WATER MASS STRATIFICATION AND CURRENTS DISTRIBUTION OF TIMOR AND ARAFURA SEAS AT FIRST TRANSITIONAL SEASON IN 2010

• Main Author: El-islamy Qomaruddin, Nida
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/38829
• Institution: Institut Teknologi Bandung

The Timor and Arafura Seas are part of the Eastern Archipelago waters which directly meet the Indian Ocean and make the Timor Sea as the largest exit of Indonesian Throughflow. The aims of this research are to study the structure of stratification, types and contribution of water masses, and study the distribution of current vertical movements in the Timor and Arafura Seas. This study used temperature, salinity, density, oxygen, and current data from Conductivity, Temperature, and Depth (CTD) and Acoustic Doppler Current Profiler (ADCP) measurements in the 2010 Arafura and Timor Seas Ecosystem Action Program (ATSEA), and temperature, salinity, and currents data from the HYbrid Coordinate Ocean Model (HYCOM). The water masses stratification was determined by calculating the temperature and salinity gradient per one meter depth, the type of water masses was determined by the T-S, T-O, and S-O diagrams, the contribution of each type of water masses is known from the Optimum Multi Parameter (OMP) analysis, and the current distribution is known from the results of the HYCOM model. The results showed that there are three water masses layers in the Timor Sea, namely the mixed layer, thermocline and halocline, and the deep layer; and two layers in the Arafura Sea are the mixed layer and the thermocline and halocline. There are 6 types of water masses identified in the Timor Sea with its contributions as follows; in the mixed layer there are Halmahera – Misool Water (HMW) contributing around 40 – 70% and Seram – Banda Water (SBW) contributing around 50 – 60%; in the thermocline layer there are Southern Subtropical Lower Water (SSLW) contributing around 30 – 40% and Indonesian Upper Water (IUW) contributing around 40 – 50%, and in the deep layer there are Austral Asian Intermediate Water (AAMW) contributing around 100% and Antartic Intermediate Water (AAIW) contributing around 20 – 70%. In the Arafura Sea, 2 types of water masses were identified with its contribution as follows; Halmahera – Misool Water (HMW) contributing around 30 – 50% and Seram – Banda Water (SBW) contributing around 100%. Currents in the Timor Sea move to the southwest with water masses from the Banda Sea in mixed layers and thermoclines, as well as water masses of the Indian Ocean and Banda Sea in the deep layer. Mixed layer currents in the Arafura Sea move to the south – southwest with water masses from the Seram Sea and the northern part of the Banda Sea, and in the east part of the Arafura Sea there is a mixture of seawater and river flow from the western part of Papua Island.