[A-OS17] Climate variability and predictability on subseasonal to decadal timescales

[AOS17-P02] Parameter sensitivity analysis for predicting two types of El Niño with an intermediate coupled model

*Haibo Chen^1,2,3 (1.CAS Key Laboratory of Ocean Circulation and Waves, Institute of Oceanology, Chinese Academy of Sciences, 2.Pilot National Laboratory for Marine Science and Technology, 3.Center for Ocean Mega-Science, Chinese Academy of Sciences)

Keywords:Parameter sensitivity, OPSA, Predictability, El Niño diversity, Intermediate coupled model

Sensitivity of El Niño simulation to model parameters is analyzed using the OPSA method, based on four El Niño events (two EP events and two CP events) simulated by an intermediate coupled model. Results show that the coefficient of entraining anomalous subsurface temperature and the ocean-atmosphere coupling coefficient are two important parameters, while the coefficient of anomalous heat flux is another important parameter for CP events. Observation system simulation experiments shows that El Niño predictions of can be effectively improved if the identified sensitive parameters are more accurately estimated, whereas the improvement is very low or even negative if the estimation of only the insensitive parameters is improved, indicating the significance of the sensitivity analysis result for El Niño prediction.