Project Details
Projekt
Exploring annually laminated lake sediments for solar activity reconstructions and Sun-climate studies
Applicant
Dr. Markus Czymzik
Subject Area
Palaeontology
Term
from 2014 to 2016
Project identifier
Deutsche Forschungsgemeinschaft (DFG) - Project number 256277935
Solar forcing of climate variability is one of the most controversially discussed topics in climate research. For example, global warming during the last century occurred in the context of increasing greenhouse gas emission and high levels of solar activity, while the unexpected temperature plateau since 1998 coincides with a decreasing trend in solar activity. Therefore, improved knowledge of the role of the Sun in climate change is essential for projecting future climate developments. The satellite-based records of solar activity are too short to cover the full range of available solar variations and distinguish anthropogenic from natural effects on the climate system. Paleoclimate and solar reconstructions can provide a key to address this problem. However, uncertainties in available solar forcing records from cosmogenic radionuclides 10Be in ice cores and 14C in tree rings and a lack of sufficiently long and well-resolved paleoclimate time-series with precise chronologies hamper such studies so far. Therefore, for better understanding the role of solar variations on climate change it is necessary to explore new ways to complement existing solar activity records and study solar-climate linkages with virtually no uncertainties in the relative timing between solar forcing and climate responses. The potential of 10Be in annually laminated (varved) lake sediments for solar activity reconstruction is, to date, largely unexplored and existing preliminary records contain biases that can be corrected for by applying the latest analytical techniques. It is hypothesized that 10Be contents in sediments from well-chosen lakes reflect the solar induced atmospheric production signal. Main scientific objectives of this proposal are to (1) explore the potential of 10Be in the varved sediment records of Central European Lakes Czechowski and Tiefer See as new type of solar activity proxy, complement existing solar activity estimates from 10Be in ice cores and 14C in tree rings, and (2) test the hypothesis of a solar influence on climate. To reach the outlined objectives this proposal will, for the first time, integrate precisely dated and up to annually resolved 10Be time-series from varved lake sediment archives and verification of the expected solar activity proxy data by calibration against instrumental solar activity and meteorological records as well as onsite monitoring. Comparison of the unprecedented solar activity data with existing paleoclimate proxy data from the same lakes will allow us to investigate potential solar-climate links and related feedback mechanisms, without time-scale uncertainties. Synchronizing the expected solar activity and paleoclimate records from Lakes Czechowski and Tiefer See to those from polar ice cores and tree rings using 10Be and 14C will provide us insights into leads and lags of the climate system and their possible relation to solar activity worldwide.
DFG Programme
Research Fellowships
International Connection
Sweden
