Upwelling Intensity During Indian Ocean Dipole Period in Southern Waters of Java

Abstract In recent years, the prevalence of IOD has been increasing, leading to widespread and severe consequences. It is imperative to closely monitor this phenomenon in order to comprehend the ecological repercussions and their subsequent outcomes. The objective of this investigation is to examine the occurrence of upwelling in the southern Java waters under neutral conditions and to evaluate potential variations in its intensity during the Indian Ocean Dipole (IOD) season. The research was conducted in the southern waters of Java during the pronounced IOD period from 2016 to 2023. Data were obtained from the Copernicus Marine website, encompassing wind, current, temperature, salinity, and chlorophyll measurements for the eastern season. Subsequent data processing was performed using ArcGIS, ODV, and descriptive statistical methods. The results indicated that during positive IOD events, upwelling in the study area exhibited increased intensity, characterized by reduced surface temperature values, accompanied by elevated salinity and surface chlorophyll concentrations, in comparison to neutral periods. Conversely, during negative IOD events, upwelling demonstrated diminished intensity, as evidenced by higher surface temperatures and comparatively low surface salinity and chlorophyll levels. The vertical distribution of temperature and salinity further corroborated the ascent of subsurface water masses.