Land–Ocean Pathways Linking Indo‐Pacific Sea Surface Temperature Variability to Tropical Atlantic Coastal Salinity

Abstract This study aims to identify and understand the drivers of interannual variability in coastal salinity in the tropical Atlantic Ocean. Using a combination of satellite, in situ and reanalysis data, we show how ocean‐basin‐scale sea surface temperature gradients in the tropical Pacific and Indian Oceans associated with major climate modes such as the El Niño Southern Oscillation (ENSO) and the Indian Ocean Dipole (IOD) modify large scale atmospheric circulation and moisture transport and thus the hydrological cycle and coastal salinity in the tropical Atlantic ocean. We find that interannual variability in coastal salinity in western tropical Atlantic (WTA) is significantly correlated with changes in the Amazon basin precipitation and river discharge, suggesting a significant causal relationship with ENSO. Additionally, interannual variability in coastal salinity in eastern tropical Atlantic (ETA) is correlated with changes in the hydrological cycle over the Congo basin significantly influenced by IOD. ENSO and IOD account for 44% and 43% of the interannual variance in coastal SSS over the WTA and ETA, respectively, with no significant contribution from the tropical Atlantic climate indices. The sequence of linkages between land precipitation, river discharges and coastal salinity variability in WTA and ETA is associated with a measurable lag of a few months. This study reveals a multi‐phase, multi‐location “super teleconnection” linking WTA with the tropical Pacific and ETA with the tropical Indian Ocean through coupled atmosphere–hydrology–land–sea interactions. The identified lag relationships between climate modes, rainfall, river discharge, and coastal salinity offer improved predictability of near‐surface coastal hydrography in the tropical Atlantic Ocean.