Tropical Pacific Zonal Temperature Gradient Intensified by the Tibetan Plateau Surface Darkening

The Tibetan Plateau (TP) is experiencing substantial changes in land properties, particularly a decrease in albedo, known as “TP surface darkening.” These changes have profound impacts on global climate, but whether and how TP darkening influence Pacific climate variability is unknown. Here, using an Earth System Model, we find TP darkening contributes to North Pacific Meridional Mode-like cooling anomaly over the subtropical Pacific particularly in boreal winter and spring. This anomaly induces persistent annual near-surface easterly winds in equatorial Pacific and strengthens Walker Circulation in a series of atmosphere-ocean interactions, culminating in an intensified tropical Pacific zonal temperature gradient especially during boreal summer and autumn. Our finding underscores TP darkening might be taken into account in the debate of tropical Pacific El Niño-like warming pattern under greenhouse warming, and demonstrates that the tropical Pacific could serve as intermediaries for TP-driven changes to influence global climate.