Modelling the oxygen-18 and rapid glacial climatic events: a data–model comparison

Using a coupled climate model of intermediate complexity that explicitly simulates the oxygen-18 behaviour, we evaluate a recent scenario of abrupt climatic variability during the last glacial period against a sediment core record of the coast of Portugal (MD95-2042). In particular, we focus on a period centred on the Heinrich Event 4 (about 40 kyrs BP) and the surrounding Dansgaard–Oeschger events to explain some features of the sediment core record and question some choices of the suggested scenario. We demonstrate here (1) that the oxygen-18 signal recorded in the planktic foraminifera during D/O events is likely to be due almost entirely to temperature at the location of this core, and (2) that we cannot reproduce the observed oxygen-18 variations in calcite for Heinrich events if we consider that the melting of icebergs occurred elsewhere than in the IRD belt. To cite this article: D.M. Roche, D. Paillard, C. R. Geoscience 337 (2005).