Relationships Among the Stratospheric and Tropospheric Zonal Flows and the Southern Oscillation

Abstract

Abstract Relationships among the high-latitude stratospheric zonal wind, the tropospheric zonal wind in the region of the subtropical jet and over the equator, the Southern Oscillation, and the stratospheric tropical quasi-biennial oscillation (QBO) were examined from monthly anomaly data for 13 years (1968–80). Patterns of correlation wore found which are broadly consistent with the theory on vertical and latitudinal Rossby wave propagation, with high correlations diminishing rapidly in association with easterly basic flow. Lag correlations as high as 0.8–0.9 were found for leads of ∼1–7 months, based on three-month average anomalies for successive months. The simplified lead path is from Southern Oscillation to equatorial winds to subtropical winds to stratospheric high-latitude winds. Relationships involving the QBO appear weak compared to those involving the extratropical flows, the tropospheric equatorial flow of the east Pacific, and the Southern Oscillation. Even so, the structure of correlation fo...