ENSO impacts during west and east monsoon to the ocean current and water mass characteristics in the Makassar Strait

Ocean and atmospheric interactions are known by the presence of El-Nino Southern Oscillation (ENSO) in the Pacific Ocean, dipole mode in the Indian Ocean, and Indonesian-Throughflow (ITF). Those interactions have impacts to oceanographic conditions of Indonesian waters, especially Makassar Strait as main route of ITF which carries warm water masses to Indian Ocean due to the El-Nino and La-Nina as part of global scale oceanic belt. The purpose of this research is to understand the ENSO effect on spatio-temporal of current patterns and characteristics of water mass, namely temperature and salinity during west and east monsoon in the Makassar Strait. This study are using the ENSO index data from NOAA between year 2000-2015 and 1/4 degrees resolution of temperature, salinity, and currents monthly model from Copernicus Marine Environment and Monitoring System (CMEMS) with focus in February and August 2010 and 2015 to represents respectively for west and east monsoon period during the ENSO year. The results showed that surface currents were stronger during La-Nina with speeds of 0.8 to 1.2 m/s compared to El-Nino event with speeds of 0.6-0.7 m/s and it is higher in east monsoon. During west monsoon the current leads to the east and reversely the current pattern changes to the west during east monsoon. The temperature and salinity when La-Nina events are about 1°C higher and 0.7 psu lower than El-Nino events. Based on the results, in general that the impacts of El-Nino an La-Nina events to the Makassar Strait are clearly shown during east monsoon.