Collaborative Research: Testing the Northern Route for Younger Dryas Meltwater

合作研究：测试新仙女木融水的北方路线

• 批准号: 1203944
• 负责人: Neal Driscoll
• 金额: $ 40.15万
• 依托单位: University of California-San Diego Scripps Inst of Oceanography
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-07-01 至 2016-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1203944&HistoricalAwards=false
• 关键词: Collaborative; Research; Testing; Northern; Route

The PIs propose a three-year project to investigate the origin of the Younger Dryas cooling. New evidence suggests that glacial Lake Agassiz released fresh water to the Arctic through the Mackenzie River and they propose that this signal should be detectable along the western margin of the Canadian Archipelago in the oxygen isotope ratio in the shells of planktonic foraminifera. The project involves a three-week expedition to survey the seafloor and subbottom layers and collect sediment cores from the eastern Beaufort Sea, a region that is remote and has not been well explored. Besides the sediment processing and micropaleontology that are part of generating the isotope data that reflect sea surface salinity, two complementary shore-based projects are proposed. The first is to integrate the new geophysical data on the continental margin with the climate history of the open sea, sediment transport, relative sea level change, and terrestrial climate, as they have done previously for the Chukchi Sea. The second is to compare the geochemical data with results from a high resolution General Circulation Model that is configured to reveal the path and the mixing of the melt water. Although the paleoceanographic data will be spatially limited, model runs will show the low salinity distribution in the Arctic as well as in the Nordic seas where the freshening may have affected deep ocean overturning and caused the Younger Dryas cooling.The Younger Dryas was a period of climatic cooling that began about 13,000 years ago and lasted more than 1000 year. It reversed a period of climatic warming, even though insolation continued to increase. This study will attempt to determine the mechanism that allowed such a reversal in temperature trend to occur and, thus, inform discussions of whether similar changes are probable in the future.

PI提出了一个为期三年的项目，以研究年轻的Dryas冷却的起源。新的证据表明，冰川湖Agassiz通过Mackenzie河向北极释放了淡水，他们建议应在浮游有孔虫的壳中以氧同位素比的氧气比率以加拿大群岛的西部边缘检测到该信号。该项目涉及进行为期三周的探险，以调查海底和子底层层，并从东波福特海（Eastern Beaufort Sea）收集沉积物核心，该地区遥远，尚未得到很好的探索。除了产生反映海面盐度的同位素数据的一部分的沉积物加工和微岩石学外，还提出了两个基于海岸的项目。首先是将大陆边缘的新的地球物理数据与公海的气候历史，沉积物传输，相对海平面变化和陆地气候相结合，就像以前为chukchi Sea所做的那样。第二个是将地球化学数据与高分辨率一般循环模型产生的结果进行比较，该模型的配置为揭示熔体水的路径和混合。尽管古环学数据将在空间上受到限制，但模型运行将显示北极以及北欧海洋中的低盐度分布，在北欧海洋中，鲜明的鲜明可能影响了深海的推翻，并引起了年轻的Dryas冷却。幼小的天气冷却时期是一段时间以前，大约13,000年开始，持续了大约1000年。 即使暴发持续增加，它也扭转了一段气候变暖。 这项研究将尝试确定允许温度趋势发生这种逆转的机制，从而告知讨论将来是否可能发生类似变化的讨论。