VARIABILITAS KLOROFIL-a PERIODE INDIAN OCEAN DIPOLE DI SELAT BALI BERDASARKAN ANALISIS EMPIRICAL ORTHOGONAL FUNCTION

Abstract

The waters of the Bali Strait are indirectly affected by phenomena in the Indian Ocean South of Java. Variability of surface chlorophyll-a concentration (SSC) seasonally and inter-annually, is closely related to the Indian ocean dipole (IOD) and upwelling phenomena that occur along the South Coast of Java. This study aims to analyze the spatial and temporal seasonal and inter-annual variability of the chlorophyll-a parameter in the IOD period. Oceanographic data were obtained from the Aqua/Terra MODIS (Moderate Resolution Imaging Spectroradiometer) Satellite level 2 daily, during March 2000-May 2020. Data analysis used Empirical Orthogonal Function (EOF). The results of the EOF analysis show a coherent temporal variation in chlorophyll-a pumping in the Bali Strait. The first mode of the time series shows strong seasonal variation rather than inter-annual variation. Inter-annual variation is seen in the second mode, which shows high concentrations of chlorophyll-a along the coast of the Bali Strait. Based on the correlation analysis on the time series of the EOF mode shows a significant relationship with IOD. This condition is seen during the peak phase of the IOD period along with the southeast monsoon there is an increase in the concentration of chlorophyll-a along the coast of the Bali Strait compared to the previous season.