El Niño-Southern Oscillation Dynamics – Scale Interactions and Response to Greenhouse Warming in the ICCP High-Resolution CESM Simulation

The El Niño-Southern Oscillation (ENSO) phenomenon is investigated in a high-resolution global climate model simulation conducted with the Community Earth System Model (CESM). The grid spacing is 0.25° in the atmosphere and 0.1° in the ocean. Results are presented for a suite of control and greenhouse warming simulations. Under present-day conditions the high-resolution CESM simulates ENSO with realistic amplitude and spectral features. Our analysis highlights the roles of well-resolved tropical instability waves, westerly wind bursts, stratification and seasonal cycle changes in the inception and termination processes of ENSO. We will present a novel perspective of scale-interactions in ENSO dynamics and their changes in response to increasing greenhouse gas concentrations.