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

在这个项目中，来自南卡罗来纳州、夏威夷、加州-圣巴巴拉大学和国际科学技术组织的研究人员将对这些物质的物理、化学、和生物学特征的冷心气旋漩涡，形成在背风的主要夏威夷群岛。这一地区作为一个天然实验室，提供了极好的，如果不是唯一的，了解涡流增强生产和碳输出在一个可访问的亚热带贫营养环境的机会。计划进行三次巡航，将在三个阶段对涡流进行采样：自旋上升（巡航I）、成熟（巡航II）和自旋下降（巡航III）。卫星数据将用于指导船载密集观测的时间安排和采样地点。通过涡流的采样被设计成平衡水平分辨率（即，XBT和CTD站之间的间距）与天气性。该小组将描述相对于夏威夷附近贫营养沃茨的漩涡中浮游植物和食草动物的生物量、大小结构和分类组成。这一信息将与浮游植物生长和微型浮游动物摄食率的估计数相结合，并与初级生产力和新/出口生产的同步率估计数（Th-234通量估计数、沉积物捕集器、营养物清单和稳定碳同位素质量平衡）相联系。将分别使用卫星（GOES-10、SeaWiFS、MODIS和TOPEX/ERS）和漂移器监测目标涡旋的轨迹和次表层温度结构，并估计当地气旋涡旋场对碳输出的贡献。拟议的采样策略将提供一个4维（x，y，z，t）的数据集调查的联系和时间滞后之间的营养投入，生物反应，和向下流动的有机碳。这些地球化学和物理数据集将提供缺失的环节，以促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，并为建模者提供硬数据，以测试他们的基本假设和公式。最终目标是提供中尺度涡流对当地营养物和食物网动态影响的上限和下限的现场估计，以便它们可以用于测试，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流域尺度上的生态地球化学后果。为此，将进行基于高度计的硝酸盐通量模型的实验模拟。这种比较应允许从夏威夷岛的背风面到北太平洋副热带环流的涡旋场的结果的外推，使用混合TOPEX/ERS产品和用当地原位数据校准的计算的硝酸盐通量。

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.