Kelvin wave amplification facilitated by air-sea interactions during El Niño development

The Madden-Julian Oscillation (MJO) excites Kelvin waves in and above the equatorial thermocline. Some of these waves appear to break or otherwise form warm fronts during the early development stages of warm events of the El Niño/Southern Oscillation. Data from the Tropical Atmosphere Ocean (TAO) buoy array will be utilized in this discussion to demonstrate by case study and a multiple linear regression model that an air-sea interaction occasionally occurs in association with these wave fronts. In this interaction, the wave modulates SST, winds accelerate in response, and the resulting stress acts to amplify the wave itself. This result indicates that though these select waves are initially triggered by the MJO, this interaction may sustain the forcing and continue to amplify the wave even after the MJO has weakened and exited to the east.