Water mass along eastern pathway of Indonesia Throughflow from a CTD Argo Float

Abstract

Eastern pathway of the Indonesia Throughflow (ITF) conveys a secondary ITF inflow that brings North/South Pacific water entering interior Indonesian Seas. The transformation occurred along the Pacific water mass journey towards the Indonesian sea. For the first time since 2016, CTD Argo float measurement is available following the ITF path- A long Maluku-Seram-Banda Seas, providing prime datasets to be able seen change of ITF water. This paper aims to investigate transformation of ITF water masses and the percentage of water mass contribution (with Optimum MultiParameter method) along its eastern path of ITF between Maluku-Seram and Banda Seas. The result shows that along the path, North Pacific water origin is predominant in Southern Banda Sea, but lower thermocline water of South Pacific water origin in South Maluku and Seram Sea. Large transformation of ITF water is indicated with salty upper-thermocline water in Maluku-Seram Seas, but fresh thermocline water in Banda Sea. Spatial variation of mixing layer depth and thermocline depth is also found. The percentage of the water mass contribution of the North Pacific water NPSW and NPIW gets bigger along the journey to the Banda Sea, while the dominant of SPSLTW was found in Maluku Sea and Seram Sea.