Observations and Analysis Throughflow Indonesian Seas, Upwelling, and Mixing Physics (TRIUMPH) Data

The goal of this project is to analyze oceanographic data from the Indonesian Through Flow (ITF) region taken during the TRIUMPH (ThRoughflow Indonesian seas, Upwelling, and Mixing PHysics) oceanographic field program, a collaboration with researchers from Indonesia and China. TRIUMPH has deployed seven moorings in the main direct ITF pathways and the upwelling region of south Java since Fall 2019. The project will examine: the full-depth of ITF transport variability and its associated heat and freshwater fluxes in the Makassar, Lombok, and Alas Straits on tidal, intraseasonal, and seasonal timescales; tidal mixing variability; and, propagation of Kelvin waves from the tropical Indian Ocean-Makassar Strait. The Indonesian Through Flow (ITF) is an essential conduit for the flow of low latitude Pacific Ocean waters into the Indian Ocean. Its variability is particularly significant because it plays a vital role in global ocean circulation and climate. Even though ITF has been measured the last three decades, no detailed measurements of full depth variability have been done nor has its impacts on mixing and upwelling along the eastern tropical Indian Ocean been investigated. This absence of data represents a significant gap in our understanding of the role of this shallow choke point in regulating the Pacific-Indian Ocean exchange, air-sea interactions, and water-mass transformation in the chokepoint of the shallow Meridional Ocean Circulation. Hence, it is essential to have detailed simultaneous measurements of the ITF, mixing, and upwelling. 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.