Eddy Currents Variablity from Satellite Altimetry and Its Relation to Physical Conditions of Java Sea

Current pattern in Java Sea highly depends on monsoonal cycles, which create alternating conditions according to the seasons throughout the year and potential impacts on eddy currents variability. Using the surface geostrophic current data from satellite altimetry during 2013-2017, this study aims to understand the variability of eddy currents and its relations to the physical condition of the Java Sea such as sea surface temperature (SST), sea surface height (SSH), and chlorophyll-a concentration (CHL). Results showed 60 occurrence of eddy currents in the study area, 40 cyclonic and 20 anticyclonic. The largest cyclonic eddy observed in April 2013 (112.05, -5.37) with a diameter of 134.07 km, while the largest anticyclonic eddy observed in October 2017 (114.54, -6.24) with a diameter of 159.69 km. Cyclonic eddy has lower SSH and cold core while anticyclonic eddy has higher SSH and warm core. Despite having an unclear pattern during the five years period, the occurence of Eddy current has a potentially indirect influence on Chl-a concentration

THE OCEAN CURRENT PATTERN AND WATER MASS CHARACTERISTIC IN THE RESPONSE OF CLIMATE EVENTS ON THE NORTHWESTERN SUMATRA WATER

El Nino lemah dan positif Indian Ocean Dipole (pIOD) yang diikuti La Nina moderat dan negatif Indian Ocean Dipole (nIOD) pada tahun 2017 memberikan pengaruhnya terhadap kondisi pantai barat laut Sumatera. Penelitian untuk menganalisis hal tersebut dilakukan menggunakan RV Baruna Jaya VIII pada Desember 2017. Pelayaran ini bertujuan menganalisis pengaruh perubahan iklim terhadap pola arus laut dan karakteristik massa air. Data hidrografi dari pelayaran tersebut didukung oleh data satelit altimetri suhu permukaan laut (SST), data anomali angin yang bersumber dari The European Centre for Medium-Range Weather Forecasts (ECMWF), dan data arus yang bersumber dari Ocean Surface Current Analysis Real-Time. Hasil penelitian menunjukkan adanya warmer sea surface temperature saat fenomena weak El Nino diikuti positive IOD (pIOD) and cooler sea surface temperature saat fenomena moderat La Nina diikuti negative IOD (nIOD). Karakteristik massa air yang diamati pada lapisan atas maupun tengah bersumber dari perairan Samudera Hindia. Data arus mendukung hal tersebut dengan menunjukkan bahwa arus pada bulan Desember bergerak dari barat sebagai bagian dari musim barat dan pengaruh dari Wyrtki Jets