Collaborative Research: Disentangling physical and biological controls on Indian Ocean carbon storage during the last glacial-interglacial transition

合作研究：理清末次冰期-间冰期过渡期间印度洋碳储存的物理和生物控制

基本信息

批准号：
2002642
负责人：
Elisabeth Sikes
金额：
$ 12.86万
依托单位：
Rutgers University New Brunswick
依托单位国家：
美国
项目类别：
Standard Grant
财政年份：
2020
资助国家：
美国
起止时间：
2020-08-01 至 2024-07-31
项目状态：
已结题

来源：
https://www.nsf.gov/awardsearch/showAward?AWD_ID=2002642&HistoricalAwards=false
关键词：
Collaborative Research Disentangling physical biological

项目摘要

Evidence suggests more carbon dioxide was stored in deep ocean waters during the last ice age and released to the atmosphere as the Earth warmed. There are several ways that this might happen. Carbon dioxide could be released when the total amount of algae in ocean waters decreases after the last ice age. Or the amount of carbon dioxide stored in the deeper ocean waters could change with differing pathways of deep currents. Recent work suggest the Indian Ocean might play an important role in one or both of these processes. Newly collected sediment cores collected from the Indian Ocean will be examined for subtle changes in the chemistry that will provide scientists a way to document how carbon dioxide moves between the oceans and atmosphere over long periods of time. The social media platform of the American Museum of Natural History will be used to produce short video segments and visualizations of ocean circulation and climate to share with educators and the general public. The question of physical versus biological controls of CO2 sequestration in the glacial ocean remains unresolved after decades of research. During glaciations, changes in thermohaline circulation, Southern Ocean ventilation, and nutrient utilization are all believed to have played an important role in reducing atmospheric CO2. An improved understanding of the different roles of biological transfer versus physical transfer of CO2 requires examining multiple water masses in multiple ocean basins. The scientific objective is to reconstruct the magnitude and mechanisms driving carbon storage in the southern Indian Ocean by determining the temporal evolution and vertical distribution of Delta14C and oxygenation (using quantitative proxies: Delta-delta13Cwuel-globo, and alkenone preservation) in Indian Ocean interior water masses across the last glacial-interglacial transition. These proxies have been chosen to distinguish between the rate of water mass circulation and respiration-driven CO2 accumulation to assess the roles these mechanisms played in CO2 sequestration. The use of multiple sediment cores across latitude and longitude has been fundamental in determining that critical indicators of oceanic CO2 storage (Delta14C and oxygenation) differed substantially in the Atlantic and Pacific through time. Work proposed here will fill a substantial gap in our knowledge by making use of the first new core material from the Southern Indian Ocean in nearly 30 years. We have selected a suite of three suitable cores from depths (1,118 to 3,164 m) that are bathed by the major interior water masses that reflect both respiration and circulation driven CO2 storage in the region today. Results created here will be the first from this area using these techniques to determine the magnitude and mechanisms of Southern Indian Ocean CO2 storage.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

有证据表明，在上一个冰河时代，更多的二氧化碳储存在深海水域中，并随着地球变暖而释放到大气中。发生这种情况的方式有多种。在最后一个冰河时代之后，当海水中的藻类总量减少时，就会释放二氧化碳。或者，储存在更深海水中的二氧化碳量可能会随着深海流路径的不同而变化。最近的研究表明印度洋可能在其中一个或两个过程中发挥重要作用。从印度洋收集的新沉积物岩心将被检查化学成分的细微变化，这将为科学家提供一种记录二氧化碳如何长期在海洋和大气之间移动的方法。美国自然历史博物馆的社交媒体平台将用于制作海洋环流和气候的短视频片段和可视化，以便与教育工作者和公众分享。经过数十年的研究，冰川海洋中二氧化碳封存的物理与生物控制问题仍未得到解决。冰川时期，温盐环流、南大洋通风和养分利用的变化被认为在减少大气二氧化碳方面发挥了重要作用。为了更好地了解二氧化碳的生物转移与物理转移的不同作用，需要检查多个海洋盆地的多个水团。科学目标是通过确定印度洋内水 Delta14C 和氧合的时间演化和垂直分布（使用定量代理：Delta-delta13Cwuel-globo 和烯酮保存）来重建南印度洋碳储存的规模和驱动机制跨越末次冰期-间冰期过渡期的大量物质。选择这些代理来区分水团循环速率和呼吸驱动的二氧化碳积累速率，以评估这些机制在二氧化碳封存中发挥的作用。使用跨越纬度和经度的多个沉积物岩心对于确定大西洋和太平洋中海洋二氧化碳储存的关键指标（Delta14C和氧合）随时间的推移存在显着差异至关重要。这里提出的工作将通过利用近 30 年来来自南印度洋的第一个新核心材料来填补我们知识的巨大空白。我们从深度（1,118 至 3,164 m）选择了一套三个合适的岩心，这些岩心沐浴在主要的内部水团中，反映了当今该地区呼吸和循环驱动的二氧化碳储存。这里创建的结果将是该领域首次使用这些技术来确定南印度洋二氧化碳储存的规模和机制。该奖项反映了 NSF 的法定使命，并通过使用基金会的智力价值和更广泛的影响审查进行评估，被认为值得支持标准。