Collaborative Research: Measurements and Modelling of the Indonesian Throughflow International Experiment (MINTIE)

印尼海在控制地球气候方面起着重要作用。它们位于大气深层对流的最大中心附近，代表了热带与全球翻转环流的联系。在这个地区，太平洋暖池的水被冷却和变新鲜，形成了一个独特的水团，可以追溯到整个印度洋盆地和更远的地方。在其他过程中，潮汐驱动的混合在这种水团转变中起着关键作用，并影响区域上升流、海表温度（SST）模式，从而影响全球气候。该项目将成为国际合作研究MINTIE（印度尼西亚通流国际实验的测量和建模）的美国组成部分，该研究旨在了解该地区的海洋过程。国际MINTIE观测工作是一个新颖的组合，在印度尼西亚主要的通流（ITF）通道内部署运输和水质量解决系泊阵列。此外，它还包括利用剖面浮标、湍流耗散和内海细尺度切变的水文测量，以及海峡的船舶详细测量。系泊阵列将由美国、中国和印度尼西亚共同努力，而浮动阵列将由美国、澳大利亚和印度尼西亚共同努力。除了现场测量外，该项目还利用最先进的数值模拟和诊断工具来探测印度尼西亚通流的驱动因素和动力学。美国研究生和本科生将得到该项目的支持，并接受远洋海洋学和前沿数值模拟方面的培训。与此同时，学生们将接触到国际科学合作。结果和数据将通过有针对性的讲习班、海洋学会议上的报告和一个网站在科学界内外广泛传播。对这一关键区域的运输控制和混合过程的洞察和量化将应用于海洋和气候预报所使用的全球模拟系统。美国科学家参与国际合作项目保持了美国的科学竞争力。主要合作伙伴印度尼西亚将提供船舶时间和后勤支持；当地学生和早期职业科学家将参与实地计划和分析，促进该国积极的海洋观测能力。浮筒的部署将为正在进行的区域Argo阵列奠定基础，这到目前为止是不可能的。12年前，由美国和另外5个国家参与的非常成功的“即时移民”项目极大地增进了我们对“印尼过境移民”项目的了解。从那时起，稀疏的持续观测和区域建模研究暴露了我们仍然存在的知识差距。对于ITF、来袭的远程强迫风驱动的行星波能和本地产生的内部潮汐波之间的相互作用以及它们产生的混合影响输出热量和淡水通量以及海温，我们知之甚少。这些问题将通过更详细地观察内部水文、混合率和流入/流出热量和淡水通量来解决。此外，自2006年INSTANT结束以来，印太体系发生了重大变化，ITF可能也发生了重大变化。这种转变的驱动因素仍未得到解释。虽然INSTANT揭示了平均输运及其变率，但切变和耗散观测基本上没有，海峡和内海的水团观测很少，输运估计的巨大不确定性限制了对混合和转化过程的推断。本项目提供的进出海峡的水团和输运变化的同时观测，以及水文、速度精细尺度和内海耗散，将有助于揭示变化是如何发生的以及在哪里发生的。这些前所未有的观测结果将与一套量身定制的高分辨率、潮汐解析和动态嵌套模拟和诊断工具相结合，这些工具可以量化水团转换，隔离流量驱动因素和路径可变性以及对海温的控制。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

The Indonesian Seas play a fundamental role in controlling the Earth's climate. They are located near the largest centers of atmospheric deep convection and represent the connection of the tropics to the global overturning circulation. In this area, Pacific Warm Pool waters are cooled and freshened forming a unique water mass that it can be traced across the Indian Ocean basin and beyond. Amongst other processes, tidally-driven mixing plays a critical role in this water mass transformation and impacts regional upwelling, sea surface temperature (SST) patterns and thus global climate. This project will be the US component of an international collaborative study, called MINTIE (Measuring and Modeling the INdonesian Throughflow International Experiment), developed for the understanding of the oceanic processes in the region. The international MINTIE observational effort is a novel combination of a 3-year deployment of a transport and water mass resolving mooring array within the major Indonesian Through Flow (ITF) passages. In addition, it includes simultaneous measurements of hydrography using profiling floats, turbulence dissipation and fine-scale shear in the interior seas, and ship-based detailed surveys in the straits. The moored array will be a joint effort between USA, China, and Indonesia, while the float array is a coordinated joint effort between USA, Australian, and Indonesia. The project, in addition to the in-situ measurements utilizes state-of-the-science numerical simulations and diagnostic tools to probe the drivers and dynamics of the Indonesian Through Flow. US graduate and undergraduate students will be supported by the project and trained in sea-going oceanography and cutting-edge numerical modelling. At the same time the students will be exposed to international scientific collaborations. Results and data will be broadly disseminated within and beyond the scientific community through targeted workshops, presentations at oceanographic meetings, and a web site. Insights and quantification of transport controls and mixing processes in this key region will have application in global modelling systems used for ocean and climate forecasts. The participation of US scientists in a collaborative international project maintains US scientific competitiveness. Indonesia, a principal partner, will provide ship time and logistical support; local students and early career scientists who will participate in the field program and analysis advancing an active ocean observing capability in that country. The float deployments will lay the groundwork for an ongoing regional Argo array, which to date has not been possible.The highly successful INSTANT program, a multinational effort that involved the US and 5 more countries increased significantly our understanding of the Indonesian Through Flow (ITF) over 12 years ago. Since then, sparse ongoing observations and regional modelling studies have exposed our remaining knowledge gaps. We have little knowledge on how the interplay between the ITF, incoming remotely-forced wind-driven planetary wave energy and locally generated internal tidal waves and the mixing they produce impacts export heat and freshwater fluxes and SST. These issues will be addressed using more detailed observations of internal hydrography, mixing rates and Inflowing/outflowing heat and freshwater fluxes. In addition, since the end of INSTANT in 2006, a significant shift has occurred in the Indo-Pacific system, and likely also the ITF. The drivers of this shift remain unexplained. While INSTANT shed light on the mean transport and its variability, shear and dissipation observations were largely absent, water mass observations both in the straits and internal seas were sparse and large uncertainties in transport estimates limited inferences about mixing and transformation processes. The simultaneous observations of water mass and transport variability in inflow and outflow straits, provided by this project, along with hydrography, velocity fine-scale, and dissipation in the internal seas, will shed new light on how and where transformation occurs. These unprecedented observations will be combined with a tailored set of high resolution, tidally resolving and dynamically nested simulations and diagnostic tools that allow quantification of water mass transformation, isolation of drivers of flow and pathway variability and controls on SST.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.