Impacts of the ENSO Lifecycle on Stratospheric Ozone and Temperature

This study examines the variations of stratospheric temperature and ozone associated with the lifecycle of El Nino-Southern Oscillation (ENSO). Significant stratospheric temperature and ozone anomalies are found not only during El Nino and La Nina, but also during the transition phases in between, and anomalies during the cold-to-warm transition generally mirror those during the warm-to-cold transition. Zonal mean temperature anomalies propagate slowly upward over northern midlatitudes but downward over the Arctic. The strongest ozone anomalies over Antarctica occur one year after El Nino and La Nina, which show a dipole structure between the upper stratosphere and the lower stratosphere. The ozone anomalies are associated with anomalous Brewer-Dobson circulation and anomalous Eliassen-Palm flux divergence.