Abstract

Author:

Shinta O. Yudowaty, Ivonne M. Radjawane, Faiz Rohman Fajary, Gandhi Napitupulu

Doi: 10.26480/magg.01.2025.38.44

This is an open access article distributed under the Creative Commons Attribution License CC BY 4.0, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited

The Indonesian Throughflow (ITF) transports warm water masses from the Pacific Ocean to the Indian Ocean through the Makassar Strait. Ocean currents and sea temperature data from the HYCOM model estimate the heat transport associated with the ITF within the Makassar Strait. Heat transport is calculated as the product of volume transport, temperature, density, and specific heat. The calculation is applied to two study areas, the northern and southern sides of the Makassar Strait, representing the incoming and outgoing passages, respectively. Heat transport within the Makassar Strait is directed southward, with Maximum heat transport occurring between 0 and 100 meters, where the ITF is strong. Makassar Strait heat transport is influenced by the monsoon. The most substantial average seasonal heat transport occurs during the east monsoon, reaching a maximum value of 1.09 PW in the incoming passage and 1.05 PW in the outgoing passage. The minimum volume transport occurred during the second transitional monsoon, with values of 0.82 PW in the incoming passage and 0.78 PW in the outgoing passage. Heat transport in the outgoing passage decreased by an average of 0.03 PW. This variability is due to the temperature in the outgoing passage varying more significantly over time. Additionally, the dynamics of adjacent seas to the south of the Makassar Strait directly influence the outgoing passage. Interannual variations also influence heat transport, specifically El Niño and La Niña. During El Niño, both southward volume and heat transport decrease in both passages. However, the impact of La Niña is not clearly observed, likely because its peak during this study period occurred between the second transitional monsoon and the west monsoon, a period in which southward transport is weakened.