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尺度的海洋环流以及气候至关重要的过程。温暖的深水（WDW），发现在近海中深度，使入侵到大陆架上，有可能推动快速撤退的菲尔希纳-罗恩冰架。WDW的改良形式与沿海冰穴产生的高盐度陆架水混合，并与海洋终止冰川底部融化产生的冰架水混合，产生南极底层水（AABW）。AABW的净出口为地下海洋提供了约50%的通风，全球储存的碳约为大气的30倍。因此，在过去几十年中，观测到的AABW显著变暖和变淡可能表明南极环流的重新排列，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，但这些影响尚未量化。该项目正在使用高性能数值模拟（高分辨率MIT全球环流模型）来评估潮汐和涡旋在导致ABW产生的一系列水团转化中的相对作用。湍流特征，如中尺度和次中尺度特征（有时称为？海洋天气？）小，使其在模型中的空间和时间表示计算密集型。 被问到的关键问题是中尺度涡旋的作用，在运输环极温暖的深水到大陆架上，他们放弃了他们的热量，并在出口的AABW到深中央威德尔环流。中尺度、次中尺度和潮汐涡旋对于理解AABW水团的变化和更广泛的南大洋环流是至关重要的，而南极海洋环流特征的变化或重排反过来可能对海洋吸收过量的CO2和热量、南极冰架的稳定性和海平面上升产生影响。该项目将提供一个博士后研究职位，并帮助开始一个早期职业教师的职业生涯。将向更广泛的科学界提供区域模型速度和特性场，以便规划观测活动，并促进今后的合作，调查南极大陆边缘周围的地球化学示踪剂迁移和大气-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