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 establish stratigraphic 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.
