By using composite, correlate analysis and SVD (Singular Value Decomposition) technique, the relationships among the onset of the South China Sea Summer Monsoon (SCSM), its associated circulation anomalies from April to June and SST anomalies in the tropical Indian-Pacific Ocean were investigated. The results indicate the impacts of SST anomalies in the tropical Indian-Pacific Ocean on the onset of SCSM and its associated monsoon circulation anomalies are significant. The onset of SCSM is early (late) when SST anomalies in the tropical central-eastern Pacific Ocean, Indian Ocean (mainly in the southwestern region) and South China Sea are negative (positive), while SST anomalies in the western Pacific Ocean and Australia's adjacent seas are positive (negative). SST anomalies in different regions of the ocean influence the monsoon in different time: the Indian Ocean is from April to June, South China Sea is May-June, while the influence of the tropical Pacific Ocean can persist from the last winter to this summer. Different SST anomalies can induce different monsoon circulation regimes; circulation anomalies in early or late SCSM are basically reverse. A close relationship exists between SCSM and the activities of the western Pacific subtropical high in previous winter and spring: when the western Pacific subtropical high is weak (strong), the onset of SCSM is early (late). Monsoon circulation and Walker circulation anomalies induced by SST anomalies in the tropical Pacific-Indian Ocean maybe play an important role in influencing SCSM in terms of its onset time.
onset of South China Sea summer monsoonanomaly of tropical sea surface temperatureatmospheric circulation anomaly
NETL
NSTL
维普
万方数据
