Malugao, Mac Euan D.Mac Euan D.MalugaoJan, SenSenJanHo, Tung-YuanTung-YuanHoChang, Ming-HueiMing-HueiChangYang, Yiing JangYiing JangYang2025-12-192025-12-192025-07https://www.scopus.com/pages/publications/105003803577https://scholars.lib.ntu.edu.tw/handle/123456789/734802This study investigates the connection between the current velocity variations in the central South China Sea (SCS) and westward-propagating tropical Rossby waves in the western North Pacific, using satellite altimeter observations and coastal tide-gauge data supplemented by numerical modeling. This work is focused on the dynamic link between the intraseasonal velocity oscillations observed in the central-eastern SCS in summer 2017 and the Rossby waves that impinge on the east coast of the Philippine Archipelago. Low-pass-filtered satellite sea level anomaly (SLA) data and coastal sea level records suggest that Rossby waves can propagate into the Celebes Sea and Sulu Sea, eventually reaching the central SCS. A three-dimensional, primitive equation model shows that Rossby wave-associated SLA signals transmit through the Philippine Archipelago to the central SCS via the Celebes Sea-Sibutu Passage-Sulu Sea-Mindoro Strait route, with modeled SLA propagation timings that are consistent with the observations. As the Rossby wave reaches the eastern Philippines, approximately one-third of the incident wave energy from a meridional section east of the Philippines (132°E, between 2°N and 15°N) is transmitted into the Celebes Sea and Luzon Strait, whereas approximately two-thirds of the energy is dissipated, transformed, or reflected along the Philippine coast. Approximately 15 % of the energy entering the Celebes Sea passes through the Sibutu Passage into the Sulu Sea, and ∼10 % exits the Mindoro Strait into the central SCS. These suggest that 2−5 % of the incident energy from the western North Pacific transmitted into the central SCS and influences sea level and velocity variations there.Intraseasonal oscillationPhilippine ArchipelagoRossby wavesSea level anomalySouth China SeaTransmission[SDGs]SDG13[SDGs]SDG14journal article10.1016/j.pocean.2025.103481