Physical and Biological Controls of CO2 Levels in the Southern Ocean: A Multi-Tracer Approach

小行星9530824 该研究项目是美国联合全球海洋通量研究（JGOFS）南大洋计划的一部分，旨在（1）更好地了解南大洋有机和无机碳通量，（2）确定调节这些通量的大小和变化的物理，生态和生物地球化学因素和过程，（3）将这些通量置于当代全球碳循环的背景下。 这项工作是南大洋实验中合作的44个项目之一，南大洋实验是一项为期三年的努力，在南极极地锋区以南跟踪碳通过其有机和无机途径从空气-海洋界面通过整个水柱进入底部沉积物的流动。 实验将使用两艘船，RVI B纳撒尼尔B。帕默和汤普森号 海洋模型表明，南大洋是海洋吸收温室气体产生的二氧化碳的一个重要区域。 然而，几乎没有数据来证实这些模型的预测。 南大洋有三个特点可能对该区域作为二氧化碳汇的强度产生重大影响：靠近海面的深层沃茨上升，高风速导致海气之间的热量和气体迅速交换，在开阔洋和冰缘都有生物生产力。 这三个过程之间的相互作用控制了表面二氧化碳浓度，从而控制了海气交换的方向和幅度。 该项目将结合使用化学测量和风驱动的环流模型，以确定该区域的深水上升流如何与表层交换二氧化碳，以及海气交换和生物生产力如何抵消上升流对表层二氧化碳水平的影响。 测量和模拟活动将定量解释南大洋二氧化碳的海气通量如何受到环流、气体交换和生物生产力的影响。 模型结果将用于预测海洋表层二氧化碳水平和海洋溶解无机碳库中碳同位素的比例如何对不同大气条件引起的循环速率和路径的变化作出反应。 这些结果将有助于重建南大洋过去的CO2水平状况，这些状况是基于海洋沉积物和大陆冰芯的替代测量。 ***

9530824 Quay This research project is part of the US Joint Global Ocean Flux Study (JGOFS) Southern Ocean Program aimed at (1) a better understanding of the fluxes of carbon, both organic and inorganic, in the Southern Ocean, (2) identifying the physical, ecological and biogeochemical factors and processes which regulate the magnitude and variability of these fluxes, and (3) placing these fluxes into the context of the contemporary global carbon cycle. This work is one of forty-four projects that are collaborating in the Southern Ocean Experiment, a threeyear effort south of the Antarctic Polar Frontal Zone to track the flow of carbon through its organic and inorganic pathways from the air-ocean interface through the entire water column into the bottom sediment. The experiment will make use of two ships, the RVIB Nathaniel B. Palmer and the R/V Thompson. The Southern Ocean has been implicated, by ocean models, as an important region of oceanic uptake of anthropogenically produced carbon dioxide. There is however, little data to corroborate these model predictions. There are three characteristics of the Southern Ocean that likely have a major impact on the strength of this region as a carbon dioxide sink: deep waters upwell close the surface, high wind speeds cause rapid air-sea exchange of heat and gases, and biological productivity occurs both in the open ocean and at the ice edge. The interplay between these three processes controls the surface carbon dioxide concentrations and thus the direction and magnitude of air- sea gas exchange. This project will use a combination of chemical measurements and a wind-driven circulation model to determine how deep water upwelling in this region exchanges carbon dioxide with the surface layer, and how air-sea exchange and biological productivity offset the effects of upwelling on the surface carbon dioxide levels. The measurement and modeling activities will yield a quantitative explan ation of how the air-sea flux of carbon dioxide in the Southern Ocean is affected by circulation, gas exchange and biological productivity. The model results will be used to predict how the surface carbon dioxide levels and the ratio of carbon isotopes in the dissolved inorganic carbon pool of the ocean respond to changes in circulation rates and pathways caused by different atmospheric conditions. These results will help reconstructions of past conditions of CO2 levels in the Southern Ocean that are based on proxy measurements in marine sediments and continental ice cores. ***