Collaborative Research: Anslope, Cross-slope Exchanges at the Antarctic Slope Front

合作研究：南极斜坡前缘的安坡、跨坡交换

• 批准号: 0125172
• 负责人: Arnold Gordon
• 金额: $ 91.18万
• 依托单位: Columbia University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2002
• 资助国家: 美国
• 起止时间: 2002-06-01 至 2005-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0125172&HistoricalAwards=false
• 关键词: Collaborative; Research; Anslope; Cross; slope

This study will investigate how the Antarctic Slope Front and continental slope morphology determine the exchanges of mass, heat, and fresh water between the shelf and the deep ocean, in particular those leading to outflows of dense water into intermediate and deep layers of the adjacent basins and into the world ocean circulation While the importance to the global ocean circulation and climate of cold water masses originating in the Antarctic is unquestioned, the processes by which these water masses enter the deep ocean circulation are not. The primary goal of this work therefore is to identify the principal physical processes that govern the transfer of shelf-modified dense water into intermediate and deep layers of the adjacent deep ocean. At the same time, it seeks to understand the compensatory poleward flow of waters from the oceanic regime. The upper continental slope has been identified as the critical gateway for the exchange of shelf and deep ocean waters. Here the topography, velocity and density fields associated with the nearly ubiquitous front must strongly influence the advective and turbulent transfer of water properties between the shelf and oceanic regimes. The study has four specific objectives: [1] Determine the mean frontal structure and the principal scales of variability, and estimate the role of the front on cross-slope exchanges and mixing of adjacent water masses; [2] Determine the influence of slope topography and bathymetry on frontal location and outflow of dense Shelf Water; [3] Establish the role of frontal instabilities, benthic boundary layer transports, tides and other oscillatory processes on cross-slope advection and fluxes; and [4] Assess the effect of diapycnal mixing, lateral mixing identified through intrusions, and nonlinearities in the equation of state on the rate of descent and the fate of outflowing, near-freezing Shelf Water.

这项研究将调查南极陆坡前缘和大陆坡形态如何决定大陆架和深海之间的物质、热量和淡水交换，特别是那些导致稠密水流出到邻近盆地的中层和深层以及进入世界海洋环流的问题。毫无疑问，这些水团进入深海环流的过程是不确定的。 因此，这项工作的主要目标是确定控制陆架改性的稠密水转移到邻近深海的中层和深层的主要物理过程。与此同时，它试图了解补偿性极向流的沃茨从海洋制度。 上大陆坡已被确定为大陆架和深海沃茨交换的关键门户。 在这里，地形，速度和密度场与几乎无处不在的前必须强烈影响的平流和湍流之间的货架和海洋制度的水的性质转移。 本研究有四个具体目标：[1]确定平均锋结构和主要变率尺度，并估计锋在跨坡交换和相邻水团混合中的作用; [2]确定斜坡地形和水深测量对锋位置和密集陆架水流出的影响;[3]确定锋面不稳定性、海底边界层输送、潮汐和其他振荡过程对跨坡平流和通量的作用;和[4]评估渗透混合、通过侵入体识别的横向混合以及状态方程中的非线性对下降速率和外流、接近冻结的陆架水的命运的影响。