Work

Decadal Variability of Eddy Kinetic Energy Along the Eastern Boundary of the Subtropical South Indian Ocean

Year: 2026

Type: article

Abstract: Using more than three decades (1993–2024) of satellite altimetry and ocean reanalysis, we reassess the dominant timescales of low‐frequency mesoscale eddy variability along the eastern boundary of the subtropical South Indian Ocean. After removal of the seasonal cycle, eddy kinetic energy (EKE) is primarily modulated on decadal timescales (8–16 years), with a pronounced spectral peak near 10–12 years, whereas interannual variability (2–7 years) is comparatively weak. Decadal EKE variability is governed by baroclinic instability associated with vertical shear between the poleward Leeuwin Current (LC) and the equatorward Leeuwin Undercurrent. Decadal changes in LC strength dominate shear variability and are strongly linked to Pacific decadal forcing. These findings improve our understanding of the dynamics of mesoscale eddies in this dynamically distinct eastern boundary system.

Source: Geophysical Research Letters

DOI: 10.1029/2025gl120546

Authors: Yifei Zhou, Xuhua Cheng

Institutions: Hohai University, Ministry of Natural Resources

Language: English

Topic: Oceanographic and Atmospheric Processes

Subfield: Oceanography

Field: Earth and Planetary Sciences

Domain: Physical Sciences

SDGs: Life below water, Climate action

Open Access status: gold

Estimated APC paid: $3,190