The influence of ENSO events on the stratospheric QBO in a multi-model ensemble

• DOI: 10.1007/s00382-020-05131-7
• Publication Date: 2020-01-23T17:04:16Z
• Authors: Federico Serva; Chiara Cagnazzo; Bo Christiansen; Shuting Yang
• Keywords: Forcing (mathematics); Quasi-biennial oscillation

Abstract The Quasi-Biennial Oscillation (QBO) and the El Niño–Southern (ENSO) are two dominant modes of climate variability at Equator. There exist observational evidences mutual interactions between these phenomena, but this possibility has not been widely studied using model simulations. In work we assess how current models represent ENSO/QBO relationship, in terms response amplitude descent rate stratospheric wind regimes, by analyzing atmosphere-only ocean–atmosphere coupled simulations from a large multi-model ensemble. annual cycle QBO is well represented both uncoupled models. Previous results regarding phase alignment after 1997/98 strong warm ENSO event confirmed larger ensemble experiments. However, general find that relatively high horizontal resolution necessary to reproduce observed modulation under events, while generally weak any resolution. We argue biases mean state over-dependence on parameterized wave forcing undermine realism simulated coupling ocean stratosphere tropics emission scenario consistently differs historical period, suggesting relationship sensitive changes large-scale circulation.