Dongliang Yuan, Xueli Yin, Xiang Li, Corry Corvianawatie, Zheng Wang, Yao Li, Ya Yang, Xiaoyue Hu, Jing Wang, Shuwen Tan, Dewi Surinati, Adi Purwandana, Adhitya Kusuma Wardana, Mochamad Furqon Azis Ismail, Asep Sandra Budiman, Ahmad Bayhaqi, Praditya Avianto, Priyadi Dwi Santoso, Edi Kusmanto, Dirhamsyah, Zainal Arifin & Larry J. Pratt

Published in Nature Communications, April 2022

The Indonesian Throughflow plays an important role in the global ocean circulation and climate. Existing studies of the Indonesian Throughflow have focused on the Makassar Strait and the exit straits, where the upper thermocline currents carry North Pacific waters to the Indian Ocean. Here we show, using mooring observations, that a previous unknown intermediate western boundary current (with the core at ~1000 m depth) exists in the Maluku Sea, which transports intermediate waters (primarily the Antarctic Intermediate Water) from the Pacific into the Seram-Banda Seas through the Lifamatola Passage above the bottom overflow. Our results suggest the importance of the western boundary current in global ocean intermediate circulation and overturn. We anticipate that our study is the beginning of more extensive investigations of the intermediate circulation of the Indo-Pacific ocean in global overturn, which shall improve our understanding of ocean heat and CO₂ storages significantly.

Fig. Map and locations of the eastern Indonesian sea moorings, with topography (unit in meters). The moorings from west to east are M01, M02, M00, M03 in the Maluku Channel.

Yuan, D., Yin, X., Li, X. et al. A Maluku Sea intermediate western boundary current connecting Pacific Ocean circulation to the Indonesian Throughflow. Nat Commun 13, 2093 (2022). https://doi.org/10.1038/s41467-022-29617-6