印尼贯穿流出流海域海表高度时空变化
The Spatial-Temporal Variation of Sea Level Anomalies in the Indonesian Throughflow Outflow Region
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摘要: 采用经验正交分解(Empirical Orthogonal Function,EOF)分析方法对印尼贯穿流出流海域卫星测高海面高度异常资料进行了分析,分析结果显示研究海域海面高度异常存在多时间尺度变化特征。1993—2013年期间,研究海域海面高度异常场存在明显的升高趋势,其升高速率为0.6 cm/a;研究海域海面高度异常存在显著的年际变化,其与Niño3.4指数的相关系数超前滞后相关最大可达0.65,且厄尔尼诺年偏高,拉尼娜年偏低;海面高度异常年周期变化显著海域主要受印尼贯穿流、印度洋南赤道流和Eastern Gyral Current(EGC)季节变化的影响,半年周期变化则对应于爪哇沿岸流与南赤道流共同作用下形成的涡旋的半年周期变化;另外,研究海域海面高度异常还存在显著的季节内变化特征。Abstract: The Empirical Orthogonal Function (EOF) is used to analyze the sea level anomalies in the outflow region of the Indonesian Throughflow, and the results show that multi-scale variations of sea level anomalies exist in the study region. Significant ascending trend in the sea level anomalies with a value of 0.6 cm/a is found from 1993 to 2013. The sea level anomaly in the region shows interannual variation and is correlated with the Niño3.4 index,with a correlation coefficient of up to 0.65, implying positive/negative sea level anomalies during El Niño/La Niña events, respectively. The annual cycle of the sea level anomaly is mainly influenced by the Indonesian Throughflow, the South Java Current and the Eastern Gyral Current, and the semi-annual cycle is mainly caused by the eddy generated by the interaction between the South Java Current and the South Equatorial Current. Analysis also reveals that the sea level anomaly exhibits distinct intraseasonal variation in the outflow region of the Indonesian Throughflow.