High Northern Latitude Linkages between Atlantic Water, DSOW Formation and GIS Stability during the Holocene

University Of Colorado At Boulder, Boulder CO

Investigators

Abstract

This award will provide funds to test three hypotheses related to the formation of intermediate and deep water in the Nordic Seas north of Iceland. Specifically, was 1) Denmark Straight Overflow Water (DSOW) formation dampened by freshening of Atlantic Water entering the Nordic Seas through the end of the deglaciation of the Laurentide Ice Sheet, ca. 6,700 cal years ago? 2) Does the middle Holocene interval of greatest DSOW flow correspond to a time of minimal freshwater forcing from north and south and maximal salinity and inflow of the Irminger Current? 3) Was diminished DSOW formation in the late Holocene due to freshwater forcing from the Arctic Ocean by southward advancing Polar Water and sea ice? These hypotheses will be tested via analyses of sediment geochemistry and Mg/Ca, d18O and Cd/Ca of foraminifera assemblages from a suite of North Atlantic deep sea cores, as part of a broader international collaboration including the IPY project WARMPAST. Broader impacts include graduate and undergraduate involvement in the research, a strong international collaborative component and research on a societally-relevant scientific question related to ocean-climate linkages and mechanisms of climate change during the Holocene (last 10,000 years).