remain one of the largest challenges in atmospheric research partly due to a gap in statistically significant observations of cloud macro- and microphysical properties. The most detailed and continuous observations available today come from the combination of state-of-the-art ground-based sensors at a few 'super sites' worldwide. The integrated profiling technique (IPT) developed by the proposers has been established to provide cloud liquid water (LWC) profiles with their error and the associated environmental conditions (temperature, humidity) from a combination of microwave radiometer, cloud radar and ceilometer. Here we propose to extend this method by incorporating satellite observations by Meteosat SEVIRI into the IPT optimal estimation framework for the additional retrieval of cloud microphysics (effective radius, optical thickness) and cloud radiation budget. In addition SEVIRI measurements will be exploited to provide auxiliary information on a) the history of the cloud observed at the super site (lifetime, microphysical development, environment) and b) the representativeness of the cloud for the cloud field around the site. The method will be developed on the basis of existing data sets from observation sites at Cabauw, Lindenberg and AMF/Murg Valley.
Das Projekt "Using the HALO Microwave Package (HAMP) for cloud and precipitation research" wird vom Umweltbundesamt gefördert und von Universität Hamburg, Fachbereich Erdsystemwissenschaften, Meteorologisches Institut durchgeführt. Representation of cloud and precipitation processes is one of the largest sources of uncertainty in climate and weather predictions. This project aims at exploring the potential of the novel HALO microwave package (HAMP) for airborne cloud and precipitation research by participating in all cloud related missions of the research aircraft HALO. HAMP is a unique combination of a 23 channel microwave radiometer and a cloud radar. To make HAMP a valuable research instrument, we will develop synergistic retrieval algorithms which convert the measured passive and active microwave signals into profiles of temperature, humidity and hydrometeor content with corresponding error estimates. A comprehensive evaluation of HAMP with existing observational systems, like e.g. satellites and ground based remote sensing super-sites will allow an assessment of its added value. In particular, we will analyze whether HAMP can resolve the fine-scale structure of cloud and precipitation fields and can thus relate point observations with area averaged data from satellites and models. Finally, observations from the NARVAL campaign will be used to demonstrate the benefit of HAMP for model development by revising the frequently used model assumption that shallow convective clouds do not precipitate.
Das Projekt "CARBOEUROPE-IP - QA/QC für Kohlendioxid-Flussmessungen" wird vom Umweltbundesamt gefördert und von Universität Bayreuth, Bayreuther Zentrum für Ökologie und Umweltforschung (BayCEER), Abteilung Mikrometeorologie durchgeführt. Activity 'Quality control and improvement of eddy flux data'. Task 1.2.1 Footprint and quality assessment of main flux sites: Each of the Main Sites of the cluster flux network will be evaluated by means of quality checks on eddy covariance data as well as for the representativeness of the fluxes of the respective footprints. To this purpose each Main Site footprint will be evaluated on the basis of a georeferenced land use/cover digital map. This information will be provided to the flux database as additional information for modellers as well for further flux corrections and error analysis. Task 1.2.2 Improvement of quality control procedures on eddy covariance data: New methodological components (planar fit rotation, ogive-test) as well as suitable quality control procedures will be developed. An high quality sensor set-up and associated methodical issues will be developed to investigate the energy balance closure as a control method for eddy covariance measurements. The Waldstein-Weidenbrunnen site of the University of Bayreuth will be used as a data quality test station.
Das Projekt "Assessment of satellite constellations for monitoring the variations in earth s gravity field" wird vom Umweltbundesamt gefördert und von Universität Stuttgart, Geodätisches Institut durchgeführt. More than a decade has passed since the launch of the GRACE satellite mission. Although designed for a nominal mission lifetime of 5 years, it still provides valuable science data. An eventual systems failure and, thus, mission termination is expected any time soon, though. Despite a relative low spatial and temporal resolution, the monthly gravity fields have proved an invaluable and novel parameter set in several geoscience disciplines, allowing new research venues in the study of Global Change phenomena. The hydrological cycle is now subject to quantification at continental scales; the state of the cryosphere, particularly ice sheet melting over Greenland and Antarctica, can be monitored; and steric effects of sea-level change have become separable from non-steric ones. The enormous success of the mission has driven the need for continuation of monitoring mass changes in the Earth system. Indeed, a GRACE Follow-On (GFO) mission has been approved for launch in August 2017. Like its predecessor it will consist of two satellites flying en echelon with intersatellite K-Band ranging as the main gravitational sensor. Despite a number of planned technological improvements, including a laser link as demonstrator, GFO will mostly be based on GRACE heritage. Given a similar orbit configuration and a similar systems setup, the quality of eventual gravity field products can be expected to be in the same range as the current GRACE products. To guarantee the continuation of such successful gravity field time series ESA has embarked several years ago on a long term strategy for future gravity field satellite missions, both in terms of technology development and in terms of consolidating the user community. Scientists from academia and industry held a workshop on The Future of Satellite Gravimetry at ESTEC premises, 12-13 April 2007, (RD-9). Similar workshops have been organized by other organizations, e.g. the joint GGOS/IGCP565 workshop Towards a Roadmap for Future Satellite Gravity Missions in Graz, September 30 - October 2, 2009. ESA furthermore played a key role in consolidating the international user community by funding a series of study projects, cf. (RD-1) to (RD-5). Similar projects have been funded and conducted at national level, e.g. the German BMBF-funded Geotechnologies III project Concepts for future gravity field satellite missions (PI: N. Sneeuw). These studies, together with GRACE experience, have provided a clear understanding of the current limitations of a GRACE-type mission. In particular the limitations in sampling and sensitivity of a single pair of satellites with in-orbit in-line sensitivity are well documented. At the same time, these studies have shown the design options and a roadmap towards a next generation gravity field mission.
Das Projekt "Watershed sediment yield modelling for data scarce areas; a case study, Awash River Basin, Ethiopia" wird vom Umweltbundesamt gefördert und von Universität Stuttgart, Institut für Wasserbau durchgeführt. The main goal of the research was to device an alternative solution for watershed sediment yield modelling for data scarce areas where the existing physically based models can not be applicable. Awash River Basin in Ethiopia was selected as case study area. GIS data on soil, land use, precipitation, temperature, stream flow and suspended sediment yield was collected from the Federal Ministry of Water Resources of Ethiopia (FMWRE) and from the National Metrology Service Agency (NMSA) offices. Soil data obtained from FMWRE and Food and Agriculture Organization (FAO) world soil 1974 database was used for derivation of the soil erodibility factor (ERFAC) estimation equation. The ratio of silt to sand and clay content was considered as the governing factor for soil erodibility in developing the ERFAC equation. The SWAT2005 model was selected for calibration and validation of stream flow and sediment yield. A sensitivity analysis was carried out to prioritize model calibration parameters. From the sensitivity analysis, curve number II (CN2), soilwater available to plants (SOL-AWC) and ground water base flow factor (ALPHA-BF) were selected as major stream flow calibration parameters. Similarly CN2, SURLAG (surface lag), slope and sediment routing factor (SPCON) were taken as the major sediment calibration parameters. Parameters related to the soil properties and river channel characteristics were given special attention during the model calibration. Eleven years (1990-2000) stream flow and sediment data were used for model calibration and six years data (2001-2006) were used for model validation. Calibration has been done at three gauging stations located in the Awash River basin. The statistical indicators, Coefficient of determination (R2), Nash-Sutclife efficiency (NSE), Root mean square error observations standard deviation (RSR were applied to evaluate the calibration and validation results. The values of these indicators were used to ratethe performance of the model. Watershed geomorphologic and topographic factors were extracted from the SWAT2005 watershed configuration, using a GIS tool and empirical equations. The relative importance of the factors was determined using Pearsons correlation coefficient based on the sediment yield output obtained from the SWAT2005 model calibration. The results show that, the sediment yield is highly correlated with stream flow, watershed area and watershed slope. Based on the identified parameters and the SWAT2005 model output, an alternative sediment yield estimation equation was derived and checked for its validity.
Das Projekt "Entwicklung eines statistischen Designs für die zweite Bodenzustandserhebung Wald (BZE 2)" wird vom Umweltbundesamt gefördert und von Universität Hamburg, Arbeitsbereich für Weltforstwirtschaft und Institut für Weltforstwirtschaft des Friedrich-Löffler-Institut, Bundesforschungsinstitut für Tiergesundheit durchgeführt. Project objectives: Some fundamental statistical questions are existing in the end of implementation phase for the second soil condition survey (BZE 2) in Germany. These are described in a memorandum from the Referat 533 of BMVEL (533-7673-1/4) from 30.07.2004. This project is to be supposed to develop and implement a mathematical-statistical way for evaluation of the second soil condition survey. In a first Step possibilities and the potential for stratification to reduce the sampling error will be show. Existing Follow-up Inventory Concepts will be discussed under the special context of BZE. Soil parameters vary on a very small spatial scale. To estimate the error arising from the kind of sampling design on a sampling plot samples on a scale from 0 to 20 meters will be collected and completed by data sets suited for such questions. These data are the base for geo-statistical analysis. The error due to the sampling design can be quantified by various simulations. In the preface of BZE a set of soil samples are analysed from different laboratories and by different laboratory methods. The Varity of these results could be seen as a scope of bias. All these errors lead to an overall error budget, which shows the proportion between the individual error sources and the source for future research. Project results: This project is to be supposed to develop and implement a mathematical-statistical way for evaluation of the second soil condition survey under the scope, given by the memorandum from the Referat 533 of BMVEL (533-7673-1/4) from 30.07.2004. With the end of the project an objective scale for evaluating different versions for taking soil samples is available. First times, the relation of used resources and the realized sampling error for soil inventories can be evaluated. So there is the chance for a better estimation of error scope and for the decrease of costs in future inventories. Contribution of University of Hamburg: - developing and suggesting a mathematical statistical way for the evaluation of the second soil condition survey; - analyzing the potential of stratification to reduce the sampling error; - compiling an overall error budget estimated from errors of sampling design, local variability of soil parameters and different means of analyzing soil parameters in the laboratory.
Das Projekt "Änderungen der Cant Speicherung und Änderungen in den Bildungsraten für Zwischen- Tiefen- und Bodenwasser im globalen Ozean, 1982 - 2015" wird vom Umweltbundesamt gefördert und von Universität Hamburg, Fachbereich Geowissenschaften, Institut für Meereskunde durchgeführt. Die erste Antragsphase war auf die Bildungsraten und die Speicherung von anthropogenem Kohlenstoff (Cant) im Antarktischen Zwischenwasser (AAIW) fokussiert. Mit Hilfe von Freon (CFC) Daten konnten wir eine signifikante Reduktion der AAIW Bildungsrate von den 1990ern zu den 2000ern Jahren feststellen. Dies führte zu einer geringeren Steigerung der Cant Speicherung als vom atmosphärischen Cant Anstieg und einem unveränderten Ozean zu erwarten war. Um den Schwierigkeiten mit den Randbedingungen auszuweichen (Pazifisches AAIW strömt über die Drake Passage auch in den Atlantik und weiter in den Indischen Ozean) planen wir nun ein globales Vorgehen um in allen Ozeanen die Bildungsraten und Cant Speicherungen in den Zwischen- Tiefen- und Bodenwassermassen zu berechnen. Darüber hinaus wird der Zeitraum bis 2015 ausgedehnt, und wo immer die Datenlage es zulässt, Pentaden- anstatt Dekadenmittelwerte gebildet. Verwendet wird der aktualisierte GlODAPv2 Datensatz und eigene Daten.Die Berechnungen aus den Beobachtungen werden mit den Ergebnissen eines wirbelauflösenden globalen Ozeanmodells (1/10 Grad) kombiniert. Das POP Modell (Los Alamos Laboratory Parallel Ocean Program) mit eines horizontalen Auflösung von 0.1 Grad und 42 Tiefenstufen wird für die letzten 20 Jahre mit einem realistischen Forcing angetrieben und enthält außerdem die Freone als Tracer. Neben dem Vergleich mit einem klimatologischen Antrieb wird das Modell zur Weiterentwicklung der Tracer-Methode verwendet wir z.B. die Unsicherheit von zu wenig Datenpunkten und der Extrpolationsroutine auf die Bildungsraten / Cant Speicherungen. Ein weiterer wichtiger Punkt wird die Bestimmung der TTDs aus Lagrange Trajektorien und der Vergleich mit TTDs aus Tracermessungen sein, sowie die Untersuchung der Rolle der Wirbel, der Vermischung durch Wirbel und der vertikalen Vermischung.
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