Asymmetric Biogeochemical Responses To Wind Forcing During Climate Oscillation In The South China Sea And The West Philippine Sea: Observations And Implications

It has long been demonstrated that the seasonal variation of phytoplankton growth in the South China Sea is mainly controlled by wind intensity. However, it has also been observed that the anomaly of sea surface Chl-a responding to wind anomaly at the SEATS station is asymmetric during different phases of climate oscillation. Under positive MEI (Multivariate ENSO Index), the response was considerably stronger than under negative MEI in the past 14 years. The situation was reversed in the West Philippine Sea at the same latitude. There is evidence suggesting that the asymmetric responses were related to the water column structure governed by regional ocean circulation. We will explore the potential tool of biogeochemical responses at sea surface to reveal regional ocean dynamics.