Ocean Dynamics Impacting Shelf Sea Level in Eastern Atlantic (ODISSEA)

这是一个由美国国家科学基金会地球科学理事会（NSF/GEO）和英国国家环境研究委员会（NERC）通过NSF/GEO-NERC牵头机构协议共同资助的项目。该协议允许美国/英国提交一份联合提案，并由其调查员拥有最大比例预算的机构进行同行评审。在成功地共同确定一个奖项推荐后，每个机构资助预算的比例，以支持各自国家机构的科学家。由于陆地冰融化和海洋热膨胀的共同作用，全球平均海平面正在上升。然而，从区域来看，海平面也受到大尺度洋流强度和路径变化的强烈影响，长期趋势往往被几年的大幅度变化所掩盖。对沿海社区来说，量化和预测区域模式至关重要，因为极端海平面事件的规模和频率与社会直接相关。在美国东海岸，海平面上升和变化模式与大西洋经向翻转环流（AMOC）有关。然而，在西北欧洲大陆架，人们对AMOC对海平面变化、变率和极端事件的影响知之甚少。该项目将结合直接观测和数值模拟，以更好地了解沿海海平面在一系列时间尺度上变化的驱动因素。这种理解对于保护沿海人口、生态系统、基础设施和海运业至关重要。对未来海平面变化的高度关注，以及ODISSEA对知识和数据差距的战略重点，确保了该项目将对海平面研究界产生重大影响。从这个项目中学到的新知识将传播到相关的学术团体（通过高影响力的海洋和气候期刊以及领先的国际会议）和佛罗里达当地对海平面上升有浓厚兴趣的社区（通过COAPS/FSU的教育计划和外展活动）。该项目还将支持FSU的博士后培训和职业发展，以获得分析观测和模型输出的经验。该项目包括：1)在月-年时间尺度上建立深海环流与陆架海平面变化之间的因果关系；2)提供未来30年英国西部和爱尔兰沿海海平面变化的估计，并提高对这些变化发生的地点和原因的理解；3)分离观测和预估的AMOC变化对区域海平面变化、变率和极端事件的影响。量化和预测海平面变化的区域模式的一个关键障碍是了解大陆斜坡上的海洋动力学-深海和浅大陆架之间的界面。从深海流向大陆架的洋流要么继续流入大陆架，要么流入环绕欧洲大陆架西北部的快速沿坡边界流。此外，预计大尺度洋流将随着气候变暖而变化，预计AMOC将在未来30年急剧减弱。然而，产生这些预测的气候模式缺乏所需的精细分辨率，无法在区域尺度上捕捉这些变化对陆架海平面的影响，特别是窄边界流在调节海岸深海环流影响方面的作用。使用直接观测和高分辨率模型将使该项目能够量化和了解开放海洋环流，它们如何随时间变化，以及它们如何影响沿海海平面变化。该奖项反映了美国国家科学基金会的法定使命，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。

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.Global mean sea level is rising due to the combined effects of melting land ice and ocean thermal expansion. Regionally however, sea level is also strongly influenced by changes in the strength and the pathways of large-scale ocean currents, and the long-term trend is often masked by large-amplitude changes over several years. Quantifying and predicting regional patterns are crucial for coastal communities where the magnitude and frequency of extreme sea level events are of immediate societal relevance. At the U.S. East Coast, sea level rise and variability patterns have been linked to the Atlantic meridional overturning circulation (AMOC). On the NW European shelf, however, comparatively little is known about the impact of AMOC on sea level change, variability, and extremes. This project will combine direct observations and numerical modeling to better understand the drivers of coastal sea level change on a range of timescales. Such understanding is vital for protecting coastal populations, ecosystems, infrastructure, and maritime industries. The high level of interest in future sea level change, together with the strategic focus of ODISSEA on knowledge and data gaps ensures that the project will have significant impact in the sea level research community. New knowledge learned from this project will be disseminated to the relevant academic communities (via high-impact ocean and climate journals and at leading international conferences) and local Florida panhandle community in which sea level rise is a keen interest (through education programs and outreach activities at COAPS/FSU). The project will also support the training and career development for a post-doc at FSU to gain experience in the analysis of both observations and model outputs.This project includes efforts to 1) establish the causal links between deep ocean circulation and shelf sea level changes on monthly to decadal time scales; 2) provide estimates of coastal sea level change for the western UK and Ireland over the next 30 years, with an improved understanding of where and why these changes will occur; and 3) isolate the impact of observed and projected AMOC changes on regional sea level change, variability, and extremes. A key barrier to quantifying and predicting regional patterns of sea level change is understanding the ocean dynamics over the continental slope – the interface between the deep ocean and the shallow continental shelf. Currents directed from the deep ocean towards the slope may either continue onto the shelf or feed into the rapid along-slope boundary current which encircles the NW European shelf. Further, the large-scale ocean currents are predicted to change with the warming climate, with the AMOC being projected to weaken dramatically in the next 30 years. However, the climate models which yield these predictions lack the fine-scale resolution required to capture the effect of these changes on shelf sea level at a regional scale, in particular the role of narrow boundary currents in modulating the influence of the deep ocean circulation at the coast. The use of direct observations and high-resolution models will allow this project to quantify and understand the open ocean circulation, how they change over time, and how they impact the coastal sea level change.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.