Prolonged Low‐Salinity in the Eastern Arabian Sea Associated With the 2020–2023 Triple‐Dip La Niña

Abstract Prolonged low salinity was observed in the eastern Arabian Sea (EAS) from autumn 2020 to autumn 2023, closely associated with the 2020–2023 triple‐dip La Niña. Oceanic planetary wave bridge was a key driver of the extremely low salinity during winter, whereas freshwater flux remained an important contributor in other seasons. Anomalous autumn equatorial westerlies associated with the triple‐dip La Niña triggered equatorial Kelvin waves in the eastern Indian Ocean, which further propagated toward Sri Lanka through reflected Rossby waves and coastal Kelvin waves. These waves ultimately traveled northward along India's western coast as downwelling coastal Kelvin waves, strengthening the horizontal advection of low‐salinity waters into the EAS in winter. These findings highlight the remote influence of the El Niño‐Southern Oscillation on salinity variability in the Arabian Sea and contribute to a deeper understanding of the coupling between climate modes, oceanic planetary waves, and marine environments.