Surface Thermal Front Persistence in Malacca Strait

The Malacca strait is an essential seaway for international sea traffic and a provider of biological and non-biological resources. This strait has dynamic conditions resulting from the interaction between the Indian Ocean in the north and the Pacific Ocean in the south. The characteristic of the thermal front is the strait dynamics that have not been studied comprehensively. This research aims to map and identify the spatial and temporal pattern of the thermal front in Malacca Strait. The data used are sea surface temperature of AquaMODIS level 3 satellite images and bathymetry data of Malacca Strait, Ocean Nino Index (ONI), and Dipole Mode Index (DMI). The sea surface temperature data were processed from 2010 to 2020 using the Single Edge Image Detection (SIED) method. This research denotes the thermal front phenomenon found with several variations in each season. The highest (lowest) number of thermal fronts was discovered in the east season (first transitional season). The total number of thermal fronts each year happened to be maximum in 2015 and minimum in 2019. Annual variability (ENSO and IOD) impacts the number of thermal front events, but the observation period has to be explicitly adjusted in the analysis needed. Persistent thermal fronts in the Malacca Strait occurred in 1-5 repetitions at the exact location. Thermal fronts are commonly found in the northern region of the strait and areas with significant depth changes.Keywords: Malacca Strait; sea surface temperature; thermal front.AbstrakSelat Malaka terkenal sebagai perairan penting dalam lalu lintas laut internasional serta penyedia sumber daya hayati dan non hayati. Perairan ini juga memiliki kondisi yang dinamis sebagai hasil interaksi antara Samudera Hindia di bagian utara serta Samudera Pasifik di bagian selatan selat. Dinamika perairan yang belum dikaji secara komprehensif di perairan ini adalah karakteristik thermal front. Sehingga tujuan dari penelitian ini adalah memetakan secara spasial dan temporal kejadian thermal front di perairan Selat Malaka serta menganalisis karakteristik dari thermal front yang dipetakan tersebut. Data yang digunakan pada penelitian ini adalah data suhu permukaan laut citra satelit AquaMODIS level 3, data batimetri Selat Malaka, serta data Ocean Nino Index (ONI) dan Dipole Mode Index (DMI). Metode Single Edge Image Detection (SIED) digunakan untuk mengolah data suhu permukaan laut pada periode pengamatan tahun 2010 hingga 2020. Hasil penelitian ini menunjukk