How are ENSO evolution and predictability influenced
by stochastic forcing of the Madden-Julian Oscillation?

ENSO (El Nino – Southern Oscillation) is governed by large-scale atmosphere-ocean coupling in the equatorial Pacific. External stochastic forcing plays crucial roles in maintaining the ENSO evolution when the Pacific coupled system is in a stable dynamic regime, and in generating ENSO irregularity when the coupled system is in an unstable dynamic regime. Figure ? illustrates that the Madden-Julian Oscillation (MJO) is a dominant component of stochastic forcing of ENSO when the coupled system is stable. Combining data analyses and coupled model simulations, current research at RSMAS strives to understand how interactions between the MJO and ENSO would affect ENSO predictability and its multi-decadal variability, and how ENSO prediction may benefit from our knowledge of the MJO. Figure caption: Simulations of the ENSO evolution by an atmosphere-ocean coupled model. Plotted are equatorial Pacific sea surface temperatures forced by (a) observed stochastic forcing, (b) the MJO component of the stochastic forcing, and (c) the non-MJO component of the stochastic forcing.