Abstract
The Indonesian Throughflow (ITF) significantly influences global climate and interoceanic exchange. This review synthesizes recent findings on the Halmahera Sea’s role within the ITF, emphasizing its physical mechanisms, climatic modulation, and ecological consequences. Despite being a minor route, the Halmahera Sea transport volume is approximately 1.5 to 2.44 Sv, bringing water mass from the Southern Pacific Ocean. Seasonal and interannual variability, driven by monsoonal winds and phenomena like the El Niño-Southern Oscillation (ENSO), significantly affect the flow dynamics in this region. The Halmahera Sea also plays a pivotal role in nutrient cycling and marine biodiversity, influencing local ecosystems and fisheries. Understanding these dynamics is essential for predicting climate change impacts and managing marine resources in the Indo-Pacific region. This review highlights the need for enhanced observational efforts and high-resolution modeling to better understand the Halmahera Sea’s contribution to the broader ITF framework and its implications for regional and global climate systems.