Collaborative Research:Influences of Cyclonic Eddy Activity on Planktonic Food Web Dynamics and Carbon Export in the Lee of Hawaii

合作研究：夏威夷李岛气旋涡流活动对浮游食物网动力学和碳输出的影响

• 批准号: 0241121
• 负责人: Tommy Dickey
• 金额: --
• 依托单位: University of California-Santa Barbara
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2003
• 资助国家: 美国
• 起止时间: 2003-09-15 至 2007-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0241121&HistoricalAwards=false
• 关键词: Collaborative; Research; Influences; Cyclonic; Eddy

ABSTRACTOCE-0241645 / OCE-0241897 / OCE-0241121 / OCE-0241852In this project, investigators at the University of South Carolina, the University of Hawaii, the University of California - Santa Barbara, and Science and Technology International will conduct interdisciplinary investigation of the physical, chemical, and biological characteristics of cold-core cyclonic eddies that form in the lee of the main Hawaiian Islands. This area serves as a natural laboratory, providing excellent, if not unique, opportunities for understanding eddy-enhanced production and carbon export in an accessible subtropical oligotrophic setting. Three cruises are planned in which eddies will be sampled during three phases: spin-up (cruise I), maturity (cruise II), and spin-down (cruise III). Satellite data will be used to direct the timing and sampling locations of the intensive ship-based observations. Sampling through the eddy is designed to balance horizontal resolution (i.e., spacing between XBT and CTD stations) with synopticity. The team will characterize the biomass, size structure and taxonomic composition of phytoplankton and grazers in the eddy relative to the ambient oligotrophic waters off Hawaii. This information will be coupled with estimates of phytoplankton growth and microzooplankton grazing rates and related to concurrent rate estimates of primary productivity and new/export production (Th-234 flux estimates, sediment traps, nutrient inventories and stable carbon isotope mass balance). The trajectory and subsurface temperature structure of the target eddy will be monitored using satellites (GOES-10, SeaWiFS, MODIS, and TOPEX/ERS) and drifters, respectively, and the contribution of the local cyclonic eddy field to carbon export will be estimated. The proposed sampling strategy will provide a 4-dimensional (x,y,z,t) data set for investigating the linkages and temporal lags between nutrient inputs, biological responses, and the downward flux of organic carbon. These biogeochemical and physical data sets will provide missing links for advancing our understanding of the nature and importance of eddies in facilitating organic carbon export, as well as hard data for modelers to test their fundamental assumptions and formulations. The ultimate goal is to provide in situ estimates for the upper and lower limits of mesoscale eddy effects on local nutrient and food web dynamics such that they can be used to test, evaluate and reformulate the various models being developed to study eddy phenomena and their biogeochemical consequences on regional and basin scales. Towards that end, experimental simulations of altimeter-based nitrate flux models will be performed. This comparison should allow extrapolation of the results from the lee of the Island of Hawaii to the eddy field in the North Pacific Subtropical Gyre, using the blended TOPEX/ERS product and calculated nitrate fluxes calibrated with local in situ data.

ABSTRACTOCE-0241645 / OCE-0241897 / OCE-0241121 / OCE-0241852在该项目中，南卡罗来纳大学、夏威夷大学、加州大学圣塔芭芭拉分校和科学技术国际组织的研究人员将对在 夏威夷主要岛屿。该区域是一个天然实验室，为了解亚热带贫营养环境中的涡流增强生产和碳输出提供了极好的（如果不是独一无二的）机会。计划进行三次巡航，在三个阶段对涡流进行采样：旋转上升（巡航 I）、成熟（巡航 II）和旋转下降（巡航 III）。卫星数据将用于指导密集船基观测的时间安排和采样地点。通过涡流采样旨在平衡水平分辨率（即 XBT 和 CTD 站之间的间距）与天气情况。该团队将描述涡流中浮游植物和食草动物相对于夏威夷附近环境贫营养水域的生物量、大小结构和分类组成。该信息将与浮游植物生长和微型浮游动物放牧率的估计相结合，并与初级生产力和新/出口产量的并发率估计相关（Th-234通量估计、沉积物捕集器、养分库存和稳定碳同位素质量平衡）。将分别使用卫星（GOES-10、SeaWiFS、MODIS 和 TOPEX/ERS）和漂移器监测目标涡流的轨迹和地下温度结构，并估计当地气旋涡流场对碳输出的贡献。所提出的采样策略将提供 4 维 (x,y,z,t) 数据集，用于研究养分输入、生物反应和有机碳向下通量之间的联系和时间滞后。这些生物地球化学和物理数据集将为增进我们对涡流在促进有机碳输出方面的性质和重要性的理解提供缺失的环节，并为建模者测试其基本假设和公式提供硬数据。最终目标是提供中尺度涡流对当地营养物和食物网动力学影响的上限和下限的原位估计，以便它们可用于测试、评估和重新制定正在开发的各种模型，以研究涡流现象及其在区域和盆地尺度上的生物地球化学后果。为此，将对基于高度计的硝酸盐通量模型进行实验模拟。这种比较应该允许使用混合的 TOPEX/ERS 产品和用当地现场数据校准的计算硝酸盐通量，将结果从夏威夷岛的背风处外推到北太平洋副热带环流的涡流场。