STUDY OF UPWELLING IN THE BANDA AND ARAFURA SEA 2007-2016

• Main Author: BAMBANG IRAWAN, WILLY
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/31618
• Institution: Institut Teknologi Bandung

<p align="justify">Banda and Arafura Sea are waters that are influenced by local and global factors that cause upwelling phenomena. The purpose of this study was to analyze the characteristics of upwelling and the influence of seasonal and inter-annual variations in the Banda Sea and Arafura. The data used are SST, chlorophyll-a data, surface wind speed, and Ocean Niño Index (ONI) with a span of time from January 2007 to December 2016 (10 years). SST and chlorophyll-a data are level 3 Aqua Moderate Resolution Imaging Spectroradiometer (MODIS) satellite imagery with 4 km resolution. 0.25o resolution surface wind speed data obtained from the European Center for Medium-Range Weather Forecasts (ECMWF). The results of this study show that upwelling in the Banda Sea and Arafura have alternating types. The phenomenon of upwelling occurs longer for 6 months in the months of May-October, followed by the phenomenon of downwelling from December to March, which is shorter for 4 months. Strong intensity upwelling occurred in the western Aru Basin in August with an average SST value of 25.8 oC and a SST anomaly of 4.2 oC and a chlorophyll-a value of 1.25 mg/m³. Upwelling in the Banda Sea is indicated as a result of divergence offshore, while upwelling in the Arafura Sea is a type of coastal upwelling. The upwelling phenomenon is also identified by Ekman and Ekman transport pumping which is calculated from wind speed. The highest Ekman transport occurred in July with Ekman transport values ranging from 1–3.7 m²/s, while the lowest Ekman transport values occurred in April and November with Ekman transport values ranging from 0.03–0.5 m²/s. Although the wind speed in the Banda Sea is greater than the Arafura Sea, the Ekman pumping value in the Arafura Sea is greater. The highest Ekman pumping value in the Banda Sea occurred in May and June, while in the Arafura Sea occurred in July. At the time of El Niño, the SST value experienced a decrease, while in the case of La Niña the SST value increased. When El Niño occurs, it also causes the chlorophyll-a concentration and Ekman transport to be higher than during La Niña.<p align="justify">