Sea surface height, sea surface temperature, and chlorophyll-a as indicators for determining eddy in Indonesian waters

Sea surface height, sea surface temperature, and chlorophyll-a are parameters that can identify and monitor the presence and characteristics of eddies more accurately in the complex and dynamic waters of Indonesia. The identification and monitoring of eddies are important for understanding ocean variability and its implications for marine ecosystems. The objective of this study is to determine the distribution and characteristics of eddies in Indonesian waters. The data used were obtained from HYCOM (Hybrid Coordinate Ocean Model). The study area covered Indonesian waters with coordinates 6°N - 11°S and 95°E - 141.5°E, then processed using MATLAB software. Eddy detection was performed using the Automated Eddy Detection (AED) method. Sea surface height, sea surface temperature, and chlorophyll-a data were calculated and overlaid with the eddy detection results. The results of the study show that the highest concentration of eddies occurs in the waters west of Sumatra, south of Java, and the Indian Ocean with 107 occurrences, and in the waters north of Papua and the Pacific Ocean with 101 occurrences. The average diameter of cyclonic eddies is 90.626 km and 95.834 km for anticyclonic eddies. The average SSH value was 0.547 m for cyclonic eddies and 0.644 m for anticyclonic eddies. The average temperature was 29.209 °C for cyclonic eddies and 29.356 °C for anticyclonic eddies. The average chlorophyll-a value is 0.069 mg/m3 for cyclonic eddies and 0.074 mg/m3 for anticyclonic eddies.