Impacts of Quasi-Biennial Oscillation and El Niño–Southern Oscillation on Stratospheric Isentropic Mixing Process

The present study investigates the influences of stratospheric quasi-biennial oscillation (QBO) and El Niño–Southern Oscillation (ENSO) on intensity isentropic mixing based ERA-Interim MERRA-2 reanalysis products. It is found that in stratosphere modulated by QBO ENSO. An analysis basis function multiple regression model reveals lower suppressed equatorial region WQBO phase, while enhances subtropical mid-latitude regions. This result not consistent with Holton–Tan mechanism. However, mid-latitudes becomes stronger middle EQBO which agrees well effect. Composite indicates QBO-induced changes direction speed zonal wind can affect wave propagation breaking. In weakens, a planetary anomalously converging near 30°N, leads to an increase mixing; contrary, large, upward divergence, lead mixing, weak 60°N. relatively around 60°N, strong. Multiple ENSO impact shows high latitudes strong low Niño years. stratosphere, due intensified waves but weakens polar region. clear relationship between strength zones La Niña years position jet speed.