OFES reveals imprint of PDO on South China Sea Throughflow Kai Yu and Tangdong Qu Analysis of the OFES hindast reveals the imprint of the Pacific Decadal Oscillation (PDO) on the transport of Pacific Water through Luzon Strait into the South China Sea (SCS). The transport is stronger during positive PDO phases and weaker during negative phases. The PDO modulates the transport into the SCS through the North Pacific Tropical Gyre: during positive PDO phases, the northeasterly trades weaken, and the North Equatorial Current bifurcation shifts northward, leading to weaker Kuroshio flow and stronger Luzon Strait transport. During negative PDO phases the opposite sequence of events takes place. (a) Time series of Luzon Strait transport (blue) and PDO index (red), (b) long-term mean wind stress, and (c) difference between the strong and weak PDO years as marked by the black circles in (a).