This paper investigates sea surface height to geoid (SSHG) and mixed layer depth (MLD) variations in the West Sumatera Coastal Area dominated Indian Ocean Dipole (IOD) evolutions using the data of MLD and (SSHG) from 2004 to 2017. The MLD variations in West Sumatera Coastal Area are explicitly investigated through spatial and temporal variations Empirical Orthogonal Functions (EOF). In the previous research, MLD variations in these extensive ocean-atmospheric circulations mainly focused on seasonal variations. The first results of EOF mode indicate 12% of the variability and show MLD variations in West Sumatera Coastal area during boreal fall (September – November). This result indicates that seasonal variation of MLD is slightly weak to the IOD event caused by ENSO signals from atmospheric teleconnection. On the other situation, the seasonal variations of SSHG is tightly related to the Indian Ocean Dipole (IOD) evolutions. The EOF results of SSHG shows 30% variabilities and is stronger than the MLD. The weak (dominant) pattern of these MLD and SSHG variations affects a shoaling layer over the west Sumatra coastal area associated with the negative Indian Ocean during 2010. We suggest that this MLD and SSHG product could be used as a reference for future studies and predict fish productivity.

This study aimed to detect the water content in peatland and cropland associated with rainfall deficiencies and positive Indian Ocean Dipole (IOD) events. The condition of water content is a biological indicator of peatland ecosystems that commonly contributes to hot spots in Sumatra. The water content and rainfall data were processed using the spatial average at two study areas, and the variabilities were analyzed with the Indian Ocean Dipole index (DMI). From 2015 until 2020, this study employed the Dipole Mode Index to evaluate five positive IOD events. The analysis of the water content conditions and deficiency rainfall correlated to positive IOD events. In the peatland, the water content was a sensitive parameter, and even though the value decreased by a small amount, it potentially inflamed. Even if the water content was low in cropland areas, it did not trigger forest fires. The effect of rainfall deficiency was related to land response to water content conditions. Different land types will have different sensitivities. Understanding the correlation between deficiency rainfall with water content can be helpful for an early warning system.