Chlorophyll-a Variability in Upwelling Regions in Labuan and Kariamta Strait
Gandhi Napitupulu1, Ivonne Milichristi Radjawane1, Ejria Saleh2, Rais Abdillah1, Mohd Azamuddin2

1Department of Earth Sciences, Faculty of Earth Sciences and Technology, Institut Teknologi Bandung, Bandung, Indonesia
2Borneo Marine Research Institute, Universiti Malaysia Sabah, Sabah, Malaysia

Abstract

Information about sea surface chlorophyll-a variability has an important role as predictive means of the potential fish catching area. The aim of this research is to study sea surface chlorophyll variability at temporal and spatial scale in upwelling areas during the ENSO (El Nino Southern Oscillation) and Indian Oscillation Dipole Mode (IOD). The study sites take place in Labuan (Malaysia) and Karimata Strait (Indonesia). Sea surface chlorophyll variability was analyzed using Global Ocean Biogeochemistry Hindcast data. Sea surface chlorophyll value varies in time and area from an inter-annual variation of global climate (El Nino, positive IOD, El Nino, negative IOD). The range of chlorophyll-a value is 0.2-1.3 mg/m3. Chlorophyll-a value started to increase in March to the peak in April and after that decreased to normal in Karimata strait. The value of chlorophyll-a value started to increase in December to the peak in February and after that decreased to normal in Labuan. Empirical Orthogonal Function is used to decompose chlorophyll-a data. ENSO index has a negative correlation with PC-1 which shows La Nina increases chlorophyll-a value, and El Nino decreases chlorophyll value at JJA, MAM, and DJF periods. ONI index positively correlates with PC-1 which shows positive IOD increases chlorophyll-a value and negative IOD decreases chlorophyll value at SON periods. Chlorophyll-a in Kariamta Strait and Labuan at MAM and DFF period slightly influence by ENSO compared to IOD, which negatively correlates with the ENSO index and chlorophyll-a.

Keywords: Chlorophyll-a Karimata strait Labuan Variability Upwelling

Topic: Ocean Sciences