This study aims to investigate the spatial and temporal impacts of El Niño-Southern Oscillation (ENSO) and Indian Ocean Dipole (IOD) on Sea Surface Temperature (SST) variations in the Natuna Sea and its adjacent waters. In this study, Cross Wavelet Transform (XWT) and Partial Correlation were used to determine the time-frequency relationship and isolate the specific influence of ENSO and IOD on SST. These primary methods were substantiated by Time Series Analysis, Power Spectral Density (PSD), and Cross Correlation, which first identified the dominant interannual periodicities and lag phases required for causal analysis. Analysis reveals that the interannual phenomenon (in a period of 2-7 years) is dominant in controlling the SST anomalies in the Natuna Sea. The XWT analysis shows that SST responds to ENSO and IOD within a 2-7 year band, though with varying lag phases of 2-3 months in the northern region and 7-10 months in the southern region. Meanwhile Partial Correlation analysis confirms a positive relationship across the basin with the IOD exhibiting a stronger and more uniform influence (r = 0.5-0.8) compared to ENSO (r = 0.1-0.7). These results suggest that SST warming in the Natuna Sea is driven primarily by atmospheric teleconnections rather than direct oceanic advection, particularly in the northern region.
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