Early Grant in Exploratory Research: Acquisition and analysis of sediment cores from the eastern tropical Indian Ocean

热带印度洋的动力在气候系统的许多大尺度方面的预估中是一个主要的不确定因素。原则上，南亚季风的强度、整个热带地区年际-百年变率的海洋间联系以及温室气体引起的上层海洋变暖的表现都必须受到热带温跃层的影响或通过热带温跃层介导。尽管它很重要，但仍有许多关于该系统的动力学和可变性的一级问题尚未得到解答。这项工作的主要目标是收集和分析采样不足地区的沉积物岩心，最终目标是解决冰期循环期间热带印度洋中上层的动力学问题。该项目利用了学生训练考察的优势，该考察将主要集中在巽他弧的地球物理测绘上，但也为附近地区的测量和重力取芯提供了充足的时间。后续工作将包括对这些沉积物岩心进行实验室分析，以确定地层背景，并测试新方法（例如，个别有孔虫分析）的潜力，以实现该项目的总体目标。本项目主要的广泛影响在于为学生提供了在海洋学样本和数据收集方面进行启发式培训的特殊机会。学生们将从头到尾体验沉积物取心过程——从巡航计划的战略设计，到船上重力取心的执行，最后到科学应用。取芯和调查的结果也将为研究长时间尺度热带气候变化的更大的全流域倡议提供基础。

The dynamics of the tropical Indian Ocean represent a major wildcard in the projections of many large-scale aspects of the climate system. In principle, the strength of the South Asian monsoon, the inter-ocean linkages of interannual-centennial variability throughout the tropics, and the expression of greenhouse gas induced warming of the upper ocean must all be influenced by, or mediated through the tropical thermocline. Despite its importance, there are a number of first order questions about the dynamics and variability in this system that remain unanswered.The primary objective of this work is to collect and analyze sediment cores from an under-sampled region with the eventual goal of resolving the mid- to upper tropical Indian Ocean dynamics over ice age cycles. The project takes advantage of a student training expedition that will focus primarily on geophysical mapping of the Sunda Arc, but also allow ample time for surveying and gravity coring of nearby areas. Follow-on work will include laboratory-based analysis of the those sediment cores to establishstratigraphic context and to test the potential of new methods (e.g., individual foraminiferal analysis) for addressing the overall objectives of the project.The primary broader impact of this project lies in the exceptional opportunity for heuristic student training in oceanographic sample and data collection. Students will experience the sediment coring process from start to finish--from the strategic design of the cruise plan, through the shipboard execution of gravity coring, and ultimately to the scientific applications. The outcomes of the coring and surveys will also provide the basis for larger basin-wide initiatives to study long-timescale tropical climate change.