Eddy/tidal Water Mass Transformation and Transport in the Weddell Sea

威德尔海支持一系列对南极和全球范围的海洋环流和气候至关重要的过程。温暖的深水（WDW），在近海的中深度被发现，入侵到大陆架上，有可能推动费尔奇纳-罗纳冰架的快速退缩。一种改型的南极底水与沿海多冰湖产生的高盐度陆架水混合，与终止海洋的冰川基底融化产生的冰架水混合产生南极底水（AABW）。AABW的净出口通风了大约50%的地下海洋，并且在全球范围内储存了大约30倍于大气的碳。因此，在过去几十年里观测到的显著的AABW变暖和变新鲜可能表明南极环流的重新排列，这对深海氧气浓度、大气二氧化碳浓度和海平面上升的长期变化有影响，但这些变化尚未量化。该项目使用高性能数值模拟（高分辨率MIT全球环流模型）来评估潮汐和涡流在一系列水团转化中所起的相对作用，这些转变导致了ABW的产生。湍流特征，如中尺度和亚中尺度特征(有时称为？海洋天气？)很小，这使得它们在模型中的空间和时间表征需要大量的计算。关键的问题是，中尺度涡旋在将环极温暖的深水输送到大陆架上并释放热量的过程中所起的作用，以及在向威德尔环流中心深处输出AABW的过程中所起的作用。众所周知，中尺度、亚中尺度和潮汐涡旋对于理解AABW水团转变和更广泛的南大洋环流至关重要。南极海洋环流特征的变化或重新安排反过来可能对过量二氧化碳和热量进入海洋的吸收、南极冰架的稳定性和海平面上升产生影响。该项目将提供博士后研究职位，并帮助早期职业教师开始职业生涯。区域模型速度和性质场将提供给更广泛的科学界，以便规划观测运动，并促进未来的合作，以调查南极大陆边缘周围的生物地球化学示踪剂运输和大气-海洋交换

The Weddell Sea supports a range of processes that are critical to the Antarctic and global-scale ocean circulation and to climate. Warm Deep Water (WDW), found offshore at mid-depth, makes incursions up onto the continental shelf that have the potential to drive rapid retreat of the Filchner-Ronne ice shelf. A modified form of WDW mixes with High Salinity Shelf Water produced in coastal polynyas, and with Ice Shelf water produced by basal melting of marine-terminating glaciers produces Antarctic Bottom Water (AABW). The net export of AABW ventilates around 50% of the subsurface ocean, and globally stores around 30 times as much carbon as the atmosphere. Thus the significant observed warming and freshening of AABW over the past few decades may indicate a rearrangement of the Antarctic circulation, with implications for long-term changes in deep-ocean oxygen concentration, atmospheric carbon dioxide concentration, and rises in sea level that are yet to be quantified. This project is using high performance numerical simulation (high-res MIT Global Circulation Model) to evaluate the relative roles of tides and eddies in the series of water mass transformation that leads to ABW production. Turbulent features such as mesoscale and sub-mesoscale features (sometimes called ?ocean weather?) are small, making their spatial and temporal representation in models computationally intensive. Key questions being asked are the role of mesoscale eddies in transporting circumpolar Warm Deep Water up onto the continental shelves where they give up their heat, and in export of AABW into the deep central Weddell Gyre. Mesoscale, submesoscale and tidal eddies are known to be critical to understanding AABW water mass transformation, and to the broader Southern Ocean circulation.Changes or rearrangements in Antarctic oceanic circulation features in turn may have implications for the uptake of excess CO2 and heat into the oceans, stability of the Antarctic ice shelves, and sea level-rise. The project will provide a post-doctoral research position and help commence the career of an early career faculty member. Regional model velocity and property fields will be made available to the wider scientific community for the purpose of planning observational campaigns, and in order to foster future collaborations to investigate biogeochemical tracer transport and atmosphere-ocean exchange around the Antarctic continental margins