Interannual variability of winter eddy patterns in the eastern South China Sea

Abstract

AbstractMerged altimetry data collected over 21 years are analyzed to study the interannual variability of winter eddy activities in the eastern South China Sea (SCS) associated with the El Niño–Southern Oscillation. Composite analyses of eddy probability reveal that a Luzon cold eddy (LCE) northwest of the Luzon Island, an anticyclonic eddy northwest of the Mindoro Island (referred as MAE) and a cyclonic eddy west of the Mindoro Island (referred as MCE) are common for winter. Further studies indicate that LCE and MAE weaken and MCE strengthens in El Niño winters, whereas data show the opposite behavior for La Niña winters. In addition, the geographical pattern of MAE and MCE in an El Niño winter is different from that in a La Niña winter. The interannual wind curl anomalies west of the Luzon and Mindoro Islands and the outflow from the SCS via the Mindoro Strait may be responsible for the interannual eddy variability.