Collaborative Research: Do Holocene Variations In Arctic Sea Ice And Greenland Icebergs Drifting Through Denmark Strait Reflect Natural Cycles?

历史观测和理论表明，流冰的范围和持续时间对气候系统的重要性，通过在半球冰的变化和淡水输出从北冰洋和格陵兰冰盖的温盐环流的影响。提供资金，以开发50-100年的分辨率记录的变化，海冰出口从北冰洋和冰山运输从东北格陵兰岛的冰川冰流，到达丹麦海峡，并制定一个详细的历史，冰筏碎片（IRD）在过去的12,000 cal yr BP。丹麦海峡位于极地和北极沃茨向南出口与北大西洋漂移带以Irminger海流形式存在的西北翼之间的边界，因此被认为是研究的关键区域。这项研究将探讨沿着格陵兰东北/东大陆架和横跨丹麦海峡的源-汇模型，利用沉积物特性记录丹麦海峡两侧和沿着格陵兰东北大陆架的一系列日期明确的高分辨率岩心成分的时空变化。这一信息将用于推断海冰通过丹麦海峡输送的变化情况，鉴于对北极海冰性质变化的持续观测，进入格陵兰-挪威海和北大西洋的海冰流量的变化，以及冰山崩解可能加速格陵兰冰盖的冰损失，更好地了解这些过程在过去是如何变化的，将有助于为预测未来的气候变化提供信息。 该项目将开发有助于这一理解的数据集。

Historical observations and theory suggest the importance of the extent and duration ofdrift ice on the Climate System through changes in the Hemispheric albedo and the impact of freshwater export from the Arctic Ocean and Greenland Ice Sheet on the Thermohaline Circulation. Funds are provided to develop 50-100 yr resolution records of changes in sea ice export from the Arctic Ocean and iceberg transport from tidewater ice streams of NE Greenland that reach the Denmark Strait and to develop a detailed history of ice-rafted debris (IRD) over the last 12,000 cal yr BP. Denmark Strait is believed to be a critical area for study as it lies at the boundary between the southward export of Polar and Arctic waters and the northwestern limb of the North Atlantic Drift in the form of the Irminger Current. The research will explore a sources-to-sink model along the ENE/E Greenland shelf and across the Denmark Strait using sediment characteristics to document spatial and temporal changes in composition in a series of well-dated, high-resolution cores from either side of the Denmark Strait and along the NE Greenland shelf. This information will be used to infer changes in the transport of sea ice through the Denmark Strait.Given the ongoing observations of changing sea ice character in the Arctic, changes in the flux of sea ice into the Greenland-Norwegian Seas and the North Atlantic Ocean, and possible acceleration of ice loss from the Greenland Ice Sheet through iceberg calving, a better understanding of how these processes varied in the past will help inform projections of future climate variations. This project will develop data sets that contribute to that understanding.