IDENTIFICATION OF TIDAL CURRENT ELLIPSE VERTICAL STUCTURE IN INDONESIA’S EASTERN SEAS

• Main Author: Beliyana, Erlin
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/39305
• Institution: Institut Teknologi Bandung

Indonesian seas are strongly affected by strong semidiurnal tidal signals (M2 and S2) from the Indian Ocean and diurnal signals (K1 and O1) from the Pacific Ocean. Therefore, within the internal seas, there is possibility of mixed tides (semidiurnal and diurnal signals). This research is focused on determining tidal current ellipses based on the velocity data measured during the INSTANT (International Nusantara Stratification and Transport) program. The velocity data from Makassar, Lombok, and Ombai Straits and Timor passage from January 18, 2004 to December 31, 2004 are analyzed. Characteristics of tidal current data at certain fixed depths (50, 100, 350 and 750 meters) are processed and calculated using MATLAB software and present the magnitude and variability of total and residual currents as well as vertical variability of tidal ellipses at these straits. In Makassar strait and Lombok Strait currents tend to move meridionally (north – south) and show both diurnal and semidiurnal tidal signals. Meanwhile, in Timor Passage and Ombai Strait tend to move zonally (east – west) which dominated by semidiurnal signals. The dominant tidal currents are observed at 350 and 750 meters, while subtidal (nontidal) current dominant occurs with 50 to 150 meters. Diurnal components K1 and O1 and semidiurnal components M2 and S2 have different rotation of current vectors and different direction of initial. The semidiurnal M2 component is most dominant tidal signal in the four study areas.