Investigation of Mesoscale Eddies Properties in the Southeastern Tropical Indian Ocean: A Comparison between Altimetry and Reanalysis Data
M. Rizqi Ramadhan (a*), Rahaden Bagas Hatmaja (b)

a) Oceanography Department, Faculty of Earth Sciences and Technology, Bandung Institute of Technology, Bandung, Indonesia.
*rizqiramadhan.23112001[at]gmail.com
b) Research Centre for Climate and Atmosphere, National Research and Innovation Agency (BRIN), Bandung, Indonesia.

Abstract

The southeastern tropical Indian Ocean (SETIO) is characterized by high mesoscale eddies activity, as the result of baroclinic instabilities that are associated with the South Java Current (SJC), South Equatorial Current (SEC), and Indonesian Throughflow (ITF), which play a key role in ocean dynamics, environment, and bio-system of this region. Satellite altimetry data and the GLORYS12V1 CMEMS reanalysis ocean product were used to investigate the features of mesoscale eddies in the SETIO. An autonomous eddy tracking system was used to identify the eddies. Along 2019, a total of 263 and 217 eddies were spotted and tracked based on satellite and reanalysis data, respectively. The results elucidates that the analysis of mesoscale eddies variability in ocean reanalysis data shows consistent manner with altimetry observations. Cyclonic eddies appeared to be more abundant and smaller compared to anticyclonic eddies. Larger amplitudes and radii are related with high eddy kinetic energy zones near the SJC, SEC, and ITF outflow. Furthermore, this study strengthens the quantitative understanding of mesoscale eddies dynamics in this region, including eddy formation and propagation.

Keywords: mesoscale eddies- Southeastern Tropical Indian Ocean- reanalysis ocean data- altimetry

Topic: Ocean-Atmosphere Dynamics