Long term variation of sea level anomaly (September 1992-January 2017) in the Indonesian sea from multi-mission satellite altimetry data

Abstract

Sea level anomaly (SLA) is one of the oceanic parameters that play a crucial role in the ocean dynamics. In the Indonesian region, spatio-temporal characteristic of SLA is significantly affected by local topographic features of the region. In this research, we investigate long-term variation of SLA over the region based on Topex/Poseidon, Jason-1 and Jason-2 data, during the period of Sept 1992 to January 2017. After removing some geophysical effects, time series of SLA values at each point of the collinear tracks are analyzed. The result show the long term MSSH in Indonesia area have increase from western part of Indonesia to eastern part with range -40 m to 80 m. The long term SST in Indonesia have almost same trend with the deviation from geoid undulation full degree with short wavelength type, and this phenomena represent the local effect such as shallow bathymetry and close sea. And for long term SLA, Indonesia shows positive value that the anomaly increasing with variable from western part to eastern part of Indonesia from 2.5 mm/year until 7 mm/yr.