High Resolution UK37 Alkenone Paleothermometry at Bermuda Rise: The Last Interglacial to the Little Ice Age

百慕大海隆高分辨率 UK37 烯酮古体温测量：最后一次间冰期到小冰期

• 批准号: 9610128
• 负责人: Scott Lehman
• 金额: $ 54.22万
• 依托单位: University of Colorado at Boulder
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1997
• 资助国家: 美国
• 起止时间: 1997-04-15 至 2000-03-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9610128&HistoricalAwards=false
• 关键词: Resolution; UK37; Alkenone; Paleothermometry; Bermuda

Abstract ATM-9610128 Lehman, Scott J. University of Colorado Title: High Resolution UK37 Alkenone Paleothermometry at Bermuda Rise: The Last Interglacial to the Little Ice Age Subtropical sea surface temperature (SST) is an important climate boundary condition within much of the North Atlantic basin. It is not known, however, whether sub-polar millennial- and century- scale SST changes also affected the subtropical gyre, and to what degree such changes were connected with variations in the rate of formation of North Atlantic Deep Water (NADW). Recently recovered long cores, by the Marion Dufresne, provide an unparalleled opportunity to study highly resolved proxy records of SST and NADW variations. Work supported by this grant will establish a time series of SST at 50-yr to 100-yr sample spacing for the past 150 kyr in sediments of the Bermuda Rise using the alkenone paleo-temperature estimation technique. Similar measurements made in a pilot study of the last 15 kyr provide evidence of large swings in SST during the last deglaciation. This is consistent with SST estimates from foraminiferal assemblage data. The pilot results demonstrate that the proposed studies are likely to yield a high-amplitude signal of SST variations for the North Atlantic subtropical gyre. The fidelity and geographic representativeness of the Bermuda Rise results can be cross-checked at key intervals by analysis of a second high deposition-rate core from Blake-Bahama Outer Ridge. Combining this work with other proxy studies will produce paired proxy records of SST and NADW variation and will allow the evaluation of the role of the ocean thermohaline circulation in climate changes occurring on these timescales.

美国科罗拉多州科罗拉多大学ATM-9610128。标题：百慕大隆起的高分辨率UK37烷酮古温度计：末次间冰期至小冰期的亚热带海面温度是北大西洋盆地大部分地区的一个重要气候边界条件。然而，尚不清楚亚极、千年和百年尺度的海温变化是否也影响副热带涡旋，以及这种变化与北大西洋深水形成速度(NADW)的变化有多大程度的联系。最近由Marion Duresne发现的长岩心，为研究SST和NADW变化的高分辨率替代记录提供了一个无与伦比的机会。这项赠款支持的工作将利用烯酮古温度估计技术，建立百慕大隆起沉积物中过去150KYR的50年至100年样本间隔的SST时间序列。在对最近15个KYR的初步研究中进行的类似测量提供了最后一次冰川消融期间SST大幅波动的证据。这与从有孔虫组合数据中估计的SST是一致的。试验结果表明，拟议的研究可能会产生北大西洋副热带环流海温变化的高幅度信号。百慕大隆起结果的保真度和地理代表性可以通过对来自布莱克-巴哈马外脊的第二个高沉积速率岩心的分析，在关键间隔进行交叉验证。将这项工作与其他替代研究相结合，将产生SST和NADW变化的配对替代记录，并将能够评估海洋温盐环流在这些时间尺度上发生的气候变化中的作用。