Meteorologische Mess- und Beobachtungsdaten und daraus abgeleitete Datensätze für die Vergangenheit (vom Vortag oder älter) und für die Zukunft (Klimaprojektionen bis 2100). Die Klimadatensätze sind stationsbezogene, gebietsbezogene Daten oder Rasterdatenfelder für Deutschland. Klimadatensätze, die über Deutschland hinausgehen, werden hier ebenfalls bereitgestellt, wenn ihre entgeltfreie Bereitstellung geregelt ist (z.B. im Rahmen der WMO oder in Projektvereinbarungen der international beteiligten Partner). Die Datensätze stehen entgeltfrei unter https://opendata.dwd.de/climate zur Verfügung. Weitere Infos finden Sie auch auf dem Leistungssteckbrief unserer Internetseite https://www.dwd.de/DE/leistungen/opendata/opendata.html.
Das Projekt "BioArchiv Tswaing Krater (Teilprojekt der Forschungsinitiative Inkaba yeAfrica.)" wird vom Umweltbundesamt gefördert und von Helmholtz-Zentrum Potsdam Deutsches GeoForschungsZentrum durchgeführt. Das heutige Klima Afrikas wird maßgeblich von globalen atmosphärischen Phänomenen wie Monsun (in NE Afrika) und El-Nino-Southern Oscillation (SE und S Afrika) beeinflusst. Dies wird v. a. im saisonalen Regime der Niederschläge deutlich. Welche Rolle dabei der Antarktische Vortex spielt, ist noch nicht wirklich geklärt. Auch die Verbindungen zwischen Atmosphärischer und Ozeanischer Zirkulation sind noch immer unklar. Ein Zusammenhang scheint erkennbar zwischen Trockenperioden in Südafrika, feuchten Phasen in Ostafrika und wärmeren Temperaturen im Indischen Ozean. Auch Computermodelle bestätigen, dass Konvergenz und Niederschlag über Südafrika reduziert sind während Warmphasen im Indischen Ozean. Die Sedimente des Tswaing-Kraters stellen eines der wenigen langen und kontinuierlichen, terrestrischen Klimaarchive Südafrikas dar. Ihre Untersuchung kann dazu beitragen Veränderungen des Klimas in der Region und damit auch Veränderungen globaler Phänomene über einen Zeitraum von bis zu 200.000 Jahren zu verstehen. Durch die parallele Verwendung unterschiedlichster Methoden (Geochemie, XRF, organische Petrologie, Rock-Eval Pyrolyse, Biomarkeranalyse und Isotopenuntersuchungen) konnten wir Veränderungen in der Bioproduktivität (Algen und Bakterien), in der Karbonatsedimentation und damit verbunden auch im klastischen Eintrag und der Salinität rekonstruieren. Während der letzten 70.000 Jahre gab es immer wieder Veränderungen im Niederschlag und damit auch in der Stratifizierung der Wassersäule. Heute spielen im Kohlenstoffkreislauf des Ökosystems C3-, C4-Pflanzen und aquatische Mikroorganismen eine Rolle. Sehr niedrige ä13C-Werte von Diplopten, einem Biomarker für Bakterien, beispielsweise, deuten drauf hin, dass methanotrophe Bakterien in der tieferen Wassersäule oder auf dem Sediment leben. Veränderungen in der Menge und im ä13C-Verhältnis ausgewählter Biomarker zeigen deutliche Veränderungen im Ökosystem des Kraters für den Zeitraum 14.000-2.000 Jahre vor heute an: ( ) Mögliche Ursache für die trockeneren Bedingungen zwischen 10.000-8.000 Jahre vor heute ist eine Verschiebung der Innertropischen Konvergenzzone (ITCZ) nach Norden. Ein ähnliches Szenario wird auf Grund von entsprechenden Daten aus mehreren Klimaarchiven in Afrika postuliert. Sektion 4.3: Mit einem Multiproxy-Ansatz (Mikrofaziesanalyse an Dünnschliffen, hochauflösende Elemantbestimmungen, Korngrößenverteilungen, Biomarker und Diatomeen) wird die Klimavariabilität glazialer/interglazialer Schlüsselabschnitte untersucht: z.B. Termination II (MIS 5.5-6), Heinrich- und Dansgaard-Oeschger-Ereignisse, die Klimastabilität/-instabilität des letzten Interglazials, etc. Die Entwicklung stellt eine verlässlichen Altersmodells für das Sedimentprofil aus dem Tswaing-Kratersee dar. Mit diesem Projekt werden wir ein einzigartiges Archiv für ein besseres Verständnis der Klimaprozesse in der Südhemisphäre erstellen. Die erzeugten Daten werden in globale Synthesen wie den IGBP PEP III-Transekt eingearbeitet.
Das Projekt "EBISCO - Energy budget in snow covered forests" wird vom Umweltbundesamt gefördert und von Eidgenössische Forschungsanstalt für Wald, Schnee und Landschaft durchgeführt. Hintergrund: Die zeitliche Entwicklung einer Schneedecke im Wald verläuft wesentlich anders im Vergleich zu einer Schneedecke ausserhalb des Waldes. Die Baumkronen vermögen Strahlung zu absorbieren, turbulente Flüsse abzuschwächen und Niederschlag aufzufangen. Die heterogene Struktur typischer Waldkronen verursachen eine hochkomplexe räumlich-zeitliche Dynamik der Massen- und Energiebilanz von Schneedecken im Wald. Da Wälder grosse Teile der nördlichen Hemisphäre bedecken, spielen Prozesse rund um die Schneedeckenentwicklung im Wald eine wichtige Rolle für Wetter und Hydrologie, sogar auf grösseren räumlichen Skalen. Projektansatz: In diesem Projekt konzentrieren wir und auf die Strahlungsbilanz innerhalb von subalpinen Wäldern im Winter. Ein neuartiges Messgerät wurde entwickelt, welches die räumlich-zeitliche Variabilität der Strahlung im Wald zu erfassen vermag: Dazu wurde ein 4-Komponenten Strahlungsmessgerät auf einen Schlitten montiert, der entlang einer 10-m Schiene periodisch hin und her bewegt wird. Weitere Strahlungsreferenzmessungen werden über dem Wald und auf einer offenen Fläche ausserhalb des Waldes durchgeführt. Testgebiete: Die Strahlungsmessungen werden auf zwei Langzeit-Forschungsflächen durchgeführt. Zwischen 2003 und 2007 war das Messgerät auf unserer Forschungsfläche im Alptal auf 1200 m üM installiert. Seit dem werden die Messungen auf unserer Testfläche im Seehornwald bei Davos auf 1650 m üM weitergeführt. Link zu anderen Projekten: Dieses Projekt trägt zur Entwicklung unserer Schneedeckenmodelle Snowpack and Alpine3D bei. Diese Modelle berücksichtigen viele Prozesse rund um die Wirkung von Vegetation auf Massen- und Energiebilanz von Schneedecken im Wald. Unsere Daten dienen u.a. zur Verifikation dieser Modellkomponenten. Ausserdem wurden unsere Daten für das internationale Projekt SnowMIP2 zum Vergleich von Schneedeckenmodellen zur Verfügungen gestellt.
Das Projekt "Understanding the isotope signal of trees growing on continuous permafrost in northern Siberia" wird vom Umweltbundesamt gefördert und von Paul Scherrer Institut durchgeführt. The main goal of the project is to improve the use of carbon and oxygen isotope ratios in tree-rings as a tool to detect the response of Siberian larch forests on permafrost to the recent climate change. The goal will be achieved by a detailed analysis of the incorporation and fractionation of isotopes in a Siberian forest ecosystem (64 N, 100 E) on a seasonal scale, at an approximately weekly time resolution during the vegetation period. A new approach involving compound-specific isotope analysis of different plant components will be applied to enhance the understanding of post-photosynthetic fractionation and carbon allocation processes. These results will be used to calibrate isotope fractionation transfer models along the leaf and stem. Oxygen isotope values of water samples extracted from soil, leaves and branches will be the basis for a better understanding of the water-use of trees, with a focus on time-lags caused by storage and release of permafrost water. Earlywood and latewood isotope chronologies covering the last 100 years on sites contrasting in permafrost depth will enable the application of the results on longer timescales. This will reveal if the thawing of permafrost and the deteriorating summer drought conditions are the key factors influencing forest growth. The results will be compared to studies conducted in the Alpine region in the Lötschental, where tree growth is also temperature-limited, but where the soil conditions (without permafrost) are very different. Siberian larch forests in the continuous permafrost region are sensitive ecosystems and have been especially exposed to the global warming of the recent decades. These forests are vulnerable, as the vegetation period is short, and water and nutrient availabilities are low. Our previous research on Siberian sites indicated a complex interplay of environmental factors, isotope ratios and tree growth. The t and provoke a risk of an additional radiative forcing of the climate system. 2 century were detected. The permafrost in this region has an important role as a direct water source during summer drought due to extremely low precipitation. Increasing temperatures in the future will enhance the leaf-to-air vapour pressure difference, thus the evaporative demand and water loss of the plants, which may reduce productivity and carbon sequestration of these forests. Furthermore, higher decomposition rates in the uppermost part of soils and accessibility of carbon currently stored in permafrost to microbial degradation could release COthemperature signal in the isotope chronologies was lower than expected, but indications for an increasing drought situation in the 20
Das Projekt "Isotope pathway from atmosphere to the tree ring along a humidity gradient in Switzerland" wird vom Umweltbundesamt gefördert und von Eidgenössische Forschungsanstalt für Wald, Schnee und Landschaft durchgeführt. Temperatures in Switzerland increased about 0.57 C over the last three decades and climate models predict that this increase will continue during the 21st century and beyond. Accompanied by changes in the water supply due to the expected increase in the frequency and intensity of heavy precipitation and/or drought events, these effects will strongly force changes in forest productivity, spatial distribution of tree species, and changes in the species composition within forests. Projections of the future dimensions and interactions of these effects require detailed understanding of short and long-term changes in eco-physiological responses to past and present climate variation. Stable isotopes in tree rings have become a significant tool in obtaining retrospective insight into the plant physiological response to climate and other environmental variables. The increasing number of isotope records, however, also highlights important unsolved questions and current limitations of this tree-ring parameter. Obviously, an improved understanding of the mechanisms leading to variations in the tree's internal carbon and water cycle in relation to climate, soil moisture conditions, transpiration and expansion of the root system is urgently needed. ISOPATH aims to decipher the origin and variability of the isotopic signal in the tree rings of two alpine species, frequently used in climate reconstructions, and to understand the environmental and physiological information encoded. We will develop weekly resolved records of carbon and oxygen isotopes in xylem and needle water, needle sugars, phloem sugars and stem wood/cellulose of two physiologically differing species (larch and spruce) growing under varying temperature, soil moisture and relative humidity conditions. Those data will be related to a large suite of external variables including precipitation and soil water, temperature, and vapour pressure deficit. We act (i) on a spatial scale by following the complete pathway of stable isotopes from the atmosphere into the tree ring under varying environmental conditions and (ii) on a temporal scale by studying seasonal cycles of the isotope signals in all these different components, covering four growth seasons (2008-2011). This unique dataset in terms of length, resolution and number of measured variables will be used to test and improve advanced models for isotope fractionation at the leaf level and in the tree ring, in relation to species-specific traits, temperature and soil moisture conditions. The measured and modelled isotope signatures will allow to predict plant physiological adaptation in the alpine environment to climate change of the 21st century.
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 "Ground-based remote sensing measurements of CO2 and CH4 using the moon as light source during the polar night" wird vom Umweltbundesamt gefördert und von Universität Bremen, Institut für Umweltphysik durchgeführt. Throughout the last years measurement techniques have been developed to measure total columns of atmospheric CO2 and CH4 with sufficient precision using the ground-based solar absorption remote sensing spectrometry in the near-infrared spectral region. These observations are internationally organized in the Total Column Carbon Observing Network (TCCON). These observations have been initiated for the satellite validation, because they sample the atmosphere in a similar way as satellites. However, the measurements itself have been found extremely valuable to investigate the sources and sinks of the trace gases, because the interpretation of the ground-based total column data depend to a less extent on assumptions on the vertical mixing in the atmosphere compared to surface in-situ data. We perform such observations at our site in the high Arctic on Spitsbergen (79°N). However, during the polar night from October until mid-March no observations can be performed, because the sun is below the horizon. Since the seasonal cycle of CO2 is largest in the high northern latitudes the lack of total column data for the winter period limits our understanding of the carbon budget. Within this project we plan to modify the measurement and analysis technique to measure the total columns of CO2 and CH4 in the near-infrared using the moon as light source during the polar night. This will allow us to perform observations on +-3 days around full moon, and thus, obtain data throughout the polar night for about three full moon periods. This allows measuring the complete seasonal cycle of total column measurements of CO2 and CH4 in the high Arctic, which is not known so far. Finally, the whole set of data will be compared to the existing in-situ surface data at that site and both data sets, in-situ and total column, will be compared with appropriate models.
Das Projekt "E 1.2: Multi-layer drying models for optimising high value crop drying in small scale food industries" wird vom Umweltbundesamt gefördert und von Universität Hohenheim, Institut für Agrartechnik, Fachgebiet Agrartechnik in den Tropen und Subtropen durchgeführt. Fruit tree cultivation is a suitable option for erosion control in mountainous regions of Southeast Asia. However, seasonal overproduction and insufficient access to markets can cause economic losses. The possibility of processing fruits locally could contribute considerably to increase and stabilize farm income. Currently, fruit drying methods in these areas are yielding products of inferior quality. Pre-treatments such as sulphurizing are commonly used, but can make the product undesirable for international markets. In addition, high energy requirements increase production costs significantly. Therefore, the objective of subproject E1.2 is to optimize the drying process of small-scale fruit processing industries in terms of dryer capacity, energy consumption and efficiency and end product quality. During SFB-phase II in E1.1, drying fundamentals for the key fruits mango, litchi and longan were established. In laboratory experiments, impacts of drying parameters on quality were investigated and numerical single-layer models for simulation of drying kinetics have been designed. In SFB-phase III this knowledge will be expanded with the aim of optimizing practical drying processes. Therefore, the single-layer models will be extended to multi-layer models for simulating bulk-drying conditions. The Finite Element Method (FEM) will be adapted to calculate heat and mass transfer processes. Thermodynamic behavior of batch and tray dryers will be simulated using Computational Fluid Dynamics (CFD) software. Drying facilities will be optimized by systematic parameter variation. For reduction of energy costs, the potential of solar energy and biomass will be investigated in particular. Further research approaches are resulting from cooperation with other subprojects. A mechanic-enzymatic peeling method will be jointly used with E2.3 for studying the drying behavior of peeled litchi and longan fruits. Furthermore, a fruit maturity sensor based on Acoustic Resonance Spectroscopy (ARS) will be developed in cooperation with E2.3 and B3.2. Finally, an internet platform will be built for exchange of farmer-processor information about harvest time and quantities to increase utilization of the processing facilities.
Das Projekt "C 1.2: Analysis and manipulation of the agro-biocoenosis for sustainable management of litchi growing systems at hillsides of Northern Thailand" wird vom Umweltbundesamt gefördert und von Universität Hohenheim, Institut für Pflanzenproduktion und Agrarökologie in den Tropen und Subtropen durchgeführt. In the hillsides of northern Thailand, the importance of fruit trees (mainly litchi) is increasing. However, fruit production is limited by a number of biotic and abiotic factors. Frequent applications of herbicides and insecticides result in a grass-dominated herbicide flora of low diversity. Further consequences are low numbers of beneficials, soil erosion and the decline of soil fertility. The aim of the proposed project is the development of a litchi production system with reduced insecticide and herbicide input, which allows both sustainable and profitable land use. This will be achieved by (a) the development of management strategies for preventive measures in pest population control and (b) the establishment of a smother vegetation which leads to an increased diversity of the system, enhancement of beneficials, improved soil conservation and fertility, and which has an additional-use potential (e.g., forage). The experimental approach for studying the effects of management measures (handling of the attendant vegetation and insecticide application in four different treatments) on plant species diversity and the beneficial fauna will be continued from phase 1 in an extended manner. In addition, the long-term monitoring of seasonal changes in abundance of the six major litchi pests, identified in the first phase, will be continued. The migration patterns of these species will also be studied since some of them migrate between the litchi plantations and the surrounding habitats. The parasitoids and predators of these pests will be identified and their abundances recorded. Participatory activities will continue in cooperation with subproject A1.2. They include regular meetings with individual farmers and group interviews for information exchange about pest problems and farmers strategies to cope with these problems. In the first phase, four promising cover legume species with potential for soil enhancement and livestock feeding have been identified. In order to increase biodiversity in fruit orchards, the effects of different mixtures of these species will be studied. At Mae Sa Mai, experiments will show if and how such mixtures, by complementary and compensatory effects, contribute to increased productivity and quality of the understorey vegetation. In addition, changes of soil chemical, physical and biological properties will be monitored. Soil scientist expert advice as well as related data flow is ensured by close cooperation with subprojects B1.2, B2.2 and B3.1. Participatory Monitoring and Evaluation (PM&E) will be carried out jointly with A1.2. In the view of the greater role of livestock in the region of the SFB's second research site (Phang Ma Pha), a parallel replication of the legume mixture research is intended for that site in the form of a complementary NRCT project, also including the pest component of the project.
Das Projekt "The effect of potassium and calcium on wood formation and xylem/phloem physology" wird vom Umweltbundesamt gefördert und von Universität Hamburg, Department für Biologie, Zentrum Holzwirtschaft, Ordinariat für Holzbiologie und Institut für Holztechnologie und Holzbiologie des Johann Heinrich von Thünen-Institut, Bundesforschungsinstitut für Ländliche Räume, Wald und Fischerei durchgeführt. Ions play a fundamental role in the physiology of cambial growth. To gain better knowledge about the role of K, Ca and P in wood formation, we intend to focus on plants grown under different K, Ca and P supply as well as on transgenic plants with modified ion transporter expression produced by P5 and/or P3. Two approaches will be applied on all differently treated plants in this project. First, structural and ultrastructural analysis of stem tissues (phloem, cambium, xylem) will be carried out throughout all seasons by image analysis and high resolution TEM. In order to correlate structural changes to biochemical variations, a second approach deals with the following analysis in all tissues: Seasonal changes of K, Ca and P will be measured by EDXA, whereas K and Ca will also be determined quantitatively by atomic absorption spectrometry. By generating antibodies against different potassium transporters we further will show their distribution in poplar stem tissues throughout all seasons by fluorescence and transmission electron microscopy. In order to correlate changes in ion content to sugar concentrations, seasonal variations of different sugars as well as starch will be determined enzymatically. To measure changes in the chemical composition of cell walls, FTIR-spectroscopy will be used to quantitatively detect a range of functional groups in the cell wall.