Oceanic Uptake of Carbon Dioxide and its Transport via the South Atlantic Ventilation

1980年至1985年期间，国家科学基金会资助了两项测量大西洋瞬时示踪剂的运动(TTO/NAS和TTO/赤道)。一个完整的海洋盆地模拟数据库将包括一项南大西洋研究，以：1.确定二氧化碳输送及其对世界气候的影响；2.该地区主要洋流的约束模型；3.确认温跃层中新碳的添加速度增加了5倍。这项研究的八个部分将由来自LDGO、普林斯顿、华盛顿大学、世界卫生组织和SIO的研究人员进行。这些科学家在赤道和北大西洋成功地完成了以前的研究，这为他们奠定了良好的记录。他们将提供物理和化学专业知识，这些专业知识将被用于合作努力，以实现地球化学研究的目标。这一部分的目的是提高我们对不同气候带形成的南极水团对二氧化碳的动态输送的理解。前人的研究表明，一个显著的绕极CO_2汇带位于纬度40度S-50度S之间，并与暖副热带水与冷副热带水的交汇带密切相关。这一区域约占全球海洋二氧化碳吸收通量的40%。该地区表层水中二氧化碳分压偏低的主要原因是暖副热带涡旋水的冷却作用以及冷却后的水与高二氧化碳的混合作用。和营养丰富的南极水域。CO2的光合作用利用进一步降低了地表水的PCO2值。在这一汇合带附近，水柱有效地倾覆到约500米，主要是由于高盐度副热带水域的冷却。这一过程将把这个二氧化碳汇区域的地表水吸收的二氧化碳输送到南大西洋温跃层。拟议调查的主要目标之一是利用实验期间获得的示踪剂和二氧化碳数据估计这种运输的速度。

Two campaigns to measure transient tracers in the Atlantic Ocean (TTO/NAS and TTO/Equatorial) were funded by NSF during the period from 1980 to 1985. A complete data base for modelling this ocean basin would include a South Atlantic Study to: 1.Determine CO2 transports and their influence on world climate, 2.Constrain models of major ocean currents in this area, and 3.Confirm an observed 5-fold increase in the addition rate of new carbon to the thermocline. Eight components of such a study will be performed by investigators from LDGO, Princeton, University of Washington, WHOI, and SIO. The track record of these scientists is well established by successful completion of previous studies in the Equatorial and North Atlantic. They will provide physical and chemical expertise which will be directed toward a cooperative effort to reach the goals of the geochemical study. This component is aimed at improving our understanding of the dynamic transport of CO2 by Antarctic water masses formed in zones of different climates. Previous investigations showed that a prominent circumpolar CO2 sink zone is located in a latitudinal range of 40 degrees S - 50 degrees S, and that it is closely associated with the zone of confluence of the warm Subtropical water with the cold Subantarctic water. This zone accounts for about 40% of the global oceanic uptake flux for CO2. The low pCO2 values in the surface water of this zone are attributed mainly to the effect of cooling of the warm Subtropical gyre waters and to the mixing of the cooled water with the high-pCO. and high-nutrient Antarctic waters. Photosynthetic utilization of CO2 further reduces the surface water pCO2 value. In the vicinity of this confluence zone, an effective overturning of the water column down to about 500 meters is induced mainly by cooling of the high-salinity Subtropical waters. This process would transport the CO2 taken up by the surface water of this CO2 sink zone into the South Atlantic thermocline. One of the major objectives of the proposed investigation is to estimate the rate of this transport using the tracer and CO2 data obtained during the experiment.