We investigate climate change in the geological and historical past and its impacts on the human habitat as well as past changes in the Earth’s magnetic field. Main foci of our research are particularly rapid climate changes that occurred within a few years or decades. Therefore, we exploit high-resolution terrestrial geo-archives as annually laminated (varved) lake sediments and tree rings. A crucial part of our approach is to date precisely and accurately our archives as main prerequisite for robust reconstructions of changes in the past.
Rapid climate changes in the past are considered natural experiments that enable us to gain deep insights into the causes and dynamics of such changes in order to be better prepared to future developments. Therefore, we use structure and chemical composition of seasonal layers (proxy data) that we calibrate with instrumental observation (monitoring). Our vision is to integrate long time series obtained from our high-resolution geo-archives and instrumental data to assessing present-day changes in a long-term context.
Die 8. REKLIM Regionalkonferenz am 25. September 2018 mit dem Titel "Auswirkungen des Klimawandels in Nordost-Deutschland: Wasser – zu viel oder zu wenig?" wird dieses Jahr von Sektion 5.2 am GFZ in Potsdam organisiert.
On the occasion of the 80th birthday of the founding director of Section 5.2 J.F.W. Negendank organizes the GFZ on 28.9.2018 a geoscientific honorary colloquium.
In the focus of the scientific lectures are research results from the Dead Sea, as part of the German-Israeli-Palestinian DFG Trilateral Project PALEX "Paleoclimate in the Eastern Mediterranean Region - Levant: Paleohydrology and Extreme Flood Events", funded by the ICDP Dead Sea Deep Drilling Project (DFG SPP 1006).
Maren Pauly, Gerhard Helle, Cécile Miramont, Ulf Büntgen, Kerstin Treydte, Frederick Reinig, Frédéric Guibal, Olivier Sivan, Ingo Heinrich, Frank Riedel, Bernd Kromer, Daniel Balanzategui, Lukas Wacker, Adam Sookdeo & Achim Brauer - Subfossil trees suggest enhanced Mediterranean hydroclimate variability at the onset of the Younger Dryas - Scientific Reportsvolume 8, Article number: 13980 (2018) | doi:10.1038/s41598-018-32251-2
Nearly 13,000 years ago, the warming trend into the Holocene was sharply interrupted by a reversal to near glacial conditions. Climatic causes and ecological consequences of the Younger Dryas (YD) have been extensively studied, however proxy archives from the Mediterranean basin capturing this period are scarce and do not provide annual resolution. Here, we report a hydroclimatic reconstruction from stable isotopes (δ18O, δ13C) in subfossil pines from southern France. Growing before and during the transition period into the YD (12 900–12 600 cal BP), the trees provide an annually resolved, continuous sequence of atmospheric change. Isotopic signature of tree sourcewater (δ18Osw) and estimates of relative air humidity were reconstructed as a proxy for variations in air mass origin and precipitation regime. We find a distinct increase in inter-annual variability of sourcewater isotopes (δ18Osw), with three major downturn phases of increasing magnitude beginning at 12 740 cal BP. The observed variation most likely results from an amplified intensity of North Atlantic (low δ18Osw) versus Mediterranean (high δ18Osw) precipitation. This marked pattern of climate variability is not seen in records from higher latitudes and is likely a consequence of atmospheric circulation oscillations at the margin of the southward moving polar front.