Collaborative Research: A new pathway of Indonesian Throughflow in the Indian Ocean: Mechanisms and role in transporting the excess heat and freshwater of the recent hiatus decade

印度尼西亚洋流是全球温盐环流的重要组成部分，对大尺度海洋环流和全球气候有重要影响。在最近的中断十年（2003-2012）中，进入地球气候系统的多余热量约有三分之二储存在印度洋中。该项目将探讨国际信托基金在南印度洋的路径模式。PI提出了东南印度洋热流的新途径，并将调查其在分配多余的热量和淡水方面的作用，这些热量和淡水在中断十年期间从ITF进入南印度洋。将采用综合办法，将观测和再分析数据集的分析与高分辨率海洋模型实验相结合。这些方法将被用来描述流动路径的空间和时间结构，调查控制ITF沃茨路径的强迫和过程，并探索不同路径在南印度洋热量和淡水分布中的作用。PI假设在东南印度洋和亚热带南印度洋之间存在ITF沃茨的流动路径，ITF的沃茨沿着这条水道沿着扩散到西亚热带南印度洋，其中一部分泄漏到南大洋。他们认为，这条路径是最近全球地表变暖间歇期ITF热量和淡水输送增强的主要渠道。为了检验这一点，将结合数值模式试验对观测资料进行分析。观测数据将包括来自系泊设备、漂流物、卫星和再分析产品的数据。模型数据将包括现有的1/10度模拟从海洋环流模型为地球模拟器和新的1/12度运行使用HYCOM。研究的总体目标是探索ITF沃茨在南印度洋的潜在新路径，调查这一新路径的管理机制，并量化其在输送多余的热量和新鲜ITF沃茨在最近的间断期间进入大厄古拉斯流系统的亚热带西南印度洋的作用。该项目的重点是2003-2012年的间歇期，当时由于ITF的增强，印度洋的热量急剧增加。该奖项反映了NSF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 Throughflow (ITF) is a key component of the global thermohaline circulation that affects the large-scale ocean circulation and global climate. During the recent hiatus decade (2003-2012) about two-thirds of the excess heat that entered Earth’s climate system was stored in the Indian Ocean. This project will address the ITF pathway patterns in the South Indian Ocean. The PIs propose a new pathway for heat flow in the Southeast Indian Ocean and will investigate its role in distributing the excess heat and freshwater that entered the South Indian Ocean from the ITF during the hiatus decade. An integral approach will be used that combines analyses of observational and reanalysis datasets with high-resolution ocean model experiments. These methods will be used to characterize the spatial and temporal structure of the flow pathway, investigate the forcing and processes that govern the pathways of ITF waters, and explore the roles of the different pathways in distributing heat and freshwater in the South Indian Ocean.The PIs hypothesize the existence of a flow pathway for waters from the ITF between the Southeast Indian Ocean and the subtropical South Indian Ocean, along which ITF waters spread to the western subtropical South Indian Ocean with a portion leaking to the Southern Ocean. They posit that this pathway was the major conduit for the enhanced ITF heat and freshwater transport of the recent global surface warming hiatus period. To test this observational data will be analyzed in combination with numerical model experiments. Observational data will include data from moorings, drifters, satellites, reanalysis products. Model data will include existing 1/10 degree simulations from Ocean General Circulation Models For the Earth Simulator and new 1/12 degree runs using HYCOM. The overall goals of the research are to explore the potential new pathway of ITF waters in the South Indian Ocean, investigate the governing mechanisms of this new pathway, and quantify its role in transporting the excess heat and fresher ITF waters during the recent hiatus period into the Greater Agulhas Current System of the subtropical Southwest Indian Ocean. The project focuses on the hiatus period 2003-2012 when a dramatic heat increase in the Indian Ocean due to enhanced ITF was observed.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.