Deep water masses exchange induced by internal tidal waves in Ombai Strait

2nd International Conference on Marine Science: Better Insight for the Healthy Ocean

Atmadipoera, A.S.^1 ; Suteja, Y.^2

Dept. of Marine Sciences and Technology, Faculty of Fisheries and Marine Sciences, Bogor Agricultural University, Bogor, Indonesia^1

Dept. of Marine Science, Faculty of Marine and Fisheries, Udayana University, Bali, Indonesia^2

关键词: Baroclinic instability;    Bottom water;    Current fluctuations;    Current structure;    Deep water mass;    Indonesian throughflow;    Internal tidal waves;    Vertical diffusivity;   

Others  :  https://iopscience.iop.org/article/10.1088/1755-1315/176/1/012017/pdf
DOI  :  10.1088/1755-1315/176/1/012017

来源: IOP

【 摘 要 】

Yoyo CTD/LADCP measurement for a 24-h tidal period and along trackshipboard ADCP, has been carried out in the northern entrance of Ombai Sill during the INDOMIX Cruise in July 2010 to investigate current structure and associated near-bottom water mass exchange induced by internal tidal waves. The results show that a strong meridional current fluctuation is observed on quasi-semidiurnal period with much stronger southward flow, related to the existence of southward Ombai Indonesian Throughflow (Ombai ITF). The vertical extent of the current deepens to the sill depth (1600m). Under 500 m depth to the sill, the southward ebb flow brings cooler and less salty water Flores water to southern Ombai Strait in Savu Sea. In contrast, the northward flood flow supplies Flores/Banda Sea with much warmer and saltier water. Thus, on tidal period there exists deep water masses exchange induced by internal tidal waves. Strong baroclinic instabilities appear when induced northward tidal flow against Ombai ITF, resulting highest vertical diffusivity.