ANALYSIS OF EL NIñO MODOKI EVENT USING SUBSURFACE TEMPERATURE IN THE EQUATORIAL PACIFIC OCEAN

• Main Author: Nur, Muhamad
• Format: Theses
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/69773
• Institution: Institut Teknologi Bandung

Analysis of the El Niño modoki event has been done using sea surface temperatures and subsurface temperatures in the Pacific Ocean. This phenomenon was analyzed using the El Niño modoki index (EMI). In addition, the analysis of temperature anomalies in the Pacific Ocean using the EOF method and the relationship between the dominant mode and the conventional El Niño and El Nio modoki phenomena are analyze through its correlation coefficients. The results of EOF analysis, the first mode of sea surface temperature anomaly represents 36.7% of the total variance, the second mode is 9.4%, the third mode is 6.0%, and the fourth mode is 4.1%. Meanwhile, the analysis of the subsurface temperature anomaly shows that the first mode represents 33.1%, the second mode is 12.1%, the third mode is 6.3%, and the fourth mode is 3.4%. Correlation analysis also strengthens the results of the EOF analysis. The relationship between first mode and the ONI shows a significant relationship with a correlation of 0.94 both at the surface temperature and at the subsurface temperature. The relationship between PC 2 and the EMI index also shows a significant relationship with a correlation of 0.77 at sea surface temperature and 0.72 at subsurface temperature. These results indicate that the first mode is a conventional El Niño event and the second mode is El Nio modoki event. Subsurface temperature variations ranging between 29 °C to 8 °C from the surface to a depth of 500m. The EMI shows that the positive SSTA is greater than the positive anomaly in the subsurface temperature. On the other hand, the negative anomaly in the subsurface temperature is greater than the negative anomaly in the surface. In general, the peak of El Niño modoki in the surface central Pacific Ocean occurs in the DJF season. Meanwhile, subsurface El Niño modoki reach its peak in the JJAS and DJF seasons, but the highest intensity occurs in the DJF season.