Collaborative Research: Wave driven flow through a shallow, fringing reef

合作研究：波浪驱动流过浅层岸礁

• 批准号: 1536502
• 负责人: Stephen Monismith
• 金额: $ 78.74万
• 依托单位: Stanford University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-10-01 至 2019-09-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1536502&HistoricalAwards=false
• 关键词: Collaborative; Research; Wave; driven; flow

Coral reefs face two significant long-term challenges to their existence: (1) Ocean acidification, which hinders the ability of corals to calcify; and (2) Ocean warming, which leads to coral bleaching. The Ofu reef (American Samoa), home to corals that seem to have exceptional bleaching resistance, is the location of active research into how corals may be able to meet those challenges biologically and biogeochemically. Given that both carbon system and temperature dynamics on the reef depend on flow, the physical insights and quantitative results from the data and modeling of this study should provide significant input to studies of ecology and biogeochemistry at Ofu and other similar reefs. In addition, the project will advance the technology for mapping reefs at high resolution. The project will involve several undergraduate and graduate students, as well as a postdoctoral scientist, providing unique material for university courses. The results of this study will be brought to the general public through a series of short online videos, produced to explain the link between hydrodynamic processes and reef health.The goals of this project are: (1) Test the concept that the relative importance of friction in the lagoon and friction on the reef crest determines the structure of the overall circulation; (2) Test the hypothesis that drag coefficients related to local, spatially averaged, flows can be estimated from data on reef topography; (3) Carry out a quantitative evaluation of the dynamics of Ofu reef flows using a depth-averaged circulation model based on detailed bathymetry and estimates of spatially variable drag parameterizations. The primary activities of this project would be: (a) Mapping of reef bathymetry at decimeter scale using an Unmanned Aerial Vehicle carrying cameras and novel image processing of the resulting images; (b) Deploying a set pressure loggers, temperature loggers, acoustic Doppler current profilers and a meteorological station for a 2-km long section of the Ofu reef for two one-month periods and analyzing the results of these observations to estimate flow properties such as drag; (c) Idealized and realistic modeling studies carried out using a three dimensional model. The design of the instrument array in combination with the mapping and modeling is intended to both test the conceptual circulation model and to evaluate how drag on different parts of the reef varies with overall depth, flow and with geometric parameters describing the physical structure of the reef.

珊瑚礁对它们的存在面临两个重大的长期挑战：（1）海洋酸化，这阻碍了珊瑚的钙化能力； （2）海洋变暖，导致珊瑚漂白。 OFU礁（American Samoa）是珊瑚的所在地，似乎具有出色的漂白耐药性，是对珊瑚如何能够在生物学和生物地球化学上应对这些挑战的积极研究的地点。鉴于礁石上的碳系统和温度动态都取决于流动，因此本研究的数据和建模的物理见解和定量结果应为OFU和其他类似礁石的生态学和生物地球化学研究提供重要的输入。此外，该项目将推进以高分辨率绘制礁石的技术。 该项目将涉及几位本科生和研究生以及博士后科学家，为大学课程提供独特的材料。 这项研究的结果将通过一系列简短的在线视频将其带给公众，这些视频是为了解释流体动力学过程与礁石健康之间的联系。该项目的目标是：（1）测试以下概念：摩擦在泻湖中的相对重要性和摩擦在礁石上的相对重要性决定了整体循环的结构； （2）检验以下假设：可以从礁石地形数据中估算与局部，空间平均的拖动系数； （3）使用基于详细的测深的深度平均循环模型和空间可变的阻力参数化的估计来对OFU礁流的动力学进行定量评估。 该项目的主要活动是：（a）使用携带摄像头的无人机和最终图像的新型图像处理，以十分计尺度的珊瑚礁进行映射； （b）部署设定的压力登录器，温度记录仪，声学多普勒电流介绍剂和气象站，以在两个月的时间内使用2公里长的OFU珊瑚礁，并分析这些观察结果以估算诸如阻力之类的观察结果； （c）使用三维模型进行的理想化和现实的建模研究。仪器阵列的设计与映射和建模结合使用，既既要测试概念循环模型，又要评估礁石不同部分的拖动如何随整体深度，流动以及描述礁石物理结构的几何参数而变化。