Das Projekt "Fire - climate feedback in the Earth System" wird vom Umweltbundesamt gefördert und von Max-Planck-Institut für Meteorologie durchgeführt. Fires are an integral Earth System process, which is controlled by climate and at the same time impacts climate in multiple ways. As such fires form a feedback mechanism in the Earth System, which might amplify or dampen climate change. At present this feedback is not well understood nor is it represented in current generation Earth System models used to study climate change. The proposed research project aims to quantify the fire-climate feedback by incorporating the integral role of fires into an Earth System Model (ESM). Together with improved observational based process understanding the project will analyze how fires have developed throughout Earth history and how single fire driven processes contribute to the overall fire climate impact. A mechanistic terrestrial biosphere fire model will be implemented into the ESM and fire mediated climate relevant processes will be coupled between the different ESM compartments, including the atmosphere, ocean and cryosphere. This cross-disciplinary research project will foster the understanding of past climate change and will hopefully allow a better assessment of human induced future climate change by further constraining the climate sensitivity of the Earth system.
Das Projekt "E 4.1: Quality and food safety issues in markets for high-value products in Thailand and Vietnam" wird vom Umweltbundesamt gefördert und von Universität Hohenheim, Institut für Agrar- und Sozialökonomie in den Tropen und Subtropen durchgeführt. The production and marketing of high-value agricultural commodities - such as fruits, vegetables, and livestock products - has been an important source of cash income for small-scale farmers in the northern mountainous regions of Thailand and Vietnam. However, against the background of recent free trade agreements and market liberalization, there is increasing national and international competition, partly leading to significant price decreases. Given structural disadvantages of farmers in northern Thailand and Vietnam, it will be very difficult for them to achieve and maintain a competitive position in markets for undifferentiated high-value products. Therefore, product differentiation - in terms of health attributes (e.g., low-pesticide residues, free from diseases and pathogens), taste (e.g., indigenous livestock breeds), time (e.g., off-season production), or processing characteristics (e.g., packaging, drying, canning) - could be a promising alternative. Quality and safety attributes play an increasing role in domestic and international food trade. The additional value generated could lead to sustainable income growth in the small farm sector, but this potential will only materialize when appropriate institutional mechanisms help reduce transaction costs and allow a fair distribution of benefits. This subproject seeks to analyze how the production and marketing of high-value agricultural products with quality and safety attributes can contribute to pro-poor development in northern Thailand and Vietnam. Quality and safety attributes can only generate value when they directly respond to consumer demand. Furthermore, since they are often credence attributes, the product identity has to be preserved from farm to fork. Therefore, the analysis will cover the whole supply chain, from agricultural production to final household consumption. Interview-based surveys of farmers, intermediate agents, and consumers will be carried out in Thailand, and to a limited extent also in Vietnam. The data will be analyzed econometrically with regard to the structure of high-value markets, trends and their determinants, and efficiency and equity implications of different institutional arrangements (e.g., contract agriculture, supermarket procurement). Since in northern Vietnam, the marketing of high-value products is a relatively recent activity, markets for more traditional crops will be analyzed as well, to better understand the linkages between different cash-earning activities in the semi-subsistent farm households. Apart from their direct policy relevance, the results will contribute to the broader research direction of the economics of high-value agricultural markets in developing countries. Moreover, they will generate useful information for other subprojects of the Uplands Program.
Das Projekt "SOLEIL: Solar variability and trend effects in layers and trace gasesin the upper atmosphere" wird vom Umweltbundesamt gefördert und von Leibniz-Institut für Atmosphärenphysik e.V. an der Universität Rostock durchgeführt. In der wissenschaftlichen Klimadiskussion steht der Einfluss des Anstiegs anthropogener Treibhausgase auf die globale Änderung unserer Atmosphäre in den untersten Kilometern im Vordergrund. Allerdings ist die bisher eingetretene mittlere globale Temperaturerhöhung mit 0.85 K von 1880 bis 2012, dies entspricht 0.06 K pro Dekade, jedoch klein. In der Atmosphäre oberhalb von etwa 8 km kehrt sich das Vorzeichen des Treibhauseffekts um: ein Anstieg der Konzentration von infrarot-aktiven Gasen führt zu einer Abkühlung durch eine gesteigerte Emission von Strahlung in den Weltraum. Die globale Veränderung der Atmosphäre findet besonders stark in einem Höhenbereich von 50-75 km statt. Antworten auf die Fragen nach den Ursachen für diese rapiden Änderungen in der mittleren Atmosphäre können uns nur numerische Atmosphärenmodelle (z.B. LIMA) geben. Letztere zeigen, dass die Strahlungsbilanz der mittleren Atmosphäre weitgehend bestimmt wird durch die Spurengase CO2 und O3. Die multivariate Trendanalyse erlaubt nun eine Aussage über den Beitrag am Gesamttrend der einzelnen Spurengase O3 und CO2. Die Spurengase CO2 und O3 tragen jeweils 2/3 bzw. 1/3 zum Trend bei. Die größten Trends liegen im Drucksystem mit 1.3 K/Dekade bei ca. 60 km, während auf geometrischen Höhen der Kontraktionseffekt der Atmosphäre die maximalen Trends auf bis zu 1.8 K/Dekade bei 70 km verstärkt. In den Höhen 80-90 km sind die Trendwerte am kleinsten und können sogar das Vorzeichen wechseln. Dieses Verhalten ist bedingt durch die sehr niedrigen Absoluttemperaturen in 80-90 km Höhe, die sehr empfindlich auf Variationen in den Strahlungsflüssen aus der Stratopausenregion reagieren. Weiterhin konnte in 'SOLEIL' gezeigt werden, dass Temperaturtrends zeitlich variabel sind. So zeigen im Teilzeitraum 1980-1996 die Temperaturen ihren stärksten Abfall aufgrund der Ozonabnahme: die Temperaturtrends können Werte bis zu 4 K pro Dekade erreichen. Im Zeitraum 1995-2009 sind die Durchschnittstemperaturen nahezu unverändert, weil sich hier das stratosphärische Ozon wieder aufbaut ('ozone recovery'). Diese Phasen starker und schwacher Abkühlung zwischen 1961 bis 2008 sind konsistent mit abgeleiteten Temperaturtrends aus französischen Lidarbeobachtungen und Phasenhöhenmessungen am Institut für Atmosphärenphysik (IAP) Kühlungsborn. Der Höhenbereich 80-90 km ist auch die Region, in der Eiswolken seit mehr als 100 Jahren beobachtet werden. Diese Eiswolken (NLC/PMC) existieren in der Sommermesopausenregion polwärts ab 50°N und können sich nur unter sehr kalten Temperaturen unterhalb von etwa 150 K ausbilden. Obwohl der Wasserdampfgehalt in der Mesopausenregion mit 1-7 ppmv sehr gering ausfällt, ist diese Feuchtekonzentration ausreichend für die Bildung von Eisteilchen. Die Nukleation und das Wachstum dieser Eispartikel reagiert sehr empfindlich auf Änderungen der Temperatur und des Wasserdampfes. Aus diesem Grund werden NLC/PMC auf ihre Rolle als potentieller Indikator für Klimaänderungen der globalen Atmosph
Das Projekt "On mechanisms of calving from Antarctic ice shelves" wird vom Umweltbundesamt gefördert und von Rheinland-Pfälzische Technische Universität Kaiserslautern-Landau, Fachbereich Maschinenbau und Verfahrenstechnik durchgeführt. This project aims to investigate the mechanisms of calving of tabular icebergs from Antarctic ice shelves. Calving is the final consequence of a fracture propagating through an ice shelf, which also behaves as a viscous material. Thus we will apply ice flow dynamical concepts in conjunction with fracture mechanical approaches. Theoretical investigations and numerical simulations lead to a formulation and determination of calving rates. Therefore, two and three dimensional finite element models will be developed, with which sensitivity studies and prognostic simulations will be carried out. The dependency of the mechanisms, and thus the calving rate, on typical geometrical setups, external forcing and material parameters is evaluated. Calving rates are crucial for the evolution of the position of the ice front. The knowledge of appropriate calving rates is required to predict the changes of the extent of the Antarctic ice sheet.
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 "Bees in Europe and Sustainable Honey Production (BEE SHOP)" wird vom Umweltbundesamt gefördert und von Universität Halle-Wittenberg, Fachbereich Biologie, Institut für Zoologie, Arbeitsgruppe Molekulare Ökologie durchgeführt. Honey is among the oldest food products of mankind and beekeeping is deeply rooted in every European culture. Numerous European and national regulations control honey quality, which reflects both the high nutritional and societal value of the product. Yet in an environment with increasing chemical pollution and the wide use of agrochemicals, honey runs high risks of becoming chemically polluted. In addition a broad spectrum of chemicals is used to treat honeybee diseases, further contaminating honey with sometimes highly toxic compounds. The BEE SHOP is a network of ten leading European honeybee research groups in honey quality, pathology, genetics and behaviour as well as selected beekeeping industries, which all share a common interest in promoting Europe's high honey quality standards. The prime goal is to reduce potential sources of honey contamination due to both foraging contaminated nectar and chemotherapy of honeybee diseases. The BEE SHOP will therefore deal with the development of biological resistance to pests and pathogens to avoid chemotherapy. Various European honeybee races and populations will be screened for their disease resistance potential to the main pressing pathogens. Differences in foraging patterns among European honeybees and their underlying mechanisms will be studied to identify behavioural traits reducing contamination. Differences in disease susceptibility will be genetically analysed by QTL mapping. Major loci in the genome will be identified with the aid of the published honeybee genome. SNPs will be developed to allow for selection of specific target genes in both drones and queens before insemination. This will greatly accelerate the selection progress in honeybee breeding allowing for the swift establishment of resistant but efficient stock. New tools for testing honey quality and authenticity will be developed to allow inspections of honey according to the current EC directives on honey quality and organic beekeeping.
Das Projekt "D 1.3: Regulation of flowering in tropical fruit crops on erosion prone sites in Northern Thailand" wird vom Umweltbundesamt gefördert und von Universität Hohenheim, Institut für Kulturpflanzenwissenschaften, Fachgebiet Ertragsphysiologie der Sonderkulturen (340f) durchgeführt. NRCT component: Assoc.Prof.Dr. Sruamsiri, Pittaya - Development of Clean Technology for Off-season Fruit Production: A Case Study of Mango, Longan, Litchi and Tangerine. Specific basic and applied science activities for each crop will be carried out in an attempt to solve the following issues. Longan: Previous research work has shown that flower induction can successfully be manipulated by application of KClO3. This crop is therefore an ideal model plant to investigate the regulatory mechanisms of flowering by: 1. determining acquisition and distribution of KClO3 using isotope labelling techniques and measuring enzyme activities in leaves to decide whether nitrate reductase is involved in the conversion and flower inducing activity of KClO3; 2. identifying mutual influences between hormones including their time-dependent changes brought about by manipulation of hormone biosynthesis through exogenously applied plant growth regulators (PGRs); 3. investigating the effect of off-season production systems on carbohydrate distribution and reserves. Mango: Paclobutrazol (PBZ) is already commercially used to manipulated flower induction in mango, however, the technique may not be sustainable due to its persistence in plant and soil. Prohexadione-Ca (Pro-Ca), another gibberellin biosynthesis inhibiting compound, and specific crop management techniques may prove to be successful and more sustainable alternatives to PBZ and warrant detailed investigation by: 1. evaluating appropriate time-of-season, concentration and application procedure (injection or spray) of Pro-Ca as possible alternative of PBZ and subsequent effects on hormonal status; 2. pruning or defoliation techniques which may induce a secondary flower through an altered hormonal status in the bud tissue. Litchi: There are still no proven orchard management practices for inducing off-season flowering in litchi. The main research objective is to study the significance of plant stress (pruning, girdling shoot tipping techniques, water and nutrient deficiency) on flowering signals by determining carbohydrate changes and hormonal status.
Das Projekt "Effects of nurse tree species on growth, environment and physiology of underplanted Toona ciliata (F. Muell.)" wird vom Umweltbundesamt gefördert und von Universität Freiburg, Waldbau-Institut durchgeführt. Toona ciliata (Australian red cedar) is highly valued for veneer and furniture production and endangered in its natural ecosystems due to exploitation. This work aims to improve the availability of this wood on the market and help reduce pressure on the species in its native environment. An afforestation project cultivating Toona ciliata was introduced to the study site in Misiones, Argentina. The local cultivation faces losses caused by drought and frost, because T. ciliata requires overstory protection when young. Consequently, Grevillea robusta, Pinus elliottii x Pinus caribaea, and Pinus taeda, nurse tree species which also produce sought-after wood were chosen to provide protection. One-year-old T. ciliata seedlings were planted underneath each of the six-year-old nurse species. An inventory after one year indicated that both survival and height increment were highest underneath G. robusta and lowest underneath P. elliottii x P. caribaea. In this study I am examining possible facilitation and competition mechanisms between the overstory and understory T. ciliata. Extensive empirical data collected over the course of 3 years will be utilized to project potential growth scenarios for several rotations using a computer based forest growth model.
Das Projekt "Process study of vertical mixing near the sea floor inside the central valley of the Mid-Atlantic Ridge near 37°N" wird vom Umweltbundesamt gefördert und von Alfred-Wegener-Institut für Polar- und Meeresforschung, Fachbereich Klimawissenschaften, Sektion Physikalische Ozeanographie der Polarmeere durchgeführt. Vertical mixing associated with dissipation of turbulent kinetic energy sustains the circulation of the deep and abyssal ocean. New evidence is emerging that the highest mixing rates are found within the central valleys and ridge flank (transform) canyons of mid-oceanic ridge systems. An expedition is proposed to take place in August 2010 during which near-bottom oceanographic and marine-geologic measurements will be carried out in the central valley of the Mid-Atlantic Ridge near 37°N, using an autonomous underwater vehicle (AUV), complemented by 'classical' lowered and mooring-based techniques. It is currently unclear, which physical mechanisms control the intense turbulent dissipation in deep ocean canyons. Recent studies point to a potential role of hydraulic jumps, which have been observed in shallow water studies. We aim at testing whether tidally varying hydraulic jumps can explain the observed large vertical mixing over a sill in the central valley. To resolve the jumps AUV-based high-resolution horizontal fields of near-bottom turbulent kinetic energy dissipation and of flow velocities will be obtained. Further, high-resolution AUV multi-beam echo sounder mapping will allow us to study (i) the relationship between vertical mixing processes and the bathymetry, and (ii) the dynamic processes underlying the 'mixing active' morphology.
Das Projekt "AURORa - Investigation of the Radar Backscatter of Rain Impinging on the Ocean Surface" wird vom Umweltbundesamt gefördert und von Universität Hamburg, Zentrum für Meeres- und Klimaforschung, Institut für Meereskunde (IfM) durchgeführt. Over land, observations of rain rates are more or less operational. To obtain information about precipitation at the coastal zones, weather radars are used. However, over the oceans, especially away from the main shipping routes, no direct precipitation measurements are performed. In these regions, satellite data can provide information about precipitation events. Satellites deploying passive and active microwave sensors can operate independently of cloud cover and time of day. Passive microwave sensors give crude estimates of rain rates over large areas but cannot resolve small-scale rain events of short duration as are often observed in the tropics, for example. Active microwave sensors with high resolutions, such as synthetic aperture radars can provide more reliable information. Though the effect of rain on the atmosphere is a very topical area of research, the radar backscattering mechanisms at the water surface during rain events combined with wind are still not well understood. The purpose of this project is to investigate the radar backscattering from the water surface in the presence of rain and wind in order to interpret satellite radar data produced by active microwave sensors. Furthermore, the results should be embedded into models of the radar backscattering from the water surface to allow for estimating rain rates by using satellite data. Research topics: Rain impinging on a water surfaces generates splash products including crowns, cavities, stalks and secondary drops, which do not propagate, and ring waves and subsurface turbulence. We are investigating this phenomena at the wind-wave tank of the University of Hamburg. The tank is fitted with an artificial rain simulator of 2.3 m2 area mounted 4.5 m over the water surface. Rain drops of 2.1 and 2.9 mm in diameter with rain rates up to 100 mm/h have been produced. Wind with speeds 10 m/s and monomolecular slicks act on the water surface. The influence of the rain on the water surface is measured with a resistance type wire gauge, a two dimensional laser slope gauge and an coherent 9.8 GHz (x band) continuous wave scatterometer operating at VV-, HH- and HV-polarization. The influence of rain below the water surface is measured with colored raindrops which are observed with a video camera to investigate the turbulent motion and the depth of the mixed layer. At the North Sea Port of Buesum in Germany, a scatterometer operating at all polarizations and five frequencies will be mounted during summer of this year. The radar backscatter of the sea surface during rain events will be measured in combination with meteorological observations. With help of these measurements, existing radar backscatter models of the water surface will be improved for the presence of rain events. To validate the improved models, ERS-2 SAR-images will be compared with weather radar data.
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