Collaborative Research: Impact of Mesoscale Processes on Iron Supply and Phytoplankton Dynamics in the Ross Sea

合作研究：中尺度过程对罗斯海铁供应和浮游植物动力学的影响

• 批准号: 0944254
• 负责人: Walker Smith
• 金额: $ 36.52万
• 依托单位: College of William & Mary Virginia Institute of Marine Science
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-07-01 至 2015-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0944254&HistoricalAwards=false
• 关键词: Collaborative; Research; Impact; Mesoscale; Processes

The Ross Sea continental shelf is one of the most productive areas in the Southern Ocean, and may comprise a significant, but unaccounted for, oceanic CO2 sink, largely driven by phytoplankton production. The processes that control the magnitude of primary production in this region are not well understood, but data suggest that iron limitation is a factor. Field observations and model simulations indicate four potential sources of dissolved iron to surface waters of the Ross Sea: (1) circumpolar deep water intruding from the shelf edge; (2) sediments on shallow banks and nearshore areas; (3) melting sea ice around the perimeter of the polynya; and (4) glacial meltwater from the Ross Ice Shelf. The principal investigators hypothesize that hydrodynamic transport via mesoscale currents, fronts, and eddies facilitate the supply of dissolved iron from these four sources to the surface waters of the Ross Sea polynya. These hypotheses will be tested through a combination of in situ observations and numerical modeling, complemented by satellite remote sensing. In situ observations will be obtained during a month-long cruise in the austral summer. The field data will be incorporated into model simulations, which allow quantification of the relative contributions of the various hypothesized iron supply mechanisms, and assessment of their impact on primary production. The research will provide new insights and a mechanistic understanding of the complex oceanographic phenomena that regulate iron supply, primary production, and biogeochemical cycling. The research will thus form the basis for predictions about how this system may change in a warming climate. The broader impacts include training of graduate and undergraduate students, international collaboration, and partnership with several ongoing outreach programs that address scientific research in the Southern Ocean. The research also will contribute to the goals of the international research programs ICED (Integrated Climate and Ecosystem Dynamics) and GEOTRACES (Biogeochemical cycling and trace elements in the marine environment).

罗斯海大陆架是南大洋生产力最高的地区之一，可能包括大量但不明显的海洋二氧化碳水槽，主要是由浮游植物生产驱动的。 控制该区域的原始产量大小的过程尚不清楚，但数据表明铁限制是一个因素。现场观测和模型模拟表明，溶解铁到罗斯海的地表水的四个潜在来源：（1）圆形深水从架子边缘侵入； （2）浅银行和近岸地区的沉积物； （3）围绕波利尼亚周围的海冰融化； （4）罗斯冰架上的冰川融化。 首席研究人员假设通过中尺度电流，正面和涡流的流体动力传输有助于从这四个来源供应溶解的铁到罗斯海Polynya的地表水。这些假设将通过原位观测和数值建模的组合进行测试，并通过卫星遥感辅助。在澳大利亚夏季为期一个月的巡游中将获得原位观察。 现场数据将纳入模型模拟，从而量化各种假设的铁供应机制的相对贡献，并评估其对初级生产的影响。这项研究将为调节铁供应，初级生产和生物地球化学循环的复杂海洋现象提供新的见解和机械理解。因此，该研究将构成预测该系统在温暖气候下如何变化的基础。 更广泛的影响包括对研究生和本科生的培训，国际合作，以及与几个正在进行的外展计划的合作伙伴关系，这些计划涉及南海科学研究。该研究还将为国际研究计划（综合气候和生态系统动力学）和地理位置（海洋环境中的生物地球化学循环和微量元素）的目标做出贡献。