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

OCE-0752254 OCE-0752110接受大河输入的边缘代表了大陆架系统碳循环和通量的极端情况。最近的研究结果在附近的密西西比河羽显示高度可变的碳通量，并强调需要更大的空间和时间的覆盖范围，以及评估的基础社区代谢驱动模式在地表CO2。 来自南密西西比大学和格鲁吉亚大学的科学家提议检验以下假设：大型河流边缘水柱在海气CO2通量方面表现出极端的季节性和空间变异性，其特征是主要由高速率的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CO2损失。 由于在这个系统中的极端变化，构建和表征空间和时间集成的海气通量不能单独从离散的现场测量外推或插值。 因此，调查人员计划开展一项多学科研究，包括连续的、船上和卫星衍生的CO2通量评估，以及对浮游生物净群落代谢、固碳率和箱形模型的过程测量，以模拟河流羽流混合，从而提供对CO2排放和吸收的新估计以及沿海边缘调节这些过程的因素。 至于更广泛的影响，作为该项目的一部分，将支助和培训南密西西比大学的一名博士后和格鲁吉亚大学的一名研究生。

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.