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arXiv · 2503.20585

Influx of Bay of Bengal waters and stirring trends in the Arabian Sea based on satellite altimetry

Nihar Paul·Manikandan Mathur·Jai Sukhatme·J. Thomas Farrar·Debasis Sengupta
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Abstract

Freshwater export from the Bay of Bengal (BoB) can drive the regional air-sea interaction in the Arabian Sea (AS). We use AVISO geostrophic and Globcurrent velocities to characterize horizontal stirring on a seasonal and interannual time scale for 1993-2022. With an example of the post-monsoon period of 2015-2016, we estimate the residence time of parcels initialized around Sri Lanka in the BoB advected to the southeastern AS is $\mathcal{O}$(1.5-2) months. Finite-time Lyapunov Exponent (FTLE) characterizes the chaotic nature of stirring through its probability density function on a sub-monthly timescale. Stirring rates are enhanced along the western boundary by 1.3 times around the Great Whirl and Socotra eddies relative to the eastern boundary and are higher in the summer monsoon season. The southeastern AS shows enhanced stirring rates during the winter monsoons. At the basin scale, the geostrophic eddy kinetic energy increases $\sim$10\% on interannual timescales associated with enhanced stirring.

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Nihar Paul, Manikandan Mathur, Jai Sukhatme, J. Thomas Farrar, Debasis Sengupta. 2025-03-26. Influx of Bay of Bengal waters and stirring trends in the Arabian Sea based on satellite altimetry. https://doi.org/10.1029/2024gl113884

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