1. Observed transport variations in the Maluku Channel of the Indonesian Seas associated with western boundary current changes
- Author
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Ya Yang, Dongliang Yuan, Adi Purwandana, D. Dirhamsyah, Praditya Avianto, Jin-Song von Storch, Yao Li, Zainal Arifin, Zheng Wang, Shuwen Tan, Hui Zhou, Dewi Surinati, Mochamad Furqon Azis Ismail, Jing Wang, Adhitya Kusuma Wardana, Xiaoyue Hu, and Xiang Li
- Subjects
geography ,Throughflow ,geography.geographical_feature_category ,010504 meteorology & atmospheric sciences ,010505 oceanography ,Ocean current ,Rossby wave ,Oceanography ,01 natural sciences ,language.human_language ,Boundary current ,Indonesian ,Current (stream) ,language ,Geology ,Sea level ,Channel (geography) ,0105 earth and related environmental sciences - Abstract
The Maluku Channel is a major opening of the eastern Indonesian Seas to the western Pacific Ocean, the upper-ocean currents of which have rarely been observed historically. During December 2012–November 2016, long time series of the upper Maluku Channel transport are measured successfully for the first time using subsurface oceanic moorings. The measurements show significant intraseasonal-to-interannual variability of over 14 Sv (1 Sv ≡ 106 m3 s−1) in the upper 300 m or so, with a mean transport of 1.04–1.31 Sv northward and a significant southward interannual change of over 3.5 Sv in the spring of 2014. Coincident with the interannual transport change is the Mindanao Current, choked at the entrance of the Indonesian Seas, which is significantly different from its climatological retroflection in fall–winter. A high-resolution numerical simulation suggests that the variations of the Maluku Channel currents are associated with the shifting of the Mindanao Current retroflection. It is suggested that the shifting of the Mindanao Current outside the Sulawesi Sea in the spring of 2014 elevates the sea level at the entrance of the Indonesian Seas, which drives the anomalous transport through the Maluku Channel. The results suggest the importance of the western boundary current nonlinearity in driving the transport variability of the Indonesian Throughflow.
- Published
- 2018