Collaborative Research: Determining the Present and Future Ocean Carbon Dynamics in the Chukchi Sea and pan-Arctic Ocean: A Contribution to Shelf-Basin Interactions (SBI) Phase III

作为对履行机构第三阶段工作的贡献，提高我们对北冰洋碳循环的了解和对未来应对环境变化的预测能力至关重要。这需要数据集成、综合和建模活动，从而在系统层面上对北冰洋当前和未来的碳循环有新的理解。这项研究要检验的一个中心假设是：H.物理强迫(例如，海冰、营养供应)和生物反应对碳循环以及楚科奇海与其他大陆架相比的海-气二氧化碳交换、净初级生产力和出口生产的速率施加了根本不同的控制。该项目将汇编在履行机构第二阶段期间收集的有机和无机碳数据，以及速率测量(例如，第234/238U出口)，以及整个北极地区的其他水文、生物地球化学和碳数据。纳入这些数据集为理解当前和气候变化情景(例如，海冰融化、河流输入、分层和生物反应的变化)下的碳动态提供了一个泛北极背景。将检验中心假设的具体目标包括：目标1：确定楚科奇海和泛北极(包括人为二氧化碳)的无机和有机碳储量；目标2：确定碳排放量，包括楚科奇和其他大陆架以及邻近北冰洋盆地的大气-海洋二氧化碳气体交换、群落净生产量和出口生产量；目标3：利用碳质量平衡办法综合碳排放量和碳储量。这项工作包括对楚科奇大陆架与其他大陆架的比较分析(流入大陆架与内部大陆架的碳循环)，以及北极碳循环的预期变化。这些分析将通过协作性综合和建模工作增进了解，并通过2008年和2010年的讲习班会议促进国家和国际协调。

As a contribution to SBI phase III efforts, it is critical to improve both our understanding of the Arctic Ocean carbon cycle and predictive capabilities for future responses to environ-mental changes. This requires data integration, synthesis, and modeling activities that lead to new system-level understanding of present and future carbon cycling in the Arctic Ocean. A central hypothesis to be tested in this research is that:H. The physical forcing (e.g., sea-ice, nutrient supply) and biological responses exert fundamentally different controls on the carbon cycle and the rates air-sea CO2 exchange, NCP and export production in the Chukchi Sea compared to other shelves.This project will compile organic and inorganic carbon data, and rate measurements (e.g., 234Th/238U export) collected during SBI phase II with other hydrographic, biogeochemical and carbon datasets from across the Arctic. Incorporation of these datasets provides a pan-Arctic context for understanding carbon dynamics in the present and under climate change scenarios (e.g., changes in sea-ice melt, river input, stratification, and biological responses). Specific objectives that will test the central hypothesis, include:Objective 1: Determine stocks of inorganic and organic carbon in the Chukchi Sea and pan-Arctic (including anthropogenic CO2);Objective 2: Determine rates, including air-sea CO2 gas exchange, net community production, and export production on the Chukchi and other shelves, and in the adjacent Arctic Ocean basin;Objective 3: Synthesize rates and stocks using carbon mass balance approaches. This effort includes comparative analyses of the Chukchi shelf with other shelves (carbon cycling on inflow versus interior shelves) and anticipated changes in the Arctic carbon cycle. These analyses will advance understanding through collaborative synthesis and modeling efforts, and, national and international coordination through workshop meetings in 2008 and 2010.