Multidecadal variations of the persistence of Tropical North Atlantic sea surface temperature

Tropical north Atlantic sea surface temperature anomalies (TNA SSTAs) have far-reaching climate impacts both locally and remotely. For the first time, this study reveals pronounced multidecadal variations in the seasonal persistence of spring TNA SSTAs, which is relatively higher at the early and late 20th century but significantly lower during the middle 20th century. Contrast to the nonstationary El Niño-Southern Oscillation (ENSO)-TNA connection, these fluctuations in TNA SSTA seasonal persistence are mainly linked to multidecadal shifts in the North Atlantic Oscillation (NAO)-TNA connection. Specifically, the asymmetric impacts of extreme NAO events drive both multidecadal fluctuations in the TNA SSTA seasonal persistence and shifts of NAO-TNA connection. The asymmetric impacts of extreme NAO events are enhanced in historical periods by external forcings and is projected to amplify further under further climate conditions.