CMIP5 Projections of Two Types of El Niño and Their Related Tropical Precipitation in the Twenty-First Century

Future projections of the eastern-Pacific (EP) and central-Pacific (CP) types of El Nino in the twenty-first century, as well as their associated tropical circulation and precipitation variability, are investigated using historical runs and representative concentration pathway 8.5 (RCP8.5) simulations from 31 coupled models in phase 5 of the Coupled Model Intercomparison Project (CMIP5). As inferred from CMIP5 models that best capture both El Nino flavors, EP El Nino sea surface temperature (SST) variability will become weaker in the future climate, while no robust change of CP El Nino SST is found. Models also reach no consensus on the future change of relative frequency from CP to EP El Nino. However, there are robust changes in the tropical overturning circulation and precipitation associated with both types of El Nino. Under a warmer climate, magnitudes of precipitation anomalies during EP El Nino are projected to increase, presenting significant enhancement of the dry (wet) signal over the we...