Climate impacts of tropical Pacific SST trends in boreal winter

Sea surface temperature (SST) trends over the satellite era show a pronounced cooling over the tropical south-eastern Pacific and enhanced warming over the West Pacific warm pool. By contrast, climate models tend to warm across all longitudes in the tropical Pacific. What does this discrepancy mean for climate model trends outside the tropical Pacific? Does capturing the observed pattern of tropical Pacific SST warming help to resolve other trend discrepancies in models? We use two complementary methods to constrain boreal winter SST trends in coupled models: pacemaker experiments, and conditioned near-term climate predictions (hindcasts). We find that the global response to constraining tropical Pacific SST trends resembles the interannual La Niña response. The Pacific SST trend explains 33-39% of the poleward zonal-mean jet shift seen in the models, and is associated with robustly reduced tropical tropospheric warming trends consistent with reanalyses. It also improves surface air temperature and precipitation trends in ENSO-sensitive regions, such as the South Asia, southern Africa, and the Americas. Our results highlight the importance of resolving discrepancies in the tropical Pacific for building confidence in climate model trends globally.