Stratospheric ozone depletion has contributed to the recent tropical La Niña-like cooling pattern

Despite the continuous global warming, over the past several decades, the tropical East Pacific has experienced a cooling trend whose origin remains an area of active research. Mounting evidence has linked tropical sea-surface temperature (SST) patterns to changes in the Southern Ocean via remote teleconnections. Using a fully-coupled global climate model, we demonstrate that stratospheric ozone depletion can produce a La Niña-like tropical SST trend pattern resembling recent observations. This tropical response initially arises from mid-latitude ocean adjustments to ozone-driven surface wind anomalies, which then enhance in the tropics via positive cloud feedback and wind-evaporation-SST feedback. Our finding suggests that the observed La Niña-like tropical SST trend pattern may have been, in part, caused by the formation of the ozone hole in the late 20^th century. It also implies that ozone recovery in the coming decades will likely contribute to a future weakening or reversal of the observed tropical SST trends.