Collaborative Research: The Influence of the Mediterranean Outflow Water on the Climatic Variability of the North Atlantic

合作研究：地中海流出水对北大西洋气候变化的影响

• 批准号: 0452706
• 负责人: Eric Chassignet
• 金额: $ 67.6万
• 依托单位: University of Miami
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-04-01 至 2006-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0452706&HistoricalAwards=false
• 关键词: Collaborative; Research; Influence; Mediterranean; Outflow

ABSTRACTOCE-0452679/0452706Convection in the Mediterranean Sea produces a warm salty water mass that flows over the Gibraltar sill into the Atlantic at mid-depth, forming one of the most pronounced property distributions tongue in the global ocean. The impact of these overflow waters on the dynamics and properties of the North Atlantic basin is disproportionate to its relatively small volume flux. The high salinity contributes to the preconditioning of the surface waters in the Nordic Seas for deep convection, either directly via advection or indirectly via mixing. Additionally, these waters establish the property fields in the eastern North Atlantic over a depth range that considerably exceeds the overflow thickness, and of the entire mid-depth subtropical basin, influence the dynamics of the eastern basin. The variability of the Mediterranean overflow wagters has been largely ignored. A recent study has shown increases in the temperature and salinity over the past fifty years. The two main questions of this study are: what is the spatial and temporal context for these changes, and what is the impact of these changes on the property fields and dynamics of the eastern North Atlantic and on the basin as a whole? To address these questions, data and modeling analyses are proposed to assess not only the consequence of Mediterranean overflow variability on the basin, but also the relative importance of other sources of variability. While past studies have focused on the mesoscale variability created by Meddies, our focus will be on interannual and decadal time scales Overall, the salinification of the Mediterranean overflow waters stands in sharp contrast to the observed freshening of high latitude surface waters and of the convective water masses emanating from the northern North Atlantic. If high latitude waters continue to freshen, the bulk of the convective activity that sends heat to the deep ocean may fall to source waters at mid-latitudes, providing added impetus for the study of the Mediterranean overflow waters. Intellectual Merit: This work will determine the source of long-term variability for a water mass that plays an important role for the properties of the eastern North Atlantic, and for the climate of the global ocean. Additionally, the dynamic response of a basin to a temporally varying overflow will be evaluated to establish the spatial and temporal variability of the basin's property fields. Broader Impacts: An improved understanding of the fate of the overflow will illuminate how changes in a marginal sea are transmitted through the open ocean, and will help improive the modeling of overflow waters throughout the global ocean. Finally, this work will train a graduate student in modeling and data analyses.

Abstractoce-0452679/0452706在地中海的注射产生温暖的咸水质量，该水质量在深度中间流过直布罗陀窗台进入大西洋，形成了全球海洋中最明显的特性分布之一。 这些溢流水对北大西洋盆地动力学和特性的影响与其相对较小的体积通量不成比例。高盐度有助于北欧海洋中地表水的预处理，以直接通过混合或间接地进行对流。 此外，这些水域在北大西洋东部建立了深度范围内的特性场，该深度大大超过了溢流厚度，并且整个中间深度亚热带盆地都会影响东部盆地的动力学。 地中海溢流摇滚乐的可变性在很大程度上被忽略了。 最近的一项研究表明，在过去的五十年中，温度和盐度升高。 这项研究的两个主要问题是：这些变化的空间和时间背景是什么？这些变化对北大西洋东部和整个盆地的财产领域和动态的影响是什么？ 为了解决这些问题，提出了数据和建模分析，不仅评估了盆地上地中海溢流变异性的结果，而且还评估了其他可变性来源的相对重要性。 尽管过去的研究集中在Meddies产生的中尺度变异性上，但我们的重点将放在整体上的年度和十年时间尺度上，但与观察到的高纬度地表水以及从北部大西洋北部大西洋北部北部地区发射的对流水质量的新鲜鲜明的地中海溢流水的盐分形成了鲜明的对比。 如果高纬度的水继续焕然一新，那么向深海发出热量的对流活动可能会落在中纬度的水源水中，这为研究地中海溢流水的研究提供了更多动力。 知识分子的优点：这项工作将决定水质量的长期变异性，这对于东北大西洋的性质以及全球海洋的气候起着重要作用。 此外，将评估盆地对时间变化的溢出的动态响应，以建立盆地性质场的空间和时间变异性。 更广泛的影响：对溢出的命运的提高理解将阐明边际海洋中的变化如何通过敞开的海洋传播，并将有助于使整个全球海洋的溢流水的建模。 最后，这项工作将培训研究生进行建模和数据分析。