BULETIN OSEANOGRAFI MARINA
Vol 15, No 1 (2026): Buletin Oseanografi Marina

Coastal Marine Heatwaves Detection in Java Using Satellite and In-situ

Willy Wulansari (Magister Program of Marine Sciences, Faculty of Fisheries and Marine Science, Universitas Diponegoro Directorate of Marine Meteorology, Indonesian Agency for Meteorology Climatology and Geophysics)
Sugeng Widada (Department of Oceanography, Faculty of Fisheries and Marine Science, Universitas Diponegoro)
Lili Maslukah (Department of Oceanography, Faculty of Fisheries and Marine Science, Universitas Diponegoro)
Anindya Wirasatriya (Department of Oceanography, Faculty of Fisheries and Marine Science, Universitas Diponegoro)
Titi Sari (Directorate of Marine Meteorology, Indonesian Agency for Meteorology Climatology and Geophysics)



Article Info

Publish Date
25 Feb 2026

Abstract

Global warming is driving an increase in the frequency and intensity of Marine Heatwaves (MHWs), which have a significant impact on coastal ecosystems. The detection of  MHWs in Indonesia's coastal regions remains understudied due to limited long term in-situ data, while satellite products often have a coarse resolution that cannot capture local coastal dynamics. This study addresses this gap by detecting MHWs on the north coast of Java. It evaluates the performance of the  Operational Sea Surface Temperature and Ice Analysis (OSTIA) product by comparing it against in-situ data from four Marine Automatic Weather Stations (Patimban, Karimunjawa, Rembang, and Paciran) from 2022–2024. To simulate an operational satellite based approach, MHWs were identified in the in-situ daily minimum temperature records using a climatology and 90th percentile threshold derived from the nearest satellite grid point. The statistical comparison reveals spatially variable differences in MHW frequency, duration, and total days between the two data sources. Event matching analysis indicates the best satellite performance at Paciran (Probability of Detection (POD)=0.74, False Alarm Ratio (FAR)=0.13), where most in-situ events were successfully captured. Conversely, the weakest performance was at Rembang (POD=0.43, FAR=0.59), where the satellite missed over half of the MHW days and exhibited a high false alarm rate. These findings demonstrate that significant MHWs occur in coastal regions, phenomena that may not be accurately captured by satellite data alone. 

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Journal Info

Abbrev

buloma

Publisher

Subject

Earth & Planetary Sciences

Description

Buletin Oseanografi Marina (BULOMA) adalah jurnal yang menginformasikan hasil penelitian dan telaah pustaka tentang aspek Oseanografi, Ilmu Kelautan, Biologi Laut, Geologi Laut, Dinamika Laut dan Samudera, Estuari, Kajian Enerji Alternatif, Mitigasi Bencana, Sumberdaya Alam Pesisir, Laut dan ...