Extended Data Fig. 5: Model QBO circulation and CFC-11 variability.

Time series of modeled extratropical average (poleward of 30°) residual mean vertical velocities regressed on the QBO zonal wind at 30 hPa (orange) and CFC-11 global mean partial pressure anomalies at 100 hPa (sky blue) and the surface (blue). The 100 hPa w* variability corresponds with the composite in Extended Data Fig. 3 that shows easterly (negative) zonal winds at 30 hPa and negative (more downward) w* in the extratropics around 100 hPa. A negative anomaly in w* (enhanced downwelling) will act on the vertical gradient of a trace gas such as CFC-11 and cause a negative tendency, and vice versa for a positive w* anomaly. The CFC-11 partial pressure anomalies at 100 hPa are positively correlated with the 100 hPa w* with a lag of ~ 6 months, consistent with the expected relationship.