Abstract:On the basis of the sea level anomalies (SLA) altimeter data provided by CNES,the mean sea level change on the East China Sea was investigated. In recent 14 years, the rising rates have reached to 0.412 cm/a,0.292cm/a respectively in the northern part and southern part of East China Sea separated by 30°N obviously,they are different. Correlative analysis shows that low frequency components of SLA have good but opposite response to that SOI and zonal wind stress anomalies, over the northern part and southern part of East China Sea. It is obvious that the sea level variation is closely related to SOI and zonal wind stress anomaly and it indicats that sea level in the East China Sea is dominated by El Nio, as well as zonal wind stress.There is also a good relationship between SOI and the wind field over the East China Sea, of which the low frequency components are corresponding to ENSO. By using correlative analysis between SLA and wind stress anomalies u component in the new coordinate system, it is found that the direction of wind stress most strongly affecting the sea level is 70 degrees and 23 degrees south of east separately, over the northern part and southern part of East China Sea. The divergence zone affects the wind field of the East China Sea strongly by atmospheric circulation, and that makes SLA and wind stress anomalies response differently between the northern part and southern part of the East China Sea. Based on the analysis above, a conclusion could be drawn that zonal wind stress affects the sea level significantly, indicating that ENSO impacts on wind filed of the East China Sea by means of atmospheric circulation, hence affecting the sea level. To sum up, ENSO and wind stress contribute to the sea level change over the East china Sea. In detail, ENSO impacts on wind filed of the East China Sea, hence affecting the interannual change of sea level, and sea surface wind responses well to ENSO, showing that ENSO could affect the sea level of the East China Sea, through mechanism of wind stress.
Liu Xueyuan,Liu Yuguang,Guo Lin et al. CHANGE OF MEAN SEA LEVEL OF LOW-FREQUENCY ON EAST CHINA SEA AND ITS RELATION WITH ENSO[J]. jgg, 2009, 29(4): 55-63.