CMIP6 Models Underestimate ENSO Teleconnections in the Southern Hemisphere

Abstract This study evaluates the capability of the Coupled Model Intercomparison Project Phase 6 (CMIP6) models to simulate El Niño‐Southern Oscillation teleconnections in the Southern Hemisphere during austral summer. The wave trains from the tropical Pacific to the Amundsen Sea are underestimated and too far westward in CMIP6 simulations. However, Atmospheric Model Intercomparison Project Phase 6 (AMIP6) experiments well capture the observed location and amplitude of the teleconnection. El Niño and La Niña‐related tropical precipitation anomalies are underestimated in CMIP6 and have their maximum amplitude too far westward, while the precipitation responses in AMIP6 simulations are similar to those observed. The weaker precipitation response in CMIP6 likely arises from a cold bias in climatological‐mean SST, which reduces the sensitivity of precipitation to SST anomalies. Increased resolution in coupled experiments eradicates the westward bias in the El Niño and La Niña‐related circulation anomalies over the Amundsen Sea, but not their insufficient amplitude.