[A-CG47] Status and future view on global ocean observation: toward achievement and development for OneArgo

[ACG47-P05] Relationship between the Indian Ocean Subtropical Mode Water thickness variability and the ocean temperature structure

★Invited Papers

*Hanani Adiwira¹, Toshio Suga^1,2 (1.Graduate School of Science, Tohoku University, 2.Advanced Institute for Marine Ecosystem Change (WPI-AIMEC), Tohoku University & Japan Agency for Marine-Earth Science and Technology (JAMSTEC))

Keywords:Argo, Subtropical Mode Water, Indian Ocean

Individual Argo profiles have been utilized to explore the impacts of the IOSTMW on the physical environment in the Western Indian Ocean. The results demonstrate that the thickness of the IOSTMW has a significant influence on the vertical temperature and stratification structure. In terms of temperature, the following phenomena are observed when the IOSTMW is thick: (1) The layer above the STMW experiences colder temperatures, while warmer temperatures are found below it. (2) The isotherms above the IOSTMW layer are shallower, whereas those below it are deeper. The colder temperatures in the upper layer can be attributed to the shallower isotherms present when the IOSTMW is thick. In addition to its effect on temperature, IOSTMW thickness variability also influences the vertical stratification structure. Our findings indicate a negative correlation between IOSTMW thickness and stratification at depths ranging from 100 to 300 dbar. This suggests that the presence of a thick IOSTMW leads to weaker stratification within this depth range. An intriguing question for future research is how the influence of the IOSTMW on temperature and stratification contributes to the occurrence of ocean heat waves.