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

这项奖励将提供资金，以检验与冰岛以北北欧海域中深水形成有关的三个假说。具体地说，1)通过约6,700年前劳伦特冰盖的冰川消融，进入北欧海域的大西洋水的淡水是否抑制了丹麦直溢水(DSOW)的形成？2)全新世中期最大的DSOW流量间隔是否对应于来自南北的淡水强迫最小的时间段，以及最大的盐度和伊明格流的流入？3)由于北冰洋淡水被南移的极地水和海冰迫使从北冰洋进入，DSOW形成在晚全新世减少？作为包括IPY项目WARMPAST在内的更广泛国际合作的一部分，将通过对北大西洋一套深海岩心的有孔虫组合的沉积物地球化学和镁/钙、d18O和Cd/Ca的分析来检验这些假设。更广泛的影响包括研究生和本科生参与这项研究，一个强有力的国际合作组成部分，以及对与海洋-气候联系和全新世(过去10,000年)气候变化机制有关的具有社会意义的科学问题的研究。

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).