4:45 PM - 5:00 PM
[AHW27-24] Seasonal variability of water hydrogen and oxygen isotopes of the Yangtze and East China Sea
Keywords:Yangtze, East China Sea, Hydrogen isotope, Oxygen isotope
In order to establish more precise interpretation scheme for oxygen isotope information reconstructed from sediment archive in this region, it is necessary to summarize the seasonal and spatial differences of the isotopes in the Yangtze drainage and the ECS water columns and clarify the basic controlling factors. For this purpose, we collected river waters from main stream and major tributaries of the Yangtze and multi-layer water samples from five stations across the Kuroshio in both summer and winter.
The oxygen isotope of the Yangtze main stream increases from -15 permil VPDB at upper reaches to -8 permil VPDB at lower reaches, being diluted by tributary waters higher in isotope values, and summer value is ~1 permil higher than in winter. Although the salinity-oxygen isotope relationship looks simple mixing from the Yangtze river mouth to the ECS shelf water, the relationship among temperature, salinity, and oxygen isotope of the seasonally variable Taiwan Warm Current, Kuroshio, and their subsurface water is complex, which makes the detection of the influence from the Yangtze fresh water to the ECS.