Das Projekt "Evolution of geomagnetic dipole moment and South Atlantic Anomaly" wird vom Umweltbundesamt gefördert und von Helmholtz-Zentrum Potsdam Deutsches GeoForschungsZentrum durchgeführt. The geomagnetic field shields our habitat against solar wind and radiation from space. Due to the geometry of the field, the shielding in general is weakest at high latitudes. It is also anomalously weak in a region around the south Atlantic known as South Atlantic Anomaly (SAA), and the global dipole moment has been decreasing by nearly 10 percent since direct measurements of field intensity became possible in 1832. Due to our limited understanding of the geodynamo processes in Earths core, it is impossible to reliably predict the future evolution of both dipole moment and SAA over the coming decades. However, lack of magnetic field shielding as would be a consequence of further weakening of dipole moment and SAA region field intensity would cause increasing problems for modern technology, in particular satellites, which are vulnerable to radiation damage. A better understanding of the underlying processes is required to estimate the future development of magnetic field characteristics. The study of the past evolution of such characteristics based on historical, archeo- and paleomagnetic data, on time-scales of centuries to millennia, is essential to detect any recurrences and periodicities and provide new insights in dynamo processes in comparison to or in combination with numerical dynamo simulations. We propose to develop two new global spherical harmonic geomagnetic field models, spanning 1 and 10 kyrs, respectively, and designed in particular to study how long the uninterrupted decay of the dipole moment has been going on prior to 1832, and if the SAA is a recurring structure of the field.We will combine for the first time all available historical and archeomagnetic data, both directions and intensities, in a spherical harmonic model spanning the past 1000 years. Existing modelling methods will be adapted accordingly, and existing data bases will be complemented with newly published data. We will further acquire some new archeomagnetic data from the Cape Verde islands from historical times to better constrain the early evolution of the present-day SAA. In order to study the long-term field evolution and possible recurrences of similar weak field structures in this region, we will produce new paleomagnetic records from available marine sediment cores off the coasts of West Africa, Brazil and Chile. This region is weakly constrained in previous millennial scale models. Apart from our main aim to gain better insights into the previous evolution of dipole moment and SAA, the models will be used to study relations between dipole and non-dipole field contributions, hemispheric symmetries and large-scale flux patterns at the core-mantle boundary. These observational findings will provide new insights into geodynamo processes when compared with numerical dynamo simulation results.Moreover, the models can be used to estimate past geomagnetic shielding above Earths surface against solar wind and for nuclide production from galactic cosmic rays.
Das Projekt "Natural variation of flowering time due to cis-regulatory evolution of FLOWERING LOCUS T and its orthologs and paralogs in Brassica napus" wird vom Umweltbundesamt gefördert und von Max-Planck-Institut für Pflanzenzüchtungsforschung, Abteilung Entwicklungsbiologie der Pflanzen durchgeführt. In many plant species, FLOWERING LOCUS T and related proteins are the mobile signal that communicates information on photoperiod from the leaves to the shoots, where the transition to flowering is realized. FT expression is tightly controlled at the transcriptional level so that it is restricted to leaves, occurs only in appropriate photoperiods, and integrates ambient temperature and developmental cues, as well as information on biotic and abiotic stress. We previously established that FT transcription in the model plant Arabidopsis thaliana requires proximal promoter cis-elements and a distal enhancer, both evolutionary conserved among Brassicacea species. In addition, FT transcription is blocked prior vernalization in biannual accessions and vernalization-dependency of FT is controlled through a CArG-box located in the first intron that binds the transcriptional repressor FLOWERING LOCUS C (FLC). Chromatin-mediated repression by the Polycomb Group (PcG) pathway is required for photoperiod-dependent FT regulation and participates in FT expression level modulation in response to other cues.In this project, I propose to explore the available sequence data from the 1001 genome project in Arabidopsis to evaluate how often changes in regulatory cis-elements at FT have occurred and how these translate into an adaptive value. Allele-specific FT expression pattern will be measured in F1 hybrids of different accessions in response to varying environmental conditions. FT alleles that show cis-regulatory variation will be further analyzed to pinpoint the causal regulatory changes and study their effect in more detail. The allotetrapolyploid species Brassica napus is a hybrid of two Brassiceae species belonging to the A- and C-type genome, which are in turn mesopolyploid due to a genome triplication that occurred ca. 10x106 years ago. We will determine allele-specific expression of FT paralogs from both genomes of a collection of B. napus accessions. The plants will be grown in the field in changing environmental conditions to maximize the chance to detect expression variation of the paralogs. We will compare the contribution of the founder genomes to the regulation of flowering time and asses variation in this contribution. A particular focus will be to study the impact of chromatin-mediated repression on allele selection in B. napus.
Das Projekt "Speläotheme aus der Sibirischen Arktis: Einzigartige Archive vergangener Temperatur- und Feuchtebedingungen während des späten Miozäns." wird vom Umweltbundesamt gefördert und von Universität Bochum, Institut für Geologie, Mineralogie und Geophysik, Lehrstuhl für Sediment- und Isotopengeologie durchgeführt. Der Beginn der nordhemisphärischen Vereisung und die Entwicklung kontinuierlichen Permafrostes in Eurasien zwischen dem Ende des Miozäns und dem frühen Pleistozän zählt zu den bedeutendsten klimatischen Ereignissen des Känozoikums. Der Zeitpunkt extensiver Vereisung auf den Kontinenten und des Arktischen Ozeans und damit verbundene Veränderungen der klimatischen Bedingungen bleibt bislang ungenau bestimmt.Speläotheme (sekundäre Höhlenkarbonate) stellen ein wichtiges Archiv kontinentaler Umweltbedingungen dar, welches durch besonders genaue radiometrische Altersmodelle für eine grosse Bandbreite an Paläoklimaproxies charakterisiert ist.Wir konnten erfolgreich diagenetisch unveränderte und datierbare Proben aus Zentral- und Nordsibirien identifizieren und schlagen eine Multi-proxy-Studie an U/Pb-datierten Stalagmiten vor. Diese Studie wird Einblicke in die thermalen und hydrologischen Bedingungen zwischen 10.3 Ma und 8 Ma liefern. Wasser aus in den Speläothemen eingeschlossenen Fluidinklusionen wird auf seine Isotopenzusammensetzung hin untersucht. Zudem wird die in den Speläothemen beobachtete Lamination genutzt, um die Saisonalität während des Torton und Messiniums zu rekonstruieren. Wir suchen finanzielle Unterstützung für die parallele Analyse der Isotopie des Fluidinklusionswassers, der Sauerstoff- und Kohlenstoffisotopie des Karbonates, und der Elementkonzentration in den Speläothemen. Diese Kombination geochemischer Methoden wird Einblicke in regionale Umweltbedingungen, die Niederschlagshistorie und Temperaturen während des Miozäns und vor der Entwicklung kontinuierlichen Permafrostes geben. Zusätzliche Proben werden genutzt, um den Wechsel vom eisfreien zu einem durch Permafrost charakterisierten Sibirien zeitlich genauer einzugrenzen.Das vorgeschlagene Projekt wird unser Wissen zur atmosphärischen Zirkulation, und daran geknüpfter Veränderungen des Feuchte- und Temperaturregimes während eines saisonal eisfreien Arktischen Ozeans erweitern.
Das Projekt "Teilvorhaben: Entwicklung von Prior-Modellen und einer Klassifizierung von Anwendungsfällen" wird vom Umweltbundesamt gefördert und von Hochschule Düsseldorf, Fachbereich Maschinenbau und Verfahrenstechnik, Zentrum für innovative Energiesysteme durchgeführt. Die fortlaufende Energiewende stellt aufgrund der Vielzahl an oft hybriden und komplexen Energieversorgungssystemen, v.a. im Bereich der Wärme- und Kältebereitstellung, eine Herausforderung dar, so dass sich die für das Gebäude passende Systemauswahl für den Planer schwierig gestaltet. Daher zielt das Projekt SmartPrior darauf ab, die bereits in einem Vorgängerprojekt entwickelten Methoden der künstlichen Intelligenz, verbunden mit Methoden der statistischen Versuchsplanung, zur automatisierten Optimierung von Energieversorgungssystemen weiterzuentwickeln. Obgleich die entwickelten Methoden bereits deutlich vorteilhafter als gängige Lösungen sind, besitzen sie noch Grenzen der kommerziellen Anwendbarkeit, v.a. in Bezug auf die benötigte Rechenzeit. An dieser Stelle setzt das Vorhaben an: Die Entkopplung von vorgelagerter rechenintensiver Modellbildung und der nachgelagerten Zuordnung des individuellen Anwendungsfalls an das sogenannte Prior-Modell, das dem konkreten Anwendungsfall entspricht. Dieses Vorgehen bietet v.a. für komplexe Energieversorgungssysteme ein erhebliches Potential zur Reduzierung der Rechenzeit während der Anwendung, bei nur wenig reduzierter Genauigkeit der Ergebnisse. Im Projektverlauf werden die zu entwickelnden Methoden an möglichst diversen und im Hinblick auf Jahressimulationen anspruchsvollen Energiesystemen angewandt und getestet. Als Ergebnis aus dem Verbundvorhaben werden Methoden und Algorithmen entwickelt, die nicht-wissenschaftlichen Anwendern komplexe und ehemals zeitkritische Analysen in einem Bruchteil der gängigen Rechenzeiten sowie weitere komplexe und anwendungsorientierte Analysen, insbesondere auch zur Einbeziehung von Unsicherheiten bezüglich der Randbedingungen, ermöglichen. Das ZIES der HSD beschäftigt sich in seinem Teilvorhaben schwerpunktmäßig mit der Entwicklung von Generalisierungsfunktionen, Prior-Modellen, einer automatisierten Klassifizierung von Anwendungsfällen sowie weitergehenden Analysemöglichkeiten.
Das Projekt "Teilvorhaben: Entwicklung von Superstrukturen zur Prior-Modellbildung sowie Umsetzung und Evaluation der Gesamtmethodik" wird vom Umweltbundesamt gefördert und von Hottgenroth Software AG durchgeführt. Im Forschungsprojekt SmartPrior werden geeignete Methoden aus dem Bereich 'Anwendung von Methoden der Künstlichen Intelligenz' recherchiert und weiterentwickelt, um damit generalisierende Näherungsmodelle zur Nutzung als Prior-Modelle für die Systemeigenschaften von Energieversorgungssystemen (EVS) erzeugen zu können. Hierzu werden Simulationsmodelle von EVS in unterschiedlichen Komplexitätsstufen benötigt und konfiguriert. Um später diversen Anwendungsfällen ein passendes Prior-Modell zuordnen zu können, werden sinnvolle Klassen mit unterschiedlichsten Randbedingungen erstellt, sowie ein Algorithmus entwickelt, der eine automatisierte Zuordnung vom Anwender individuell vorgegebener Randbedingungen zu den Klassen durchführt. So können Anwender in sehr kurzer Zeit (Größenordnung Sekunden) multikriterielle Optimierungen von EVS durchführen. Somit leistet das Projekt ein wesentlicher Beitrag zur effizienten und intelligenten Auslegung von Energieversorgungssystemen und damit zur Energieeffizienzsteigerung in Gebäuden.
Das Projekt "PEroxy rAdicals measured by OF-Cavity Enhanced spectroscopy in the free troposphere with a focus on the upper troposphere / lower stratosphere (PEACE)" wird vom Umweltbundesamt gefördert und von Universität Bremen, Institut für Umweltphysik durchgeführt. The importance of peroxy radicals, RO2* (=I(HO2)+(RO2)) in atmospheric chemistry is well established. RO2* are short lived species, which generate longer lived radiatively active (e.g. ozone, O3) and chemically or toxicologically important pollutants (e.g. O3, peroxyacetyl nitrate, CH3CO.O2.NO2, PAN, aldehydes, acids etc.). Following vertical and long-range transport, these in turn play a significant role in the chemistry of the earth's atmosphere both regionally and globally. As a result of their low concentrations, measurements of RO2* even at the ground are sparse. Thus our ability to test our understanding of RO2* chemistry and its consequences has been limited. The overarching scientific objective of PEACE addresses this deficit by the optimization of a new measurement technique and by making and analyzing measurements of RO2* in combination with other key species in the boundary layer, the free troposphere and the UT/LS region. The role of RO2* in determining O3 abundance will be one important focus, utilizing the unique capability of the new research aircraft HALO (High Altitude Long Range). In-situ measurements of RO2* from the boundary layer to the UT/LS provide unique information about these processes. Within PEACE the new RO2* detection instrument PerCEAS (Peroxy radical Cavity Enhanced Absorption Spectrometer) will be optimised for flight on HALO, prior its participation in the HALO-OMO (Oxidative Mechanisms Observations) and SHIVA/HOx-NOx-XOx (Stratospheric ozone: Halogen Impacts in a Varying Atmosphere) measurement campaigns. In addition HALO-PerCEAS will be improved to enable the speciation of RO2* and the direct detection of nitrogen dioxide, NO2. The instrument will also be adapted to measure the radical precursor, glyoxal (CHO.CHO), a key temporary reservoir, formed in both biogenic and anthropogenic emissions and biomass burning.
Das Projekt "Research application of the novel multi sensor dropsonde for HALO for investigation of cyclones and embedded convection causing high impact weather in the Mediterranean" wird vom Umweltbundesamt gefördert und von Karlsruher Institut für Technologie (KIT), Institut für Meteorologie und Klimaforschung, Department Troposphärenforschung durchgeführt. The new KITsonde multi-sensor dropsonde will have its first operational use aboard HALO for investigation of deep convection and cyclones causing High Impact Weather (HIW) in the Mediterranean during the Demonstration Mission NEPTUN in autumn 2012. Following a sequence of three days of the development of an upper tropospheric trough leading to deep convection, mesoscale convective systems, and a lower tropospheric cyclone with embedded convection, the KITsonde will be used on the one hand to detect the variability of wind temperature and humidity prior to the cyclogenesis upstream, combined with in-situ and lidar remote sensing instruments. On the other hand during the final stage of HIW development, KITsonde will provide high resolution in-situ measurements from the inside of convective cells and MCS, inaccessible for the aircraft and optical remote sensing instruments. This dataset will allow the analysis of the variability of wind, temperature and humidity in time and space on all affecting scales, responsible for vertical fluxes of energy, which themselves are decisive for the initiation of convection - an important trigger mechanism for HIW. The impact of additional high resolution profiles within convective systems on the forecast quality of the NWF model COSMO-DE will be investigated.
Das Projekt "Evaluating the impact of drought on forest die-back in Europe and western Canada (Water03 - IDDEC)" wird vom Umweltbundesamt gefördert und von Technische Universität München, Wissenschaftszentrum Weihenstephan für Ernährung, Landnutzung und Umwelt, Fachgebiet für Ökoklimatologie durchgeführt. While many forests and woodlands may be at increasing risk of climate-induced dieback, significant knowledge gaps remain in our understanding of the causes of climate-induced tree mortality. Recent publications underscore the critical importance of understanding the mechanisms that trigger plant mortality (Adams et al., 2009), particularly regarding features and traits that could be used as physiological indicators of tree death (McDowell et al., 2008). Alterations in wood formation and structure often occur prior to visual symptoms of crown decline. Thus, physiological, morphological, and anatomical traits related to xylem ('water-conducting pipes') may provide early-warning signals of drought-induced dieback. A better mechanistic understanding of drought-induced forest dieback would improve our ability to predict tree mortality and future changes in forest composition and coverage. The project aims at studying how drought episodes promote dieback via changes in xylem structure. Different genotypes of aspen (parkland region and the southern boundary of the boreal forest in western Canada), oak (Southern Europe) and pine (experiment) will be studied along gradients of moisture availability. Xylem-related traits that will be measured include ring-width, number of missing rings, quantitative wood anatomical structures (diameter and frequency of vessels/ tracheids, inter-vessel pit structure) as well as cavitation resistance, hydraulic conductivity, and water potentials.
Das Projekt "Sub project: Determination of the depth of rhyolitic magma chambers in the Snake River Plain province, USA - An experimental calibration" wird vom Umweltbundesamt gefördert und von Leibniz Universität Hannover, Institut für Mineralogie durchgeführt. The investigation of high-silica rhyolitic rocks collected in the recent ICDP drilling from the Snake River Plain (SRP) volcanic province (western United States) as well as rocks from the adjacent rhyolitic complexes offers a unique opportunity to track the evolution of magma storage conditions in time and space in the 'Yellowstone hotspot' intracontinental volcanic province. The application of various geothermometers which can be used to determine pre-eruptive temperatures show a general trend indicating a general decrease of temperature over the last 16 Ma. However, the depth (or pressure) of the magma chambers is difficult to constrain and remains mainly unknown because the mineral assemblage in the rhyolitic systems is not suitable for geobarometry. As an alternative to mineral compositions, the silica content of rhyolitic melts can be used to constrain pressure, provided that the silicate melts have cotectic compositions (melts coexisting with quartz and feldspar), which is the case for most SRP rhyolites. From studies in synthetic systems, it is well known that the silica content of cotectic melts decreases with increasing pressure and that it may be used as barometer in pressure ranges of ca 1000 - 50 MPa. However, the evolution of silica content with pressure is not calibrated for natural systems containing up to 2 wtProzent Cao and 4 wtProzent FeO. In this study, we plan to determine the role of pressure on the silica content of cotectic melts compositions relevant for SRP compositions. The experimental data are crucial to interpret the natural glass compositions (matrix glass and glass inclusions) analyzed in the ICDP core samples and will be used to extract quantitative information on the depth of magma storage prior to eruption. The dataset obtained from various eruptive events (samples from ICDP drillings and other SRP rhyolites) will be used to check if there is an evolution of the depth of magma storage over the lifetime of the 'Yellowstone hotspot' in the last 16 Ma and if there is a correlation between the pre-eruptive pressure, the volume of erupted material, the temperature (or differentiation level) and the water activity of magmas. This study will be conducted in close cooperation with other U.S. groups who are in charge of the analysis of ICDP rhyolitic samples. It is emphasized that the experimental database obtained in this project can also be applied to other case studies (high silica rhyolites, A-type granites).
Das Projekt "Multi-proxy tree-ring analysis of conifer trees disturbed by insect outbreaks" wird vom Umweltbundesamt gefördert und von University of British Columbia, Faculty of Forestry, Department of Forest Resources Management Vancouver durchgeführt. Insect outbreaks are a major disturbance influencing forest dynamics in many ecosystems and can affect forest productivity worldwide. Reconstruction of insect outbreak history is fundamental to forest management. While the action of cambium feeders on trees leads to the formation of scars, that of defoliators is observable via growth suppression in tree rings. The occurrence of past insect attacks can thus be inferred from such tree-ring signatures. However, it necessitates an accurate dating of events, with high temporal resolution, as well as their correct attribution to the right disturbance agent. Fire also leaves scars on trees that can occur on cross-sectional disks where insect scars are already present, thus making them difficult to distinguish. Furthermore, insect-elicited reductions in radial growth may not be clearly visible on samples, and the radial growth response to defoliation often bears a lag of one or more years. This project tackles these issues directly by proposing a multi-proxy approach aiming at improving tree-ring reconstructions of insect outbreaks. Tree rings will be investigated to study radial variations of tree-ring width, wood anatomy, wood density, and wood chemistry. While dendrochronologists have long relied on tree-ring width variations to track the signal induced by climate, geomorphic and ecological processes, they have scarcely exploited the potential of other proxies and rarely used them in combination. The most advanced studies that have embraced these possibilities are owed to dendroclimatologists. The core of this research therefore lies in the use of multiple wood traits to provide answers to the above mentioned dendroecological questions. Two conifer tree species from British Columbia and their respective pests are within the scope of this study: the mountain pine beetle (MPB, Dendroctonus ponderosae Hopkins), a cambium feeder, on lodgepole pine (Pinus contorta Douglas), and the western spruce budworm (WSBW, Choristoneura occidentalis Freeman), a defoliator, on Douglas-fir (Pseudotsuga menziesii Franco). It is hypothesized that insect outbreak disturbance in the form of bark beetle or defoliation events results in abrupt significant structural differences between the wood formed prior to and after the insect attack. Based on pioneering tree-ring research on insect outbreaks, there are great prospects that the variations of wood traits be proven useful for differentiating MPB scars from fire scars and for identifying WSBW defoliation events, possibly with higher temporal resolution. The study of multiple wood traits (proxies) will help gain an understanding of the influence of insect outbreak disturbance on wood formation and tree physiological processes, a prerequisite for improving the detection and dating of events in tree-ring series. (...)
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