NSFGEO-NERC: C-Streams: The Gulf Stream control of the North Atlantic carbon sink

NSFGEO-NERC：C-Streams：湾流对北大西洋碳汇的控制

• 批准号: 2329385
• 负责人: Lisa Beal
• 金额: $ 50万
• 依托单位: University of Miami
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-07-15 至 2026-06-30
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2329385&HistoricalAwards=false
• 关键词: NSFGEO; NERC; Streams; Gulf; Stream

The ocean takes up about one-quarter of the carbon dioxide (CO2) emitted by humans each year, slowing climate change. The North Atlantic Ocean is disproportionately important for anthropogenic carbon uptake. The North Atlantic also hosts a strong “natural” carbon cycle driven by both biological and physical processes. A team of scientists from the US and UK will address a fundamental knowledge gap as to how the oceanic carbon sink will evolve in the future, by focusing on the mechanisms controlling the North Atlantic carbon sink – particularly the effect of ocean circulation. This is a project jointly funded by the National Science Foundation’s Directorate for Geosciences (NSF/GEO) and the National Environment Research Council (NERC) of the United Kingdom (UK) via the NSF/GEO-NERC Lead Agency Agreement. This Agreement allows a single joint US/UK proposal to be submitted and peer-reviewed by the Agency whose investigator has the largest proportion of the budget. Upon successful joint determination of an award recommendation, each Agency funds the proportion of the budget that supports scientists at institutions in their respective countries. In addition to the US/UK collaboration, the project includes a partnership with The Island School in the Bahamas, substantial public outreach, and support for an early career postdoctoral researcher.The prevailing view of the North Atlantic’s role in carbon uptake is that it is controlled by surface fluxes, such that strengthening stratification will reduce future uptake. The project team hypothesize that the transport of nutrients and low-carbon waters by the Gulf Stream will also influence future carbon uptake over the North Atlantic. The Gulf Stream injects old nutrient rich and anthropogenic carbon-poor waters into the North Atlantic, driving some of the highest rates of CO2 uptake seen anywhere in the ocean and shaping patterns of CO2 uptake across much of the subpolar and subtropical gyres. The project objectives are to: (1) Quantify and understand the source waters that feed the Gulf Stream at Florida Straits;(2) Measure and model the processes that modify the nutrients and carbon carried by the Gulf Stream as it enters the North Atlantic; (3) Understand how the Gulf Stream affects North Atlantic carbon uptake now and into the future; (4) Disseminate this new understanding to those steering future measurements of oceanic CO2 uptake and managing our response to climate change. Specific outcomes from the project will include: (1) A two-year time series of daily physical, biogeochemical, and velocity fields across the Florida Straits, characterizing the source-point variability of Gulf Stream properties; (2) A two-year time series of dynamical and biogeochemical transports of the Gulf Stream and their southern hemisphere and recirculating components. Characterisation of the variability of these transports and how they relate to the basin-wide circulation; (3) Synthesis of the new observations with long-term in situ and satellite observations and with targeted model experiments to build an understanding of how Gulf Stream nutrient and low-carbon transports vary in relation to near-field and far-field oceanic and wind conditions and to infer how they may be changing over multi-decadal time scales.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.

海洋吸收了人类每年排放的约四分之一的二氧化碳（CO2），减缓了气候变化。北大西洋对人类碳吸收的重要性不成比例。北大西洋还拥有一个由生物和物理过程驱动的强大的“自然”碳循环。来自美国和英国的一个科学家团队将通过关注控制北大西洋碳汇的机制，特别是海洋环流的影响，解决海洋碳汇未来如何演变的基本知识缺口。这是一个由国家科学基金会地球科学理事会（NSF/GEO）和联合王国国家环境研究理事会（NERC）通过NSF/GEO-NERC牵头机构协议联合资助的项目。该协议允许美国/英国提交一份联合提案，并由研究者拥有最大预算比例的机构进行同行评审。一旦成功地共同确定了一项奖励建议，每个机构就为支助各自国家机构科学家的预算部分提供资金。除了美国/英国的合作，该项目还包括与巴哈马群岛岛屿学校的合作，大量的公共宣传，以及对早期职业博士后研究人员的支持。北大西洋在碳吸收中的作用的流行观点是，它是由表面通量控制的，这样加强分层将减少未来的吸收。项目小组假设，墨西哥湾流输送的营养物质和低碳沃茨也将影响北大西洋未来的碳吸收。墨西哥湾流将古老的富营养和人为碳贫乏的沃茨注入北大西洋，推动了海洋中任何地方都能看到的最高二氧化碳吸收率，并在大部分副极地和亚热带环流中形成了二氧化碳吸收模式。该项目的目标是：（1）量化和了解在佛罗里达海峡供给墨西哥湾流的源沃茨;（2）测量和模拟墨西哥湾流进入北大西洋时改变其携带的营养物和碳的过程;（3）了解墨西哥湾流现在和将来如何影响北大西洋的碳吸收;（4）将这一新的认识传播给那些指导未来海洋二氧化碳吸收测量和管理我们对气候变化的反应的人。该项目的具体成果将包括：（1）横跨佛罗里达海峡的每日物理、地球化学和速度场的两年时间序列，表征墨西哥湾流特性的源点变化;（2）墨西哥湾流及其南半球和再循环成分的动力和地球化学输送的两年时间序列。描述这些输送的可变性及其与全流域环流的关系;（3）将新的观测结果与长期现场和卫星观测结果以及有针对性的模型实验相结合，以了解墨西哥湾流的营养物质和低碳输送如何与近场和远场海洋和风条件相关地变化，并推断它们如何在多个区域变化。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。