Interannual and decadal variability of sea level in the South China Sea

Interannual to decadal variability of sea level in the South China Sea (SCS) is studied using altimetry data during 1993-2012 and reconstructed sea level data from 1950 through 2009. The interannual variability features significant seasonality, and wind stress curl anomalies associated with El Niño-Southern Oscillation explain the sea level anomaly pattern quite well. The sea level signals from the western Pacific also influence the sea level along the west coast of Luzon Island. By contrast, decadal variability of sea level in the SCS is very similar to that in the western Pacific with large variance found west of Luzon Island. Local atmospheric forcing has a negative contribution to decadal variability of sea level in the SCS, and ocean dynamics appears to be important. Decadal sea level averaged in the SCS is significantly correlated with the Pacific Decadal Oscillation (PDO) (r=0.98), and the linear trends of the basin-mean sea level are greatly affected by the low-frequency variability in the satellite altimeter era.