El Niño-Southern Oscillation heat engine shifts eastward under global warming
El Niño-Southern Oscillation (ENSO) is the strongest signal in interannual climate variation. El Niño increases the precipitation over the equatorial central-eastern Pacific, which releases more latent heat into the tropical atmosphere and thus drives variations of the global climate system like a heat engine. It has been reported that ENSO-induced precipitation anomalies will shift and extend eastward under global warming, projected by climate change simulations from the phase five of the Coupled Model Intercomparison Project (CMIP5). The zonal shift of the ENSO heat engine would significantly change responses of the global climate system to ENSO forcing. However, the projected result has not been supported by a robust mechanism, mainly due to the large uncertainties in the amplitude change of ENSO under the global warming.