Heinrich Event Iceberg Flux, Melting, and Ocean Circulation in the North Atlantic

海因里希事件北大西洋冰山通量、融化和海洋环流

• 批准号: 1635019
• 负责人: Jerry McManus
• 金额: $ 51.21万
• 依托单位: Columbia University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-09-01 至 2020-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1635019&HistoricalAwards=false
• 关键词: Heinrich; Event; Iceberg; Flux; Melting

This project generally aims to generate high-resolution data on a suite of deep-sea sediment cores from the North Atlantic Ocean and to conduct a comparison of the results with conceptual and computer models for the episodic production of major iceberg discharges. The researchers aim to produce a spatially systematic dataset of the concentration, provenance and flux of ice-rafted debris (IRD), derived from the North American Laurentide Ice Sheet (LIS) in an array of sites extending from west to east across the subpolar ocean, and south to the subtropics. These data will be used to test hypotheses regarding the genesis and subsequent distribution of melting icebergs associated with the Heinrich events of the last glaciation and to provide insights into the interactions of cryosphere and ocean circulation.The catastrophic iceberg discharge (Heinrich) events that punctuated the last ice age were among the largest known interactions of the Earth's cryosphere, ocean, and climate. Although there is continued debate about their causes and consequences, in at least a subset of the events, the evidence is consistent with their likely influence on the salinity and stability of the subpolar Atlantic, significant weakening of the Atlantic meridional overturning circulation (AMOC), cooling of the northern hemisphere, warming of the southern hemisphere, and shifts in the global hydrological cycle and large-scale atmospheric circulation and composition. Yet deposits associated with two of the six events originally identified during the last glaciation have very different sedimentary characteristics in the eastern subpolar North Atlantic, where they have most commonly been compared. This poses a problem for any single mechanism proposed to explain the events, requiring exceptions or contrasting explanations for different events.The Broader Impacts involve advancing understanding of the cryosphere, ocean, and climate system. The project will support an early career postdoctoral researcher and several undergraduates in the research. Research participants will take part in a research cruise to recover new sediments as part of a collaborative effort that is aligned with the goals of international efforts to understand the Coupled North Atlantic-Arctic System. The Broader Impacts also involve outreach through collaboration with for New York City public high school teachers and students. Members of the project will participate in the biennial Lamont-Doherty Earth Observatory Open House which draws thousands of visitors of all ages to the campus.

该项目的总体目标是生成北大西洋一套深海沉积物岩心的高分辨率数据，并将结果与​​主要冰山排放的间歇性产生的概念模型和计算机模型进行比较。 研究人员的目标是生成一个关于冰筏碎片（IRD）浓度、来源和通量的空间系统数据集，这些碎片来自北美劳伦泰德冰盖（LIS），分布在一系列地点，从西向东穿过副极地海洋，向南延伸到亚热带。 这些数据将用于检验有关与末次冰期海因里希事件相关的冰山融化的起源和随后分布的假设，并为冰冻圈和海洋环流的相互作用提供见解。 末次冰河时期的灾难性冰山泄洪（海因里希）事件是已知的地球冰冻圈、海洋和气候之间最大的相互作用之一。尽管关于其原因和后果的争论仍在继续，但至少在一部分事件中，证据表明它们可能对副极地大西洋的盐度和稳定性、大西洋经向翻转环流（AMOC）的显着减弱、北半球变冷、南半球变暖以及全球水文循环和大规模大气环流和成分的变化产生影响。 然而，与上次冰期期间最初发现的六个事件中的两个相关的沉积物在北大西洋副极地东部具有非常不同的沉积特征，在那里它们最常被比较。这给任何提出解释事件的单一机制带来了问题，需要对不同事件进行例外或对比解释。更广泛的影响涉及增进对冰冻圈、海洋和气候系统的理解。 该项目将支持一名早期职业博士后研究员和几名本科生参与研究。研究参与者将参加一次研究航行，以回收新的沉积物，作为合作努力的一部分，该合作努力与了解北大西洋-北极耦合系统的国际努力的目标相一致。更广泛的影响还包括通过与纽约市公立高中教师和学生的合作进行外展。该项目的成员将参加两年一度的拉蒙特-多尔蒂地球观测站开放日，该开放日吸引了数千名各个年龄段的游客来到校园。

项目成果

Evidence for Stable Holocene Basin‐Scale Overturning Circulation Despite Variable Currents Along the Deep Western Boundary of the North Atlantic Ocean

尽管北大西洋西部深部边界的洋流变化，全新世盆地稳定的证据——规模翻转环流

• DOI: 10.1029/2018gl080187
• 发表时间: 2018
• 期刊: Geophysical Research Letters
• 影响因子: 5.2
• 作者: Hoffmann, Sharon S.;McManus, Jerry F.;Swank, Emerson
• 通讯作者: Swank, Emerson

The biogeochemical impact of glacial meltwater from Southwest Greenland

• DOI: 10.1016/j.pocean.2019.102126
• 发表时间: 2019-09-01
• 期刊: PROGRESS IN OCEANOGRAPHY
• 影响因子: 4.1
• 作者: Hendry, Katharine R.;Huvenne, Veerle A. I.;Woodward, E. Malcolm S.
• 通讯作者: Woodward, E. Malcolm S.