Datensatz

Zusammenfassung

El Niño -Southern Oscillation (ENSO) is currently the strongest climate variability mode, affecting ecosystems, agriculture, and weather systems worldwide. The potential change in ENSO variability in response to global warming has been the subject of ongoing debate for some time. Although there are CMIP6 (Coupled Model Inter-comparison Project Phase 6) models available for SSP(SSP; Shared Socioeconomic Pathway) scenarios, most of them have struggled to simulate the intensified east-west SST (Sea Surface Temperature) gradient along the tropical Pacific that is observed (Seager et al., 2019). This gradient is important for predicting ENSO variability. We have compared ENSO simulation performance of several models that participated in CMIP6, including KIOST-ESM(KIOST Earth System Model). To evaluate the key ENSO characteristics to global warming, historical run and SSP5-8.5 of ScenarioMIPs of the models were analyzed. The development of ENSO phenomenon is related to positive feedbacks (Thermocline, zonal advection and Ekman feedbacks) and negative feedbacks (current damping and thermodynamic damping). The Ekman feedback and thermocline feedback are determined by the upwelling and east-west gradient terms in the equatorial Pacific. Zonal advection feedback potentially influences simulations and projections of ENSO SST in the western equatorial Pacific (Graham et al. 2017). The ENSO feedback processes varied significantly among different models. This study highlights the importance of the atmosphere-ocean system in ENSO dynamics and investigates how different feedback mechanisms respond to future climate in the Earth System Models. By conducting this analysis, we aim to provide insights into the potential features of ENSO under a warmer climate.