Project title: Assessing the response of the AMOC during times of abrupt climate change
Researcher: Megan Murphy O’ Connor
Due to the short time-series of our observations (~150 years) and lack of any abrupt climate events occurring during this time, the precise response of the Atlantic Meridional Overturning Circulation (AMOC) to abrupt changes in climate cannot yet be determined. This gap in knowledge has led to large uncertainties when estimating AMOC variability in the future (e.g. IPCC5) and to widespread complacency when addressing the threats of global climate change. The Climate Change Advisory Council (CCAC) of Ireland stresses that we need to focus our research efforts on understanding the potential risks high-impact events associated with the AMOC may have for Ireland. Carefully selected high-resolution oceanic archives can shed light on the timing and mechanisms that control the AMOC during abrupt climate events. Specifically, here we proposed to investigate abrupt transitions in climate that occurred between warm interglacial to cold glacial conditions of previous glacial cycles. While Northern Hemisphere ice build-up is believed to have occurred gradually, glacial inceptions are also characterised by abrupt regional cooling events in the North Atlantic region and beyond. The proposed project addresses these themes using an interdisciplinary research strategy that is central to palaeoceanographic research. The proposed methodologies combine isotope and trace metal geochemistry, palaeoecological techniques, with physical grain size analysis to reconstruct the response of the AMOC to abrupt climate change under various boundary conditions. At the heart of the proposed work is the analysis of marine sediment archive Deep See Drilling (DSDP) – the precursor of IODP - Site 610. The integration of these marine archives in climate research is of specific interest to the Geological Survey of Ireland.