Indonesian Through-Flow Water Mass Circulation in the Makassar Strait and Lombok Strait, Indonesia

Abstract

Indonesia through-flow has received much attention, largely because of its very important role in transporting mass, heat, and fresh water. The South Pacific water stream flows directly into the lower thermodynamics and deeper ITF components in the easternmost seas of Indonesia. In Indonesian waters, the excess regional freshwater enters the Pacific, which is subsequently altered by the mixture due to strong rushes to produce unique Indonesian waters. The aim of this study is to study the spatial patterns of marine water mass circulation in the waters of the Makassar Strait and the Lombok Strait as a basis for the development of ocean research. The research locations are in the waters of the Makassar Strait and the Lombok Strait, Indonesia. Temperature, salinity, and direction and current data from the ADCP OS75kHz and the SBE911Plus CTD instruments. The ITF in the Makassar Strait carries water masses originating from the North Pacific, namely North Pacific Subtropical Water (NPSW) thermomasses and North Pacific Intermediate Water thermomorphic underwater masses (NPIW). Domination by the southern stream component in the Makassar Strait due to the north-south-oriented stream configuration. The north-south component of the Makassar Strait's ITF stream dominates the flow from the Pacific Ocean to the Indian Ocean. On the Labani Cannel, the vertical spread of the current passing shows a higher current speed of the route in its northern part. This is due to the narrowing of the channel. Measured current speeds up to 1500 mm sec^-1. On the Lombok Strait, several layers of water are seen from its salinity. At a surface of less than 80 m, there is a water layer with a salinity of 33.8–34 PSU that tends to be homogeneous from the west to the east, with the direction of the current tending to the south. At the next layer, at a depth of over 80 m to 120 m, there are variations in the salinity of 34–34.6 PSU, with the value of the salinity tending to be homogenous on this layer in the dominant direction. The current movement that occurs in the waters of the Makassar Strait and the Lombok Strait is very complex.