Influence of the Indonesian Throughflow in the western Indian Ocean thermocline--the 20th century record from sclerosponges

University Of California-San Diego Scripps Inst Of Oceanography, La Jolla CA

Investigators

Abstract

The dynamical response of the tropical thermocline to continued greenhouse gas forcing represented one of the primary feedbacks influencing the future evolution of ocean warming, and understanding of past variability of this response based on paleo records is crucial for accurate simulation of future changes by global ocean/atmosphere models. The impact of the Indonesian Throughflow on the western Indian Ocean thermocline is rarely considered explicitly in climate models, despite the fact that it represents a substantial transfer of heat and energy. This project is aimed at analyzing trends in stable isotopes, trace elements, and radiocarbon in multiple coeval sclerosponge specimens to arrive at a robust, biennially resolved reconstruction of western tropical Indian Ocean thermocline change across the 20th century. The comparison of the radiocarbon trends with stable isotopic/trace element trends will help determine the extent to which the characteristics or strength of the Indonesian Throughflow (ITF) were responsible for the inferred thermocline changes. The research will generate valuable baseline data for assessing present and future impacts of anthropogenic environmental change on deep reef fauna. The award supports a graduate student's dissertation research, as well as outreach efforts in collaboration with the Birch Aquarium at Scripps.