인도양 서부 해역의 산소 동위원소와 염분의 상관관계

Abstract

A study of stable oxygen isotope (δ18O) in water and salinity along a meridional transect (67°E from 3°S to 25°S) in the Western Indian Ocean was carried out during April 2018. The relative water fraction of discrete water masses can be determined based on oxygen isotope and salinity relationships. In the study area, the range of oxygen isotopic values, δ18O was shown from -0.09 to 0.64‰. The relationship between salinity and δ18O values at surface water (0-100 m depth) indicate the typical trend related to surface evaporation/precipitation. Mid latitude region between 5°S and 17°S shows low salinity and δ18O, northern and southern region of the study area show high salinity and δ18O. These surfaceδ18O signatures were similar to previous studies. In the intermediate layer (100-1000 m depth), a linear correlation between salinity and δ18O is shown. Deep interior deeper than 2000 m also shows another linear relationship between salinity and δ18O with similar salinity but δ18O from -0.09 to 0.11‰. In addition, the distinct water masses along a 67°E of the Indian Ocean were identified based on both the δ18O-salinity relationships and T-S diagram.