Das Projekt "TIMECHS: Zeitlicher Verlauf und Mechanismen holozaener Klimaaenderungen in NW-Europa auf der Grundlage von stabilen Isotopen, Pollen und Makrofossilien aus Binnenseeumfeldern" wird vom Umweltbundesamt gefördert und von Universität Bern, Physikalisches Institut, Abteilung für Klima- und Umweltphysik durchgeführt. The project combines the palynological and faunal-assemblage approach with detailed geochemical investigations of calcareous lake sediments and ostracod shell contained therein, to establish a well-dated high-resolution Holocene climate record for western-most Europe. The cores are from a small deep lake, An Loch Mor, Inis O;rr (Inisheer), off the west coast of Ireland (OS grid ref. L 990 020; 9 Grad 30.2'W, 53 Grad 03.4'N). Objectives: (i) To reconstruct, at a fine temporal scale, the paleoclimatic record for the Holocene in a high resolution core from An Loch Mor, Inis Orr. The emphasis will be on establishing high-resolution records to identify periods of rapid climate change (precipitations, temperature, Atlantic storminess, etc.), and on quantifying rates of change. (ii) To reconstruct the role of human activity in bringing about change in both the lake and its catchment. Apart from the intrinsic interest in the reconstructing the timing and factors that have resulted in the present-day treeless karstic landscape, this information is critical to differentiate between chamges brougth about by climate as against those of anthropogenic origin. (iii) To evaluate the role of oceanic thermal inertia in controlling the amplitude and rate of climate fluctuations in the Holocene. This will be achieved by comparing our new high-resolution record with other well-dated records from similar latitudes in western and central Europe. (iv) To test whether climate change events recorded in cores from terrestrial situations in western Europe are synchronous with the atmosphere-driven events recorded in the Holocene parts of the Greenland ice cores, the changing temperature regimes in the North Atlantic and also patterns in North Atlantic Deep Water formation. Prime Contractor: National University of Ireland, Galway, Department of Botany Paleoenvironmental Research Unit; Galway.
Das Projekt "ADVANCE-10K: Analyse der dendrochronologischen Variabilitaet und entsprechender natuericher Kllimata in Eurasien waehrend der vergangenen 10000 Jahre" wird vom Umweltbundesamt gefördert und von Eidgenössische Forschungsanstalt für Wald, Schnee und Landschaft durchgeführt. Objective: To reconstruct a range of climate variables in different regions of northern Eurasia to enhance our knowledge of natural climate variability on a range of timescales within the last 10,000 years and advance our understanding of the mechanisms and forcings that have generated this variability. General Information: This project is focused in the area of dendroclimatology. The absolute dating control and seasonal growth of long tree-ring chronologies will be used to reconstruct a range of climate variables in different regions. The project encompasses extensive development of new densitometric chronologies in northern Siberia, part of ongoing work funded largely by The Swiss National Science Foundation. In addition, the major collections of European historical and sub-fossil oak ring-width data, principally from Great Britain, Sweden, Holland, Denmark, Germany and Poland, are being centralised, quality-controlled and entered into a common European tree-ring data base. Some modern chronology development is being undertaken to update these data and provide modern analogues for comparison with recent climate data. The project will reconstruct changes in temperature and precipitation-related variables over a range of temporal and spatial scales determined by the length, location and climate sensitivity of the available tree-ring data. This work will generate detailed individual maps of summer temperatures over several centuries across northern Siberia. These data will be interpreted in terms of large-scale atmospheric circulation patterns over western Europe and northern Eurasia and within the context of the large-scale general circulation of the Northern Hemisphere. Tree-growth and derived climate variability will be compared with (less well resolved) independent evidence of climate change in, and outside of, Europe, and with proxies of potential climate forcings such as volcanic, solar and Milankovitch changes throughout the Holocene. Evidence for the influence of ocean dynamics on European climates will be explored by comparing the statistical characteristics of the reconstructions with those of climate data produced by appropriate fully-coupled Ocean-Atmosphere General Circulation Models. Continuous regional-average timeseries will be produced spanning several millennia in specific regions of Sweden, Finland and Central Europe. These will allow an exploration of the evidence for contemporaneous, widespread and abrupt tree-growth changes that may indicate the effects of major environmental disruption potentially due to volcanic or cometary activity.