A revised orbital forcing concept of West African climate and vegetation variability during the Pliocene and the Last Glacial cycle: Molecular isotopic approach and proxy calibration

Abstract

The tropical monsoon is a pivotal feature of the atmospheric circulation and is tightly linked to global climate dynamics. Understanding the future development of the current climate change towards warmer conditions relies heavily on our knowledge of analogous situations in the past. One of the most promising time intervals to study a warmer-than-today climate is the Pliocene, since it constitutes the most recent period of the geological record with many boundary conditions similar to today. This PhD thesis focuses on the application of stable carbon and hydrogen isotopes of plant-wax-derived long-chain n-alkanes, as well as other (in)organic geochemical proxies. All studies presented herein were carried out on marine sediments from the Northeast Atlantic Ocean close to West Africa, in order to characterize past environmental conditions on the adjacent continent and their drivers (down-core analyses), as well as to strengthen the significance of the applied methods (surface mapping).