Interdecadal wind stress variability over the tropical Pacific causes ENSO diversity in an intermediate coupled model

The role of interdecadal wind stress variability in the genesis ENSO diversity is examined by using an intermediate coupled model (ICM) tropical Pacific; two types experiments are performed, one with original ICM, and other ( $${\uptau }_{interde}$$ ) effect being explicitly represented. component derived from NCEP/NCAR reanalysis dataset as follows. First, ensemble empirical mode decomposition (EEMD) used to extract anomalies on about a 10–40 yr timescale. Next, idealized cycle reconstructed principal oscillation pattern (POP) analysis based EEMD-extracted component. A 110-yr integration then performed incorporating into ICM. Compared regular interannual simulated events become highly irregular variations amplitude asymmetry when included. Especially, reproduces El Niño different spatial distribution temporal evolution SST anomalies, namely Eastern-Pacific (EP) Central-Pacific (CP) types. Further attribution analyses understand modulating effects Pacific ocean forced added effect. Two roles Interdecadal Oscillation (IPO) illustrated. On hand, warm phase IPO favors for emergence EP-El events, association initial warming signals occurring eastern equatorial Pacific, which absent cold tends shift (i.e., single type ICM) CP type, propagate eastward along equator but cannot extend boundary. This simple modeling study highlights significant contributions irregularity theoretically.