Collaborative Research: Satellite Assessment of CO2 Distribution, Variability and Flux and Understanding of Control Mechanisms in a River Dominated Ocean Margin

从大河流接受输入的Margins代表了大陆架系统在碳循环和通量方面的极端情况。最近在密西西比河羽流附近的研究结果显示，碳通量变化很大，突出了需要更大的时空覆盖面，以及对地表二氧化碳潜在群落新陈代谢驱动模式的评估。来自南密西西比大学和佐治亚大学的科学家们提议测试这一假设，即大型河缘水柱在海-气二氧化碳通量中表现出极端的季节和空间变化，其特征是主要由高自养生产驱动的局部吸收，以及由高陆地输入和异养呼吸驱动的二氧化碳损失。由于该系统的极端可变性，不能仅通过离散场测量来外推或内插来构造和表征时空综合的海气通量。因此，研究人员计划开展一项多学科研究，其中包括对二氧化碳通量的连续、船上和卫星评估，以及对浮游生物净群落新陈代谢、碳固定率的过程测量，以及模拟河流羽流混合的箱模型，以提供对二氧化碳排放和吸收以及调节沿海边缘这些过程的因素的新估计。至于更广泛的影响，南密西西比大学的一名博士后和佐治亚大学的一名研究生将作为该项目的一部分得到支持和培训。

OCE-0752254OCE-0752110Margins receiving inputs from large rivers represent the extremes of continental shelf systems in carbon cycling and fluxes. Recent findings in the vicinity of the Mississippi River plume show highly variable carbon fluxes and highlight the need for greater spatial and temporal coverage, as well as an assessment of the underlying community metabolism driving patterns in surface CO2. Scientists from the University of Southern Mississippi and the University of Georgia propose to test the hypothesis that large river margin water columns exhibit extreme seasonal and spatial variability in air-sea CO2 fluxes, characterized by localized uptake driven largely by high rates of autotrophic production and loss of CO2 driven by high terrestrial inputs and heterotrophic respiration. Because of the extreme variability in this system, constructing and characterizing spatially and temporally integrated air-sea fluxes cannot be done by extrapolation or interpolation solely from discrete field measurements. As such, the investigators plan to carry out a multidisciplinary study that includes continuous, shipboard and satellite derived assessments of CO2 fluxes, as well as process measurements of planktonic net community metabolism, carbon fixation rates and box modeling to simulate river plume mixing to provide new estimates of the emissions and uptake of CO2 and the factors regulating these processes in coastal margins. As regards broader impacts, one postdoc from the University of Southern Mississippi and one graduate student from the University of Georgia would be supported and trained as part of this project.