Abstract The El Niño–Southern Oscillation (ENSO) has significant effects on the extratropical
stratosphere. This study explores the nonlinearity and the asymmetry of these influences by
distinguishing the different effects of four types of ENSO:“moderate El Niño,”“strong El
Niño,”“moderate La Niña,” and “strong La Niña.” It is revealed that the moderate El Niño and
the strong La Niña are much more efficient than the strong El Niño and the moderate La
Niña, respectively, in modulating the northern winter stratospheric variability, resulting in …

Long‐term simulations from the Community Earth System Model with the Whole Atmosphere
Community Climate Model (CESM‐WACCM) as its atmospheric component are used to
investigate the asymmetry and the nonlinearity of the influences of El Niño–Southern
Oscillation (ENSO) on the northern winter stratosphere. As in Part 1 of this study, four
different types of ENSO are considered. The composite CESM‐WACCM results first confirm
the conclusions drawn from the observations, that the stratospheric polar jet responses to …