Comparison of the role of subsurface ocean in the east and central Pacific warmings

El Niño – Southern Oscillation (ENSO) is the most important pattern of climate variability on interannual time scales in the Pacific Ocean. It is characterized by a warming of the eastern/central equatorial Pacific that typically starts off the coast of South America and propagates westward to the central Pacific. However, recent studies have shown that the surface warming could also start in the central Pacific, suggesting that there might be different types of warm events. Most of these studies have focus on the evolution of the sea surface temperature anomalies during the different types of warming and very few have focused on the structure of the ocean subsurface temperature. Using both SODA and ECMWF subsurface temperature data, the role of the subsurface temperature in the development and evolution of the central Pacific warming is explored. Special emphasis will be placed on determine whether the central Pacific warming involve subsurface wave dynamics as the canonical El Niño events or if it is controlled by surface variability rather than by subsurface variability. The role of the atmospheric forcing is also explored by setting ocean modeling experiments to represent the evolution of the ocean during the different warming events.