Oceanic Rossby waves play a crucial role in shaping the physical and biological dynamics of both open and coastal oceans, especially within the tropical band spanning between the 10°S and 10°N parallels. Yet, the extent to which Rossby waves can transmit and impact the hydrography and ecosystem of semi-enclosed seas like the South China Sea (SCS) remains unclear. This study aims to investigate the transmission of Rossby waves through the Philippine archipelago, using satellite altimeter-derived sea level anomaly (SLA) and coastal tide gauge records. Our findings reveal that westward-propagating Rossby waves in the tropical Pacific Ocean with a wave speed of ~0.64 m s−1 first entered the Celebes Sea, and then passed through the Sibutu Passage into the Sulu Sea from April to December 2017. Subsequently, the waves propagated along the northeast coast of Sabah and the east coast of Palawan before exiting through the Mindoro Strait to the central SCS. Additionally, a β-refracted Rossby wave with wave speed of 0.28 m s−1 also penetrated the archipelago but at a latitude further north ~10°N from July to November via Surigao Strait and propagated toward the south and north of Palawan, ultimately reaching the west coast of Palawan in the eastern central SCS. This study verifies that the transmission of Rossby waves originating from the east of the Philippines could induce intraseasonal sea level oscillations off Palawan, which could subsequently propagate westward across the central SCS as identified in previous field observations.

The North Pacific Ocean is the largest basin and is located at the end point of the thermohaline circulation of deep water. Few concurrent data of Cd, Ni, Zn, and Cu in seawater have been reported in this area so far. Herein, we report the basin-scale full-depth sectional distributions of the total dissolvable, dissolved, and labile particulate Cd, Ni, Zn, and Cu along the 160°W, 165°E, and 47°N GEOTRACES transects. Our data reveal that the relations of the four dissolved metals (dMs) with Si(OH) and PO considerably differ from those in other oceans. The plot of the preformed Cd vs. the preformed PO exhibits strong linearity and passes an origin.The dCd/PO ratio is 0.34±0.02 mmol/mol at a depth lower than 800 m, which is in the range of the phytoplankton Cd/PO ratio, thus indicating the dominant effect of the biogeochemical cycling on the dCd distribution. The dMs/POratios of the other examined metals are partially or completely out of the phytoplankton ratios and generally increase with depth in waters deeper than 800 m. Specifically, the increase is the strongest for Cu and moderate for Ni and Zn. The dMs/PO ratios below 800 m decrease with the apparent oxygen utilization increasing from 150 to 300 mmol/kg by 4% for Cd, 21% for Zn and Ni, and 69% for Cu. We thus demonstrate that scavenging is an important factor that significantly affects the distributions of Zn, Ni, and Cu, whereas the effect increases in the order Cd < Ni, Zn < Cu.