Mixing in the Indonesian Throughflow: Analysis of Lagrangian observations of shear, watermass modification, and internal wave climates

印度尼西亚贯穿流中的混合：拉格朗日切变观测、水团修改和内波气候的分析

• 批准号: 2219987
• 负责人: James Girton
• 金额: $ 48.28万
• 依托单位: University of Washington
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-08-01 至 2025-07-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2219987&HistoricalAwards=false
• 关键词: Mixing; Indonesian; Throughflow; Analysis; Lagrangian

Recent computer simulations have suggested the appearance of tides at the interfaces between different layers (internal tides) in the basins and straits of the Indonesian and Philippine Archipelagos (the Coral Triangle), with subsequent mixing of the layers. These tides carry and transform waters from the Pacific on their path to the Indian Ocean. Despite the computer-generated results, direct measurements of internal tides and mixing have been scarce in this region. This project will use Lagrangian (i.e., following the horizontal flow pathway) measurements of temperature, salinity, and currents from vertically profiling floats to investigate the levels of internal waves, especially internal tides, and their role in transforming water properties through vertical mixing. The project will use existing data from the Philippines Archipelago, along with additional new float deployments in the separately funded (NSF) "Measuring and Modeling the INdonesian Throughflow International Experiment" (MINTIE). Results will be used to evaluate the internal tide and circulation characteristics of computer models being used in the region. The project will support an international (US–Australia) collaboration and facilitate the broader use of electromagnetic velocity profiler data by providing raw profiles and derived internal wave and mixing products through national data centers. The project will furnish project material for undergraduate interns in a new APL-UW program targeting minorities.Mixing along the Pacific-to-Indian Ocean throughflow pathway is a key water mass transformation step in the global thermohaline circulation and has a first-order influence on sea-surface temperature and air–sea interaction. The locations of predicted internal tide generation are very likely to be mixing hot spots, but it remains an open question where and how the radiated internal tide energy is dissipated. This proposal will test the dominance of internal tides as mixing agents. The results will be used to evaluate the internal tide and circulation characteristics of numerical models being used to test throughflow sensitivity to the level and distribution of mixing in the region. Project's goals include: 1) the description of internal tide amplitude and radiation patterns in both the Philippine and Indonesian Seas to verify sources, diurnal and semidiurnal contributions (including the spring/neap cycle of each), and vertical wavenumber structure; 2) constraining the parameters appropriate to internal tide parameterizations, especially the fraction of energy radiated and the vertical structure of the resulting dissipation; 3) evaluation of along-path water mass transformation rates; 4) establishing a shared and publicly available database for EM-APEX profiles, of use for research studies like this one and ocean state and forecast systems assimilating stratification and velocity data.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

最近的计算机模拟表明，在印度尼西亚和菲律宾群岛（珊瑚三角）的盆地和海峡的不同层（内潮汐）之间的界面处出现了潮汐，随后这些潮汐携带并改变了来自这些层的水。尽管有计算机生成的结果，但该地区很少对内潮汐和混合进行直接测量。该项目将使用拉格朗日（即遵循水平流）。通过垂直剖面浮标测量温度、盐度和水流，以研究内波水平，特别是内潮汐，及其通过垂直混合改变水性质的作用。该项目将使用菲律宾群岛的现有数据以及其他数据。在单独资助的（NSF）“印度尼西亚通流测量和建模国际实验”（MINTIE）中进行了额外的新浮标部署，结果将用于评估该地区使用的计算机模型的内潮和环流特征。项目将支持国际（美国-澳大利亚）合作，并通过国家数据中心提供原始剖面和衍生的内波和混合产品，促进电磁速度剖面仪数据的更广泛使用。该项目将为新 APL 中的本科生实习生提供项目材料。 -针对少数群体的威斯康星大学计划。沿着太平洋到印度洋的通流路径混合是全球温盐环流中关键的水团转换步骤，对海面温度和海气相互作用的位置具有一级影响。预测内部潮汐产生很可能是混合热点，但辐射内潮汐能量在何处以及如何消散仍然是一个悬而未决的问题。该提案将测试内潮汐作为混合剂的主导地位。结果将用于评估内潮汐。用于测试通流对该区域混合水平和分布的敏感性的数值模型的潮汐和环流特征 项目的目标包括：1）描述菲律宾和印度尼西亚海域的内潮幅和辐射模式，以验证来源。昼夜和半日贡献（包括每个春/小潮周期）和垂直波数结构；2）限制适合内潮参数化的参数，特别是辐射能量的比例和由此产生的耗散的垂直结构；路径水团转化率；4) 建立一个共享的、公开的 EM-APEX 剖面数据库，用于像这样的研究以及同化分层和速度数据的海洋状态和预报系统。该奖项反映了通过使用基金会的智力价值和更广泛的影响审查标准进行评估，NSF 的法定使命被认为值得支持。