Work

Planetary trapped waves drive intercontinental and trans-basin oceanic teleconnections between South America and Africa

Year: 2026

Type: article

Abstract: Oceanic coastal trapped waves (CTWs), efficiently transmit energy over long distances and strongly influence coastal variability through their impacts on currents, temperature, and nutrient fluxes impacting marine ecosystems. Previous studies in the Atlantic demonstrate the conversion of Equatorial Kelvin Waves (EKWs) into CTWs at the eastern boundary of the Basin. However, the connection between the western boundary and the equatorial band receives much less attention. Here, we identify an intercontinental oceanic teleconnection linking South America and Africa through the equatorial and coastal wave guides. We show that intraseasonal CTWs propagate northward along the South American margin and occasionally reach the equator, where they convert into eastward-propagating EKWs. These signals cross the Atlantic and subsequently generate CTWs along the African coastlines, forming a continuous trapped-wave corridor connecting the continental margins. In some occasions the connection extends even further, some waves observed in the equatorial Atlantic can be track back to the Equatorial Pacific. The CTW activity exhibits strong seasonal and interannual modulation, controlled by background circulation and large-scale atmospheric forcing associated with the Madden-Julian Oscillation, ENSO, and the Antarctic Oscillation. Our results reveal a previously undocumented pathway for oceanic connection across the tropical Atlantic, with potential implications for Atlantic Niño preconditioning.

Source: Communications Earth & Environment

DOI: 10.1038/s43247-026-03849-6