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

有证据表明，在最后一个冰河时期，更多的二氧化碳储存在深海沃茨中，并随着地球变暖而释放到大气中。有几种方式可能会发生这种情况。当海洋沃茨的总量在最后一个冰河时期后减少时，二氧化碳可能会被释放出来。或者储存在深海沃茨中的二氧化碳量会随着深海洋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。从印度洋收集的新收集的沉积物岩心将被检查化学的微妙变化，这将为科学家提供一种方法来记录二氧化碳如何在海洋和大气之间长时间移动。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，与教育工作者和公众分享。 经过几十年的研究，冰川海洋中二氧化碳封存的物理控制与生物控制的问题仍然没有得到解决。在冰川作用期间，温盐环流、南大洋通风和营养物质利用的变化都被认为在减少大气CO2方面发挥了重要作用。为了更好地了解CO2的生物转移与物理转移的不同作用，需要研究多个海洋盆地中的多个水团。科学目标是重建的规模和机制，推动碳储存在南印度洋确定的时间演变和垂直分布的Delta 14 C和氧化（使用定量代理：Delta-delta 13 Cwuel-globo，和烯酮保存）在印度洋内部水体在整个末次冰期-间冰期过渡。这些代理人已被选择来区分水团循环和呼吸驱动的CO2积累的速率，以评估这些机制在CO2封存中发挥的作用。使用多个沉积物芯横跨纬度和经度一直在确定海洋CO2储存的关键指标（三角洲14 C和氧化）有很大的不同，在大西洋和太平洋随着时间的推移。这里提出的工作将利用近30年来来自南印度洋的第一份新的核心材料，填补我们知识上的一个重大空白。我们从深度（1，118至3，164米）选择了一套三个合适的岩心，这些岩心被主要的内部水团所浸泡，这些水团反映了当今该地区呼吸和循环驱动的CO2储存。该奖项反映了NSF的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

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.