Late Quaternary paleoceanographic history of the Pacific sector of the Southern Ocean based on diatom evidence

Abstract

The last transition from a full glacial to a full interglacial state is of special importance to investigate processes that control the Earth s climate evolution especially regarding the interhemispheric climate variability. The Southern Ocean as southern limb of the Atlantic Meridional Overturning Circulation plays a crucial role in propagating signalsbetween the Pacific, Atlantic and Indian Ocean. Sea surface temperature (SST) and sea-ice extent are important surface water parameters related to the oceanic frontal and current systems as well as to water mass formation via brine release and bioproductivity changes. This thesis provides for the first time summer SSTs and winter sea-ice estimates in the Pacific sector of the Southern Ocean on a wide spatial range and for time slices within the last 30,000 years whose paleoceanographic history is crucial for the understanding of global climate change. The investigated environmental parameters point to the sensitivity of this Southern Ocean sector, concerning the drainage of the WAIS and the impact of atmospheric changes that has the high potential of triggering climate change.