Iceland-Scotland Ridge Exchange Flow Seaglider Surveys

冰岛-苏格兰海岭交换流海上滑翔机调查

• 批准号: 0550584
• 负责人: Charles Eriksen
• 金额: $ 205.22万
• 依托单位: University of Washington
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2006
• 资助国家: 美国
• 起止时间: 2006-03-01 至 2011-02-28
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0550584&HistoricalAwards=false
• 关键词: Iceland; Scotland; Ridge; Exchange; Flow

The scientific goal of the project is to document and understand the seasonal and interannual variability of both Atlantic inflow to and deep overflow from the Nordic Seas over the Iceland-Scotland Ridge, a region where meridional overturning circulation deep branches are formed and important shallow branches concentrate. Currently, the most reliable estimates of exchange across the Iceland-Scotland Ridge are based on currents and hydrography sampled with different spatial and temporal resolution, with different techniques, and with debatable values for reference temperature and salinity. The detailed spatial structure and seasonal and interannual variability of circulation in this region has yet to be resolved. In the context of global climate change, decline of the meridional overturning circulation is widely predicted. Climate models are very sensitive to these transports and resolution of them is crucial to understanding ocean climate variability, past, present and future. New observations (primarily physical) will be used to infer entrainment sites and to quantify transports by water mass type for use in improving climate models, whose predictions under global warming are sensitive to the physics of the high-latitude ocean. The intense biological productivity of the region, which depends on these circulations and water masses, will also be profiled optically. Long-range autonomous underwater vehicles (Seagliders) will be used to collect full-depth hydrography and estimate absolute geostrophic velocity sections simultaneously of both shallow northward inflow and dense southward overflow across the Iceland-Faroe Ridge and the Faroe-Shetland Channel. This domain is thought to account for about 90% of the Atlantic transport poleward and about half of the deep water transport equatorward (the remaining portion passes through the Denmark Strait). Seagliders will collect high-resolution sections of temperature, salinity, dissolved oxygen, fluorescence and optical backscatter as well as depth-averaged horizontal velocity. The sections will resolve seasonal variations and begin to detect prominent interannual variations. One Seaglider will traverse the Faroe-Shetland Channel weekly while a pair of Seagliders will survey the southwestern flank of the Iceland-Faroe Ridge, repeating a ~1000 km track monthly. The vehicles will be deployed in 4-month missions continuously for 3 years, using vessels in the Faroe Islands for launch and recovery. The plan is to collect about 30,000 full-depth (500-1000m) profiles with 3-6 km horizontal resolution across nearly 60,000 km of track during the three year project, all delivered in near real-time via satellite. Real-time command of the Seagliders will allow mapping of finescale water masses and frontal features. The observations will be carried out in conjunction with mooring/ship observations of on-going projects, and with Norwegian, Icelandic and Faroese collaborating scientists The study is a contribution to the U.S. CLIVAR (CLImate VARiability and predictability) program..Intellectual Merit. The most basic dynamic balances of the global overturning circulation of the oceans are under debate. Global change may alter the overturning circulation and with it, global climate and ecosystems. High resolution climate observations with radically new platforms, sustained in time, can guide the numerical climate models which are increasingly relied upon in matters of policy and planning Broader Impacts. Beyond physical science, this work relates to ecosystems in one of the most biologically productive sites on Earth, and a region of strong uptake of carbon from the atmosphere. The work will provide bio-optical profiles and sections at high resolution in regions of unusually high biological productivity. The interdependence of fisheries and physical oceanography in this region is extremely strong, as primary productivity is associated with buoyant, low-salinity layers which trap phytoplankton. The research contributes to our undergraduate teaching in environmental studies, in which the methods and results of science are put before young students who are the beneficiaries and custodians of the environment.

该项目的科学目标是记录和了解大西洋流入北欧海洋的季节性和年际变异性，从北欧海洋上方溢出冰岛 - 斯科特兰山脊，该地区形成了子午线翻转循环深部的深层分支，并且重要的浅分支集中。当前，跨冰岛 - 苏格兰山脊的交换最可靠的估计是基于电流和水文图，并用不同的空间和时间分辨率采样，具有不同的技术，以及参考温度和盐分的值得争议的值。该区域的详细空间结构以及季节性和年际变化尚未解决。在全球气候变化的背景下，普遍推翻循环的下降被广泛预测。气候模型对这些运输非常敏感，而它们的解决方案对于了解海洋气候变异性，过去，现在和未来至关重要。新的观察结果（主要是物理）将用于推断夹带地点，并通过水质量类型量化运输，以改善气候模型，其在全球变暖下的预测对高纬度海的物理学敏感。该地区的强烈生物生产力（取决于这些循环和水质量）也将通过光学进行分析。远程自动驾驶水下车辆（Seagliders）将用于收集全深度的水平学，并同时估算浅层北向流入和向南泛滥的绝对地质速度截面，贯穿冰岛 - 弗罗伊山脊和法罗山地通道。人们认为该域约占大西洋运输的90％，约占深水运输赤道的一半（其余部分通过丹麦海峡）。海格流行器将收集温度，盐度，溶解氧，荧光和光学反向散射以及深度平均水平速度的高分辨率部分。这些部分将解决季节性的变化，并开始检测突出的年际变化。一名Seaglider每周都会穿越Faroe-Shetland频道，而一对海上滑行者将调查冰岛 - 弗罗伊山脊的西南侧面，每月重复约1000公里的轨道。这些车辆将连续部署4个月的任务3年，使用法罗群岛的船只进行发射和恢复。该计划是在三年项目期间收集约30,000个全深度（500-1000m）的配置文件，在近60,000公里的轨道上，水平分辨率为3-6公里，所有这些都可以通过卫星实时实时交付。海格流失者的实时指挥将允许绘制罚款水块和额叶特征。这些观察结果将与正在进行的项目的系泊/船舶观察一起进行，与挪威，冰岛和法罗斯合作科学家一起，这项研究是对美国Clivar（气候变异性和可预测性）计划的贡献。全球推翻海洋循环的最基本动态平衡正在争论中。全球变化可能会改变倾覆的循环，随之而来的是全球气候和生态系统。及时持续的具有根本新平台的高分辨率气候观察可以指导数值气候模型，这些模型越来越依赖于政策和计划更广泛的影响。除了物理科学之外，这项工作还涉及地球上生物生产最高的地点之一的生态系统，以及从大气中强烈吸收碳的区域。这项工作将在异常高的生物学生产力地区高分辨率下提供生物光学概况和部分。该地区渔业和物理海洋学的相互依赖性非常强大，因为主要生产力与浮游浮游生物的浮力，低含量层有关。该研究为我们的环境研究的本科教学做出了贡献，其中科学的方法和结果是在环境的受益人和保管人的年轻学生面前。